Justine Tishinsky
Justine Tishinsky

We’ve all heard the message. Eat more fish ― even swallow fish oil tablets ― to help ward off such problems as diabetes, cardiovascular disease and obesity. But what’s the magic in fish oil and other foods containing omega-3 fatty acids?

That’s the question Justine Tishinsky hopes to help answer. A PhD student in the Department of Human Health and Nutritional Sciences (HHNS), she looks at how fatty acids help regulate health.

“We know omega-3 fatty acids are good for you,” says Tishinsky, who completed a B.Sc. at Guelph. “It’s more figuring out why they’re good.”

She studies the effects of fatty acids on release of adiponectin. Secreted from the body’s fat tissue, this hormone regulates metabolic processes. It works with insulin to regulate blood sugar levels, helping to prevent problems such as obesity, cardiovascular disease and Type 2 diabetes.

Disrupt the hormone’s function and you may cause health problems. Fat mass may increase and individual fat cells might grow. Blood flow to the cells might slow, or tissues may become inflamed.

Tishinsky wants to know how eating fatty acids can help to prevent those problems or even correct them.

She started by looking at fatty acids in cell culture. Now she’s studying groups of rats fed a low-fat control diet, a high-fat diet or a high-fat diet supplemented with fish oil. Early results show fish oil maintains and may even restore insulin sensitivity in rats.

Now she’s looking more closely at changes in expression of proteins involved in insulin signalling and fat metabolism, and is planning another round of experiments.

Insulin sensitivity is driven by a combination of genetics and lifestyle factors such as diet and exercise. Teasing out cause-and-effect can be challenging, Tishinsky says. But she hopes to help refine nutrition and diet in order to stem health problems.

Studies in the lab of her supervisor, Prof. Lindsay Robinson, have shown that fish oil can increase adiponectin secretion from fat tissue. Says Robinson: “We hope our work will advance our understanding of the role of omega-3 fatty acids in adipose tissue biology and that this will aid in establishing new approaches for managing obesity and costly obesity-related disease states, such as diabetes and CVD, and improving the health of Canadians.”

HHNS researchers study aspects of both nutrition and exercise on insulin resistance and related disorders. Tishinsky says work like hers might help in recommending dietary changes. Adiponectin levels in blood can be modulated by omega-3 fatty acids, especially DHA and EPA. Think of omega-3 eggs or milk fortified by DHA.

“It doesn’t matter where you get them as long as you get them,” says Tishinsky, who eats lots of salmon and herring and takes fish oil tablets. She visits the gym three times a week mostly for aerobic training, such as running on the treadmill.

“The idea of using diet, exercise and lifestyle choices to prevent and treat disease is very attractive to me.”

Originally from Huntsville, Ont., she worked as a summer undergrad student in Robinson’s lab. Tishinsky has received funding from the Ontario Heart and Stroke Foundation and the Natural Sciences and Engineering Research Council.