One long-held epidemiology belief is that the more vegetables you eat, the healthier your heart will be. While vegetarians and animal activists tout such claims, the actual evidence is not clear. In recent decades we've been told bacon, butter and red meat all cause heart disease. But the same groups scaremongering food have also claimed that coffee causes breast cancer, that cell phones cause all kinds of cancer, and that BPA can be an endocrine disruptor, even though they are biological and toxicological impossibilities.
So how seriously should you take changing the guidance from 5 servings of fruits and vegetables per day to eight? Dagfinn Aune, from the Norwegian University of Science and Technology (NTNU) and Imperial College London, and colleagues writing in the International Journal of Epidemiology, claims their meta-analysis shows that 7.8 million deaths worldwide could be prevented each year if people ate more fruits and vegetables, preventing heart disease, stroke, cancer and premature death.
They even boldly claim that confounding factors, such as that people who specifically count how many vegetables they eat per day, aren't more physically active, smoke less, and are more likely to avoid large amounts of alcohol. For that reason alone, you should be skeptical. But if you are not skeptical, you are enjoying an article about this weak observational claim in the New York Times and not reading here.
So they say if everyone ate 800 grams of fruit and vegetables every day, 7.8 million deaths each year would be saved. If everyone ate 500 grams of fruits and vegetables a day, 5.4 million deaths. Two to four million deaths related to cardiovascular disease could be prevented a year if everyone ate the optimal amount of fruits and vegetables, the researchers said, while for cancer that number was approximately 660,000 deaths.
All that, from a meta-analysis using studies of people trying to remember what they ate decades ago. It's always wise to be skeptical about modern epidemiology, and when it comes to vegetarian claims, even more so.
Citation: Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality-a systematic review and dose-response meta-analysis of prospective studies. Dagfinn Aune et al. International Journal of Epidemiology, advance access, published online 22 February 2017