Will we ever know for sure whether chocolate is good or bad for us? Red wine? Green tea? Fish? The confusion continues with two reports out today, one published in the Journal of the American Medical Association from the Harvard School of Public Health, about whether the benefits of eating fish outweigh the risks (from dioxin, PCBs, mercury and other contaminants).
The Harvard study, a meta-analysis of previous studies, says eating fish once or twice a week can reduce the risk of coronary disease by a whopping 36 percent and total mortality by 17 percent. Lead author Darius Mozaffarian is quoted in a NY Times article as saying “Seafood is likely the single most important food one can consume for good health.”
The article also quotes nutritional scientists criticizing the study, saying the evidence isn’t convincing enough. The Harvard author defended his work by saying it’s the best evidence available. Apparently, for some, it’s not good enough. The other report, from the Institute of Medicine, is more cautious about the benefits of eating fish.
As a journalist, I always found it difficult, and would often try to avoid, writing articles about nutrition or toxicology studies that link this environmental chemical or that food to this disease or that health outcome in lab animals or humans. These studies rarely came up with very clear links or answers. Or they did but with a long list of caveats, leading to further confusion and very unsatisfying answers.
It must be difficult to try to tease out the effects of other biological and environmental factors, only to have your work criticized as not being absolute proof. But in this field of research, is this kind of airtight proof even possible? Of course, anyone in any field of science can say that there’s no such thing as absolute proof for anything. But perhaps in some areas of science, like toxicology or nutrition, we won’t ever be able to come as close to foolproof evidence as in other fields, leaving the rest of us to have to rely more on age-old common sense, like “all things in moderation.”
A few years ago, I read an article about the risks of getting above average amounts of mercury from swordfishes and that it can be more dangerous for children and pregnant women. But more current studies have concluded that eating fish regularly far outweighs the dangers from mercury and other contaminants.
For one, there is major heart benefit from eating fish. Also, the Omega-3 fatty acids in fish help promote healthy vision and brain development in infants.