12 Is organic food ‘healthier’ than conventional food?
By Jamie Hale and Alan Aragon
Copyright © December 1st, 2008 by Alan Aragon
Home: www.alanaragon.com/researchreview
Correspondence: aarrsupport@gmail.com
2
An objective comparison of chocolate milk and
Surge Recovery.
By Alan Aragon
6
Co-ingestion of protein with carbohydrate during
recovery from endurance exercise stimulates
skeletal muscle protein synthesis in humans.
Howarth KR, et al. J Appl Physiol. 2008 Nov 26. [Epub
ahead of print] [Medline]
7
The effect of resistive exercise rest interval on
hormonal response, strength, and hypertrophy
with training.
Buresh R, et al. J Strength Cond Res. 2008 Dec 9. [Medline]
8
Substrate Metabolism and Exercise Performance
with Caffeine and Carbohydrate Intake.
Hulston CJ, Jeukendrup AE. Med Sci Sports Exerc. 2008
Dec;40(12):2096-104. [Medline]
9
The acute effects of the thermogenic supplement
Meltdown on energy expenditure, fat oxidation,
and hemodynamic responses in young, healthy
males.
Jitomir J, et al. J Int Soc Sports Nutr. 2008 Dec 16;5(1):23.
[Medline]
10 Green tea extract only affects markers of oxidative
status postprandially: lasting antioxidant effect of
flavonoid-free diet.
Golay A, et al. Int J Obes Relat Metab Disord. 2000
Apr;24(4):492-6. [Medline]
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
Page 1
of
An objective comparison of chocolate milk and Surge
Recovery.
By Alan Aragon
INTRODUCTION TO CENSORSHIP
Interrupting the regularly scheduled program
For those of you who have been on the edge of your seat for the
2nd installment of the “Culking” series, you’ll have to hang on
until the next issue. I’ve taken some liberty to interrupt the
regularly scheduled program to resolve what I consider to be a
pivotal disturbance in the Balance of the Force. Those who
follow my internet romps are chuckling right now, because you
saw this article coming a mile away.
For those who have no idea what the hell I’m referring to, here’s
the synopsis. A member of the t-nation.com forums posted a
question about whether or not it’s safe for her 12 year-old son to
have a postexercise product called Surge instead of chocolate
milk. Bill Roberts, a product formulator for Biotest (the
supplement company behind t-nation.com), said essentially that
the carb source in chocolate milk (sucrose) was inferior to the
carb source in Surge (dextrose). I then challenged him to justify
his position. My position was that using sucrose isn’t any more
of a nutritional compromise than using dextrose. His answer was
that “everyone knows” dextrose is superior to sucrose for
postworkout glycogen resynthesis, and that sucrose is inherently
more unhealthy than dextrose. I countered his position by
presenting scientific research refuting his claims. He then got all
bent out of shape and started hurling ad hominems at me,
obviously frustrated that he was losing a public battle.
“Everyone knows”
In one of Bill’s posts, he literally said “everyone knows” more
than a dozen times – while failing to provide a single trace of
scientific research supporting his claims. If indeed everyone
knew, and was in agreement with him, he would have had at
least a handful of cronies sticking up for him, if for nothing else
but to pad his fall to the mat. But alas, he received support from
no one except one moderator, who I’ll quote as saying, “I refuse
to back up my claims, so sue me”.
inability (and unwillingness) to engage in scientific debate were
right there, plain as day. Ultimately, Bill ended up looking as
prideful as he was ignorant. In order to save face, either Bill or
administrators of t-nation.com had the thread deleted.
Ironically, I recently wrote an article for t-nation.com. If I may
say so myself, it was a hit, judging by the reader feedback and
frequent links back to the article. Given that, it was downright
humorous to be censored by the forum administrators shortly
after contributing to their library of wisdom. In the following
sections, I’ll compare the components of Surge with chocolate
milk for postexercise recovery. For the sake of simplicity and
context-specificity, I’ll judge the application of the two products
to the target market of Surge, which consists of general fitness
and bodybuilding fans.
MEET THE COMPETITORS
In the brown corner, we have chocolate milk. The ingredients of
chocolate milk vary slightly across brands, but in general, the
ingredients are: milk, sugar (or high fructose corn syrup), cocoa
processed with alkali, natural and artificial flavors, salt,
carrageenan, vitamin A palmitate, vitamin D3. Like regular
milk, chocolate milk is available in varying levels of milk fat.
For the purposes of this comparison, I’ll use the one most
consumers are most likely to choose, the low-fat variety.
In the red corner, we have Surge Recovery (which I’ll continue
to abbreviate as Surge). The ingredient list is as follows: dglucose (dextrose), whey-protein hydrolysate, maltodextrin,
natural and artificial flavors, sucralose. Other ingredients include
L-leucine and DL-phenylalanine.
Research behind the products
What’s exciting about this comparison is that both of these
products have been highly heralded and hyped in their respective
arenas. Surge in its exact formulation doesn’t have any peerreviewed research behind it. However, Berardi et al reported that
a solution of similar construction to Surge (33% WPH, 33%
glucose and 33% maltodextrin) was slightly superior for
glycogen resynthesis at 6 hrs postexercise compared to a 100%
maltodextrin solution.1 Effects on muscle protein flux were not
measured.
It’s not surprising that people’s posts were blocked from
appearing in the thread because eventually, my own posts never
made it into the thread. At that point, I knew that continuing the
debate was just not going to happen. Nevertheless, all of the key
posts made it through; all of the posts that clearly showed Bill’s
Chocolate milk has thus far had an impressive run in the
research examining its applications to various sporting goals.2,3
It has performed equally well for rehydration and glycogen
resynthesis compared to carb-based sports drinks, and it has
outperformed them (and soy-based drinks) for protecting and
synthesizing muscle protein. A standout study in this area was a
comparison of chocolate milk, Gatorade, and Endurox R4 (a
sports drink with a 4:1 carb to protein ratio).4 Chocolate milk
was equally effective as Gatorade for total work output and
prolonging time to exhaustion. Interestingly, both of the latter
products outperformed Endurox R4 in both tests. The
researchers speculated that the use of maltodextrin rather than
sucrose (yes, you read that correctly) as the dominant
carbohydrate source was the Achilles heel of Endurox R4. More
on the virtues of sucrose instead of straight glucose for exercise
applications will be covered.
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
To Bill’s credit, the soccer mom who asked the original question
wouldn’t listen to anyone but him, so kudos to Bill on his
politician-like rhetorical skills. In the mean time, several
members expressed their disappointment in Bill’s neglect for
citing research evidence to back his stance. I also know for a fact
that a good handful of posts from innocent observers (supporting
my side of the debate) were censored from posting in the thread.
This was presumably because their posts made Bill look even
more uninformed.
Page 2
QUANTITATIVE MACRONUTRIENT COMPARISON
Macronutrient comparison
Product
Serving
Kcal
Protein
Carb
Fat
________________________________________________________
Surge
3 scoops
340
25 g
46 g
2.5 g
Ch. Milk
17.3 oz
340
17.3 g
56.3 g
6.5 g
When isocalorically matched, Surge and lowfat chocolate milk
have the expected similarities and differences. The suggested
serving of Surge has 7.7g more protein than chocolate milk,
while chocolate milk has 10.3g more carbohydrate. While the
lesser protein content of chocolate milk might on the surface
seem like a point scored for Surge, this is actually a non-issue.
Recent research by Tang et al found that as little as 10g whey
plus 21g fructose taken after resistance exercise was able to
stimulate a rise in muscle protein synthesis.5 Considering that an
isocaloric serving of lowfat chocolate milk has 17.3g protein
plus 56.3g carbohydrate, a hike in muscle protein synthesis (as
well as inhibition of protein breakdown) would be easily
achieved. Chocolate milk has 4g more fat than Surge. Again, this
might be viewed as a detriment for those conserving fat calories,
but it’s still a low absolute amount of fat. This also may have a
potential benefit which I’ll discuss in a minute. Bottom line:
there’s no clear winner in this department, there’s too many
contingencies to make a blanket judgement.
