A misleading study that links high-protein diet to an increased risk for middle-aged eaters is being used to attack the Paleo diet movement. But there’s more to the study than meets the eye.
Study co-author, Valter Longo, professor of biogerontology at the USC Davis School of Gerontology, said in a press release, “We provide convincing evidence that a high-protein diet, particularly if the proteins are derived from animals, is nearly as bad as smoking.” Articles began springing up around the net using the findings as ammunition to undermine the Paleo diet, a nutrition regiment than promotes the idea of eating only things a caveman would have eaten such as organic vegetables, clean meats, and some fruit.
The study, spanning 18 years, was published in Cell Metabolism on March 4 and shows that people aged 50-65 who eat a diet high in animal proteins from meat, milk and cheese suffer increased risk of death as compared to people within the same age group who consumed low-protein diets. The study also identified the role that a hormone called insulin-like growth factor-1, or IGF-1, plays in driving diseases like cancer. The study included the observation of 6,831 middle-aged and older adults. Those with diets consisting of more than 20 percent of their calories from protein were four times more likely to die of cancer.
So, it seems that a high-protein diet is just bad news for people, especially ones who are middle-aged, but the study is misleading as it concerns Paleo eaters. First, strict Paelo eaters avoid dairy altogether while other Paleo eaters who do consume milk and cheese, limit their intake and choose natural dairy products over processed ones. Second, strict Paleo eaters avoid processed and hormone-treated, grain-fed meat, a major source of IGF-1, along with cow’s milk. Third, people in Dr Longo’s study were considered high-protein eaters if they met the threshold of their diet being at least 20 percent protein. How much of the other potential 80 percent of those eater’s diets were carbohydrates, which Paleo diet observers dismiss as unhealthy, and what portion of those carbohydrates were in the form of processed carbs and food high in sugar? There is more to this study than is being reported on and that makes it a poor weapon against Paleo in general.
Opinion by Matt Stinson
Image credit: Carnivore Style