While a diet rich in saturated fat and polyunsaturated fats from olives, nuts and fish is still thought to benefit overall health, excessive amounts of omega-3 fats, especially with omega-6 fats already concentrated in the body, could trigger inflammation responses in tissues. In other words, this research study found that attempts to “balance” omega-6 levels with omega-3 supplements may actually be doing more damage to tissue health than good. Read the full National Post news story here: http://life.nationalpost.com/2013/01/23/excessive-omega-fatty-acids-may-make-heart-health-worse-not-better-b-c-researchers/
Comments from Jennifer Broxterman, MSc, RD
Registered Dietitian & Sports Nutritionist
NutritionRx | Professional nutrition counselling services in London, Ontario, Canada.
“This finding continues to support the healthy eating message that a diet rich in fatty fish (a whole food naturally high in omega-3s) and not omega-3 supplements, combined with a reduction of omega-6 oils/processed foods and the inclusion of some healthy saturated fats (e.g. coconut oil) seems to promote a more natural balance in fats in the body.”
-Jennifer Broxterman, MSc, RD
Want to go right to the source? Check out the actual research article below:
Journal Article: Diets rich in n-6 PUFA induce intestinal microbial dysbiosis in aged mice.
Authors: Sanjoy Ghosh a1, Erin Molcan a1, Daniella DeCoffe a1, Chaunbin Dai a1, and Deanna L. Gibson a1 c1
a1 ASC 368, 3333 University Way, Department of Biology, The Irving K. Barber School of Arts and Sciences, University of British Columbia Okanagan, Kelowna, BC, Canada V1V 1V7
British Journal of Nutrition
- British Journal of Nutrition / FirstView Article, pp 1-9
- DOI: http://dx.doi.org/10.1017/S0007114512005326, Published online: 08 January 2013
Controversies have emerged regarding the beneficial v. detrimental effects of dietary n-6 PUFA. The alteration of the intestinal microbiota, a phenomenon termed dysbiosis, occurs during several chronic inflammatory diseases, but has not been well studied in an aged population. With present ‘Western’ diets predominantly composed of n-6 PUFA, we hypothesised that PUFA-rich diets cause intestinal dysbiosis in an aged population. C57BL/6 mice (aged 2 years) were fed a high-fat (40 % energy), isoenergetic and isonitrogenous diet composed of rapeseed oil, maize oil or maize oil supplemented with fish oil. We examined ileal microbiota using fluorescence in situhybridisation and stained tissues by immunofluorescence for the presence of immune cells and oxidative stress. We observed that feeding high-fat diets rich in n-6 PUFA promoted bacterial overgrowth but depleted microbes from the Bacteroidetes and Firmicutes phyla. This corresponded with increased body mass and infiltration of macrophages and neutrophils. Fish oil supplementation (rich in long-chain n-3 PUFA like DHA and EPA) restored the microbiota and inflammatory cell infiltration and promoted regulatory T-cell recruitment. However, fish oil supplementation was associated with increased oxidative stress, evident by the increased presence of 4-hydroxynonenal, a product of lipid peroxidation. These results suggest that an n-6 PUFA-rich diet can cause dysbiosis and intestinal inflammation in aged mice. However, while fish oil supplementation on an n-6 PUFA diet reverses dysbiosis, the combination of n-6 and n-3 PUFA, like DHA/EPA, leads to increased oxidative stress, which could exacerbate gastrointestinal disorders in the elderly.