QUALITATIVE MACRONUTRIENT COMPARISON
Protein
Surge uses whey protein hydrolysate (WPH). In theory, WPH is
favorable because it’s already broken down into peptide
fragments. This spurred the assumption that it would have faster
absorption and uptake by muscle, which in turn would result in
greater net anabolism. However, a recent study by Farnfield et al
observed the exact opposite when WPH was compared with
whey protein isolate (WPI), which consists of intact whole
protein.6 WPH not only was absorbed more slowly, but its levels
in the blood also declined more rapidly, resulting in a much
weaker response curve. Leucine and the rest of the BCAAs were
significantly better absorbed from WPI than WPH. The
researchers concluded that total amino acid availability of WPI
was superior to WPH.
Chocolate milk’s protein is no different than that of regular milk.
Milk protein is roughly 80% casein and 20% whey. Thus far in
the scientific literature, comparisons of casein-dominant proteins
with whey for sports applications are evenly split. Some studies
show casein as superior (in spite of a higher leucine content in
the whey treatments),9,10 while others point to whey as the
victor.11,12 The only certainty is that it can’t be assumed that
faster is better when it comes to promoting net anabolism. An
acute study on post-ingestion amino acid kinetics by LaCroix
suggests that milk protein is best left as-is rather than isolating
its protein fractions.13 Compared to total milk protein, whey’s
amino acid delivery was too transient, and underwent rapid
deamination during the postprandial period. The authors
concluded that milk proteins had the best nutritional quality,
which suggested a synergistic effect between its casein and
whey. Bottom line: chocolate milk gets the edge; WPH has thus
far bit the dust compared to WPI in a head-to-head comparison,
and whey has not been consistently superior to total milk
protein.
Carbohydrate
Surge has dextrose (synonymous with glucose) as its sole
carbohydrate source, while chocolate milk has an even mix of
sucrose (in the form of either sucrose or high-fructose corn
syrup) and lactose. While it’s common to assume that dextrose is
superior to sucrose for postexercise glycogen resynthesis,
research doesn’t necessarily agree. A trial by Bowtell et al
showed a glucose polymer to synthesize more glycogen by the
2-hr mark postworkout.14 However, two other trials whose
postexercise observation periods were 4 and 6 hours respectively
saw no significant difference in glycogen storage between
sucrose and glucose.15,16
Perhaps the most overlooked advantage of a fructose-containing
carbohydrate source (sucrose is 50% fructose) is that it supports
liver glycogen better than a glucose-only source, as in the case
of Surge. A little-known fact is that hepatic glycogenolysis (liver
glycogen use) occurs to a significant degree during exercise, and
the magnitude of glycogenolysis is intensity-dependent.17
Illustrating the potential superiority of sucrose over glucose,
Casey et al saw no difference in muscle glycogen resynthesis 4
hrs postexercise.15 However, more liver glycogen was restored
in the sucrose group, which correlated with greater exercise
capacity.
Of note, Surge is fortified with leucine, a branched chain amino
acid (BCAA) that plays a critical role in muscle protein
synthesis. An isocaloric serving of chocolate milk has 1.7g
leucine. This may or may not have any impact, especially within
the context of a high protein intake typical of the athletic
population. It’s important to keep in mind that most high-quality
animal-based protein is 18-26% BCAA.7 Adding a few grams of
supplemental BCAA to a pre-existent high intake within the diet
is not likely to yield any magic. Surge is also fortified with
phenylalanine, presumably for the purpose of enhancing the
insulin response. Again, this is an unnecessary tactic since
insulin’s primary action is the inhibition of muscle protein
breakdown. This antiproteolytic effect of nutrient-mediated
insulin response is maximal at elevations just slightly above
fasting levels.8
One of the potential concerns of consuming a large amount of
sucrose instead of glucose is how the 50% fructose content in
sucrose might be metabolized from a lipogenic standpoint.
Answering this question directly, McDevitt saw no difference in
de novo lipogenesis (conversion to fat) between the massive
overfeeding of either glucose or sucrose at 135g above
maintenance needs.18 Another potential concern is the use of
high-fructose corn syrup (HFCS) in chocolate milk. The
common fear of HFCS being some sort of special agent that
undermines health is simply not grounded in science. HFCS is
virtually identical to sucrose both in chemical structure and
metabolic effect.19 Independent researcher John White
eloquently clarified HFCS misconceptions in a recent review,
which I’ll quote:20
Alan Aragon’s Research Review – December, 2008
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Page 3
“Although examples of pure fructose causing metabolic upset at
high concentrations abound, especially when fed as the sole
carbohydrate source, there is no evidence that the common
fructose-glucose sweeteners do the same. Thus, studies using
extreme carbohydrate diets may be useful for probing
biochemical pathways, but they have no relevance to the human
diet or to current consumption. I conclude that the HFCSobesity hypothesis is supported neither in the United States nor
worldwide.”
It bears mentioning that lactose intolerance can prohibit regular
milk use for certain susceptible individuals. However, this can
be remedied by using Lactaid brand milk, or by using lactase
pills or drops. Bottom line: For those who can digest lactose or
are willing to take the extra step to make it digestible, chocolate
milk wins. But since there are those who can’t or won’t do
what’s required to tolerate lactose, I’m calling this a tie.
Fat
Coincidentally, Surge and chocolate milk have identical
proportions of saturated fat. Lowfat chocolate milk has more fat
than Surge, which would cause some folks to call a foul for
postworkout purposes. However, a trial by Elliot et al found that
postexercise ingestion of whole milk was superior for increasing
net protein balance than fat-free milk.21 The most striking aspect
about this trial was that the calorie-matched dose of fat free milk
contained 14.5g protein, versus 8.0 g in the whole milk.
Apparently, postworkout fat intake – particularly milk fat – is
nothing to fear, and may even be beneficial from the standpoint
of synthesizing muscle protein. Bottom line: it’s a tie, since there
is very little evidence favoring one fat profile/amount versus the
other. On one hand, you can be saving fat calories by going with
Surge. On the other hand, postworkout milk fat might
potentially enhance protein synthesis. Things come out even.
OTHER CONSIDERATIONS
Price
Chocolate milk by the half gallon (64oz, or about 2000 ml) is
approximately $3.00 USD. Sticking with our 340 kcal figure,
this yields 3.7 servings, which boils down to $0.81 per serving.
A tub of Surge costs $36.00 and yields 16 servings (3 scoops,
340 kcals per serving). This boils down to $2.25 per serving.
That’s 277% more expensive than chocolate milk. Even on a
protein-matched basis, Surge is still roughly double the price.
Bottom line: chocolate milk is many times easier on your wallet.
Convenience & taste
Convenience is the single area where Surge wins. Being a
powder, it’s non-perishable, requiring no refrigeration. This
makes it more easily portable. Taste will always be, well, a
matter of taste. I highly doubt that in a blinded test that Surge
would win over chocolate milk. Bottom line: Surge is more
convenient, but I’ll go out on a limb and guess that chocolate
milk would taste better to most people.
CONCLUSION
I have no vested interest in glorifying chocolate milk, nor do I
stand to benefit by vilifying Surge. My goal was to objectively
examine the facts. Using research as the judge, chocolate milk
was superior or equal to Surge in all categories. The single
exception was a win for Surge in the convenience department.
So, if a consumer was forced to choose between the two
products, the decision would boil down to quality at the expense
of convenience, or vice versa. I personally would go for the
higher quality, lower price, and strength of the scientific
evidence. Chocolate milk it is.
