Modified Mediterranean diet twice as healthy as original - Israeli study

The Mediterranean diet has been praised by clinical dietitians around the world as being the most healthful of all. But now, a modified Mediterranean diet called the “Green Mediterranean/high polyphenols diet” has been found to be twice as good – promoting dramatic proximal unstiffens the aorta. This largest artery of the body carries oxygenated blood throughout the body.

Polyphenols are naturally occurring compounds found mostly in fruits like grapes, apples, pears, cherries and berries along with vegetables, cereals and beverages such as coffee and green tea. Many fruits contain up to 200 to 300 mg. polyphenols per 100 gr. fresh weight.

Protection against oxidative stress

Polyphenols are reducing agents, and together with other dietary reducing agents including vitamin C, vitamin E and carotenoids (also known as antioxidants), they protect the body’s tissues against oxidative stress and associated pathologies such as cancers, coronary heart disease and inflammation.

But one must not exaggerate, as animal studies show that very high-dose polyphenol supplements could cause an imbalance in thyroid levels, kidney damage and tumors, and in humans, they could raise the risk of stroke and premature death.

The DIRECT-PLUS trial research team was the first to introduce the concept of the green-Mediterranean, high polyphenols diet. This modified Mediterranean diet is distinct from the traditional Mediterranean diet because of its more abundant dietary polyphenols and lower amounts of red or processed meat. On top of a daily intake of walnuts (28 grams), the green-Mediterranean dieters consumed three or four cups of green tea and one cup of Wolffia-globosa (mankai) plant green shake of duckweed per day over a year and a half. The aquatic green plant mankai is high in bioavailable iron, B12, 200 kinds of polyphenols and protein and is therefore a good substitute for meat.

The green Mediterranean-high polyphenols diet substantially regresses proximal aortic stiffness (PAS), a marker of vascular aging and increased cardiovascular risk. The green Mediterranean diet was pitted against the healthy Mediterranean diet and a healthy guideline-recommended control diet in the DIRECT PLUS, a large-scale clinical intervention trial.

Researchers found that the green Mediterranean diet regressed proximal aortic stiffness by 15%, the Mediterranean diet by 7.3%, and the healthy dietary guideline-directed diet by 4.8%. The study was recently published in the top-ranked journal in the field of cardiology, the Journal of the American College of Cardiology under the title “Effect of Lifestyle Modification and Green Mediterranean Diet on Q1 Proximal Aortic Stiffness.”

This is the first time that scientists have presented a powerful, potent effect of diet on the age-related proximal aortic stiffness. DIRECT PLUS was a large-scale, long term clinical trial over 18 months among 300 participants, using MRIs to measure aortic stiffness, which are the most-accurate noninvasive measure of the elasticity of the blood vessel wall. It occurs when the elastic fibers within the arterial wall (elastin) begin to fray due to mechanical stress.

PAS reflects the aortic stiffness from the ascending to the proximal-descending thoracic aorta; the section of the aorta. Proximal aortic stiffness is a distinct marker of vascular aging and an independent cardiovascular risk factor to predict morbidity and mortality.

Changing the lifestyle to be healthier

CHANGING ONE’S lifestyle to a healthier one is the first and most widely taken intervention for treating obesity and its metabolic complications. But although intense exercise reduces PAS, the effect of weight loss interventions on PAS remains uncertain. The Mediterranean diet is the most substantiated dietary intervention for cardiometabolic risk reduction and cardiovascular disease prevention, the team wrote.

“However, the effects of the Mediterranean diet on PAS are unclear. Recently, we reported that hypocaloric-green Mediterranean diet enriched with plant-based polyphenols and less meat and simple carbohydrates could offer benefits beyond hypocaloric-Mediterranean and healthy dietary guidelines to improve cardiometabolic risk,” they added.

The research was led by Prof. Iris Shai of Ben-Gurion University of the Negev in Beersheba, Israel who is also an adjunct professor from the Harvard School of Public Health and an honorary professor at the University of Leipzig, Germany – along with her doctoral student Dr. Gal Tsaban, a cardiologist from Soroka-University Medical Center – and colleagues from Harvard and Leipzig Universities.

The team has showed in previous studies that the Green Mediterranean/high polyphenols diet has various beneficial effects ranging from reshaping the microbiome to halting atrophy of the brain and regressing hepatosteatosis intrahepatic (fat of at least 5% of the liver’s weight) and visceral adiposity (fat stored deep inside the abdomen and wrapped around organs including the liver and intestines).

“A healthy lifestyle is a strong basis for improving cardiometabolic health,” explained Shai. “We learned from the results of our experiment that the quality of the diet is crucial for mobilizing atherogenic adipose tissues (involving chronic inflammation and repair of the vessel wall endothelium and smooth muscle cells that result in thickened vessel walls with a narrowed opening), lowering cardiometabolic risk and improving one’s fat profile. Dietary polyphenols – consumed while substituting red meat with equivalent plant-based protein – show can significantly improve various aspects of human health.

However, to date, no dietary strategies have been shown to impact vascular aging physiology, Shai added. “This study, to our knowledge, is the first to show that PAS might be regressed by maintaining a healthy lifestyle; beyond weight loss, the Green-Mediterranean diet may have greater influence on the regression of PAS, a predictor of lower risk of cardiovascular disease, compared with the other Mediterranean diets. Maintaining a healthy diet alone is associated with PAS regression, but 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,” Tsaban concluded.