Research Identifies 6 Food Groups With Largest Impact on Cardiovascular Outcomes

New research suggests that including or excluding unprocessed red meat and whole grains in a healthy diet may not have a significant impact on overall cardiovascular outcomes and can be consumed in moderation. Instead, focus should be put on consuming higher amounts of fruits, vegetables, nuts, and legumes, as well as a moderate amount of fish and whole-fat dairy, to reduce the risk of cardiovascular disease (CVD) and associated mortality.

According to the researchers, these findings are applicable to all world regions, especially in lower-income countries where consumption of these recommended foods is low.

“In recent years, major new dietary recommendations have been revised to drop upper limits on total fat or dietary cholesterol, and a greater focus has been placed on protective foods (and the accompanying food matrix found in whole foods) and healthy diet patterns,” the researchers said. “Despite these changes, public purchasing choices, industry formulations, and policy actions have not yet been updated with this newer evidence.”

Findings were published in European Heart Journal and are based on data from 4 large, international prospective cohort studies from 80 countries and 2 case–control studies from 62 countries. Overall, the analysis included 244,597 individuals and nearly 50,000 recorded CVD events.

The researchers’ aim was to develop a healthy diet score using data from the large Prospective Urban Rural Epidemiology (PURE) cohort study, which involved 147,642 people from 21 countries in 5 continents. They also investigated the consistency of the associations between the PURE healthy diet score and occurrences of events by replicating the PURE study in 3 independent prospective studies and 2 case-control studies for myocardial infarction (MI) or stroke; assess whether the PURE healthy diet score is applicable to those living in countries with different levels of income from various regions of the world, and to individuals with and without prior CVD; and compare the performance of the PURE healthy diet score with that of other commonly used diet scores such as the Mediterranean diet, HEI-2010 and 2015, DASH, and Planetary Diet scores.

The PURE diet score was determined based on 6 specific foods previously linked to longer life. The healthy PURE diet included the following weekly servings:

• 2-3 servings of fruits
• 2-3 servings of vegetables
• 3-4 servings of legumes
• 7 servings of nuts
• 2-3 servings of fish
• 14 servings of dairy products (mainly whole-fat, excluding butter or whipped cream)

Each food item received a score of 1 if the intake was above the group's median, indicating a healthy intake, and a score of zero if it was at or below the median, suggesting an unhealthy intake. The total score could range from zero to 6, with a higher score indicating a healthier diet.

Over a median follow-up of 9.3 years in the PURE study, researchers recorded 15,707 deaths and 40,764 cardiovascular events. Compared with individuals with a diet score of ≤ 1 point, individuals with a diet score of ≥ 5 points had a 30% lower risk of death, an 18% lower likelihood of CVD, a 14% lower risk of MI, and a 19% lower risk of stroke.

These associations between the healthy diet score and outcomes were confirmed in 5 independent studies. In the 3 independent studies involving patients with vascular conditions, higher diet scores were associated with lower mortality (HR, 0.73; range, 0.66-0.81), CVD (HR, 0.79; range, 0.72-0.87), and MI (HR, 0.85; range, 0.71-0.99), with a non-statistically significant lower risk of stroke (HR, 0.87; range, 0.73-1.03). Additionally, the 2 case-control studies showed that a higher diet score was linked to lower first MI (odds ratio [OR], 0.72; range, 0.65-0.80) and stroke (OR, 0.57; range, 0.50-0.65).

North America, Europe, the Middle East, and South America had the highest median diet scores and intake of food components in the diet score. Meanwhile, South Asia, Africa, Southeast Asia, and China had lower scores and intake of its food components.

“Further, with unprocessed red meat and whole grains included or excluded from the diet score in these sensitivity analyses, the results were again similar,” the researchers noted.

The study also found that a higher diet score demonstrated a significantly lower risk of CVD or associated death in regions with lower gross national incomes compared to regions with higher gross national incomes.

Overall, the analysis revealed a mean (SD) PURE healthy diet score of 2.95 (1.50), and a higher healthy diet score was associated with higher gross national income per capita (P < .0001).

“Our findings indicate that the risks of deaths and vascular events in adults globally are higher with inadequate intake of protective foods,” the researchers concluded.

Reference

Mente A, Dehghan M, Rangarajan S, et al. Diet, cardiovascular disease, and mortality in 80 countries. Eur Heart J. 2023;44(28):2560-2579. doi:10.1093/eurheartj/ehad269