High saturated fat diet dulls dopamine system, impairs cognitive function

July 15, 2015 in Brain Health, Nutrition Topics in the News

High saturated fat diet dulls dopamine system, impairs cognitive function

Chances are if something is bad for the heart, it’s bad for the brain too. According to a recent study published in the journal Neuropsychopharmacology, a diet high in saturated fat can lead to cognitive function impairment, specifically by dulling the dopamine reward system while increasing the dependency on unhealthy foods.

The consumption of saturated fat and trans fat can raise low-density lipoprotein (LDL, or "bad" cholesterol). This is considered bad cholesterol because it contributes to plaque that can clog the arteries and make them less flexible.

It’s no surprise that what we eat has a profound impact on brain function, according to a team of researchers at the University of Montreal. "Our research shows that independent of weight gain and obesity, high-fat feeding can cause impairments in the functioning of the brain circuitry profoundly implicated in mood disorders, drug addiction, and overeating — several states and pathologies that impinge on motivation and hedonia”.

In an effort to show the effects of unrestrained intake of saturated fats on the brain, the researchers worked with three groups of rats. The first group, the control group, was given a low-fat diet containing equal amounts of monounsaturated (e.g. the type in olive oil, avocado and almonds) and saturated fats (e.g. animal fat, palm oil). The second group was given a diet high in monounsaturated fat where 50 percent of the calories came from oil. The third group was given a high saturated fat diet where 50 percent of the calories were from palm oil.

The high-fat diets were the same in regard to sugar, protein and calories. Fat intake was unrestricted. After eight weeks, all of the rats still had comparable body weights and levels of insulin and blood glucose.

The three groups were tasked to undergo a series of behavioral and biochemical tests that are indicative of the functioning of rats’ dopamine systems.

The findings revealed that the rats on the saturated fat palm diet showed significantly dulled dopamine function.

The researchers hypothesize this is what leads the brain to try to compensate by heightening reward-seeking behavior, similar to how a drug addict increases their drug dose over time to get the same high. In this case, someone who is consuming too much saturated fat may compensate by consuming more high-fat and high-sugar foods to get the same level of pleasure and reward.

The researchers have separate evidence that brain inflammation may be involved in this process, as it is triggered by saturated high-fat feeding.

A similar 2012 study published in the journal Annals of Neurology found bad fats can undermine cognitive function, including short- and long-term memory as you age. Women who consumed the highest amounts of saturated fat, had worse overall cognitive function and memory throughout four years of testing when compared to women who ate the lowest amounts of these fats. Contrastingly, women who consumed the most monounsaturated fats fared better on the cognitive tests over time.

It’s theorized that saturated fat is linked to inflammation or changes in lipid profiles that interfere with brain function.

Limiting the intake of high saturated fat foods can prevent the impairment of cognitive function and the dulling of the brain’s pleasure center. Eating a diet rich in whole nutrient-dense, high-fiber natural foods can help restore dopamine sensitivity. Overeating to compensate can cause the brain to down-regulate receptors and lead to less enjoyment from other activities.

Source: Neuropsychopharmacology, July 2015.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.