Study Questions Link Between Vegetable Intake, CVD Risk

FRIDAY, March 4, 2022 (HealthDay News) -- Higher intake of raw vegetables is inversely associated with cardiovascular disease (CVD) risk, but confounding accounts for most of the association, according to a study published in the February issue of Frontiers in Nutrition.

Qi Feng, Ph.D., from the University of Oxford in the United Kingdom, and colleagues examined data from the U.K. Biobank cohort for 399,586 participants without prior CVD. A validated dietary questionnaire was used to measure raw and cooked vegetable intakes. The association between vegetable intake and CVD incidence and mortality was estimated.

The researchers found that for raw and cooked vegetables, the mean intakes were 2.3 and 2.8 tablespoons per day, respectively. There were 18,052 major CVD events and 4,406 CVD deaths during 12 years of follow-up. An inverse association was seen for raw vegetable intake with both CVD incidence and CVD mortality (adjusted hazard ratio for the highest versus the lowest intake, 0.89 and 0.85, respectively); no association was seen for cooked vegetable intake. After adjustment for potential confounding variables, the associations of raw vegetables with CVD incidence and mortality were reduced by 82 and 87 percent, respectively.

"This study highlights the need for rigorous assessment for residual confounding in studies of the effects of diet and other lifestyle factors on disease risk and suggests the need to reappraise the evidence on the burden of CVD disease attributable to low vegetable intake in high-income populations," the authors write.

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