Study Finds No Heart Benefit From Veggies. Nutritionists Disagree.
Eating vegetables may not help protect you against heart disease, according to a new study that's triggered strong reactions from critics.
The analysis of the diets of nearly 400,000 British adults found that raw vegetables could benefit the heart, but not cooked vegetables. However, the researchers said any heart-related benefit from vegetables vanished altogether when they accounted for lifestyle factors such as physical activity, smoking, drinking, fruit consumption, red and processed meat consumption, and use of vitamin and mineral supplements.
"Our large study did not find evidence for a protective effect of vegetable intake on the occurrence of CVD [cardiovascular disease]," researcher Qi Feng, an epidemiologist in the University of Oxford's Nuffield Department of Population Health, told CNN.
"Instead, our analyses show that the seemingly protective effect of vegetable intake against CVD risk is very likely to be accounted for by bias ... related to differences in socioeconomic situation and lifestyle," Feng added.
The study was published Feb. 21 in the journal Frontiers in Nutrition.
The findings challenge a host of previous research showing that a plant-based diet is good for your heart and overall health, including a recent study showing that a young person could live an additional 13 years by eating more vegetables, legumes, whole grains, fruit and nuts.
So it's little surprise that the new study sparked a strong response from experts.
"Although this study found that eating more vegetables wasn't associated with a lower risk of heart and circulatory diseases once other lifestyle and other factors were taken into account, that doesn't mean we should stop eating vegetables," Victoria Taylor, senior dietitian at the British Heart Foundation, told CNN.
"There is good trial evidence that eating foods rich in fibre such as vegetables can help lower weight, and improve levels of risk factors known to cause heart disease," Naveed Sattar, a professor of cardiovascular and metabolic medicine at the University of Glasgow, told CNN. "The present observational study cannot overcome such evidence and its conclusions can be debated since the authors may have over-adjusted for factors that account for lower intake of vegetables."
One American nutrition expert noted the picture on heart health is much more complicated than one single factor.
"The results are not surprising. Picking out one single component and assuming just adding it to the diet, e.g., vegetables, is not likely to result in the desired effect," Alice Lichtenstein, director and senior scientist at Tufts University's Cardiovascular Nutrition Laboratory, told CNN.
"One thing that has become clear over the past decade is we should not be looking at single foods or nutrients, rather the whole dietary pattern," added Lichtenstein.
"The best advice we can give people is to focus on their whole diet, what foods to emphasize as well as what to minimize," Lichtenstein said. "In general, I think the data still supports beneficial effects of a dietary pattern rich in fruits, vegetables, whole grains, legumes, fish, fat-free and low fat dairy and relatively low in added sugar and salt."
U.S. dietary guidelines recommend that most adults eat at least 1.5 to 2 cups of fruit and 2 to 3 cups of vegetables each day as part of a healthy diet. Translating cups into tablespoons, a healthy intake of vegetables would include up to 48 tablespoons of veggies every day.
Visit Harvard Health for more on vegetables and heart disease.