A new study from Harvard links fish and omega-3 oils to type 2 diabetes. Following almost 200,000 adults for up to 18 years, researchers found that the more fish or long chain omega-3 fatty acids participants consumed, the higher their risk of developing diabetes. Those who ate fish occasionally had a modest increase in risk, but those eating fish five or more times per week had a 22 per cent increase. Prior studies have suggested that fat building up in muscle cells can lead to insulin resistance which, in turn, contributes to diabetes. Vegetarians and vegans have less fat in their cells and much less risk of developing diabetes. A low-fat vegan diet has also been shown to help people with diabetes reduce or even stop taking medication.
Kaushik et al., 2009. Long-chain omega-3 fatty acids, fish intake, and the risk of type 2 diabetes mellitus. American Journal of Clinical Nutrition. 90 (3) 613-620.