Study links cheap, omega-6-laden vegetable oils to TV-watching and diabetes
The list of ills linked to overconsumption of omega-6 fatty acids continues to grow.
Americans consume vastly greater amounts of omega-6 fats than they did 30 years ago.
Combined with low intake of omega-3 fats, that excess creates “silent”, chronic inflammation.
And worrying evidence linking chronic inflammation to fatigue and inactivity has begun to emerge.
Five years ago, researchers from the National Cancer Institute found that breast cancer patients with comparatively high omega-3 levels — and low omega-6 blood levels — showed substantially less inflammation and fatigue … see Omega-3s May Fight Breast Cancer Fatigue.
And a recent clinical study from the University of Michigan found that a Mediterranean-style diet — rich in fruits, vegetables, whole grains, and omega-3 fats — eased fatigue and aided sleep among breast cancer survivors (Zick SM et al. 2017).
Significantly, that Mediterranean-style diet lowered the women’s omega-6 blood levels and raised their omega-3 levels.
Those findings were supported by the results of a recent, “red-flag” rodent study from the University of British Columbia, which linked diets high in omega-6 fats to both inactivity and insulin resistance — a key risk factor for diabetes.
As the Canadian researchers wrote, their findings signal a link between unprecedentedly high omega-6 fat intakes in America — and much of the world — and a parallel rise in sedentary behavior and insulin resistance. (Wong CK et al. 2017)
Before we review the alarming new findings in people, let’s quickly review the causes and consequences of America’s “omega imbalance”.
America’s sickening omega-3/6 imbalance
Humans spent most of their history consuming about three parts omega-6 fat to one part omega-3 fat (3:1 ratio) — but now get an unhealthful 15 parts omega-6 fat to one part omega-3 fat (15:1 ratio).
Most Americans get most of their omega-3s from plant foods, which the body must convert, very inefficiently, into the forms — omega-3 DHA and EPA — it actually needs.
And diets high in omega-6 fats drastically cut conversion of the omega-3 found in plant foods (ALA) into DHA and EPA.
(The only foods rich in DHA and EPA are fish, shellfish, and algae, except farmed catfish and tilapia are low in those omega-3s but high in omega-6 fats.)
Omega-6 fat intakes have risen sharply since the late 1960s, largely because people and food companies were pressed to replace saturated fats (butter and lard) with vegetable oils.
Until relatively recently, the most widely used vegetable oils — corn, safflower, sunflower, and soy — were also the ones highest in omega-6 fats.
Those cheap oils have few or no omega-3s (soy oil is highest at 8%) and very little of the “health-neutral” monounsaturated fat (oleic acid) that abounds in avocados, olive oil, high-oleic sunflower or safflower oil, canola oil, and macadamia nut oil.
That situation has improved somewhat thanks to the rise of canola oil, which is relatively low in omega-6s (22%) and high in monounsaturated fat (60%) and omega-3 ALA (11%).
Now, a new study from the University of British Columbia underscores the threats posed by the world’s growing omega fats imbalance.
Canadian team links omega-6 fats to laziness and diabetes
Scientists from the University of British Columbia report that omega-6-laden cooking oils may sabotage people’s efforts to stay healthy (Pither J et al. 2017).
The UBC team was led by Professor Sanjoy Ghosh, Ph.D., co-author of the rodent study described above, whose concerning, "red-flag" results prompted this new research.
Using data from 21 European countries, the UBC scientists focused on health factors in two groups:
• Activity levels in pre-teen girls
• Blood sugar (glucose) levels in adult women
They used measures such as the hours spent watching TV, and adjusted their analysis to account for known “confounding” factors like per-capita income, urbanization, and latitude (people move less in hotter southern regions).
The UBC findings strongly link higher omega-6 intakes to sedentary behavior among pre-teen girls and — more weakly — to diabetes among adult women.
Disturbingly, the link between higher omega-6 intakes and sedentary behavior was seen in girls as young as 11 years of age.
Ghosh and his team ask whether we can blame — at least partially — the steady, decades-long rise in omega-6 intakes for the physical laziness documented in Canadian and American adults and children alike.
“This data is extremely significant,” said Ghosh. “Nobody has made this connection and it’s time for an intervention. And if someone is beginning an exercise program without taking a close look at the fats, especially [omega-6] PUFA, they are consuming, or changing what they’re eating, then it might be doomed to failure.”
“Doomed to failure” is probably an exaggeration — but it’s an understandable and forgivable one, given the importance of his team’s landmark finding.
And, given the other known evils of America’s enormous omega-6 overload, evidence that it may also sap your energy could provide critical motivation for some to make an “oil change”.
Funding for the research team from the Canadian Diabetes Association, the Natural Sciences and Engineering Research Council of Canada, and the Egg and Dairy Farmers of Canada — who would of course prefer that people choose animal fats over vegetable oils.
- Alfano CM, Imayama I, Neuhouser ML, Kiecolt-Glaser JK, Smith AW, Meeske K, McTiernan A, Bernstein L, Baumgartner KB, Ulrich CM, Ballard-Barbash R. Fatigue, inflammation, and ω-3 and ω-6 fatty acid intake among breast cancer survivors. J Clin Oncol. 2012 Apr 20;30(12):1280-7. doi: 10.1200/JCO.2011.36.4109. Epub 2012 Mar 12.
- Karshikoff B, Sundelin T, Lasselin J. Role of Inflammation in Human Fatigue: Relevance of Multidimensional Assessments and Potential Neuronal Mechanisms. Front Immunol. 2017 Jan 20;8:21. doi: 10.3389/fimmu.2017.00021. eCollection 2017. Review.
- Pither J, Botta A, Maity C, Ghosh S. Analysis using national databases reveals a positive association between dietary polyunsaturated fatty acids with TV watching and diabetes in European females. PLoS One. 2017 Mar 29;12(3):e0173084. doi: 10.1371/journal.pone.0173084. eCollection 2017
- Zick SM, Colacino J, Cornellier M, Khabir T, Surnow K, Djuric Z. Fatigue reduction diet in breast cancer survivors: a pilot randomized clinical trial. Breast Cancer Res Treat. 2017 Jan;161(2):299-310. doi: 10.1007/s10549-016-4070-y. Epub 2016 Dec 2.
- Zick SM, Sen A, Han-Markey TL, Harris RE. Examination of the association of diet and persistent cancer-related fatigue: a pilot study. Oncol Nurs Forum. 2013 Jan;40(1):E41-9. doi: 10.1188/13.ONF.E41-E49.