Subscribe
The latest psychology and neuroscience discoveries.
My Account
  • Mental Health
  • Social Psychology
  • Cognitive Science
  • Psychopharmacology
  • Neuroscience
  • About
No Result
View All Result
PsyPost
PsyPost
No Result
View All Result
Home Exclusive Cognitive Science

Chronic intake of refined carbohydrates between meals is associated with decreased cognitive performance, study finds

by Vladimir Hedrih
May 22, 2023
in Cognitive Science
Share on TwitterShare on Facebook
Stay on top of the latest psychology findings: Subscribe now!

A new study in France found that chronic consumption of refined carbohydrates between meals was associated with worse cognitive performance in both men and women. This effect persisted even when energy intake and a number of other factors were controlled. The study was published in Personality and Individual Differences.

Each animal species is adapted to a specific diet. Their digestive processes tend to be specialized to effectively digest a particular type of food. Due to this, when their diet suddenly changes, this typically leads to health problems as the digestive system is not adapted to the new food types.

For most Western people, a substantial diet change occurred in the second half of the 20th century, when industrialized foods started becoming common. These foods often contained high concentrations of refined carbohydrates – primary sucrose, fiber-depleted gelatinous starches, high sugar corn syrup, and others.

This dietary change was associated with an increase in the occurrence of obesity, type II diabetes, cardiovascular diseases, dental caries, hypertension and many other diseases. The physiological mechanisms involved in the development of these diseases are now thought to involve repeated excessive concentrations of glucose (hyperglycemia) and insulin (hyperinsulinemia) in the bloodstream accompanied by cells becoming less responsive to the effects of insulin (insulin resistance). Glucose is a simple sugar that is the primary energy source in our body, while insulin is a hormone that facilitates the uptake of glucose into cells.

Study author Leonard Guillou and his colleagues wanted to explore whether the consumption of refined carbohydrates affects cognition in healthy young adults. They noted that studies of long-term effects of carbohydrate consumption so far were mostly carried out on older individuals and in the context of certain illnesses. Data on effects of chronic consumption of refined carbohydrates on young, healthy adults are lacking. They organized an experiment.

Participants were 95 healthy young adults between 20 and 30 years of age, recruited at the University of Montpellier in France. They came in groups of 3 or 4 early in the morning to the laboratory. Researchers first measured their blood glucose level. Participants then completed a cognitive assessment test (Wechsler’s digit symbol substitution cognitive test). They were then served one of two types of breakfasts.

Each type of breakfast contained 500 kilocalories, but one was composed of non-refined carbohydrates (whole wheat bread, butter, cheese, a raw fruit and a non-sweetened beverage) and the other of refined carbohydrates (French baguette from industrially milled flour, jam, fruit juice and a non-sweetened beverage with sugar available).

The breakfast to be served was randomly chosen each day. After breakfast, participants completed questionnaires about their demographic characteristics, physical activity levels, and dietary habits. An hour and a half after breakfast, participants’ blood glucose level was measured again and they completed one more cognitive assessment (Wechsler cognitive test). Between these steps, researchers measured participants’ height and weight.

Results showed that 40% of males and 54% of females ate afternoon snacks (corresponding to Le Goûter, a traditional afternoon snack or tea time). 25% of both men and women ate snacks between meals. Higher consumption of refined carbohydrates between meals and higher energy intake in the afternoon snack were associated with worse cognitive performance.

A similar association, but weaker, was observed for energy intake at breakfast. Breakfast consumed on the same day was not associated with cognitive performance. Men, but not women, with higher body mass index values tended to perform worse on the cognitive assessments.

“The recent Western dietary change, characterized mainly by the massive increase in refined carbohydrate consumption, has well-known detrimental health consequences. Given the increasing number of people affected by these pathologies and the repeated failure of many medical treatments, our study reinforces the belief that the most promising research should focus on prevention in healthy persons,” the study authors concluded.

The study makes a valuable contribution to the scientific knowledge about links between dietary choice and cognitive performance. However, it should be noted that the study design does not allow for any cause-and-effect conclusions. It is possible that higher consumption of refined carbohydrates between meals leads to decreased cognitive performance, but it may also be the case that people whose cognitive performance is worse tend to eat lots of refined carbohydrates between meals. These are not the only possibilities.

The study, “Chronic refined carbohydrate consumption measured by glycemic load and variation in cognitive performance in healthy people”, was authored by Leonard Guillou, Valerie Durand, Michel Raymond, and Claire Berticat.

