A diet rich in saturated fats could suppress the brain’s ability to process certain neural chemicals, leading to lack of motivation and depression, a Canadian study suggests.

The research, published by the University of Montreal, connected overconsumption of saturated fat to decreased function in mesolimbic dopamine release and signalling, reported The Olive Oil Times on 16 July.

Dopamine – sometimes called the reward or pleasure chemical – is a neurotransmitter that has a large role in how we experience motivation and the feeling of gratification after completing a task. A good example of dopamine function is the so called “runner’s high”.

The Canadian study discovered that intake of saturated lipids could suppress dopamine signalling, which put a damper of the feeling of gratification and thus resulted in lower motivation.

The lack of motivation to complete daily tasks, such as exercise, could in the long run lead to a sedentary lifestyle that could exacerbate the development of obesity, which has also been associated with a high saturated fat intake.

“The association between depression and obesity may be partly rooted in diets biased toward saturated fat intake as circulating levels of the saturated fatty acid palmitate correlate positively with depression severity in humans,” the research paper read.

The study noted, however, that fats’ effect on brain chemistry was dependent on the lipid class and not on weight gain or associated metabolic change, suggesting that saturated fats affected dopamine function before inducing weight gain.

The study compared the effects of saturated fat with those of monounsaturated fat from olive oil and noted that monounsaturated lipids did not produce the kinds of dopamine-inhibiting effects that saturated fats did.

However, the researches pointed out that they could not overrule the possibility of overconsumption of monounsaturates also developing similar effects over an extended period of time.