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The good oil

Wed, 21 Oct 2009 10:04:00 +1100

Alfred Deakin Postdoctoral Fellow Dr Sunil Ratnayake has brought a new dimension to research at Deakin to identify and eliminate life-shortening toxic substances in canola oil.

It has been known for more than a decade that canola oil has life-shortening effects in rats and possibly susceptible humans when compared with other oils like soybean and olive oil.

Researchers initially suspected this toxic effect was due to the fats and the plant sterols in canola oil, however both these have been ruled out.

Current research at Deakin is trying to identify the compound or compounds that lead to the life-shortening effects of canola oil and investigate the mechanism that causes them.

As part of this research program a team led by Dr Paul Lewandowski and including Dr Ratnayake has established the only colony of Stroke Prone Hypertensive rats in Australia and these have been used to study the toxic effects of canola oil on a variety of organs.

But this is both time-consuming and expensive.

So since taking up his Alfred Deakin Postdoctoral Fellowship, Dr Ratnayake has been working to develop a process that will not only speed up the testing but also reduce the loss of rats in Dr Lewandowski's colony.

"I have been looking at experiments with human cell lines to help find the toxic compound or compounds in the canola oil," Dr Ratnayake said.

"We can use human kidney cells and human liver cells.

"When we find what it is that causes the toxic effect, we can remove it and thus make it safer to use canola oil.

"This will have a very positive impact on what these days is a major industry in the world, particularly in Canada."

Canola is in fact short for Canadian Oil Low Acid. (Canola = Canadian oil low acid). "Canola oil is not the product of evolution," Dr Ratnayake explained.

"It (Canola) is a naturally bred variety from rape plant and oil extracted from rape seed was originally used for lubricant. Original rape seed oil contain toxic acid called Erucic acid.

"In the 1970s scientists reduced the amount of Erucic acid through breeding methods and on the canola packets it says there is zero acid/ (double law acid).

"However, we still have this situation where the rats fed canola oil die more quickly than rats given other oils.

"So we need to discover just what it is that causes the toxic effect and remove it."

Once that is achieved, the Deakin team will be applying for a patent. "It is very exciting work to be involved in," Dr Ratnayake said.

"I am very grateful to Deakin for the fellowship and also to my mentor Dr Lewandowski for enabling me to come here and do this work."

Dr Ratnayake's academic career began in Kandy in Sri Lanka, where he obtained his first degree.

He has also worked and studied in New Zealand, Japan and Western Australia before joining Deakin and settling in Geelong with his wife Gayani, an accountant, and sons Thamal and Hirun.

Needless to say coming from Sri Lanka, Dr Ratnayake is a keen cricketer and this summer plans to play a few games with a local club, as well as watching his boys play.

No doubt they would have if not the best-oiled bats in the club, at least the safest oiled ones.

Alfred Deakin Postdoctoral Fellow Dr Sunil Ratnayake
Alfred Deakin Postdoctoral Fellow Dr Sunil Ratnayake

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27th February 2015