David W.L. Ma, Ph.D.

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Key Contributions

Omega-3’s and Breast Cancer
My laboratory has shown that lifelong exposure to omega-3 fatty acids (EPA and DHA) reduces tumour size and numbers in a novel rodent model of breast cancer. This novel mouse model is capable of synthesizing omega-3 fatty acids and spontaneously develops mammary tumours. Thus, this model provides for the first time a direct causal relationship between omega-3 fatty acids and tumour outcomes. These findings provide strong support for a role of omega-3 fatty acids in the prevention of human breast cancer.

Maclennan MB, Clarke SE, Perez K, Wood GA, Muller WJ, Kang JX, David WL Ma. Mammary tumor development is directly inhibited by lifelong n-3 polyunsaturated fatty acids. J Nutr Biochem. 2013 Jan;24(1):388-95. doi: 10.1016/j.jnutbio.2012.08.002. Epub 2012 Sep 29. PMID: 23026490

Liu J, Abdelmagid SA, Pinelli CJ, Monk JM, Liddle DM, Hillyer LM, Hucik B, Silva A, Subedi S, Wood GA, Robinson LE, Muller WJ, Ma DWL. Marine fish oil is more potent than plant-based n-3 polyunsaturated fatty acids in the prevention of mammary tumors. J Nutr Biochem. 2017 Dec 27;55:41-52. doi: 10.1016/j.jnutbio.2017.12.011. [Epub ahead of print]. PMID: 29413488.

 

Disease Reduction Health Claim
I contributed to the development of the recently approved disease-reduction health claim (2012) by Health Canada entitled, “Replacement of Saturated Fat with Mono- and Polyunsaturated Fat and Blood Cholesterol Lowering.  My laboratory conducted the scientific literature review showing that replacement of saturated fat by unsaturated in human trials results in consistent reduction in total cholesterol and LDL-cholesterol.  Cholesterol is a recognized biomarker of heart disease which is a leading cause of death in Canadians.  The literature review contributed to the health claim application submitted by Vegetable Oils Industry of Canada.

http://www.hc-sc.gc.ca/fn-an/label-etiquet/claims-reclam/assess-evalu/sat-mono-poly-fat-gras-eng.php

 

Alpha Linolenic Acid Acts Independent of Conversion to EPA and DHA
Using the novel delta-6 desaturase knock-out mouse model we provide evidence that alpha-linolenic acid (ALA) has biological activity that is independent of its conversion to EPA and DHA. While there is limited conversion of ALA to EPA and DHA, it is not possible to determine whether the beneficial effects are directly attributable to ALA or metabolism to EPA and DHA.  This is important given that the majority of omega-3 fatty acids consumed in the diet of North Americans is from ALA.

Monteiro J, Askarian F, Nakamura MT, Moghadasian MH, David WL Ma. Oils rich in α-linolenic acid independently protect against characteristics of fatty liver disease in the Δ6-desaturase null mouse. Can J Physiol Pharmacol. 2013 Jun;91(6):469-79. doi: 10.1139/cjpp-2012-0308. Epub 2012 Dec 13. PMID: 23746194

 

Conference Organization and Chairing
I have been involved in the organization and chairing of major national scientific conferences and workshops. I have chaired and helped organize the Canadian Nutrition Society  Annual Meetings (since 2010) http://www.cns-scn.ca/CONFERENCE/default.asp. Most recently, I had the pleasure to organize and chair the first Canadian Nutrition Society regional one-day conference on Advances in Dietary Lipids in Nutrition http://www.cns-scn.ca/LIPIDSCONFERENCE2013/default.asp. I am currently involved in the organization of the 2016 CNS Annual Meeting (May 2016, Ottawa/Gatineau) and 2016 regional thematic meeting (Toronto, Jan 2016).