The Curious Case of
Campbell’s Rats
Zeroing In on the Myths Purveyed in Chapter 3
of The China Study
Chris Masterjohn, PhD
Portland Regional Wise Traditions, September, 2013
“A Revelation to Die For”
“A Revelation to Die For”
“Turning Off Cancer” With Diets Low in
Protein, as Depicted in The China Study
Campbell’s Research Showing “Dairy” Protein
Promoting Cancer as Depicted in Forks Over Knives
The China Study: Dietary Protein,
Not Carcinogens, Promote Cancer
The China Study: Low Dietary Protein “Turns
Off” the Dose Response Between
Carcinogens and Cancer
Campbell Mocks the Unrealistic Doses of
Carcinogens Used in Cancer Experiments
Campbell Mocks the Unrealistic Doses of
Carcinogens Used in Cancer Experiments
Campbell Mocks the Unrealistic Doses of
Carcinogens Used in Cancer Experiments
The China Study: Milk Protien (Casein), But
Not Wheat Protein (Gluten), Promoted Cancer
The China Study: “Plant Protein”
Does Not Promote Cancer
The China Study: Plant-Based Nutrients Protect
Against Cancer, Animal-Based Nutrients
Promote Cancer
Revisiting the “Revelation
to Die For”
A Toxic Revelation: Rats Fed Low Protein
More Vulnerable to Aflatoxin Toxicity
A Revelation Rats Fed Diets Low in
Protein Could Die For
A Revelation Rats Fed Diets
Low in Protein Could Die For
Number and Percentage of Rats
That Spontaneously Died
Percentage of Rats
50
10/22
40
30
20
10
0/34
0
High
Protein
Low
Protein
The China Study: The MFO Drug-Detoxifying
Enzyme Turns Aflatoxin Into a Carcinogen
The China Study: Low Protein Decreases the Activity
of the Dangerous Drug-Detoxfying MFO Enzyme
Does “Protein Deficiency” Protect Against
Cancer? Quotes From Campbell in 1972
“The effect of protein
deficiency
in male
weanling
“A
deficiency
of dietary
protein
rats
onshown
the activity
of the the
was
to increase
hepatic
toxicitymicrosomal
of aflatoxin enzyme
for rats.”
system was studied.”
Campbell’s Low-Protein Rats Ate Less Food
Campbell’s Rats Should Have Grown
From 50 to 100 Grams
Campbell’s Low-Protein Rats
Had Very Low Body Weight
Campbell’s Low-Protein
Rats Hardly Grew at All
Campbell’s Low-Protein Rats Were
Malnourished and Had Fatty Liver –
Quotes From Campbell, 1972
“First, the reduced DNA content could be indicative of a
lower cell number per gram of liver and would
accordingly imply larger cells in the protein-deprived
group. These cells could be larger in response to lipid
infiltration since the livers of the low protein group were
observed to be very fatty. Consequently, the normal
rate of cell proliferation would have been decreased
during protein deprivation, which is similar to the
retardation of brain cell growth of young malnourished
animals described by Winick and Rosso.”
A Toxic Revelation – Quotes
From Campbell, 1983
Some degree of bile duct proliferation was
observed in all animals dosed with
[aflatoxin]. However, the groups fed the 5%
casein diet during the dosing period had
relatively severe bile duct proliferation and
cholangiofibrosis [fibrosis of the bile duct]. In
these groups, the architecture of the liver
was often distorted by fibrous septa. Groups
fed the 20% casein diet during the dosing
period had mild bile duct proliferation and no
cholangiofibrosis.
Protein Deficiency Disappears Down the
Memory Hole – Quotes From Campbell, 1991
“Although a 5% casein diet is not
generally considered nutritionally
adequate (i.e., it does not support
maximal growth), for every health
index we have thus far measured,
the 5% casein diet supports better
health in rats than does the 20%
casein diet.”
But Don’t We Want Low Protein to Avoid
Making Aflatoxin Toxic?
Aflatoxin Detoxification Depends on
Protein and Glutathione
Campbell’s Low-Protein Rats
Had 40-71% Lower Glutathione
The China Study: Dietary Protein,
Not Carcinogens, Promote Cancer
The Protein vs. Aflatoxin Dose Study Was Much
More Complex Than Presented in The China Study
How Different Are the High-Protein Low-Aflatoxin
and the Low-Aflatoxin High-Protein Groups?
