Sunday, June 23, 2013

Vitamin D May Help Reduce Diabetes Risk

Alison Duncan, left, and Vanessa Hoytfox

Cheese study looks at vitamin’s effect on insulin resistance and sensitivity

GUELPH, Ontario June 21, 2013 - AT GUELPH - Cheese lovers probably don’t need another reason to enjoy their favourite snack. But by participating in a cheese study at the University of Guelph, you could help researchers better understand how vitamin D affects risk factors for developing diabetes.

Most vitamin D studies have focused on its role in bone health, says Prof. Alison Duncan, Department of Human Health and Nutritional Sciences (HHNS), but few studies have looked at the vitamin’s effect on other aspects of health.

Getting enough vitamin D from diet alone can be difficult. “There aren’t a lot of food sources that are naturally high in vitamin D,” she says. Some foods such as milk are supplemented with vitamin D. People also naturally produce the vitamin when their skin is exposed to the sun.

The cheese being tested in the study has been fortified with vitamin D; the placebo cheese has none. Vitamin D is believed to improve insulin resistance and sensitivity.

“Those are two of the major markers for Type 2 diabetes,” says Vanessa Hoytfox, a master’s student in HHNS working with Duncan on the study. “If the treatment does work, it will help people process sugars better.”

The study is looking at cheese as a test food because of its popularity among consumers of dairy products. Cheese may be fortified with vitamin D for people who don’t drink milk. It’s also more convenient for participants to take home a supply of cheese than milk.

The multi-centre Canadian study is looking for participants aged 18 to 75 in Guelph, Toronto and Montreal. Participants will be required to eat a 30-gram serving of cheese once a week for six months (they will receive an eight-week supply at a time).

They will also need to visit the Human Nutraceutical Research Unit every eight weeks. There they will provide blood samples for biomarkers such as fasting blood glucose and glycated hemoglobin, and undergo an oral glucose tolerance test.

“These are clinically relevant markers” for monitoring glucose tolerance, says Duncan, adding that targets for these tests have been set by the Canadian Diabetes Association.
To be eligible for the study, participants must not be taking vitamin D supplements.

The study is also looking at whether vitamin D can affect gene expression.

“There’s over 3,000 vitamin D receptors throughout your organs and tissues,” says Hoytfox.
Some of those receptors are believed to be linked to insulin resistance.

Adds Duncan,

“Considering a food to address your vitamin D status and possibly improve your risk of diabetes is quite exciting.”

Some people may prefer to obtain their vitamins from food instead of from supplements, says Hoytfox, and they may be more willing to choose a fortified food over vitamins in supplement form.

An optional part of the study asks participants to provide a fecal sample for bacterial analysis by Prof. Emma Allen-Vercoe, Department of Molecular and Cellular Biology. Her lab will extract genomic DNA from the samples for sequencing and further analysis at Western University.

By Susan Bubak - Friday, June 21, 2013