Consumption of fruit, coffee, chocolate and wine reduces risk of metabolic syndrome by up to 23%

A diet rich in produce such as grapes, strawberries, açaí, oranges, chocolate, wine and coffee can reduce the risk of metabolic syndrome by as much as 23%, according to the findings of a study involving more than 6,000 Brazilians, the largest in the world to associate the effects of consuming polyphenols with protection against cardiometabolic problems.

An article on the study is published in the Journal of Nutrition. 

Metabolic syndrome, a cluster of metabolic abnormalities and hormone alterations, is the main risk factor for cardiovascular disease. Polyphenols are bioactive compounds with well-known anti-oxidant and anti-inflammatory properties.

“This is good news for people who like fruit, chocolate, coffee and wine, all of which are rich in polyphenols. Although the link between consumption of polyphenols and a reduction in the risk of metabolic syndrome had already been identified in previous studies, it had never before been verified in such a large study sample [6,378 people] and over such a long period [eight years]. Our findings in this study leave no room for doubt: promoting diets rich in polyphenols can be a valuable strategy for reducing the risk of cardiometabolic disease and preventing metabolic syndrome,” said Isabela Benseñor, a co-author of the article and a professor at the University of São Paulo’s Medical School (FM-USP) in Brazil.

The data analyzed in the study was retrieved from ELSA-Brazil, a longitudinal adult health survey that has tracked since 2008 some 15,000 public servants employed by six Brazilian universities and research institutions, with funding from the Ministry of Health and the National Council for Scientific and Technological Development (CNPq), an arm of the Ministry of Science, Technology and Innovation (MCTI). The analysis was conducted at the same university’s School of Pharmaceutical Sciences (FCF-USP) as part of the postdoctoral research of Renata Carnaúba, under the aegis of the Food Research Center (FoRC), one of the Research, Innovation and Dissemination Centers (RIDCs) funded by FAPESP.

Out of 6,378 participants analyzed, 2,031 developed metabolic syndrome, which is clinically diagnosed when at least three of the following conditions are present: abdominal obesity, high blood pressure, high blood sugar (hyperglycemia), high triglycerides, and high lipids (dyslipidemia). 

The prevalence of metabolic syndrome is rising globally at epidemic proportions. In Brazil, it rose from 29.6% in 2013 to 33% in 2022, according to previously published studies. 

“We plan to conduct further research on the role of polyphenols in protection from cardiometabolic disease. What we know so far relates to the anti-inflammatory and anti-oxidant properties of these compounds, as well as a possible positive influence on the gut microbiota,” said Benseñor, who coordinates ELSA-Brazil.

Dietary polyphenol intake

More than 8,000 polyphenols have been identified in nature. The best known and most studied are phenolic acids (found in coffee and wine), flavonoids (fruit in general, beans, and chocolate), lignans (seeds and oranges), and stilbenes (red grapes and red wine).

Detailed interviews based on questionnaires were conducted to find out about the participants’ dietary habits and the frequency with which they ingested 92 polyphenol-rich foods. The effects of different cooking and processing methods were taken into consideration to assure accurate measurement of polyphenol intake.

The main conclusion was that consumption of polyphenols from different foods at the highest estimated level (469 mg per day) reduced the risk of developing metabolic syndrome by 23% compared with the lowest polyphenol consumption (177 mg per day). Consumption of phenolic acids (a specific class of polyphenols abundant in coffee, red wine and tea) reduced the risk by a similar amount.

According to Carnaúba, the quantity of polyphenols associated with a reduction in the risk of metabolic syndrome was derived from total dietary intake. “Food variety is important since one of the justifications for the beneficial effects of polyphenol on health is their capacity to modulate the gut microbiota. This process can stimulate the growth of probiotic or ‘good’ bacteria. However, the more diverse a person’s dietary intake and sources of polyphenols, the better the effect on their gut microbiota and hence on their overall health,” she said.

The analysis also showed that elevated consumption of flavan-3-ols, a flavonoid subgroup, was associated with a 20% lower risk of developing metabolic syndrome. Red wine was the main source of flavan-3-ols for the study sample, accounting for 80% of total intake of this compound. Chocolate was also a significant source, accounting for 10%.

The researchers also studied the impact of polyphenols on other cardiometabolic disorders linked to metabolic syndrome, such as hypertension, insulin resistance, and elevated triglycerides, for example.

“The results showed that the effects of polyphenols on the metabolism and heart disease were far from negligible. Regardless of the various cardiometabolic risk factors, such as sex, age, smoking and physical activity, participants who ingested more polyphenols were up to 30 times less likely to develop high blood pressure or insulin resistance, and 17 times less likely to have elevated triglycerides,” Carnaúba said.

About FAPESP

The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the state of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration.