Going Paleo? Study Says It's No Better Than Other Diets for Glucose, Insulin Regulation

February 17, 2020

There’s not much research available comparing the Paleolithic diet to other popular nutritional plans. A new study sought to scour existing data to see the Paleolithic diet’s effect on glucose and insulin regulation. The data showed no significant impact.

The Paleolithic diet might have health benefits, but a new meta-analysis of peer-reviewed research finds the diet does not appear to be any better than other diets when it comes to fostering glucose and insulin regulation.

The so-called “Paleo” diet has become a popular dieting trend in the United States and abroad in recent years. A 2018 study from the State University of New York estimated that about 3 million Americans were following the diet at the time. As its name suggests, the nutrition plan is premised on the idea that our hunter-gatherer ancestors from the Paleolithic Era had a preferable diet. Adherents to the Paleo diet are told to focus on the types of foods a Stone Age person would eat, including meat, fish, and poultry, as well as fruits and vegetables. Processed foods, including dairy products and cereals, are to be avoided.

Writing in the Journal of Clinical Medicine, a team of Polish and German investigators note that a person on the Paleolithic diet would end up getting about one-third of his or her energy from each of 3 categories: fats, carbohydrates, and proteins. In that sense, the Paleo diet is similar to other low-carbohydrate diets.

“However, the hunter—gatherer diet provides a higher amount of dietary fiber (up to 45–100 g per day) than a low‐carbohydrate diet,” writes corresponding author Jaroslav Walkowiak, MD, PhD, of the Department of Pediatric Gastroenterology and Metabolic Diseases at Poznan University of Medical Sciences, in Poland.

Other research has suggested the Paleolithic diet might have cardiovascular health benefits, as well as anti-inflammatory effects.

What Walkowiak and colleagues wanted to know is whether the diet might affect glucose and insulin levels, something that would be of significant interest to those with diabetes or pre-diabetes.

To investigate the question, the team reviewed the medical literature for randomly controlled trials that compared the Paleolithic diet to other dietary interventions. They zeroed in on studies that compared the effects of the diet on fasting glucose and insulin levels, HbA1c, homeostasis assessment of insulin resistance, and area under the curve for glucose and insulin (AUC 0-120) during the oral glucose tolerance test.

The search criteria netted 4 studies involving 98 subjects. After reviewing the data, Walkowiak and colleagues found the Paleo diet had no significant impact.

“The present meta‐analysis demonstrates that the Paleolithic diet did not differ from other types of diets commonly perceived as healthy regarding its effect (on the above-mentioned criteria),” Walkowiak and co-authors noted.

Despite the lack of a benefit over the other diets studied, the authors noted that the research has generally affirmed that low-carbohydrate diets can improve fasting glucose levels, particularly in patients with type 2 diabetes. Thus, while the Paleolithic diet might not have a statistically significant impact when compared to other low-carb diets, it may still have benefits over less-healthy diets. They write that longer-term studies would be needed in order to more concretely characterize the impact of such diets.

The new study aligns with a report released last year by the American Diabetes Association. It found, in part, that a “one-size-fits-all” approach to nutrition therapy in patients with diabetes or pre-diabetes was not feasible. However, the report did recommend that patients in these categories ought to consume at least the recommended daily amount of fiber, and that they ideally would get that fiber from fruits, vegetables, and whole grains.

Reference

Jamka M, Kulczyński B, Juruć, A, Gramza-Michałowska A, Stokes CS, Walkowiak J. The effect of the paleolithic diet vs. healthy diets on glucose and insulin homeostasis: A systematic review and meta-analysis of randomized controlled trials. J. Clin. Med. 2020, 9, 296. doi: 10.3390/jcm9020296