This is a surprisingly large study published in the journal Frontiers in Nutrition. According to British researchers, eating vegetables would have no impact on the risk of developing cardiovascular disease. They even explain why we have long thought the opposite!
Eating vegetables has been associated with better health for decades. Antioxidants, fibers, minerals and the fact that they have a low energy density and a poverty in fatty acids, in particular saturated, would help them to protect us from many non-communicable diseases, such as cardiovascular diseases.
What if we got it all wrong from the start?
In any case, this is what a study by the Universities of Oxford, Bristol and Hong Kong claims. For its authors,that the consumption of vegetables can reduce the risk of cardiovascular disease may seem plausible at first glance, since their ingredients such as carotenoids and alpha-tocopherol (a form of vitamin E, editor’s note) have potentially protective properties. But the scientific evidence is so far inconsistent.“.
So why would the positive results obtained so far be wrong?
To answer this question, the scientists relied on the UK Biobanka large prospective study of how genetics and environment contribute to the development of common and life-threatening diseases.
They analyzed data from nearly 400,000 people, 4.5% of whom developed cardiovascular disease. Each of the participants had entered their daily consumption of vegetables, whether raw or cooked.
Many biases?
Scientists have tried to establish an association between this consumption and the risk of hospitalization or death from myocardial infarction or stroke. Not insignificant, they also integrated into their work confounding factors such as the socio-economic status of the participants, their levels of physical activity…
Result: the risk of dying from cardiovascular disease was 15% lower in people who consumed the most vegetables compared to those who ate the least. So far, nothing out of the ordinary. But by integrating these famous confounding factors, the predictive power of cardiovascular risk lost 80% of its effectiveness!
As Dr Qi Feng of the University of Oxford and lead author of the study explains, “we found no evidence of a protective effect of vegetable consumption on the occurrence of cardiovascular disease. Instead, our analyzes show that this apparently protective effect is most likely explained through residual confounding factors, related to differences in socioeconomic status and lifestyle..”
Undoubtedly to counter any controversy, the researchers nevertheless point out that a “A balanced diet and maintaining a healthy weight remain important elements for maintaining good health and reducing the risk of major diseases, including certain cancers. It is widely recommended to eat at least five servings of fruits and vegetables each day..”
For other observers, the results are hardly surprising. “Choosing a single food, here vegetables, and assuming that just adding it to the diet, to get benefits is not enough“says Alice Lichtenstein, director of the Cardiovascular Nutrition Laboratory at Tufts University (Massachusetts). “What is clear is that we should not be looking at single foods or nutrients, but rather the whole diet.“