REFERENCES
MICRONUTRIENT COMPARISON
A quick glance at the above chart shows that chocolate milk is
markedly more nutrient-dense, with the exception of a
higher content of leucine and phenylalanine in Surge, whose
significance (or lack of) I discussed earlier. As an interesting
triviality, both have low cholesterol content, but Surge has 4.6
times more. Chocolate milk has more sodium, but it also has a
significantly higher potassium-to-sodium ratio. Bottom line:
chocolate milk wins this one decisively.
1. Berardi JM, et al. Postexercise muscle glycogen recovery
enhanced with a carbohydrate-protein supplement. Med Sci
Sports Exerc. 2006 Jun;38(6):1106-13. [Medline]
2. Roy BD. Milk: the new sports drink? a review. J Int Soc
Sports Nutr. 2008 Oct 2;5:15. [Medline]
3. McDonald L. (Review of) Milk the new sports drink? a
review. 2008 [Bodyrecomposition]
4. Karp JR. Chocolate milk as a post-exercise recovery aid. Int J
Sport Nutr Exerc Metab. 2006 Feb;16(1):78-91. [Medline]
5. Tang JE, et al. Minimal whey protein with carbohydrate
stimulates muscle protein synthesis following resistance
exercise in trained young men. Appl Physiol Nutr Metab.
2007 Dec;32(6):1132-8. [Medline]
6. Farnfield MM, et al. Plasma amino acid response after
ingestion of different whey protein fractions. Int J Food Sci
Nutr. 2008 May 8:1-11. [Medline]
7. Millward DJ, et al. Protein quality assessment: impact of
expanding understanding of protein and amino acid needs for
optimal health. Am J Clin Nutr. 2008 May;87(5):1576S1581S. [Medline]
8. Rennie MJ, et al. Branched-chain amino acids as fuels and
anabolic signals in human muscle. J Nutr. 2006 Jan;136(1
Suppl):264S-8S. [Medline]
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
Micronutrient comparison (per 340 kcal serving)*
Surge Recovery
Chocolate Milk
__________________________________________________
Calcium
Cholesterol
Leucine
Magnesium
Phenylalanine
Phosphorus
Potassium
Sodium
180 mg
75 mg
4000 mg
20 mg
2000 mg
120 mg
400 mg
200 mg
624 mg
16 mg
1714 mg
70 mg
844 mg
558 mg
920 mg
329 mg
*This comparison is limited to the micronutrients on the Surge label. And
yes, I realize that not all of the above are technically micronutrients.
Page 4
9. Demling RH, Desanti L. Effect of a hypocaloric diet,
increased protein intake and resistance training on lean mass
gains and fat mass loss in overweight police officers. Ann
Nutr Metab. 2000;44(1):21-9. [Medline]
10. Kerksick CM, et al. The effects of protein and amino acid
supplementation on performance and training adaptations
during ten weeks of resistance training. J Strength Cond Res.
2006 Aug;20(3):643-53. [Medline]
11. Lands LC, et al. Effect of supplementation with a cystein
donor on muscular performance. J Appl Physiol
1999;87:1381-5. [Medline]
12. Cribb PJ, et al. The effect of whey isolate and resistance
training on strength, body composition, and plasma
glutamine. Int J Sport Nutr Exerc Metab. 2006
Oct;16(5):494-509. [Medline]
13. LaCroix M, et al. Compared with casein or total milk
protein, digestion of milk soluble proteins is too rapid to
sustain the anabolic postprandial amino acid requirement.
Am J Clin Nutr. 2006 Nov;84(5):1070-9. [Medline]
14. Bowtell JL, et al. Effect of different carbohydrate drinks on
whole body carbohydrate storage after exhaustive exercise. J Appl
Physiol 2000; 88 (5): 1529-36. [Medline]
15. Casey A, et al. Effect of carbohydrate ingestion on glycogen
resynthesis in human liver and skeletal muscle, measured by
(13)C MRS. Am J Physiol Endocrinol Metab. 2000
Jan;278(1):E65-75. [Medline]
16. Blom PC, et al. Effect of different post-exercise sugar diets
on the rate of muscle glycogen synthesis. Med Sci Sports
Exerc. 1987 Oct;19(5):491-6. [Medline]
17. Suh SH, et al. Regulation of blood glucose homeostasis
during prolonged exercise. Mol Cells. 2007 Jun
30;23(3):272-9. [Medline]
18. McDevitt et al. De novo lipogenesis during controlled
overfeeding with sucrose or glucose in lean and obese
women. Am J Clin Nutr. 2001 Dec;74(6):737-46. [Medline]
19. Melanson KJ, et al. High-fructose corn syrup, energy intake,
and appetite regulation. Am J Clin Nutr. 2008
Dec;88(6):1738S-1744S. [Medline]
20. White JS. Straight talk about high-fructose corn syrup:
what it is and what it ain't. Am J Clin Nutr. 2008
Dec;88(6):1716S-1721S. [Medline]
21. Elliot TA, et al. Milk ingestion stimulates net muscle
protein synthesis following resistance exercise. Med Sci
Sports Exerc. 2006 Apr;38(4):667-74. [Medline]
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
Page 5
Co-ingestion of protein with carbohydrate during
recovery from endurance exercise stimulates skeletal
muscle protein synthesis in humans.
Howarth KR, et al. J Appl Physiol. 2008 Nov 26. [Epub ahead of
print] [Medline]
PURPOSE: Co-ingestion of protein with carbohydrate (CHO)
during recovery from exercise can affect muscle glycogen
synthesis, particularly if CHO intake is suboptimal. Another
potential benefit of protein feeding is an increased synthesis rate
of muscle proteins, as well documented after resistance exercise.
In contrast, the effect of nutrient manipulation on muscle protein
kinetics after aerobic exercise remains largely unexplored. We
tested the hypothesis that ingesting protein with CHO after a
standardized 2 h bout of cycle exercise would increase mixed
muscle fractional synthetic rate (FSR) and whole body net
protein balance (WBNB) versus trials matched for total CHO or
total energy intake. We also examined whether post-exercise
glycogen synthesis could be enhanced by adding protein or
additional CHO to a feeding protocol that provided 1.2 g
CHO/kg/hr, which is the rate generally recommended to
maximize this process. METHODS: Six active men ingested
drinks during the first three h of recovery that provided either
1.2 g CHO/kg/hr (L-CHO), 1.2 g CHO +0.4 g PRO/kg/hr (PROCHO) or 1.6 g CHO/kg/hr (H-CHO) in random order.
RESULTS: Based on a primed constant infusion of L-[ring(2)H5]-phenylalanine, analysis of biopsies (v. lateralis) obtained
at 0 and 4 h of recovery showed that muscle FSR was higher
(p<0.05) in PRO-CHO (0.09+/-0.01 %/hr) versus both L-CHO
(0.07+/-0.01%/hr) and H-CHO (0.06+/-0.01%/hr). WBNB
assessed using 1-(13)C-leucine, was positive only during PROCHO and this was mainly attributable to a reduced rate of
protein breakdown. Glycogen synthesis rate was not different
between trials. CONCLUSION: We conclude that ingesting
protein with CHO during recovery from aerobic exercise
increased muscle FSR and improved WBNB, as compared to
feeding strategies that provided CHO only matched for total
CHO or total energy intake. However, adding protein or
additional CHO to a feeding strategy that provided 1.2 g
CHO/kg/hr did not further enhance glycogen resynthesis during
recovery. Key words: protein turnover, stable isotopes, amino
acids, glycogen. SPONSORSHIP: Natural Sciences and
Engineering Research Council of Canada (NSERC).
potentially contribute to its favorable effect. An important
improvement upon the latter study’s design was the present
study’s inclusion of an all-carb treatment that was calorically
equal to the protein-containing one. Finally, this trial was a
within-subject design. Subjects inevitably differ from one
another, and this can introduce confounding variability across
individuals. In within-subject designs, subjects are used as their
own controls. As such, in the present trial, the same subjects
were tested in each condition. Therefore, differences among
subjects were measured and separated from error. Finally, In
addition to the general measures of nutritional control, all
subjects were provided with a standardized, prepackaged meal
on the day prior to each experimental trial. Subjects were
instructed to ingest the meal as breakfast at a standardized time
on the day of the trial, after having fasted overnight.
