Paleo systematic review
What is it about?
The paleo diet was the most searched diet-related term on Google in 2014. However, a 2015 US News and World Report ranking of 35 diets with input from a panel of health experts placed the paleo diet dead last, citing a lack of randomized trials that showed clinical benefits. Several randomized trials have been published recently, but these have not, as yet, been systematically reviewed. The paleo diet is modeled on the nutritional patterns of our ancestors from the Paleolithic era (2.6 million to ~10,000 years ago), before the advent of modern (industrial) agriculture. Archeological, anthropological, and genetic evidence suggests that Paleolithic nutrition consisted of meat, fish, eggs, vegetables, fruit, and nuts in variable proportions and did not include dairy, grain products, or legumes. Current pre-industrial hunter-gatherer societies, consuming Paleolithic-like nutrition, are largely free of the degenerative diseases of Western civilization. It has been hypothesized that our physiologic architecture, which came of age over millions of years, cannot adapt rapidly enough to the changes in dietary habits occurring since the agricultural revolution. The ensuing mismatch has been proposed to contribute to the epidemic of chronic disease, which the world faces today. If this hypothesis holds true, one would expect Paleolithic nutrition to ameliorate risk markers of chronic disease, particularly in people who are (genetically) predisposed to develop any of these disorders. Manheimer and coworkers applied Cochrane systematic review methods to evaluate whether current randomized trial evidence supports the postulate that Paleolithic nutrition improves risk factors for chronic disease more than do other dietary interventions in people with one or more components of the metabolic syndrome.
Why is it important?
This systematic review found evidence to suggest that the Paleolithic diet can improve metabolic syndrome components more than currently recommended control diets. These beneficial effects and their longer-term sustainability warrant further evaluation. Moreover, state-of-the-art nutritional science readily explains the metabolic benefits of a (modest) restriction of carbohydrates, a lack of high–glycemic index products, a low ω-6 over ω-3 fatty acid balance, and a reduction of salt intake in patients with insulin resistance and the metabolic syndrome. In contrast, it is less clear whether the avoidance of whole grains and dairy products is a prerequisite for optimal control of metabolism. Additional studies should carefully examine the health significance of avoiding these food groups in the context of Paleolithic nutrition.
The following have contributed to this page: Dr Zbys Fedorowicz, Dr Esther J van Zuuren, Hanno PIjl, and Dr Eric W Manheimer