I had a question from a reader about the 2005 study on German vegetarians that showed higher mortality for vegans compared to other health-conscious eaters.

The researchers asked nearly 2,000 subjects about diet, exercise and smoking habits, and then followed up over a period of 21 years, tracking deaths from cardiovascular disease, cancer and other causes. Overall, the death rate was similar for lacto-ovo vegetarians and meat-eaters (most of whom had moderate meat consumption), but higher for vegans.

But while that fact was reported in some news media, the researchers didn’t even mention it in their discussion of the findings. There were only 60 vegans in the entire study, just a little bit more than 3% of the whole study population. Given the size of that group, it’s not possible to draw any conclusions about effects of vegan diet and it’s clear that the researchers didn’t consider this to be a very important finding.

It’s important to always be careful with epidemiologic studies of this type. They show associations, but not cause and effect. And they are prone to any number of confounding variables. In this case, the researchers noted that the questionnaire used to assess dietary intake was not an especially strong one so that “fine” differences among diets were not detected.

Also, many subjects may have changed their diets during the follow-up period. Who is to say that some who were vegans at the start of the study weren’t chowing down on Big Macs ten years later? With a large study group, these kinds of issues are less important—but again, the number of vegans in this study was small.

Based on limited research overall, there is no reason to believe that vegans who follow well-balanced diets are at greater risk for chronic disease. We also don’t really have much data to support the idea that vegan diets protect against most diseases compared to other vegetarian or semi-vegetarian diets.

The strongest and most compelling reasons for going vegan are based on ethics and animal welfare. But vegans can also feel assured that their dietary choice is a healthful one.