The effect of high-polyphenol Mediterranean diet on visceral adiposity: the DIRECT PLUS randomized controlled trial

Abstract

Background Mediterranean (MED) diet is a rich source of polyphenols, which benefit adiposity by several mechanisms. We explored the effect of the green-MED diet, twice fortified in dietary polyphenols and lower in red/processed meat, on visceral adipose tissue (VAT). Methods In the 18-month Dietary Intervention Randomized Controlled Trial PoLyphenols UnproceSsed (DIRECT-PLUS) weight-loss trial, 294 participants were randomized to (A) healthy dietary guidelines (HDG), (B) MED, or (C) green-MED diets, all combined with physical activity. Both isocaloric MED groups consumed 28 g/day of walnuts (+ 440 mg/day polyphenols). The green-MED group further consumed green tea (3–4 cups/day) and Wolffia globosa (duckweed strain) plant green shake (100 g frozen cubes/day) (+ 800mg/day polyphenols) and reduced red meat intake. We used magnetic resonance imaging (MRI) to quantify the abdominal adipose tissues. Results Participants (age = 51 years; 88% men; body mass index = 31.2 kg/m2; 29% VAT) had an 89.8% retention rate and 79.3% completed eligible MRIs. While both MED diets reached similar moderate weight (MED: − 2.7%, green-MED: − 3.9%) and waist circumference (MED: − 4.7%, green-MED: − 5.7%) loss, the green-MED dieters doubled the VAT loss (HDG: − 4.2%, MED: − 6.0%, green-MED: − 14.1%; p < 0.05, independent of age, sex, waist circumference, or weight loss). Higher dietary consumption of green tea, walnuts, and Wolffia globosa; lower red meat intake; higher total plasma polyphenols (mainly hippuric acid), and elevated urine urolithin A polyphenol were significantly related to greater VAT loss (p < 0.05, multivariate models). Conclusions A green-MED diet, enriched with plant-based polyphenols and lower in red/processed meat, may be a potent intervention to promote visceral adiposity regression. Trial registration ClinicalTrials.gov, NCT03020186

Cardiovascular prevention in women: an update by the Italian Society of Cardiology working group on ‘Prevention, hypertension and peripheral disease’

“…43 The beneficial effects of the green-MED diet on visceral adiposity loss might be explained by polyphenols. 42 In foods and beverages, phenolic compounds are mainly stored as a glycone or, mostly, as glycosidic conjugates. In the organism, they are widely metabolized due to enzymes that are differently expressed in men and women.…”

Mediterranean Diet Adherence Is Associated with Favorable Health-Related Quality of Life, Physical Activity, and Sleep Quality in a Community-Dwelling Greek Older Population

“…In addition, the MD exerted a substantial and beneficial impact on the quality of life and disease symptom scores in 475 individuals with multiple sclerosis [98]. An 18-month MD supplemented with plant-based polyphenols and lower levels of red and processed meat was found to be a promising intervention in promoting visceral adiposity regression in a randomized controlled clinical trial of 294 participants [99].…”

Systematic Review and Meta-Analysis of the Impact of Bariatric Surgery on Future Cancer Risk

“…There is evidence to suggest that, although exercise, a Mediterranean-style diet and medical management may not be successful in patients with Class II and III obesity, they can be synergistic when combined with bariatric surgery in reversing metabolic syndrome, maintaining a robust postoperative weight loss and potentially contributing to a decrease in future cancer risk [ 25 , 97 ]. This is likely related to continuing adipokine and exosome release from dysfunctional adipocytes and abnormal neurohormonal homeostasis if patients resume a poor diet or sedentary lifestyle with associated weight regain post-surgery.…”

“…Lifestyle interventions have poor sustainability due to an established hypothalamic ‘set point’ and compensatory neurohormonal responses to attempted caloric restriction during dieting and increased energy expenditure during exercise. This ultimately conserves weight or promotes weight regain in obese patients who attempt to lose weight [ 25 , 26 , 27 , 28 ]. Other factors limiting the efficacy of conventional treatments include persistent systemic inflammation, OSA, a dysfunctional adipocyte secretome and metabolic syndrome in patients with morbid obesity, as well as individual comorbidities such as poor mobility, osteoarthritis, depression, sarcopenia or micronutrient deficiencies [ 25 ].…”

“…This ultimately conserves weight or promotes weight regain in obese patients who attempt to lose weight [ 25 , 26 , 27 , 28 ]. Other factors limiting the efficacy of conventional treatments include persistent systemic inflammation, OSA, a dysfunctional adipocyte secretome and metabolic syndrome in patients with morbid obesity, as well as individual comorbidities such as poor mobility, osteoarthritis, depression, sarcopenia or micronutrient deficiencies [ 25 ].…”