UBC study warns against consumption of PUFAs or polyunsaturated fats

A UBC study has made a link between consumption of polyunsaturated fats and a more sedentary lifestyle, putting into question decades worth of health initiatives that have promoted the virtues of polyunsaturates over their saturated fat alternatives.

“This data is extremely significant,” says Sanjoy Ghosh, professor at UBC’s Okanagan campus and co-author of the new study, in a press release. “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 PUFA they are consuming, or changing what they’re eating, then it might be doomed to failure.”

Animal product-derived saturated fats, as everyone knows, have long been deemed less healthy than polyunsaturated fatty acids (PUFAs), found in cooking oils like soybean oil, corn oil and sunflower oil along with fatty fish like salmon and mackerel, and monounsaturated fatty acids (MUFAs), found in olive oil, canola oil, as well as many nuts and seed. Saturated fats have been linked to high cholesterol levels and heart disease, and the Canada Food Guide calls for people to limit the amount of saturated fats while including unsaturated fats as part of a healthy diet.

As a result, between the 1970s and 2000s, Canadians have increased their intake of both PUFAs and MUFAs, a phenomenon which has been observed in Europe and the United States, as well. Yet, during that same time period rates of diabetes in Europe and North America have shot up, along with a rise in sedentary behaviour — so goes the argument presented in a new study from researchers from the Department of Biology, UBC Okanagan, and the Department of Biochemistiry, KPC Medical College in West Bengal, India. “Is it possible that sedentary behaviour is caused by dietary unsaturated fats?” say the study’s authors. “Indeed, 4–8 yr old children in USA and Canada increasingly consume a diet rich in unsaturated fats.”

The researchers took cross-sectional data on sedentary activity and diabetes prevalence from a 2012 European report and correlated it with age and gender-specific nutritional data from 21 European countries. The results showed a strong correlation between sedentary lifestyle in 11-year-old girls and dietary PUFA consumption along with a weaker association between dietary PUFA consumption and diabetes indicators in adult women across Europe.

“Our study does present new evidence that dietary PUFA is strongly associated with sedentary behaviour among pre-teen girls and weakly associated with diabetes among adult women across Europe,” says Ghosh.

The study follows on earlier research conducted by the same team which showed metabolic insufficiencies in mice fed diets high in corn oil, a PUFA, versus mice fed diets with olive oil, a MUFA. The researchers found that after six weeks, the corn oil-fed mice had reduced spontaneous locomotor activity, lower respiratory ratio, excess levels of insulin in the blood and impaired glucose disposal from the bloodstream in comparison to the olive oil-fed mice.

The researchers state that further study on the health effects of PUFAs should be conducted. The new study is published in the journal PLOS One.