Study limitations
This study was well designed and executed; its procedures
fulfilled its purpose. Pointing out limitations boils down to
nitpicking, so here’s its main flaw other than its small sample
size. Although standardizing a breakfast on the trial day was a
conscientious move since athletes don’t compete in an
overnight-fasted state, the composition of the breakfast was
oddly low in protein and fat. The meal was 700 kcal, consisting
of 82% CHO, 10% fat, and 8% protein. This was perhaps
intentionally done in order to minimize the presence of residual
plasma amino acids near the exercise protocol. However, it
shouldn’t be ignored that an optimal pretraining feeding setup
aims to raise blood amino acid levels during training in order to
promote muscle protein synthesis and inhibit muscle protein
breakdown.2
Comment/application
Previously, Levenhagen et al reported that muscle protein
synthesis was increased after aerobic exercise when protein was
added to a carbohydrate-fat supplement compared to the
supplement without protein.1 However, in addition to not
eliminating the possibility that an increased energy intake was
responsible for the increased protein synthetic response, the
authors relied on arterio-venous measurements. The present
study’s methodology was stepped up a notch via direct
measurement of muscle protein synthesis by combining stable
isotope infusion with muscle biopsy sampling.
While there’s a decent body of research on protein and
carbohydrate intake after resistance training, this study provided
novel information for endurance exercise recovery. Research by
Levenhagen et al examined a similar question to the present one,
and compared the postexercise effect of protein added to a CHOfat solution to the same solution without protein.1 The
comparison was 10g protein versus none in a solution containing
8g CHO and 3g fat. As expected, they observed a net increase in
essential amino acid uptake and whole-body protein gain only in
the protein-containing treatment. A confounding possibility
explaining the benefit of the protein treatment on muscle protein
synthesis is that it simply had more calories, which could
The main finding in this study was that co-ingestion of protein
with CHO during recovery from endurance exercise increased
mixed skeletal muscle fractional synthetic rate (FSR) and
induced a more positive whole-body net protein balance as
compared to drinks matched for total CHO or total energy
intake. Glycogen synthesis was not enhanced with additional
protein nor carbohydrate beyond the base CHO dose of
1.2g/kg/hr. In addition to matching energy intake between
treatments, this study was the first to examine the effect of CHO
and protein ingestion during recovery from endurance exercise
on muscle FSR using the needle biopsy technique. Interestingly,
unlike Levenhagen’s trial that found no change in protein
breakdown, the present trial attributed the increased protein
balance to the prevention of breakdown rather than an increase
in synthesis. Chalk up yet another point for postworkout protein.
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
Study strengths
Page 6
The effect of resistive exercise rest interval on
hormonal response, strength, and hypertrophy with
training.
Buresh R, et al. J Strength Cond Res. 2008 Dec 9. [Medline]
PURPOSE: The purpose of this study was to compare the
effects of different between-set rest periods (1 and 2.5 minutes)
on changes in hormone response, strength, arm cross-sectional
area (CSA), thigh muscular cross-sectional area (MCSA), and
body composition during a 10-week training period.
METHODS: Twelve untrained males (24.8 +/- 5.9 years)
engaged in resistance training using either 1 minute (short rest
[SR], n = 6) or 2.5 minutes (long rest [LR], n = 6) of rest
between sets, with a load that elicited failure on the third set of
each exercise. Body composition, thigh MCSA, arm CSA, and
five-repetition maximum (RM) squat and bench press were
assessed before and after training. Blood samples were collected
after exercise in weeks 1, 5, and 10. RESULTS: In week 1,
postexercise plasma testosterone levels were greater in SR (0.41
+/- 0.17 mmol.L) than in LR (0.24 +/- 0.06 mmol.L, p < 0.05),
and postexercise cortisol levels were greater in SR (963 +/- 313
mmol.L) than in LR (629 +/- 127 mmol.L, p < 0.05). Week 1
postexercise GH levels were not different (p = 0.28). The
differences between hormone levels in weeks 5 and 10 were not
significant. Arm CSA increased more with LR (12.3 +/- 7.2%)
than with SR (5.1 +/- 2.9%, p < 0.05). There were no differences
in strength increases. CONCLUSION: These results show that
in healthy, recently untrained males, strength training with 1
minute of rest between sets elicits a greater hormonal response
than 2.5-minute rest intervals in the first week of training, but
these differences diminish by week 5 and disappear by week 10
of training. Furthermore, the hormonal response is highly
variable and may not necessarily be predictive of strength and
lean tissue gains in a 10-week training program.
SPONSORSHIP: University Committee on Research of the
University of Nebraska at Omaha.
Study strengths
The question investigated here is very practical in nature, and
can potentially provide valuable information for those who are
short on training time. Another design strength was the
measurement of the 5-repetition maximum (5RM) as opposed to
the more traditional assessment of the 1RM. Aside from the
greater safety and broader applicability of the 5RM testing,
neurological factors stand a greater chance of affecting the
performance of 1RM, particularly in untrained subjects.
Additionally, strength tests were done on both upper-body and
lower-body movements. Whereas a large proportion of similar
research limits cross-sectional area (CSA) measurement to a
single limb, the present study measured CSA in both the thigh
and the arm. Since dietary control is typically absent in exercise
research, it was refreshing to see that subjects were instructed to
consume protein at 1.7g/kg /day to insure adequate nutritional
support for muscular size and/or strength gains.
duration. This is a significant design flaw considering that the
subjects were untrained. This introduces the possibility of a lack
of maximal engagement and progression of the training protocol.
Having been a trainer for several years before I transitioned into
the gloriously sedentary field of nutrition, I can personally attest
that it takes new trainees weeks, if not months, of careful
supervision to become adept at various exercises. This is
especially the case with exercises that involve free weights
(including bodyweight-only movements), which require a higher
level of coordination and stabilization than machines with a
fixed path of motion. An indirect method of obtaining CSA was
employed via equations involving skinfold and circumference
measurements. While these may correlate reasonably well with
direct means, the data would be stronger if direct means such as
magnetic resonance imagery (MRI), dual-energy X-ray
absorptiometry (DEXA), or computed tomography (CT) were
employed. Finally, although a rare effort was made to make sure
subjects consumed adequate protein, no other dietary guidelines
(including total calories) were administrated.
Comment/application
The outcome of this trial is interesting but it still leaves some
important questions unanswered. By week 8, although the
difference in protein intake compliance levels was not
statistically significant, one could argue that an 11.6% greater
compliance level in the long rest (LR) group could translate to a
clinically significant advantage (roughly 20-30g more protein
per day). This, among other potentially uncontrolled dietary
factors, might explain the increase in arm CSA in the LR group.
Notably, the LR group also showed a statistically insignificant
increase in thigh CSA compared to the SR group. Another
possible explanation for the superior hypertrophic effects seen in
the LR group was the baseline differences between groups. The
squat 5-RM at baseline was significantly lower for LR than for
SR. Additionally, though not statistically significant, LR tended
to have lower 5-RM bench press strength and arm and leg
muscle CSA. This opens up the possibility that the lower
baseline muscular fitness levels in LR raised this group’s
potential for improvements in strength and muscle hypertrophy.
Although exercise supervision was provided by Certified
Strength & Conditioning Specialists (NSCA-CSCS), this only
occurred in the participants’ first two exercise bouts of the trial.
They were left to train on their own for the rest of the 10-week
Would there have been a difference in trained individuals?
Possibly not. Robinson et al saw no significant differences in
muscular hypertrophy among treatments of 180, 90, or 30
seconds between 10-rep sets.3 Interestingly, despite an increase
in maximal strength in the longest-resting group, a lack of
significant difference in body composition change was seen.
