Frank Hu and his colleagues from Harvard followed over 120,000 people (about 30% men and 70% women) for almost three decades, looking at their health and diet habits. It wasn’t good news for red meat eaters. If you eat a daily serving of red meat, you could be increasing your risk of dying from cardiovascular disease or cancer by up to 20%.
A few caveats about this study. First, the dietary information came strictly from questionnaires. In other words, the researchers relied on participants to tell them exactly what they ate. People are notoriously poor at this, both due to faulty memory and the desire to make themselves look good. How often have you eaten ground beef in the past two years? Unless you’re a vegetarian, you probably have no idea.
Second, frequent red meat eaters tended to be a surprisingly unhealthy bunch. As a group, they were inactive, overweight smokers who didn't eat their fruits and vegetable. Who knew red meat would be associated with such bad health habits? To be fair, the authors did their best to account for known confounders such as smoking, body mass index or family history of diabetes, cancer or heart disease.
Even accounting for these potential problems, the news for red meat eaters was pretty grim. People may not have remembered exactly how much meat they ate, but they probably did know whether to put themselves in the ‘rarely’ or ‘daily’ categories. Therefore, the broad generalizations of this study probably hold true, if not the exact risk assessments.
So, will red meat kill you? I wouldn’t panic if you’re having dinner out and hamburgers are all that’s on offer. But unless further studies refute these results, it seems clear that you don’t want to eat red meat too often. Substituting other protein sources (beans, fish, poultry, nuts, etc) as much as possible is an excellent idea.
Now if you’ll excuse me, I have to go and convince myself that I really enjoy veggi-dogs. So far, it’s not going well.