Feed a bunch of rodents saturated fat and what happens to their brains? New Canadian research suggests that the unhealthy fat – found in cookies, cakes and processed goods – affects more than just our waistlines.
A diet filled with fat-laden foods also tampers with the reward centres of the brain, encouraging us to eat more, they warn.
University of Montreal researchers enlisted the help of rats that were fed special diets: one group was fed a low-fat diet packed with healthy amounts of monounsaturated (good) and saturated fats, a second group was fed a diet in which 50 per cent of calories came from good fats, such as olive oil, while the last group had 50 per cent of its calories come from saturated fat in the form of palm oil.
The high-fat diets had the same amounts of sugar, protein, fat and calories, and the rats were allowed to eat as much as or as little as they liked for eight weeks.
During the two-month timeframe, the scientists conducted behavioural and biochemical tests on the rats to measure changes in the brain.
They suggest that the rats on the saturated fat-heavy diet faced adjustments in the brain tied to mood disorders, drug addiction and overeating.
“We established that the rats on the palm diet had a significantly blunted dopamine function,” lead researcher, Cecile Hryhorczuk, said.
Each time we indulge in something tasty and gluttonous, they suggest that our brains are hit with dopamine. We may be dulling the high from the reward centres of the brain if we overindulge, though.
“Our research group and others hypothesize that this leads the brain to try to compensate by heightening reward-seeking behaviour, much like the phenomenon of drug tolerance where one has to increase the drug dose over time to get the same high. So a person consuming too much saturated fat may then compensate a reduced reward experience by seeking out and consuming more high-fat and high-sugar foods to get the same level of pleasure or reward,” she explained.
The researchers note that their findings offer another drawback, aside from weight gain, that people should be cognizant of. They say their study is the first of its kind to show that, aside from tipping the scales and hurting your heart health, “unrestrained intake” of saturated fat also toys with your brain.
“As we were able to control for changes in body weight, hormones and glucose levels, we think that the fats may be affecting the dopamine system by a direct action in the brain,” co-author, Dr. Stephanie Fulton, said.
Shortening, butter, margarine and lard are prime examples of saturated fat. They’re solid at room temperature.
Health officials warn that too much saturated fat in your diet could increase cholesterol levels and clog arteries.
Saturated fat is also found in animal protein, such as fatty cuts of steak, processed meats, bacon, sausages and hot dogs.