Whole foods, Mediterranean diet help improve endothelial function

Eating whole foods such as fruits and vegetables regularly, as well as following a Mediterranean diet, can enhance endothelial function as measured by flow-mediated dilation (FMD), suggests a study.

“Overall, the habitual consumption of specific whole foods and dietary patterns, particularly those rich in (poly)phenols, polyunsaturated fatty acids, and fibre, appear to play a meaningful role in enhancing endothelial function, as evidenced by improvements in fasting FMD,” the investigators said. 

“The consistent benefits were observed with fruits, vegetables, soy, nuts and seeds, cocoa, tea, and the Mediterranean diet,” they added.

This study included 133 randomized controlled trials examining the effects of whole foods or dietary patterns for ≥28 days on endothelial function in adults, measured as FMD. 

The investigators performed meta-analyses and meta-regression analyses to explore the effects of whole foods and dietary interventions on FMD. They also conducted Grading of Recommendations Assessment, Development and Evaluation (GRADE) and risk of bias and publication bias assessments.

Of the eligible studies, 102 involved whole food interventions comparing 14 food groups and 31 involved dietary intervention comparing 11 dietary patterns. [Am J Clin Nutr 2025;122:1204-1232]

Among whole food interventions, the following consistently showed improvements in FMD: fruits (mean difference [MD], 0.86 percent, 95 percent confidence interval [CI], 0.16–1.55), vegetables (MD, 1.37, 95 percent CI, 0.34–2.40), soy (MD, 1.58 percent, 95 percent CI, 0.32–2.832), nuts and seeds (MD, 1.39, 95 percent CI, 0.17–2.60), cocoa (MD, 1.58, 95 percent CI, 0.08–3.29), and tea (MD, 3.22, 95 percent CI, 2.01–4.42), which showed the greatest improvement.

For dietary patterns, only the Mediterranean diet (MD, 1.68, 95 percent CI, 0.08–3.29) was found consistent in improving FMD across studies.

On the other hand, weight loss interventions did not result in a significant change in FMD with a weight loss of <10 percent body weight. The GRADE certainty of evidence was moderate to low.

"[These] findings should be interpreted with caution owing to moderate-to-low certainty of evidence and some concerns or high risk of bias in many cases,” the investigators said.

Tea

Regular consumption of tea improved fasting FMD potentially due to its high concentrations of flavonoid. Moreover, tea is rich in catechins, and during the processing of black tea, catechins are converted to theaflavins and thearubigins. [Basic Res Cardiol 2009;104:100-110]

Cocoa is also rich in flavanols, particularly epicatechin. “These polyphenols stimulate NO production and vasodilation, as well as reduce systolic and diastolic blood pressure, through activation of eNOS and inhibition of nicotinamide adenine dinucleotide phosphate oxidase,” the investigators said. [Proc Natl Acad Sci USA 2006;104:1024-1029; Eur J Nutr 2014;53:1299-1311; PLOS ONE 2014;9:e103247]

An earlier study also found the association of daily intake of tea with a reduced risk of all-cause mortality among adults and a lower risk of cardiovascular disease (CVD)-specific mortality in older adults. [Adv Nutr 2020;11:790-814]

“Energy restriction interventions showed limited impact on FMD, suggesting that the composition of the diet may be more critical than weight loss alone,” the investigators said. “These findings reinforce the potential of targeted dietary strategies to significantly reduce CVD risk.”