A large dietary study from 18 countries, across 7 geographic regions has found that even relatively moderate intake of fruit, vegetables and legumes such as beans and lentils may lower a person's risk of cardiovascular disease (CVD) and death.
Analysis of the Prospective Urban Rural Epidemiology (PURE) study was presented at ESC Congress today and published in the Lancet.
"To our knowledge, this is the first study to report on the associations of fruit, vegetable and legume intake with CVD risk in countries at varying economic levels and from different regions," said study investigator Dr Andrew Mente, PhD, from the Population Health Research Institute, McMaster University, Hamilton, Canada.
"Previous research, and many dietary guidelines in North America and Europe recommended daily intake of these foods ranging from 400 to 800 grams per day, but this is unaffordable for many people in low to middle-income countries," he explained.
"Our findings indicate that optimal health benefits can be achieved with a more modest level of consumption, an approach that is likely to be much more affordable."
Using country-specific food frequency questionnaires, PURE documented diet in 135,335 individuals, aged 35 to 70 years, from countries in North America and Europe, South America, the Middle East, South Asia, China, South East Asia and Africa.
For this analysis, investigators assessed associations between fruit, vegetable, and legume consumption at baseline and risk of CVD and mortality after a median of 7.4 years of follow-up.
Looking at the total of 5,796 deaths, 1,649 CV deaths, and 4,784 major CVD events, and adjusting for demographic, lifestyle, health, and dietary factors, the study showed greater fruit, vegetable, and legume intake was associated with lower total mortality, and non-CV mortality.
Of particular importance, an intake of 3 to 4 servings per day (equivalent to 375-500 grams per day) was just as beneficial on total mortality as higher amounts (hazard ratio [HR] of 0·78; 95% CI 0·69 to 0·88).
Looking at the dietary components separately showed that the benefits were attributable to fruit and legumes, with vegetable intake not significantly associated with improved outcomes.
Specifically, compared to fewer than three servings of fruit per week, more than 3 per day was associated with an 18% reduced risk in non-CV mortality (HR: 0·82: 95% CI 0·70 to 0·97; P-trend=0·0008), and 19% reduction in total mortality (HR: 0·81; 95% CI 0·72 to 0·93; P-trend<0·0001).
Regarding legumes, higher consumption was associated with significant reduction in both non-CV mortality and total mortality risk.
As compared with less than one serving of legumes per month, more than one serving per day was associated with an 18% reduction in non-CV mortality (95% CI 0·70 to 0·97; P-trend=0·0019) and a 26% reduction in total mortality (95% CI 0·64 to 0·86; P-trend=0·0013).
Finally, comparing vegetable preparation, the study showed a trend towards lower risk of cardiovascular disease and death with raw versus cooked vegetable intake "but raw vegetables are rarely eaten in South Asia, Africa and Southeast Asia," said Dr. Mente.
"Since, dietary guidelines do not differentiate between the benefits of raw versus cooked vegetables - our results indicate that recommendations should emphasize raw vegetable intake over cooked."
In conclusion he said that findings from the study "are robust, globally applicable and provide evidence to inform nutrition policies. Many people in the world don't consume an optimal amount of fruit, vegetables and legumes. The PURE data add to the substantial evidence from many studies and extend them globally".