More recently, Goto et al compared the effects of a
“hypertrophy-type” treatment (10 RM with an interset rest
period of 30 seconds and progressively decreasing load)
“strength-type” treatment (90% of 1RM) and a “combinationtype” treatment (strength-type protocol immediately followed by
a low-intensity/high-repetition treatment).4 This protocol worked
best for maximal strength gains as well as muscular endurance.
Although not to a statistically significant degree, CSA increase
was greatest in the combination group as well. Back to the
present trial, postexercise hormonal elevations proved to be
unreliable correlates of size and strength gains. The authors
speculate that the transient hormonal elevations might possibly
be maintained and thus capitalized by periodization, which was
not part of the training protocol used in this study.
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
Study limitations
Page 7
Comment/application
Substrate Metabolism and Exercise Performance with
Caffeine and Carbohydrate Intake.
Hulston CJ, Jeukendrup AE. Med Sci Sports Exerc. 2008
Dec;40(12):2096-104. [Medline]
PURPOSE: 1) To investigate the effect of caffeine on
exogenous carbohydrate (CHO) oxidation and glucose kinetics
during exercise; and 2) to determine whether combined ingestion
of caffeine and CHO enhanced cycling performance compared
with CHO alone. METHODS: Ten endurance-trained cyclists
performed three experimental trials consisting of 105 min
steady-state (SS) cycling at 62% VO2max followed by a time
trial (TT) lasting approximately 45 min. During exercise,
subjects ingested either of the following: a 6.4% glucose
solution (GLU), a 6.4% glucose plus caffeine solution providing
5.3 mg kg(-1) of caffeine (GLU + CAF), or a placebo (PLA).
Glucose solutions contained a trace amount of [U-C]glucose,
and eight subjects received a primed continuous [6,6-H2]glucose
infusion. RESULTS: Peak exogenous CHO oxidation rates
were not significantly different between GLU and GLU + CAF
trials (52.6 +/- 2.7 and 49.1 +/- 2.1 micromol kg.min(-1),
respectively). Rates of appearance (Ra) and disappearance (Rd)
of glucose were significantly higher with CHO ingestion than
PLA (P < 0.01) but were not significantly different between
GLU and GLU + CAF trials. Performance times were 43.45 +/0.86, 45.45 +/- 1.07, and 47.40 +/- 1.30 min for GLU + CAF,
GLU, and PLA, respectively. Therefore, GLU + CAF ingestion
enhanced TT performance by 4.6% (P < 0.05) compared with
GLU and 9% (P < 0.05) compared with PLA. CONCLUSION:
The coingestion of caffeine (5.3 mg kg(-1)) with CHO during
exercise enhanced TT performance by 4.6% compared with
CHO and 9.0% compared with water placebo. However, caffeine
did not influence exogenous CHO oxidation or glucose kinetics
during SS exercise. SPONSORSHIP: Glaxo-SmithKline
Consumer Healthcare, United Kingdom.
Study strengths
Subjects were endurance-trained cyclists, eliminating the
“newbie effect”, and making this data more applicable to
advanced and well-conditioned athletes. Since all subjects were
identified as caffeine users, this makes the outcomes applicable
to a sizable segment of the athletic population, who indeed are
caffeine-habituated to varying degrees. To reduce the potential
confounding influence on substrate metabolism of prior exercise
and diet leading into the testing period, subjects recorded food
intake and physical activity for 2 days before the first trial.
Study limitations
Other very common limitation of a small sample size, it’s
difficult to fault this study. It was straightforward and wellcontrolled. However, one thing lacking in the scant body of trials
examining CHO-caffeine combinations is the addition of protein
or amino acids. Excluding the latter from the substrate mix is not
optimal, since the ingestion of protein during endurance exercise
has been consistently shown to prevent muscle protein
breakdown.5-8 Hopefully, future research will examine the
present study’s combination with protein during training.
Alan Aragon’s Research Review – December, 2008
The present study was primarily an investigation of the
mechanisms behind caffeine’s enhancing effect on ergogenesis
when combined with CHO (no mechanism was clear, more on
that in a minute). In a previous study done by the present trial’s
authors, a very high dose of caffeine (10mg/kg) in combination
with a relatively high CHO ingestion rate (0.8g/kg/min).9 Since
these high rates of ingestion may not represent what athletes use
in the field, exogenous CHO oxidation and glucose kinetics with
a smaller dose of caffeine (5.3mg/kg) and lower rate of CHO
ingestion (0.71g/min) were used in the present trial.
Given the results of their previous study using a high caffeine
dose, the authors hypothesized that a more realistic dose of
caffeine coingested with glucose would increase exogenous
CHO oxidation compared with glucose alone. However, the
combination did not increase exogenous CHO oxidation
compared with an isoenergetic amount of glucose alone. Just to
refresh some of the readers on the significance, increased rates
of exogenous CHO oxidation has the potential to improve work
performance. It’s never been proven, but theoretically exogenous
CHO oxidation can “spare” or prevent glycogen use. Despite the
lack of effect of the caffeine on exogenous CHO oxidation or
glucose kinetics during exercise, the CHO-caffeine combination
enhanced time trial performance by 4.6% compared to CHO
alone, and 9% compared to placebo.
As pointed out by the authors, some studies report performance
benefits with far lower (and perhaps more practical) caffeine
doses than the amount used in the present trial (5.3 mg/kg).
Illustrating this, Cox et al observed enhanced time trial cycling
performance with just 1.5 mg/kg.10 Kovacs et al reported that 3.2
mg/kg was equally as effective as 4. Mg/kg, but both were more
effective than 2.1mg/kg.11 Nonetheless, the present trial and
others demonstrate that combined ingestion of caffeine and CHO
enhances endurance exercise performance beyond CHO alone.
Unfortunately, the authors could not find a clear mechanism for
the additional performance effect of caffeine. The original
hypothesis proposed by Costill et al almost three decades ago
suggested that caffeine mobilized free fatty acids (FFA) from
adipose tissue and facilitated higher rates of fat oxidation, which
helped stave off the use of glycogen.12 However, the present trial
shows that caffeine neither elevated plasma FFA or glycerol
concentrations, nor did it increase rates whole-body fat oxidation
These findings are in agreement with other recent research
showing that plasma FFA concentrations are not always elevated
with caffeine ingestion. Astutely, the authors pointed out
previous research showing that even if higher plasma FFA
concentrations are observed, respiratory exchange ratio (RER) is
unaffected.13 This indicates that caffeine may exert its ergogenic
effects in the absence of altered substrate metabolism.
The current research shows that a mix of carbohydrate sources
ingested during exercise, as opposed to a singular source, is
more gastrically tolerable. Furthermore, glucose and fructose
have different transporters that can be utilized simultaneously
for faster availability to muscle and liver. Thus, in future
research, I’d like to see an exercise performance comparison of a
combination of glucose and fructose with a solution of straight
glucose – both treatments with caffeine, both with protein.
[Back to Contents]
Page 8
The acute effects of the thermogenic supplement
Meltdown on energy expenditure, fat oxidation, and
hemodynamic responses in young, healthy males.
Jitomir J, et al. J Int Soc Sports Nutr. 2008 Dec 16;5(1):23.
[Medline]
PURPOSE: The purpose of this study was to evaluate the
effects of a thermogenic supplement, Meltdown, on energy
expenditure, fat oxidation, and hemodynamics before and after
maximal treadmill exercise. METHODS: In a double-blind,
randomized, placebo-controlled, cross-over design, 12 male
participants underwent two testing sessions after consuming
either the Meltdown or placebo supplement. While in a fasted
state, participants rested for one hour, orally ingested either
Meltdown or placebo, rested for another hour, performed a
maximal treadmill exercise test, and then rested for another hour.
Throughout the testing protocol resting energy expenditure
(REE), respiratory exchange ratio (RER), heart rate (HR), and
blood pressure (BP) were assessed. RESULTS: Meltdown
increased REE significantly more than placebo at 45 min (1.44 +
0.25 vs. 1.28 + 0.23 kcal/min; p= 0.003), 60 min (1.49 + 0.28 vs.
