An associate professor with the Department of Biochemistry has a tip for anyone taking fish oil supplements – switch to seal oil instead.
Dr. Sukhinder Kaur Cheema has spent seven years researching the benefits of fish oil on a species of hamster that is prone to atherosclerosis, a common arterial disease in which raised areas of degeneration and cholesterol deposits plaques form on the inner surfaces of the arteries obstructing blood flow. The hamster is a good model for such research because its lipid and cholesterol factors and metabolism are very similar to that of humans.
She found that past studies into the benefits of fish oil in human population have been varied, with some showing positive effects, such as a reduction in triglyceride levels, and others showing negative results, like an increase in plasma cholesterol levels. Most of the animal studies to investigate the mechanisms of action of fish oil have been conducted using mice and rats as an animal model. Dr. Cheema wanted to see what would happen if similar studies were done using hamsters.
“We took that particular hamster and fed them different amounts of fish oil in their diet, from low to high amounts,” she said. “It was really shocking for us to see that when we gave them a high fat fish oil diet the hamster’s blood turned very thick and milky. I thought my student had made a mistake, but further research showed this hamster had a problem processing fat.”
Dr. Cheema discovered that this hamster model had a very low activity level of a particular enzyme that helps people and animals digest and absorb fat and while it could digest other fats, fish oil fat was proving to be more than it could handle.
The health benefits of fish oil are due to the presence of long chain omega-3 polyunsaturated fatty acids. Seal oil, like fish oil, is also a rich source of omega-3 polyunsaturated fatty acids. However, seal oil contains high amounts of another omega-3 fatty acid that is low in fish oil. It is high in mono-unsaturated fat, a “good” fat, while fish oil contains a lot of saturated fat, a “bad” fat.
“So seal oil is already looking better than fish oil,” said Dr. Cheema. “We repeated the exact study to see if the alternate oil would make a difference and after four weeks of feeding seal oil to our hamsters we saw that they had no trouble digesting and absorbing it, compared to the fish oil.
“The enzyme that is low in this particular hamster is also deficient in some people in the human population,” she added. “So we believe people who already have a problem digesting and absorbing fat will likely not benefit from taking fish oil but may benefit from taking seal oil instead.”
Dr. Cheema believes that mutations in certain genes can change the way how different fat sources are processed in the body. Conversely, our diet can also change our genes.
The professor is currently looking into the possibility of beginning a clinical trial to test this theory on humans. She has presented her research at a number of conferences to overwhelming positive response. She hopes that this could lead to a positive economic benefit for the province, which has been challenged for its continuation of the annual seal hunt.