Global Health

Beyond the waistline: the impact of sugar and fat on your brain

Research suggests that a diet high in fat and sugar can also have a significant impact on our cognition – the way we learn, remember, and think.

Katie Boyd
PhD Candidate, University of Sussex
Share:
Our Impact
What's the World Economic Forum doing to accelerate action on Global Health?
The Big Picture
Explore and monitor how Global Health is affecting economies, industries and global issues
A hand holding a looking glass by a lake
Crowdsource Innovation
Get involved with our crowdsourced digital platform to deliver impact at scale
Stay up to date:

Global Health

A lot of research has been conducted to establish the risks that a high energy diet – high in saturated fat and sugar – poses to our health. The most common known results of such diets include obesity, heart disease and diabetes, but research suggests that a diet high in fat and sugar can also have a significant impact on our cognition – the way we learn, remember, and think.

Back in 2010, Scott Kanoski, assistant professor of biological sciences at Perdue University in the US, showed that as little as three days of a diet that is high in saturated fat and sugar was enough to change cognition in rats.

During the research, rats were fed either a high energy diet or one that was nutritionally balanced, and had to learn where to find the food while inside a maze. After only three days, the rats on the high energy diet were less able to find the food rewards than those that had been given the nutrient-balanced diet. They didn’t gain any weight, which suggests the damaging effects of a high energy diet are more than the production of excess body fat – it also affected their brains.

Further research by Kanoski indicated that the hippocampus, the area of the brain that is important for learning and memory, is especially vulnerable to the effects of a high energy diet. The fact that this brain region appears to be affected earlier than others is worrying, as it proves that the earliest detrimental effects of a high energy diet are on cognition.

This effect on memory could be explained by insulin resistance which happens on an energy rich diet. Insulin is used as a signalling chemical that tells the body to remove glucose from the blood to use as energy. So, when the body becomes insulin resistant, it can’t do this as effectively, which leads to high blood sugar levels. Insulin resistance has been mostly associated with obesity, as these people typically have had high energy diets over a long time period, and can sometimes progress into type 2 diabetes.

In fact, researchers at the University of Mexico found that rats showed evidence of insulin resistance after only seven days on a high energy diet. In this case the hippocampus’ response to insulin changed and it appeared to alter the structure of nerve cells in that region. It meant that the nerve cells were less able make new connections with other nerve cells, which is required to make new memories, and suggests that a high energy diet can impact the way we learn through this developed insulin resistance.

Cognitive decline has also been previously linked to insulin resistance in humans. One study, in 2011, showed that after five days of a high fat, low sugar diet, people performed worse on cognitive tasks such as focusing their attention and such diets have also been linked to the development of Alzheimer’s Disease. However, further research into the very short-term effects of high energy diet in humans is currently lacking.

A vicious circle?

Terry Davidson, professor of psychology at Perdue University, suggested that changes of this kind to the hippocampus could even affect the way we eat and even lead to obesity. The hippocampus is responsible for learning and perhaps also for us associating the feeling of hunger with pleasure when we eat. But, when there is damage to the hippocampus, this could be disrupted and it might cause you to eat even when you don’t feel hungry. And if you turn to food which is high in fat and sugar in this instance, it could create a vicious circle of further hippocampus damage – and more overeating.

Although our knowledge regarding the short-term effects of a high energy diet on our brains is limited, we should still be encouraged to make healthier choices when it comes to food and it’s especially important when the food we eat could impact our minds as well as our bodies. It’s unfortunate that a bad diet can affect the way we think and learn – and long before most of us would be concerned about having a few too many treats.

Loading...
Loading...
Don't miss any update on this topic

Create a free account and access your personalized content collection with our latest publications and analyses.

Sign up for free

License and Republishing

World Economic Forum articles may be republished in accordance with the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International Public License, and in accordance with our Terms of Use.

The views expressed in this article are those of the author alone and not the World Economic Forum.

Related topics:
Global HealthMental Health
Share:
World Economic Forum logo
Global Agenda

The Agenda Weekly

A weekly update of the most important issues driving the global agenda

Subscribe today

You can unsubscribe at any time using the link in our emails. For more details, review our privacy policy.

Why we need to strengthen health responses in humanitarian crises

Hans Kluge

February 26, 2024

About Us

Events

Media

Partners & Members

  • Join Us

Language Editions

Privacy Policy & Terms of Service

© 2024 World Economic Forum