Deep Dive: Fruit, vegetables, and cardiovascular risk factors

Cardiovascular diseases are the leading cause of death^[1] around the globe. They are diseases that affect the heart and/or vasculature. Obesity and hypertension are two of the main, modifiable risk factors for cardiovascular disease. Both obesity and hypertension can be improved through dietary interventions, either through weight loss or through changes in nutrient intake (e.g. lower sodium intake can lower blood pressure). One specific dietary intervention that has been examined as an effective intervention for reducing the risk of cardiovascular disease is fruit and vegetable intake.

The advice to eat more fruits and vegetables is omnipresent, and not without reason. There are several lines of evidence supporting the role of fruit and vegetable intake on cardiovascular disease. There are large observational trials, such as the Nurses’ Health Study and Health Professionals Follow-Up Study^[2], which demonstrated that people who consumed the highest amounts of fruits and vegetables had an approximately 17% lower risk of heart disease than people who consumed the lowest amounts of fruits and vegetables. The dose-response trend is shown in Figure 1. Furthermore, there have been several randomized controlled trials that have shown the beneficial effects of diets rich in fruits and vegetables on cardiovascular disease risk factors, such as blood lipids^[3], blood pressure^[4], and fasting glucose. Additionally, previous meta-analyses^[5] have also shown an effect of fruits and vegetables on cardiovascular risk factors. However, there has been little research that would allow reliable quantification of the benefits in the form of dose-response analyses and meta-analyses that examine the effect of high versus low fruit and vegetable intake. Therefore, the purpose of this meta-analysis was to evaluate the impact of increased dietary fruit and vegetable intake on cardiovascular disease risk factors through a systematic review of randomized controlled trials.

Figure 1: Relative risk for coronary heart disease, with 95% confidence intervals

Cardiovascular disease is the leading cause of death worldwide. Obesity and hypertension are two leading risk factors for heart disease and both can be improved through nutritional interventions. Fruit and vegetable intake has been shown to lower cardiovascular risk factors. The study under review was a meta-analysis examining the effect of high and low intakes of fruits and vegetables on cardiovascular risk factors.