Fish oils most effective against cancer

OMEGA-3 oils derived from fish pack a stronger punch than other sources such as flaxseed when it comes to cancer prevention, according to a first ever study by a leading Canadian research university.
Prof David Ma from the University of Guelph, near Toronto in Ontario, said he has discovered that marine based omega-3s, of which salmon is a rich source, are eight times more effective at inhibiting tumour development and growth.
The professor, who works in the Department of Human Health and Nutritional Sciences at Guelph, explained: ‘This study is the first to compare the cancer fighting potency of plant versus marine derived omega-3s on breast tumour development.
‘There is evidence that both omega-3s from plants and marine sources are protective against cancer, and we wanted to determine which form is more effective.’
There are three types of omega-3 fatty acids: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
ALA is plant based and found in such edible seeds as flaxseed and in oils, such as soy, canola and hemp oil. EPA and DHA are found in marine life, such as fish, algae and phytoplankton.
The study, published in the Journal of Nutritional Biochemistry, involved feeding the different types of omega-3s to mice with a highly aggressive form of human breast cancer called HER-2. This affects 25 per cent of women and has a poor prognosis.
Ma exposed the mice to either the plant based or the marine based omega-3s, beginning in utero.
‘The mice were exposed to the different omega-3s even before tumours developed, which allowed us to compare how effective the fatty acids are at prevention.
‘It’s known that EPA and DHA can inhibit breast tumour growth, but no one has looked directly at how effective these omega-3s are compared to ALA.’
Professor Ma found overall exposure to marine based omega-3s reduced the size of the tumours by 60 to 70 per cent and the number of tumours by 30 per cent.
Conversely, higher doses of the plant based fatty acid were required to deliver the same impact as the marine based omega-3s.