Canola rapeseed oil may reduce heart disease risk: Study
According to research, published in the journal Prostaglandins, Leukotrienes and Essential Fatty Acids, the consumption of canola-type rapeseed oil may decrease the levels of fibrinogen, an important blood clotting factor which at high levels is associated with coronary heart disease.
High fibrinogen levels, thought to be caused by an imbalance of essential fats in the diet, were found to reduce by 30 percent when dietary saturated fats were replaced with rapeseed oil.
“The fatty acid composition of canola-type rape- seed oil is, so far, the closest to the optimum to meet the basic requirements of essential fatty acids in the body,” stated the researchers, led by Dr Tuulikki Seppänen-Laakso at the University of Helsinki, Finland.
“The unique competitive functions of ALA, which emerged through effective fat replacement, can favorably affect homeostasis by reducing fibrinogen. ALA should therefore be the first ‘omega-3’ to be used in correcting omega-6/omega-3 PUFA imbalances in the body,” they wrote.
The authors stated that when omega-3-alpha linolenic acid levels are too low “the body starts to manufacture more harmful omega-6 arachidonic acid out of the omega-6-linoleic acid, creating hormone-like compounds that cause thrombosis and inflammation.”
The authors noted that pervious studies have shown that in human plasma, the proportions of long chain omega-6 and omega-3 polyunsaturated fatty acids (PUFA) are related to the intake of linolenic acid and alpha- linolenic acid.
They stated that an imbalance of essential fats in the diet can lead to high levels of plasma fibrinogen, an important blood coagulation factor.
High levels of fibrinogen promote thrombosis and maintain inflammation within the body. In addition an increase in fibrinogen is closely linked with, increased risk of cardiovascular disease, strokes, diabetes, Alzheimer’s disease and dementia.
In the new study, the researchers investigated the effects of canola-type rapeseed oil on serum lipids, plasma fibrinogen, and fatty acids in 42 research subjects – many of whom had high levels of fibrinogen and cholesterol.
Subjects replaced one quarter of the food fat (margarine, cheese, and butter) used to canola-quality spring turnip rapeseed oil.
Dr Seppänen-Laakso and colleagues observed that increased rapeseed oil intake doubled the intake of ALA during the six week trial.
They reported canola-type rapeseed oil substitution to reduce fibrinogen levels by approximately 30 percent – an average decrease of 0.95 grams per litre.
The researchers also found “efficient competitive inhibition by ALA” – seen as a decrease in long chain omega-6 PUFA – after 3 weeks of rapeseed oil replacement.
In addition plasma docosahexaenoic acid (DHA) levels were found to slightly increase in people with initially low fibrinogen levels, after rapeseed substitution.
According to the researchers significant health benefits may be associated with canola- type rapeseed oil substitution, through the reduction of coronary heart disease risk.
They stated that the fat composition of rapeseed oil is optimal in relation to fatty acids essential in the body, and is consequently well-suited to reduce levels of fibrinogen in the blood.
According to Dr Into Laakso from the University of Helsinki, and second author of the research, the harmful effects of fats in, for example, elderly people could be easily rectified by switching one quarter of fats to rapeseed oil.
“The research shows that controlling fibrinogen and cholesterol by changing the fat consumed is a point of departure in the prevention of diseases as well as from the perspective of successful individual medical treatment,” stated the researchers.
They added that dietary fat changes “must therefore be aimed at lowering elevated fibrinogen, which may prevent the development of pro-thrombotic and pro-inflammatory conditions.”
Source: Prostaglandins, Leukotrienes and Essential Fatty Acids
Volume 83, Issue 1, Pages 45-54, doi: 10.1016/j.plefa.2010.02.001
“Elevated plasma fibrinogen caused by inadequate α-linolenic acid intake can be reduced by replacing fat with canola-type rapeseed oil”
Authors: T. Seppänen-Laakso, I. Laakso, T. Lehtimäki, R. Rontu, E. Moilanen, T. Solakivi, L. Seppo, H. Vanhanen, K. Kiviranta, R. Hiltunen