1.30 + 0.22 kcal/min; p= 0.025), and 120 min (1.51 + 0.26 vs.
1.33 + 0.27 kcals/min; p = 0.014) post-ingestion. Meltdown
significantly decreased RER at 30 min (0.84 + 0.03 vs. 0.91 +
0.04; p = 0.022) and 45 min post-ingestion (0.82 + 0.04 vs. 0.89
+ 0.05; p = 0.042), and immediately post-exercise (0.83 + 0.05
vs. 0.90 + 0.07; p = 0.009). Furthermore, over the course of the
evaluation period, area under the curve assessment demonstrated
that REE was significantly increased with Meltdown compared
to placebo (9,925 + 1,331 vs. 8,951 + 2,961 kcals; p = 0.043),
while RER was significantly less than placebo (5.55 + 0.61 vs.
5.89 + 0.44; p = 0.002) following ingestion. HR and BP were not
significantly affected prior to exercise with either supplement (p
> 0.05) and the exercise-induced increases for HR and BP
decreased into recovery and were not different between
supplements (p > 0.05). CONCLUSION: These data suggest
that Meltdown enhances REE and fat oxidation more than
placebo for several hours after ingestion in fully rested and postexercise states without any adverse hemodynamic responses.
SPONSORSHIP: Vital Pharmaceuticals, Inc. (FL, USA).
Study strengths
Subjects who consumed any other form of supplementation than
a multivitamin were excluded from participation. A crossover
was done, meaning that a switch-up of treatments between
groups was administrated after a wash-out period. This gave all
subjects a chance to be tested with the supplement, and it serves
to strengthen the outcomes in the face of a small sample size.
Subjects were required to keep dietary records 48 hours prior to
the testing period. Diet records were evaluated with nutritional
software.
the potential for variability in substrate use during exercise the
following morning.
Comment/application
Vital Pharmaceuticals is better known in fitness circles as VPX
Sports. In my experience, VPX has been more abreast of the
science of things than the typical supplement company, many of
which don’t necessarily have the concept of “integrity” apparent
in their general approach. Nevertheless, I’ll boldly assume that
VPX will soon sponsor a longer-term trial lasting at least a few
weeks. I’ll also boldly predict that the fat loss results will be
favorable, and comparable or better than what’s been seen in
ephedrine-containing supplements. The label information and
advertising hype can be seen here. This product is a cornucopia
of thermogenic substances that the manufacturer claims will
work synergistically to get you ready for that pool party coming
up way too soon.
The striking aspect of this trial was the apparent win-win effect
caused by Meltdown: increased resting energy expenditure
(REE), decreased respiratory exchange ratio (RER) indicating a
greater use of fat for fuel – all this without any significant effects
on heart rate or blood pressure. The big deal about this is that
although ephedrine-containing compounds were modestly
effective for fat loss, they also raised heart rate and blood
pressure. The use of synephrine instead of ephedrine is likely the
reason. The increase in REE seen in the present trial was
comparable to ephedrine-induced REE increases, but occurred
approximately 120 minutes earlier than ephedrine.
One thing to bear in mind is that this entire study was conducted
under fasted conditions. The effect of the fed state on this
supplement’s action is unknown, but likely to be significantly
suppressive in most populations. This means that unless fasted
training is part of one’s regimen, supplements such as Meltdown
stand to be significantly less effective that what was seen in the
present trial. Although, there is the possibility that if highly
trained subjects were used in an endurance-type protocol, fat
oxidation might not be affected by prior meal ingestion during
exercise. For example, Febbraio et al demonstrated that there
was no difference in fat oxidation between the fasted and fed
subjects despite the elevated insulin levels in the carb-fueled
treatments during 2 hrs of exercise at an intensity level of 63%
VO2 max.14 Therefore, it’s conceivable that the lean, fit
population may stand to reap more benefit from this supplement
than the regular Joes or Janes.
Acute effects were measured in this trial. As such, long-term
safety and/or effectiveness is yet to be determined. As
mentioned by the authors themselves, the subjects were healthy,
lean young men, and the outcomes may not translate similarly to
obese or morbidly obese populations in different gender or age
brackets. Finally, although diet records were taken 2 days prior
to testing, imposing a standardized dinner may have decreased
Repeatedly throughout the manuscript, the authors mention
ephedrine-containing supplements (particularly the caffeineephedrine stack) as the competitive standard that Meltdown has
the potential to match or beat. However, the resounding data that
comes to mind is a recent meta-analysis by Shekelle et al
showing that a rather unimpressive 0.9 kg (1.98 lb) monthly
weight loss beyond placebo can be expected from ephedrinecontaining supplememts.15 An unwelcome finding was a 2.23.6-fold increase in the odds of psychiatric, autonomic, or
gastrointestinal symptoms, and heart palpitations. The hope for
Meltdown is that its long-term effects have all of the good and
none of the bad. With only VPX standing to gain any return on
research dollars invested in Meltdown, it’s likely that the
outcomes will suit their commercial agenda.
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
Study limitations
Page 9
the low-flavonoid diet and low-flavonoid diet plus green tea
extract.
Green tea extract only affects markers of oxidative
status postprandially: lasting antioxidant effect of
flavonoid-free diet.
Young JF, et al. Br J Nutr. 2002 Apr;87(4):343-55.. [Medline]
PURPOSE: Epidemiological studies suggest that foods rich in
flavonoids might reduce the risk of cardiovascular disease and
cancer. The objective of the present study was to investigate the
effect of green tea extract (GTE) used as a food antioxidant on
markers of oxidative status after dietary depletion of flavonoids
and catechins. METHODS: The study was designed as a 2 x 3
weeks blinded human cross-over intervention study (eight
smokers, eight non-smokers) with GTE corresponding to a daily
intake of 18.6 mg catechins/d. The GTE was incorporated into
meat patties and consumed with a strictly controlled diet
otherwise low in flavonoids. GTE intervention increased plasma
antioxidant capacity from 1.35 to 1.56 (P<0.02) in postprandially
collected plasma, most prominently in smokers. RESULTS: The
intervention did not significantly affect markers in fasting blood
samples, including plasma or haemoglobin protein oxidation,
plasma oxidation lagtime, or activities of the erythrocyte
superoxide dismutase, glutathione peroxidase, glutathione
reductase and catalase. Neither were fasting plasma
triacylglycerol, cholesterol, alpha-tocopherol, retinol, betacarotene, or ascorbic acid affected by intervention. Urinary 8oxo-deoxyguanosine excretion was also unaffected. Catechins
from the extract were excreted into urine with a half-life of less
than 2 h in accordance with the short-term effects on plasma
antioxidant capacity. CONCLUSION: Since no long-term
effects of GTE were observed, the study essentially served as a
fruit and vegetables depletion study. The overall effect of the 10week period without dietary fruits and vegetables was a decrease
in oxidative damage to DNA, blood proteins, and plasma lipids,
concomitantly with marked changes in antioxidative defence.
SPONSORSHIP: Danish Food Technology grant (FØTEK2),
and from the Commission of the European Communities,
Agriculture and Fisheries (FAIR).
Study strengths
Comment/application
A relatively broad battery of oxidation damage and oxidation
defense parameters were measured, and green tea extract (GTE)
only had transient and relatively meaningless effects. Currently,
green tea seems to be overhyped compared to its actual effects
measured in research. While epidemiological research correlates
green tea consumption with reduced a reduced risk of
cardiovascular events and other surrogate indexes of CVD,16 the
controlled clinical research doesn’t convincingly support green
tea as the causal agent. Clearly, there are other factors within or
associated with green tea consumption that have not yet been
clearly established. In a recent review on the mechanisms and
effects of green tea on cardiovascular health, Basu and Lucas
offer the following conclusion echoing some of the present
study’s findings:17
“The role of green tea polyphenols in reducing lipid
peroxidation, particularly LDL oxidation and malondialdehyde
concentrations, have been reported from several in vitro,
animal, and limited clinical studies. […] While green tea intake
may benefit smokers who are at increased risk of developing
CVD, its role in reducing the biomarkers of oxidative stress and
inflammation in hypercholesterolemic subjects, or in those with
borderline diabetes, remains to be elucidated.”
