Eating vegetables may not protect against heart disease, study finds
A diet rich in vegetables does not protect against heart disease, according to a new study.
The findings challenge previous research that suggests eating more vegetables is linked to a lower risk of cardiovascular disease (CVD) – which can lead to strokes, heart attacks and death.
The researchers say that previous studies may not have taken into account lifestyle factors such as smoking, alcohol consumption and meat consumption – and socio-economic factors such as a person’s education, income and wealth.
They add that evidence from previous studies has been inconsistent.
New results from a large UK study show that higher consumption of raw or cooked produce is unlikely to affect CVD risk.
But experts stress that eating a balanced diet and maintaining a healthy weight are still important in reducing the risk of major diseases.
Dr Qi Feng, a researcher at Oxford University’s Nuffield Department of Population Health and lead author of the study, said: “Our large study found no evidence of a protective effect from vegetable consumption. on the occurrence of cardiovascular disease.
“Instead, our analyzes show that the apparently protective effect of vegetable consumption against CVD risk is most likely explained through residual confounding factors, related to differences in socioeconomic status and lifestyle. life.”
The researchers used data from 399,586 people (4.5% of whom developed CVD) enrolled in the UK Biobank study.
When they enrolled in the study in 2006-2010, they were asked about their diet, lifestyle, medical and reproductive history, and other factors.
Responses to questions about how many raw and cooked vegetables they ate on average per day were analyzed, along with the likelihood of them being hospitalized for a heart attack, stroke, or major cardiovascular disease, and the risk of death.
Factors such as socioeconomic status, physical activity and diet were also taken into account.
The researchers assessed whether additional unknown factors or inaccurate measurement of known factors could lead to a misleading statistical association between CVD risk and vegetable consumption.
In the study, the daily intake of total vegetables, raw vegetables, and cooked vegetables was 5.0, 2.3, and 2.8 heaped tablespoons per person.
The researchers found that the risk of dying from cardiovascular disease was about 15% lower for those who ate the most vegetables compared to the lowest.
However, this apparent effect was significantly attenuated when possible socioeconomic, nutritional, health and medical factors were taken into account.
When these factors were taken into consideration, the effectiveness of using vegetable consumption to predict CVD risk dropped by more than 80%.
According to the scientists, future studies should further assess whether particular types of vegetables or their method of cooking might affect CVD risk.
Final author Dr Ben Lacey, Associate Professor in the department at the University of Oxford, concluded: “This is an important study that has implications for understanding the dietary causes of CVD and the burden of CVD normally attributed to low vegetable intake.
“However, eating a balanced diet and maintaining a healthy weight are still important 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 a variety of fruits and vegetables each day.”
Dr Ian Johnson, nutrition researcher and Emeritus Fellow at Quadram Institute Bioscience, said: “This study raises some interesting questions about the relative importance of the many different aspects of a healthy diet and lifestyle, but it should not discourage consumers from following public health recommendations to consume diets rich in vegetables of all types.
Professor Naveed Sattar, Professor of Metabolic Medicine at the University of Glasgow, said: ‘In short, this article should in no way alter the advice to eat at least five servings of fruit and vegetables a day.
“Many people living in the UK are unfortunately well below this, and there is still a lot to be done to encourage better vegetable consumption.
“In fact, I suspect we may have underestimated the importance of healthy eating to health and disease in general.
“We are good at treating with preventative drugs, but the UK needs to up its game in helping people improve their lifestyle, including their diet and activity – that is the big goal coming after the pandemic. .
“However, the best way to do this requires more thought from government and health agencies.”
– The results are published in the journal Frontiers in Nutrition.