By Joel Fuhrman, MD  | Medically reviewed by a board-certified physician | Updated June 09, 2019

The brain uses more energy than any other organ in the human body and glucose is its primary source of fuel. But what happens when the brain is exposed to an excessive amount of sugars in the standard American diet? In this case, more is definitely not better.

In the brain, excess sugar impairs both our cognitive skills and our self-control. For many people, having a little sugar stimulates a craving for more. Sugar has drug-like effects in the reward center of the brain. Scientists have proposed that sweet foods—along with salty and fatty foods—can produce addiction-like effects in the human brain, driving the loss of self-control, overeating, and subsequent weight gain.

In early humans, this stimulus helped lead them to calorie-rich foods, which aided survival when food was scare. But now this primitive drive contributes to our epidemics of obesity and diabetes. The behavioral and neurobiochemical characteristics of substance abuse and overeating are quite similar, and the idea of food addiction is gaining ground among scientists.

Reward Response

In humans, high-glycemic foods have been found to activate regions of the brain associated with the reward response and provoke more intense feelings of hunger compared to low-glycemic foods. Foods that cause a higher elevation in blood glucose produce a greater addictive drive in the brain.

Research published in the American Journal of Clinical Nutrition used the glycemic index (GI)—a measure of how certain foods convert to sugar in the body—to test this process and found eating a high-GI meal elicited greater brain activity in regions involved in eating behavior, reward, and craving.

Sugar Addiction

Additional studies on brain activity have provided evidence supporting the idea that overeating alters our brain’s reward system, which then further drives overeating. This same process is thought to underlie the tolerance associated with addiction.

Over time, greater amounts of the substance are required to reach the same level of reward. Studies imply that overeating results in a diminished reward response and a progressively worsening addiction to low-nutrient foods rich in sugar, salt, and fat.

A study published PLoS One found that swet foods can be more addictive than cocaine. Though the research was performed on animals, investigators found that intense sweetness can surpass cocaine reward, even in drug-sensitized and -addicted individuals.

Memory

Throughout the body, excess sugar is harmful. Even a single instance of elevated glucose in the bloodstream can be harmful to the brain, resulting in slowed cognitive function and deficits in memory and attention.

Some research suggests high sugar consumption causes inflammation in the brain, leading to memory difficulties. A 2016 study published in Behavioral Brain Research found inflammatory markers were present in the hippocampus of rats fed a high sugar diet, but not in those fed a standard diet.

The good news, however, is this inflammatory damage from sugar may not be permanent.

READ MORE: https://www.verywellmind.com/how-sugar-affects-the-brain-4065218?utm_campaign=health_tod&utm_medium=email&utm_source=cn_nl&utm_content=17281425&utm_term=

 

This article submitted by Pat France, MSRN Member