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Assessing canola oil’s health benefits

Canola oil is as good for the consumer as it is for farmers who grow the crop. Several clinical trials, funded by the Canola Product Research Fund (CPRF) are underway, and already they are yielding some very positive results on the health effects of canola oil.


October 20, 2009
By Carolyn King

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Canola oil is as good for the consumer as it is for farmers who grow the crop. Several clinical trials, funded by the Canola Product Research Fund (CPRF) are underway, and already they are yielding some very positive results on the health effects of canola oil. “When you look around nowadays at food products and ingredients, there’s a tremendous focus on health. Consumers are looking for products that will improve their health,” says JoAnne Buth, president of the Canola Council of Canada. “For us the importance is to continue to provide sound science that will support the information for consumers and to be able to make sure that canola oil remains competitive in comparison to other oils.”

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Sound data on the health effects of canola oil are important for consumers and the canola industry.
Photo courtesy of the Canola Council of Canada.

 

The Canola Council is the co-ordinating agency of the CPRF, which was created in 2007. This fund supports research on canola oil’s role in reducing the risk of such conditions as diabetes and heart disease. In addition to the Canola Council, other agencies backing the fund include the canola grower associations in Alberta, Saskatchewan and Manitoba, Bayer CropScience, Dow AgroSciences Canada, Monsanto Canada, and Pioneer Hi-Bred. “We’ve already got some pretty good proof of the benefits of canola oil for cardiovascular disease, but it became clear to us that we were not keeping the research up-to-date. We needed to re-start some of the research that had been done in the 1980s on canola,” Buth explains.

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She adds, “We view it as critical that we have this type of information. You see it all over, from pomegranate juice to blueberries, it’s on Oprah for heaven’s sake! And it’s tough, when you look at competition for shelf space and competition for products, differentiating between what’s sound science and what’s the pizzazz.”

Brian Chorney, president of the Canadian Canola Growers Association, agrees with the need for this research. “The research that we’re funding here is really important because it establishes a link between canola oil and good health, which is very much a market development process. I think it’s very important that we continue to research the benefits of canola oil and use that information to go forward from a market development perspective.”

Canola oil and cholesterol
One of the clinical trials is comparing the effects of high-oleic canola oil and other dietary fats. Along with the CPRF funding, this trial is funded by Flax Canada 2015 and the Manitoba Government’s Agri-Food Research and Development Initiative. The trial was conducted at the University of Manitoba’s Richardson Centre for Functional Foods and Nutraceuticals, and Leah Gillingham, a PhD student at the university, is busy analyzing the data. “We wanted to see if high-oleic canola oil, also known as Omega-9 canola oil, could improve the participants’ cholesterol levels, as well as other risk factors for cardiovascular disease,” explains Gillingham.

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During the clinical trial, the Richardson Centre’s metabolic kitchen made all the meals for each participant to ensure reliable results, with the same type of research being done for other Manitoba-grown crops, like yellow peas.
Photo courtesy of Xichun (John) Cheng.

 

There is no other research to date on high-oleic canola oil with respect to its benefits for blood cholesterol levels or cardiovascular disease risk factors,” she notes. “High-oleic canola oil has really taken off for commercial use, and canola oil is now the second largest oil consumed in the US. During the past few years, the use of hydrogenated soybean oil in food processing has been declining, and there is an increase in the use of high-oleic canola oil in fryers and for other food processing because it’s quite stable and has great health benefits; it’s very low in saturated fat and has very low or nil trans fats.”

Chorney welcomes the study’s focus on high-oleic canola. “The high oleic varieties are very well-suited to many parts of Western Canada, and the canola oil produced from those varieties is very much in demand, so it’s a positive option
for growers.”

The trial involved 36 subjects, both men and women, all with borderline high cholesterol, but otherwise healthy. The participants were not on any medication to control their cholesterol. They were non-smokers ranging in age from 18 to 65, with a body mass index between 26 and 36.

The trial compared three diets. One diet used a blend of fats common to a typical North American diet, like butter, lard, olive oil and sunflower oil, to mimic the current North American fat intakes, high in saturated fats and Omega-6 fatty acids. The second diet used high-oleic canola oil. The third used a 50/50 blend of high-oleic canola oil and
flaxseed oil.

Gillingham says, “Flaxseed oil is very high in the Omega-3 fatty acid alpha-linolenic acid, but it can be expensive. We wanted to know, if we mix flaxseed oil with the high-oleic canola oil, will we see benefits in comparison with oils that are typically consumed in a North American diet?”

She outlines some of the protocols used to ensure compliance and reliable results: “All of the participants’ meals were completely controlled here at the Richardson Centre. We have a metabolic kitchen and the kitchen staff made all of the meals, breakfast, lunch and dinner, for each subject based on their individual daily calorie needs and with the insertion of the appropriate oil depending on the phase they were on. Every morning during each phase, the participants were weighed in before breakfast. At the start of the study if they started to lose weight we would increase their calories to maintain their weight throughout each phase. Weight loss on its own may have benefits on cholesterol reduction, and we wanted to isolate the effects of the high-oleic canola oil and the high-oleic canola oil/flaxseed oil blend.”

Thus far, the results look good for canola oil. She says, “We have done the first wave of analysis looking at cholesterol levels. Our subjects all came into the trial with borderline high cholesterol, and some of them had been advised to go on statin class drugs. After they consumed the high-oleic canola oil diet for four weeks, there was a reduction by about 10 percent in their total cholesterol and their LDL cholesterol, the bad cholesterol, as compared to their levels on the control diet with the typical North American oils. And after they consumed the high-oleic canola oil/flaxseed oil diet, their LDL cholesterol was reduced by about 16 percent as compared to the control diet. “So after only four weeks, both the high-oleic canola oil diet and the high-oleic canola oil/flaxseed oil diet brought the participants’ LDL cholesterol, as well as total cholesterol, levels below the borderline levels where doctors usually start to recommend patients going on pharmaceuticals to treat high cholesterol.”

She adds, “What’s even more interesting is that the high oleic-canola oil didn’t reduce HDL cholesterol, that’s your good cholesterol, but the high-oleic canola oil/flaxseed oil blend did lead to a reduction in HDL cholesterol. So with the high-oleic canola oil diet, you are using an oil that tastes great and that’s stable, and you’re also improving total cholesterol and LDL cholesterol while maintaining good cholesterol.”

Dr. Peter Jones, the director of the Richardson Centre, is guiding this study. He points out the value of these results for canola growers. “On the basis of the data from this clinical trial, companies like Dow AgroSciences that have developed high-oleic canola varieties can establish important relationships with big food companies in the US and beyond. And that adds to the whole value chain, including the farmer, by increasing the value of this high stability canola oil.”

Gillingham is now analyzing the trial’s data to assess the effects of the three diets on factors related to inflammation in the blood, which is a risk factor for heart disease. She will also be evaluating how the type of fat consumed relates to energy expenditure and whether the body burns the fat or stores it. Excessive fat storage leads to obesity, a risk factor for various health problems.