TweetSendScanShareSendPin34ShareShareShareShareShare

RELATED

Scientists reveal ChatGPT’s left-wing bias — and how to “jailbreak” it
Artificial Intelligence

ChatGPT and “cognitive debt”: New study suggests AI might be hurting your brain’s ability to think

July 1, 2025

Researchers at MIT investigated how writing with ChatGPT affects brain activity and recall. Their findings indicate that reliance on AI may lead to reduced mental engagement, prompting concerns about cognitive “offloading” and its implications for education.

Read moreDetails
New psychology study sheds light on mysterious “feelings of presence” during isolation
Cognitive Science

Vagus nerve signals influence food intake more in higher socio-economic groups

July 1, 2025

Researchers have found that internal physiological cues—like signals from the vagus nerve—play a stronger role in guiding eating behavior among wealthier individuals, offering new insight into why socio-economic status is linked to differences in diet and health.

Read moreDetails
Researchers identify neural mechanism behind memory prioritization
Memory

Researchers identify neural mechanism behind memory prioritization

June 30, 2025

A new brain imaging study shows that when people try to remember multiple things, their brains give more precise attention to the most important item. The frontal cortex helps allocate memory resources, boosting accuracy for high-priority information.

Read moreDetails
Scientists show how you’re unknowingly sealing yourself in an information bubble
Cognitive Science

Scientists show how you’re unknowingly sealing yourself in an information bubble

June 29, 2025

Scientists have found that belief polarization doesn’t always come from misinformation or social media bubbles. Instead, it often begins with a simple search. Our choice of words—and the algorithm’s response—can subtly seal us inside our own informational comfort zones.

Read moreDetails
Muscle contractions release chemical signals that promote brain network development
Memory

Sleep helps stitch memories into cognitive maps, according to new neuroscience breakthrough

June 28, 2025

Scientists have discovered that forming a mental map of a new environment takes more than just recognizing individual places—it also requires sleep. The study highlights how weakly tuned neurons gradually become synchronized to encode space as a connected whole.

Read moreDetails
Reduced pineal gland volume observed in patients with obsessive-compulsive disorder
Cognitive Science

Neuroscientists identify key gatekeeper of human consciousness

June 27, 2025

Using rare brain recordings from patients, scientists found that the thalamus helps trigger visual awareness. The study reveals that this deep brain region sends synchronized signals to the cortex, acting as a gateway for conscious perception.

Read moreDetails
Girls as young as 8 show cognitive sensitivity to their own body weight, new study finds
Body Image and Body Dysmorphia

Girls as young as 8 show cognitive sensitivity to their own body weight, new study finds

June 25, 2025

Girls as young as eight show a unique sensitivity to numbers representing their body weight, a new study finds. The results highlight early gender differences in attention and raise questions about how body awareness develops and affects girls’ perceptions later in life.

Read moreDetails
Schoolchildren in classrooms where trees can be seen are less prone to aggression, defiance, and rule-breaking
Cognitive Science

Critical thinking and academic achievement reinforce each other over time, study finds

June 24, 2025

A new study has found that critical thinking and academic achievement build on each other over time in elementary school students, highlighting the importance of integrating thinking skills into classroom learning to support long-term educational growth.

Read moreDetails

SUBSCRIBE

Go Ad-Free! Click here to subscribe to PsyPost and support independent science journalism!

STAY CONNECTED

LATEST

Could creatine slow cognitive decline? Mouse study reveals promising effects on brain aging

ChatGPT and “cognitive debt”: New study suggests AI might be hurting your brain’s ability to think

Frequent dreams and nightmares surged worldwide during the COVID-19 pandemic

Vagus nerve signals influence food intake more in higher socio-economic groups

People who think “everyone agrees with me” are more likely to support populism

What is the most attractive body fat percentage for men? New research offers an answer

Longer antidepressant use linked to more severe, long-lasting withdrawal symptoms, study finds

New psychology study sheds light on mysterious “feelings of presence” during isolation

         
       
  • Contact us
  • Privacy policy
  • Terms and Conditions
[Do not sell my information]

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In

Add New Playlist

Subscribe
  • My Account
  • Cognitive Science Research
  • Mental Health Research
  • Social Psychology Research
  • Drug Research
  • Relationship Research
  • About PsyPost
  • Contact
  • Privacy Policy