Energy intake was balanced with output as indicated by the
weight-stability of the subjects (weight changed less than 1 kg in
each subject throughout the entire trial). This removes the
possibility that the positive clinical outcomes resulted from
weight or fat loss. The authors of the present study mention that
it can be viewed as a 10-week dietary depletion of all food
antioxidants derived from fruits and vegetables. However, they
speculated that the improvement in oxidative status was due to
the absence of antioxidant foods which may have had prooxidant compounds co-existing with vitamin C in fruits and
vegetables. This is a rather far-fetched speculation, since as I
mentioned, the trial didn’t have a fruit and vegetable-based,
flavonoid-rich treatment arm.
This trial was well designed for its intended purpose. To nitpick
at the limitations, sample size was small (although this was
partially alleviated with the crossover). This study lacked a
treatment arm consisting of a diet high in wholefood-based
flavonoids in order to compare antioxidant effects with those of
Perhaps the most interesting aspect of this study was the
decrease in oxidative damage to proteins, DNA, and lipids
despite the subjects’ specific avoidance of tea, wine, spices,
chocolate, cocoa, fruits, berries, and vegetables except carrots
and potatoes. Without reading the full text, the abstract can
misled readers to believe that these positive effects were seen
during 10 weeks without any plant foods, period.. This actually
happened, since I recently debated with someone who tried
(unsuccessfully) to use this study to argue that plant foods are
not beneficial to health. However, the big mistake of interpreting
the data based solely on the abstract is the fact that the dietary
treatments both included significant amounts of carrots and
potatoes. Carrots were consumed daily at 3 points in the day:
breakfast, lunch (as a “carrot salad”), and late afternoon snack.
In addition to that, a carrot cake dessert was given 4x a week.
Potatoes were in the menu nearly every day at either lunch
(whole) or dinner (mashed). If anything, this diet was an
accidental study of the health benefits of a rigorously enforced
daily intake of carrots & potatoes.
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
The crossover with a 2-week washout period was implemented
in order to compensate for the small sample size (16 subjects
total). All meals were lab-prepared in individual portions
according to subjects’ energy requirements. All meals were
consumed on-site. Subjects were instructed to return any
leftovers to the department for weighing and subtraction from
planned intake and were asked daily about compliance. No food
other than that provided by the investigators was allowed to be
consumed. Now this, my dear readers, is a very rare example of
strict control over dietary variables.
Study limitations
Page 10
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Levenhagen DK, et al. Postexercise protein intake enhances
whole-body and leg protein accretion in humans. Med Sci
Sports Exerc. 2002 May;34(5):828-37. [Medline]
Tipton KD, et al. Timing of amino acid-carbohydrate
ingestion alters anabolic response of muscle to resistance
exercise. Am J Physiol Endocrinol Metab. 2001
Aug;281(2):E197-206. [Medline]
Robinson JM, et al. Effects of different weight training
exercise/rest intervals on strength, power, and high intensity
exercise endurance. J Strength Cond Res. 1995 Nov;
9(4):216-21. [JSCR]
Goto K, et al. The Impact of Metabolic Stress on Hormonal
Responses and Muscular Adaptations. Med Sci Sports
Exerc. 2005 Jun;37(6):955-63. [MSSE]
Ivy JL, et al. Effect of a carbohydrate-protein supplement on
endurance performance during exercise of varying intensity.
Int J Sport Nutr Exerc Metab. 2003 Sep;13(3):382-95.
[Medline]
Saunders MJ, et al. Effects of a carbohydrate-protein
beverage on cycling endurance and muscle damage. Med
Sci Sports Exerc. 2004 Jul;36(7):1233-8. [Medline]
Romano-Ely BC, et al. Effect of an isocaloric carbohydrateprotein-antioxidant drink on cycling performance. Med Sci
Sports Exerc. 2006 Sep;38(9):1608-16. [Medline]
Bird SP, et al. Liquid carbohydrate/essential amino acid
ingestion during a short-term bout of resistance exercise
suppresses myofibrillar protein degradation.
Yeo SE, et al. Caffeine increases exogenous carbohydrate
oxidation during exercise. J Appl Physiol. 2005
Sep;99(3):844-50. [Medline]
Cox GR, et al. Effect of different protocols of caffeine
intake on metabolism and endurance performance. J Appl
Physiol. 2002 Sep;93(3):990-9. [Medline]
Kovacs EM, et al. Effect of caffeinated drinks on substrate
metabolism, caffeine excretion, and performance. J Appl
Physiol. 1998 Aug;85(2):709-15. [Medline]
Costill DL, et al. Effects of caffeine ingestion on
metabolism and exercise performance. Med Sci Sports.
1978 Fall;10(3):155-8. [Medline]
Graham TE, et al. Caffeine ingestion does not alter
carbohydrate or fat metabolism in human skeletal muscle
during exercise. J Physiol. 2000 Dec 15;529 Pt 3:837-47.
[Medline]
Febbraio MA, et al. Effects of carbohydrate ingestion before
and during exercise on glucose kinetics and exercise
performance. J Appl Physiol. 2000 Dec;89(6):2220-6.
[Medline]
Shekelle PG, et al. Efficacy and safety of ephedra and
ephedrine for weight loss and athletic performance: a metaanalysis. JAMA. 2003 Mar 26;289(12):1537-45. [Medline]
Kutiyama S, et al. Green tea consumption and mortality due
to cardiovascular disease, cancer, and all causes in Japan:
the Ohsaki study. JAMA. 2006 Sep 13;296(10):1255-65.
[Medline]
Basu A, Lucas EA. Mechanisms and effects of green tea on
cardiovascular health. Nutr Rev. 2007 Aug;65(8 Pt 1):36175. [Medline]
Alan Aragon’s Research Review – December, 2008
[Back to Contents]
Page 11
Is organic food ‘healthier’ than conventional food?1
By Jamie Hale & Alan Aragon
In the beginning
Technically speaking, any substance that’s carbon-based is
organic.
This chemistry-derived designation has become
effectively trivialized by the organic food industry. Probably the
most common reason consumers buy organic foods is
because they perceive them to be more nutritious and safer. Is
this true? Is there really a significant difference between organic
and conventional foods? These questions are the fuel for
ongoing investigation whose results thus far have been both
enlightening and disappointing.
Recent scientific reviews
With rare exception, as in the case of a paper by Köpke,2
reviews in recent years have not been decidedly in favor of
organic foods. He asserts that organic agriculture is
environmentally sound and more sustainable than mainstream
agriculture. However, since Köpke is the head of the Institute of
Organic Agriculture, and president of the International Society
of Organic Agriculture Research, the potential for pro-organic
bias is strong.
In contrast, a review conducted by Williams and colleagues
investigated the nutritional value of organic foods.3 They
concluded that evidence either supporting or refuting the
“supreme nutritional value” of organic foods over conventional
foods is not available in the scientific literature. Although very
few compositional differences have been reported, there are
reasonably consistent findings indicating higher nitrate and
lower vitamin C within conventionally-produced leafy
vegetables. Nevertheless, there is a glaring lack of cohesive data
concerning the clinical impact on animal and human health
resulting from organic versus conventional produce. Data from
controlled studies in animal models, particularly within single
species, are limited or poorly designed, and findings from these
studies provide conflicting outcomes. To further limit any solid
conclusions, there are no reports in the literature of controlled
intervention studies in human subjects.
