In this episode of Lifespan News, Emmett Short discusses the well-known, longevity-associated Mediterreanean diet and how a variant can promote weight loss.
Script
The Mediterranean diet, rich in olive oil, vegetables, legumes, fish, and nuts, is widely considered to be one of the most healthy and longevity-friendly diets. Numerous epidemiological studies, and a handful of interventional studies, have linked the Mediterranean diet to various positive health outcomes, including decreased overall mortality along with a lower incidence of cardiovascular diseases and cancer. Now, scientists behind a new study have dug deeper to understand which of the many ingredients of the Mediterranean diet make it healthy, and along the way, they may have found a version of the diet that helps reduce visceral fat and promote weight loss!
Pitching two variants of the Mediterranean diet against each other in a randomized controlled trial, scientists have found that a plant-oriented one, which contained more polyphenols, was more effective for weight loss. In this new paper, the researchers used an interesting study design to elucidate the role of polyphenols, a class of phytochemicals known for their antioxidant and anti-inflammatory properties. Polyphenols are abundant in berries, nuts, vegetables, tea, coffee, and many other plant products.
For this new randomized controlled trial called DIRECT-PLUS, nearly 300 participants were divided into three groups. The control group ate according to Healthy Dietary Guidelines, while the two study groups were put on a generic Mediterranean diet and on a more plant-oriented Mediterranean diet that had the same amount of calories but almost double the daily intake of polyphenols as the generic group, 440 milligrams vs 800 milligrams. Patients in all groups were also put on an identical physical activity regimen.
The participants’ mean age was 51 and their mean BMI was 31, indicating obesity. 36% were prediabetic, and another 11% were diabetic. The main endpoint of the trial was weight loss, but it was measured in a more sophisticated way than just putting people on a scale. Instead, MRI technology was used to quantify abdominal adipose tissues.
Following the 18-month trial period, mean weight loss in the control group was negligible, despite patients being physically active. The two study groups, on the other hand, showed substantial weight loss, with the plant-oriented group losing the most weight. Importantly, the plant-oriented diet was shown to be much more effective in reducing the amount of visceral fat, which is considered more harmful than subcutaneous fat.
The researchers went to great lengths to establish the effects of particular dietary components. According to their calculations, higher consumption of green tea, walnuts, and dietary fiber, as well as reduced red meat consumption, were all significantly associated with greater visceral fat loss when adjusted for age and sex. The results of this randomized controlled trial confirm the importance of polyphenol consumption and hint at more plant-based variants of the Mediterranean diet being more effective for weight loss.
So, will these results impact your view of the Mediterranean diet? Let us know in the comments!