How Accurate Is This Dose Vs.
Protein Simplification After All?
This Chart Is a Little Closer to
the Truth But Still Pretty Far…
Percent of Liver Volume
Ocupied by
Precancerous Lesions
Campbell Showed That Dose
Does Matter After All…
8
At Least 200 µg/day
Is Needed to Produce a
Meaningful Response
6
4
2
0
0
100
200
300
400
500
Aflatoxin Dose (mg/kg/day on 10 days)
The Higher Doses Campbell
Used Were Highly Lethal
How Much Aflatoxin Does
It Take to Kill a Rat?
Percentage of Rats
Surviving
100
80
60
40
20
0
0
100
200
300
400
500
Aflatoxin Dose (mg/kg/day for ten days)
Highly Carcinogenic Doses of
Aflatoxin Are Highly Lethal
100
5
80
4
60
3
40
2
20
1
0
0
0
100
200
300
400
500
Aflatoxin Dose (mg/kg/day on 10 days)
Percent of Liver Volume
Ocupied by
Precancerous Lesions
Percentage of Rats
Surviving
All Animals Fed 20 Percent Casein
Aflatoxin Detoxification Depends on
Protein and Glutathione
Depleting Glutathione Pharmacologically Makes
Aflatoxin Much More Carcinogenic to Rats
Volume of Precancerous
Foci (mm3/liver)
150
125
Depleting Glutathione with a Single
Dose of BSO
Makes Aflatoxin More
Carcinogenic to Rats
69%
Control
Aflatoxin
Aflatoxin + BSO
100
75
50
25
12.6fold
2.8fold
0
3 Weeks
10 Weeks
48 Weeks
What Percentage Protein Is
Used for the Initiation Period?
?
High Protein During Initiation to Complete the
Detoxification of Aflatoxin
Protein Promotes the Growth of Cancer
Already Formed, But Prevents Its Initiation
Chronic Dosing in Monkeys: Protein Protects
Against Toxicity at High Doses and Cancer at
Low Doses
As in Rats, in Monkeys Fed Chronic
Doses of Aflatoxin, Protein Is Protective
This Graph is Missing Something…
Lysine supplementation of wheat gluten
during the postinitiation period enhanced
the gamma-glutamyltransferase-positive
response to a level comparable with that
of the high-quality protein. These results
suggest that one can inhibit the
development of foci either by decreasing
the quantity of protein intake and holding
the quality of the protein constant or by
decreasing the quality and holding the
quantity constant.
It’s a General Effect of Protein, Not Animal
Protein – Quotes From Campbell, 1989
[I]n 1945 Larsen and Heston found that the
incidence of spontaneous pulmonary
tumors was doubled in strain A mice fed
low-casein diets supplemented with cystine
(the most limiting amino acid). Silverstone
and Tannenbaum (14) showed that the
development of spontaneous hepatomas
was enhanced in C3H mice fed a gelatincontaining diet when methionine and
cystine were added.
It’s a General Effect of Protein, Not Animal
Protein – Quotes From Campbell, 1989
A review of the somewhat limited data from these
and earlier studies (1) indicated that inhibition of
tumor development as a result of marginal intakes
of various proteins could be abolished by
supplementation with the respective limiting amino
acid for each protein. . . .
It’s a General Effect of Protein, Not Animal
Protein – Quotes From Campbell, 1989
[O]ur results suggest that the enhancement of
focus development by lysine supplementation of
gluten is due to a general improvement in dietary
protein quality and not to any particular metabolic
effect peculiar to lysine. This conclusion is
supported by previous work (1, 12-14) showing
that various low-quality proteins are better able to
enhance tumor development when they are
supplemented with the amino acid in greatest
deficit.
Campbell’s Curious Rats –
Conclusions
 Adequate protein is necessary for detoxification and
other roles of glutathione such as antioxidant defense.
 Protein protects against cancer in the experiments
most closely resembling contexts experienced
naturally.
 There may be a role for restricting protein in someone
who already has cancer.
 There is no qualitative difference between animal and
plant protein except that animal protein is more
abundant and of higher biological quality.