We have defamed the shit out of fat and now carbohydrates. It was only a matter of time before someone decided to crucify dietary protein.

There seems to be this trend in the healthosphere that strength training, increased protein intake, and bulking will immediately give you CANCER.

I call bullshit. I might be wrong, but I still call bullshit. And here’s why.

This hypothesis is framed around the idea that if you run IGF-1 and MTOR signaling pathways all day every day you are putting way more bullets in the cancer Russian roulette gun because you are promoting an environment of “unlimited” growth. #gainz

The majority of this data comes from petri dishes, mouse models, caloric restriction trials, and survey data from the general population, eating the standard American diet, and getting 1.7 steps per day. Remember, the scientific community rarely has the opportunity to study healthy people and to extrapolate what is going on in an unhealthy population to a healthy population is bolux.

In fact, most of this fear mongering stems from an epi study published in Cell in 2014, where they compared high protein intakes to smoking in terms of cancer risk. Come on! I am not going to break that study down because it has more holes than the Texas/Mexico border and Examine.com already did a fantastic review which you can read here.

Now, let’s be clear growth signaling doesn’t cause cancer, so go head and throw out that more bullets in the gun analogy. BUT, if you have cancer it will make these mutant cells grow faster.

Interestingly, resistance training is used in cancer survivors to make them more resilient to treatment. Harumph.

“No adverse effects of the resistance training were reported. Based upon these results, we recommend to incorporate resistance training in cancer rehabilitation programs.”

-De Baker et al 2009

OK… so, let’s look at studies in bodybuilders who by this hypothesis should be rolling in IGF-1, and thus be riddled with cancer.

Oh wait, we have zero long term prospective trials in lean, resistance trained subjects consuming a high protein diet made up of real food. Shit.

So, let’s ask more basic questions does resistance training even raise IGF-1? Yes, best case scenario by about 20%, if you are young, but NOT so if you are above 60 (about 90% of cancer occurs in those over the age of 50…shit again). Furthermore, this research was done in untrained subjects, and there has to be some kind of threshold effect. To further complicate the issue, higher protein intakes are generally helpful in preventing sarcopenia in the elderly. I know enough about old people. I’m sorry.

In trained subjects, we even see IGF-1 bottom out in high protein, high volume training with hypocaloric conditions. WTF!

Now if this growth hormone hypothesis held weight we would see sleeping lead to increased cancer risk because sleep is the main determinant of growth hormone release. Not true. It’s the opposite, shift work has been found to increase cancer risk.

Yet, we would surely see growth hormone therapy result in increased cancer risk.

“This review of various clinical and epidemiological studies demonstrated that there is no clear evidence of a causal relationship between growth hormone treatment and tumor development.”

-Chae et al. 2015

Shiattttt again, again, and again.

Thus, while the rest of the alternative health world argues about the minute details of this bullet ridden hypothesis for the next 50 years. I’ll be squatting and eating chicken breasts with my bare hands because you can’t fear monger me out of the weight room. I’m not living not to die. That shit’s for the birds.

People always fear what they don’t understand. And deep down baby smart humans fear us big dumb humans. So LIFT and jam on some pro pro and if you get cancer LIFT some more and maybe cut down on the ribeyes…maybe.


**Yes. I cherry picked the hell out of this article, but if the hypothesis was so robust I shouldn’t be able to pick it apart so easily.


  1. Borst SE, De Hoyos DV, Garzarella L, et al. Effects of resistance training on insulin-like growth factor-I and IGF binding proteins. Med Sci Sports Exerc. 2001;33(4):648-653.
  2. Borst SE, Vincent KR, Lowenthal DT, Braith RW. Effects of resistance training on insulin-like growth factor and its binding proteins in men and women aged 60 to 85. Journal of the American Geriatrics Society. 2002;50(5):884-888.
  3. Chae HW, Kim DH, Kim HS. Growth hormone treatment and risk of malignancy. Korean J Pediatr. 2015;58(2):41-46.
  4. Chaves J, Saif MW. IGF system in cancer: from bench to clinic. Anticancer Drugs. 2011;22(3):206-212.
  5. Fontana L, Weiss EP, Villareal DT, Klein S, Holloszy JO. Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans. Aging Cell. 2008;7(5):681-687.
  6. Hansen J. Light at night, shiftwork, and breast cancer risk. J Natl Cancer Inst. 2001;93(20):1513-1515.
  7. Hansen J, Stevens RG. Night shiftwork and breast cancer risk: overall evidence. Occup Environ Med. 2011;68(3):236.
  8. Hasani-Ranjbar S, Soleymani Far E, Heshmat R, Rajabi H, Kosari H. Time course responses of serum GH, insulin, IGF-1, IGFBP1, and IGFBP3 concentrations after heavy resistance exercise in trained and untrained men. Endocrine. 2012;41(1):144-151.
  9. Levine ME, Suarez JA, Brandhorst S, et al. Low protein intake is associated with a major reduction in IGF-1, cancer, and overall mortality in the 65 and younger but not older population. Cell Metab. 2014;19(3):407-417.
  10. Maestu J, Eliakim A, Jurimae J, Valter I, Jurimae T. Anabolic and catabolic hormones and energy balance of the male bodybuilders during the preparation for the competition. J Strength Cond Res. 2010;24(4):1074-1081.
  11. Nicholson PJ. Shift work and chronic disease: the epidemiological evidence. Occup Med (Lond). 2011;61(6):443-444; author reply 444.
  12. Populo H, Lopes JM, Soares P. The mTOR signalling pathway in human cancer. Int J Mol Sci. 2012;13(2):1886-1918.

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