While the commercial food industry brags about its “healthy” food as low in carbohydrates and fats, chronic illnesses such as cancer and diabetes continue to rampage in society wrecking havoc on environmental, financial, and life quality sustainability. The medical and health communities continue to be ill informed as they demonize fat and carbohydrates while heralding protein as a savior (mostly due to media popularization).
This unhealthy cycle of thought could be slowed down by a recent ground breaking research supporting the long-overlooked body of evidence which indicates that too much protein is bad for you. In March of 2014, Cell Metabolism published a study showing that a diet high in animal protein sources is detrimental to health. A diet high in protein was defined as protein being 20% or more of caloric intake for the day. A diet low in protein was defined as 10% or less of calories from protein.
Subjects aged 50-65 years on a high protein diet had a 75% increase in overall mortality and 4-fold increase in death risk from cancer compared to subjects on low protein diet. In addition, the risks and association with high protein diet diminished to almost zero for subjects who acquired their protein from plant sources. On the other hand, this study also shows that for people over the age of 65, low protein diets resulted in poorer outcomes in terms of overall and cancer mortality.
The key lies in animal protein’s affect on insulin-like growth factor 1 (IGF-1). IGF-1 is a pro-growth hormone that reduces cell destruction and promotes cell growth. While this beneficial to a growing child or a malnourished senior citizen, IGF-1 has been implicated in cancer and diabetes development.
It has been long known of animal protein’s implication on IGF-1. The March study largely draws from a previous study published in 2011 by Guevara-Aguirre et al. in Science Translational Medicine journal. Guevara-Aguirre et al. studied a population of Ecuadorians deficient in IGF-1 and growth hormones. Researchers found the population had little to no cancer or diabetes mellitus prevalence due to their low IGF-1 levels.
This study supports a slew of evidence of what scientists have long know, a diet high in animal protein is detrimental to one’s health and significantly increases risk of developing common chronic illnesses such as diabetes mellitus, hypertension, and cancer to name a few.
Therefore, it is recommended to have your protein from sources such as nuts and beans. It is also advised against to have your protein sources from animals including dairy, eggs, and whey.
Levine ME 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 Metabolism 2014. 19(3) 407-417
Allen NE et al. The Associations of Diet with Serum Insulin-like Growth Factor I and Its Main Binding Proteins in 292 Women Meat-Eaters, Vegetarians, and Vegans. Cancer Epidemiology, Biomarkers & Prevention 2002. 11(11) 1441-1448
Guevara-Aguirre J et al. Growth Hormone Receptor Deficiency Is Associated with a Major Reduction in Pro-Aging Signaling, Cancer, and Diabetes in Humans. Science Translational Medicine 2011. 3(70) 70ra13