Cancer-fighting potency of plant- versus marine-derived omega-3
- Seafood-derived omega-3 fatty acid may protect against the formation of breast cancer.
- It is more effective than plant-derived omega-3 fatty acid.
- Both omega-3 fatty acids derived from seafood and plants are protective against cancer.
Omega-3 polyunsaturated fatty acid from seafood is more potent than those derived from plants in protection against breast cancer, recent research at the University of Guelph finds.
Prof. David Ma has discovered that marine-based omega-3 polyunsaturated fatty acids are eight times more effective at inhibiting tumor development and growth.
‘Both omega-3 polyunsaturated fatty acids from plants and marine sources are protective against cancer. But of the two, omega-3 fatty acid derived from seafood is more potent than that derived from plants.’
"This study is the first to compare the cancer-fighting potency of plant- versus marine-derived omega-3 polyunsaturated fatty acid on breast tumor development," said the professor in the Department of Human Health and Nutritional Sciences. "There is evidence that both omega-3 polyunsaturated fatty acid 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: a-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.
Omega-3 as protective agent against breast cancer
The study involved feeding the different types of omega-3 polyunsaturated fatty acids to mice with a highly aggressive form of human breast cancer called HER-2. HER-2 affects 25 percent of women and has a poor prognosis.
The researcher exposed the mice to either the plant-based or the marine-based omega-3 fatty acids, beginning in utero.
"The mice were exposed to the different omega-3 fatty acids even before tumors developed, which allowed us to compare how effective the fatty acids are at prevention," said Ma. "It's known that EPA and DHA can inhibit breast tumor growth, but no one has looked directly at how effective these omega-3 fatty acids are compared to ALA."
Ma, the author of the study, found overall exposure to marine-based omega-3 fatty acids reduced the size of the tumors by 60 to 70 percent and the number of tumors by 30 percent.
However, higher doses of the plant-based fatty acid were required to deliver the same impact as the marine-based omega-3 fatty acids.
Omega-3 fatty acids prevent and fight cancer by turning on genes associated with the immune system and blocking tumor growth pathways, said Ma.
"It seems EPA and DHA are more effective at this. In North America, we don't get enough omega-3 fatty acids from seafood, so there lies an opportunity to improve our diet and help prevent the risk of breast cancer."
Based on the doses given in the study, Ma said humans should consume two to three servings of fish a week to have the same effect.
Besides certain foods containing EPA and DHA, supplements and functional foods, such as omega-3 eggs or DHA milk, can offer similar cancer prevention effects, he added.
The next step is to investigate the effects of omega-3 fatty acids on other forms of breast cancer.
"Seeing the significant benefits omega-3 fatty acids can have in combatting a highly aggressive form of breast cancer means omega-3 fatty acids will likely be beneficial for other types of cancer."
- JiajieLiu, Salma A.Abdelmagid et al. Marine fish oil is More Potent Than Plant Based n-3 Polyunsaturated Fatty Acids in the Prevention of Mammary Tumours, Journal of Nutritional Biochemistry https://doi.org/10.1016/j.jnutbio.2017.12.011