Pavilion Publishing and Media Ltd
Blue Sky Offices Shoreham, 25 Cecil Pashley Way, Shoreham-by-Sea, West Sussex, BN43 5FF, UNITED KINGDOM
Tel: +44 (0)1273 434 943
Email: [email protected]
Eating large amounts of cooked or raw vegetables is unlikely to affect the risk of developing cardiovascular disease (CVD), according to a new, large scale study.
The study, published in Frontiers in Nutrition shows that despite previous studies reporting the beneficial impacts of vegetables on heart health, this is in fact, not the case. Instead, the researchers say that confounding factors can explain these previous spurious, positive findings.
Confounding factors can explain previous positive findings
The researchers used the data from nearly 400,000 people enrolled in the UK Biobank study – a large-scale prospective study on how genetics and environment contribute to the development of the most common and life-threatening diseases.
Upon enrolment, the participants were interviewed about their diet, lifestyle, medical and reproductive history, and other factors. They then analysed the response for the association with the risk of hospitalisation or death from myocardial infarction, stroke, or major CVD.
While the study found that the risk of dying from CVD was about 15% lower for those with the highest intake compared to the lowest vegetable intake, the researchers say this apparent effect was substantially weakened when possible socio-economic, nutritional, and health- and medicine-related confounding factors were taken into account.
Controlling for these factors reduced the predictive statistical power of vegetable intake on CVD by over 80%, suggesting that more precise measures of these confounders would have explained any residual effect of vegetable intake.
Further research now needed to confirm findings
Dr Qi Feng, a researcher at the Nuffield Department of Population Health at the University of Oxford, and the study’s lead author, said: “Our large study did not find evidence for a protective effect of vegetable intake on the occurrence of cardiovascular disease. Instead, our analyses show that the seemingly protective effect of vegetable intake against cardiovascular disease risk is very likely to be accounted for by bias from residual confounding factors, related to differences in socioeconomic situation and lifestyle.”
The authors say that future studies are now needed to further assess whether particular types of vegetables or their method of preparation might affect the risk of CVD.
Dr Ben Lacey, Associate Professor in the department at the University of Oxford, notes: “Eating a balanced diet and maintaining a healthy weight remains an important part of maintaining good health and reducing risk of major diseases, including some cancers” and recommends that people should continue to follow recommendations on eating at least five portions of fruits and vegetables every day.