For this study, the Green Mediterranean diet was compared to the standard healthy Mediterranean diet as well as a guideline-recommended control diet in the DIRECT PLUS large-scale clinical long-term intervention trial of 300 participants. Over 18 months the researchers used MRIs to measure participant aortic stiffness (PAS is a marker of vascular aging and increased cardiovascular risk), the most effective noninvasive measure.
Along with a daily intake of 28 grams of walnuts, those on the Green Mediterranean diet also consumed 3-4 cups of green tea, and one cup of Wolffia-globosa (Mankai) plant green shake of duckweed every day. Mankai is an aquatic green plant that is rich in bioavailable iron, B12, protein, and 200 kinds of polyphenols making it a good meat substitute.
According to the researchers, the team found that the Green Mediterranean diet reduced proximal aortic stiffness by 15%, the Mediterranean diet reduced PAS by 7.3% and the healthy dietary guideline-directed diet regressed PAS by 4.8%.
The DIRECT Plus trial research team was the first to introduce the concept of the Green Mediterranean diet, which is a modified version of the Mediterranean diet. It is distinct from the traditional diet because it is more abundant in dietary polyphenols that offer various health benefits, and it is also lower in red/processed meats. Previously the team has demonstrated that the Green Mediterranean diet has various salutary effects ranging from reshaping the microbiome (Gastroenterology 2021) to halting brain atrophy (AJCN 2022), as well as regressing hepatosteatosis (Gut 2021) and visceral adiposity (BMC Med 2022).
“A healthy lifestyle is a strong basis for improving cardiometabolic health. We learned from the results of our experiment that the quality of the diet is crucial for mobilizing atherogenic adipose tissues, lowering cardiometabolic risk, and improving one’s adiposity profile. Dietary polyphenols, substituting red meat with equivalent plant-based protein, show promise for improving various aspects of human health. However, to date, no dietary strategies have been shown to impact vascular aging physiology,” says Prof. Shai.
“Maintaining a healthy diet alone is associated with PAS regression. The Green Mediterranean diet provides a 15% dramatic reduction in PAS, which is gained by making simple and feasible changes to your diet and lifestyle. The results of our study highlight, once again, that not all diets provide similar benefits and that the Green Mediterranean diet may promote vascular health,” notes PhD student Dr. Gal Tsaban, a cardiologist from Soroka University Medical Center.
