Canola Oil Foods May Aid Diabetes Sufferers

2 Jul 2014 --- A diet low in simple sugars and high in healthy fats, such as those found in canola oil, could help people with type 2 diabetes to better control their blood sugar, according to a new study.

Those in the study with type 2 diabetes were advised to follow a diet with a low glycaemic index supplemented with extra canola oil. They were then found to have lower blood glucose levels and greater reductions in heart risk than those who ate a diet high in whole grains, researchers found. 

“We know that olive oil has a good pedigree among clinicians but canola oil has a good pedigree too,” said lead author Dr David Jenkins, from the University of Toronto.

Canola oil is rich in alpha-linolenic acid, a type of omega-3 fatty acid also found in walnuts, as well as monounsaturated fatty acids, which are also in avocados and olives.

A food’s glycaemic index refers to how quickly it causes blood sugar to rise. Starchy foods such as white bread and potatoes are considered to be high glycaemic index foods because they can cause blood sugar levels to spike. Low glycaemic index foods, such as lentils, soybeans, yogurt and many high-fibre grains, create a more gradual increase in blood sugar.

Sugar builds up in the blood of people with Type 2 diabetes because it can’t be absorbed by cells, ultimately increasing the risk of other health problems such as heart disease.

“We thought using canola oil might be a good way to hit the heart disease and the high glucose problem,” Jenkins said.

The researchers recruited 141 people with diabetes, all of whom were taking medication to help lower their blood sugar levels. None of the participants reported smoking, drinking excessively or having other illnesses such as heart disease, liver disease or cancer.

People in the test group were asked to supplement their diet with four and a half slices of canola oil-enriched whole wheat bread each day and were told to focus on eating foods with a low glycemic index.

Those in the comparison group were instructed to eat seven and a half slices of whole wheat bread without the added canola oil each day – providing an equivalent number of calories – and to avoid products made with white flour.

Over the following three months, blood glucose levels dropped in both groups, but the drop was about one and a half times larger among those on the canola oil-enriched diet. Improvements in other measures of heart disease risk generally favoured the test diet as well.

“The thing that really surprised us is that those who seemed to be most in need benefited the most,” Jenkins said. He said the participants who had more weight in their mid-region and those with high blood pressure had the strongest blood sugar response to the test diet.

While getting extra canola oil allowed people with Type 2 diabetes to improve their glycemic control, whole grains seemed to benefit blood flow, the team reports in Diabetes Care.