Magkos and colleagues reviewed scientific evidence regarding
organic foods and their nutrient value.4 They pointed out that
there are only a scant number of well-controlled studies that are
capable of making a valid comparison between conventional and
organic food. Since the compilation of the results is difficult,
generalization of the conclusions should be made with caution.
With the exception of a slight trend towards higher ascorbic acid
content in organically grown leafy vegetables and potatoes, there
is very little evidence that organic and conventional foods differ
in concentrations of the various essential micronutrients.
As for the rest of the nutrients and the other food groups,
existing evidence is inadequate to allow for valid conclusions.
One possible benefit for organically fed animals is a slightly
improved reproductive performance. A similar finding has not
yet been identified in humans. The investigators ultimately
Alan Aragon’s Research Review – December, 2008
conclude that despite any potential differences, a well-balanced
diet can equally improve health regardless of whether it’s
organic or conventional.
Magkos and colleagues recently conducted another review of the
literature comparing conventional foods to organic foods.5 They
asserted that scientific evidence indicating that organic food is
safer and more nutritious than conventional food is scarce.
Organic fruits and vegetables can generally contain fewer
agrochemical residues than conventionally grown alternatives.
However, the significance of this difference is questionable
because actual levels of contamination in both types of food are
generally far below acceptable limits. Some leafy, root, and
tuber organic vegetables may have lower nitrate content
compared with conventional ones.
It’s still not clear whether or not dietary nitrate in typical
concentrations constitutes any threat to human health. Data
exists indicating a protective effect of nitrate against pathogenic
microorganisms, so the risks of its absence must also be
considered. Importantly, no differences can be identified for
environmental contaminants (i.e., cadmium and other heavy
metals), which are likely contained in both organic and nonorganic foods. Regarding other food hazards, such as
endogenous plant toxins, biological pesticides, and pathogenic
microorganisms, available evidence is extremely limited. This
casts considerable doubt on the generalization that organic status
automatically equals greater safety.
Omit the pesticides, invite the pests
A rather disturbing case study by Kajiya and colleagues
suggested a possible relationship between parasite infection and
organic food.6 Heart failure was caused by hookworm in an 87year old Japanese man who had a 30-year history of eating
organic foods. In general, footwear and proper sanitation are
important for control of hookworm because the parasite is
usually transmitted through contact with contaminated soil. The
highest rates of hookworm infection occur in the world’s coastal
regions and are often associated with poverty-stricken areas.
The 87-year old Japanese man wore shoes outdoors and lived
inland. In fact, he did not go outside often. The occurrence of
hookworm infection in Japan is uncommon. Organic foods have
become relatively popular in advanced countries with good
hygiene, and increasing numbers of people buy foods grown
without pesticides. The investigators suspected that the Japanese
man became infected by eating organic food imported from
endemic areas of hookworm infection. It’s been suggested that
organic foods grown without pesticides may carry old-fashioned
diseases. The World Health Organization has stressed various
measures of monitoring organic foods for this reason.
Strong words from a public skeptic
Scientists often don’t get their points across to the public; their
relaying of data often gets lost in translation. Bridging the gap
somewhat between science and consumer culture is author and
news personality Steven Milloy, who has built career on mythdebunking. He defines his personally coined term junk science
as faulty scientific data and analysis used to advance special and,
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often, hidden agendas.7 In an article featured on FoxNews.com,
Milloy offered the following perspective:8
“No scientific study shows that organic foods are safer,
healthier, or more nutritious than conventional foods. The
“organic” label only means that the products were raised
inefficiently without benefit of several modern technologies...
Milk—whether organic, conventional, or conventionally
produced without the use of rbST—is all the same stuff.
Marketing and labels that imply otherwise hardly educate the
public. Mostly, they line the pockets of the companies selling
them at a premium, sometimes as much as twice the price of
conventional milk.”
than those produced conventionally since organic production
generally prohibits antibiotic use.
Conclusion
If you like the taste of organic food and have the extra money to
spend, go for it. However, don’t consider it a necessity. When
choosing the proper foods to consume, the first consideration
should be a reasonably varied diet that meets your
macronutritional needs. Whether it consists of conventional
foods or organic foods has little (if any) real impact on either
health or safety.
References
An authoritative organization’s perspective
While Milloy’s stance may have inherently limited authority, a
similar view is shared by the Institute of Food Technologists
(IFT), one of the longest-standing and highly regarded scientific
organizations of its kind. The IFT recently issued a Scientific
Status Summary on the organic foods industry.9 The IFT’s report
does anything but embellish the image of the organic foods
industry. Below are some of the key points from the Summary:
ƒ Organic fruits and vegetables possess fewer pesticide
residues and lower nitrate levels than do conventional fruits
and vegetables. In some cases, organic foods may have
higher levels of plant secondary metabolites; this may be
beneficial, but also may be of potential health concern when
considering naturally occurring toxins.
ƒ Some studies have suggested potential increased
microbiological hazards from organic produce or animal
products due to the prohibition of antimicrobial use, yet other
studies have not reached the same conclusion.
ƒ While many studies demonstrate these qualitative differences
between organic and conventional foods, it is premature to
conclude that either food system is superior to the other with
respect to safety or nutritional composition.
ƒ Pesticide residues, naturally occurring toxins, nitrates, and
polyphenolic compounds exert their health risks or benefits
on a dose-related basis, and data do not yet exist to ascertain
whether the differences in the levels of such chemicals
between organic foods and conventional foods are of
biological significance.
ƒ Organic fruits and vegetables rely upon far few pesticides
than do conventional fruits and vegetables, which results in
fewer pesticide residues, but may also stimulate the
production of naturally occurring toxins if organic crops are
subject to increased pest pressures from insects, weeds, or
plant diseases.
ƒ Because organic fruits and vegetables do not use pesticides
or synthetic fertilizers, they have more biochemical energy to
synthesize beneficial secondary plant metabolites such as
polyphenolic antioxidants as well as naturally occurring
toxins.
1.
2.
3.
4.
5.
6.
7.
8.
9.
This article was inspired by the Nutrition: Fact or Fiction
segment of Jamie’s book Knowledge & Nonsense:
[MaxCondition]
Kopke U. Organic foods: do they have a role? Forum Nutr.
2005;(57):62-72. [Medline]
Williams CM. Nutritional quality of organic food: shades of
grey or shades of green? Proc Nutr Soc. 2002 Feb;61(1):1924. [Medline]
Magkos F, et al. Organic food: nutritious food or food for
thought? A review of the evidence. Int J Food Sci Nutr
54(5):357–71. [Medline]
Magkos F, et al. Organic food: buying more safety or just
peace of mind? A critical review of the literature. Crit Rev
Food Sci Nutr. 2006;46(1):23-56. [Medline]
Kajiya T, et al. Heart failure caused by hookworm infection
possibly associated with organic food consumption. Intern
Med. 2006;45(13):827-9. [Medline]
Milloy S. Junk Science? (a definition) [Junkscience]
Milloy S. Organic milk industry reveals hypocrisy. 2006
Oct. [FoxNews]
Winter CK, Davis SF. Scientific status summary: organic
foods. J Food Sci. 2006;71(9): 117-24. [J Food Sci]
One of the things that separates myself and, I’m assuming, many
of the AARR readership is an intense focus on the details. I
didn’t want to use the words “obsessive” or “compulsive”, but
perhaps those are better descriptors for the keen eye some of us
keep on the pulse of physical and/or mental improvement.
Speaking of attention to detail, those of you who haven’t seen
the work of ‘microsculptor’ Willard Wiggan will be utterly
amazed at this video.
ƒ In some cases, food animals produced organically have the
potential to possess higher rates of bacterial contamination
If you have any questions, comments, suggestions, bones of
contention, cheers, jeers, guest articles you’d like to submit, or
any feedback at all, send it over to aarrsupport@gmail.com. All
suggestions are taken very seriously. I want to make sure this
publication continues to stand alone in its brotacularity.
Alan Aragon’s Research Review – December, 2008
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