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 [Back to Contents] 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, [Back to Contents] Page 12 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: 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. 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. 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. 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. 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. 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. 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 [Back to Contents] Page 13