The brain uses more energy than any other organ in the body, and glucose sugar is its main energy source. But what happens when the brain is exposed to too much sugar from diets?
Scientists suggest that sweet foods, along with salty and fatty foods, act like drugs that can trigger the brain's reward system. This can cause loss of control, overeating, and long-term weight gain.
At first, these triggers helped humans eatcalorieswhich helped them survive when food was rare. But now, this basic urge contributes to the rise of serious health issues like obesity and diabetes.
This article will explore how sugar affects the brain, including its impact on the reward response and how it affects memory, mood, and cognition.
5 Effects of Sugar on the Brain
1. Sugar's Effect on the Brain's Reward System
The reward response happens when certain brain areas activate because of a stimulus, leading to a reward. Examples include favorite food, chocolate, sex, certain drugs or addictive substances. This activation links activity with pleasure feelings, making the behavior more likely to happen again.
Studies found that foods high in sugar activate brain areas tied to the reward response and cause strong hunger feelings compared to foods low in blood sugar.
Also, foods that cause a bigger spike in blood sugar lead to a stronger drive for what’s called addiction in the brain, depending on their glycemic index GI .
The blood sugar index GI is a way to classify foods that contain carbohydrates to estimate how fast they are digested and their ability to raise blood sugar levels, different types of carbs are processed differently in the body. Some cause quick spikes and drops in blood sugar levels, while others cause slow, gradual rises and falls in sugar levels.
-
High-Glycemic foods
High-glycemic foods are those with a high glycemic index, usually 69 or more, and they are digested quickly causing rapid increases in blood sugar levels.
Examples of high glycemic foods include:-
- Processed foods.
-
Foods high in added sugar.
-
Breakfast cereals, cakes, and white bread.
-
Low-glycemic foods
Low-glycemic foods have a low glycemic index, usually 55 or less. They can help people control blood sugar, body weight, and reduce health risks like heart disease and type 2 diabetes.
Examples of foods high in glycemic index include:-
-
Milk and dairy products.
2. Sugar causes addiction-like effects
Studies have given more evidence about brain activity. This evidence supports the idea that overdoing a rewarding behavior, like eating certain food, sex, alcohol, or drugs, changes the brain's reward system. This leads to doing that behavior too much. This process is thought to be why addiction-related tolerance happens.
Over time, you need to do more of the rewarding behavior to get the same feeling. For example, studies show overeating lowers reward response and worsens addiction to low-nutrient foods high in sugar, salt, or fat.
3. Sugar's Effects on Memory
Besides sugar's bad effects on the brain, it harms the whole body too. Even one case of high sugar in the blood can be harmful to the brain, as it can cause:
-
Slowed cognitive functions.
-
Memory deficits.
-
Attention problems.
-
Brain inflammation.
Brain inflammation may worsen memory problems. Studies found inflammatory signs in the hippocampus of mice on a high sugar diet compared to those on a regular diet.
Luckily, sugar-caused inflammation damage might not be permanent. Some studies show memory damage from sugar can be reversed by switching to a low sugar, low glycemic index diet.
Also, research published in Nutrients shows that cutting sugar intake and adding supplements, plus starting to consume omega-3 fatty acids andcurcumin helps improve memory.
4. Effects of sugar on mood
Another serious effect of sugar on the brain is its impact on mood, These effects may include:-
- Impaired emotional processing:- In healthy young people, their ability to process emotions is at risk due to high blood glucose levels, according to brain imaging studies.
- Increased anxiety attacks:- Another study reported that people with type 2 diabetes experienced more episodes of sadness and anxiety during sharp spikes in blood sugar.
- Higher risk of depression:- A large study found a link between high sugar intake and higher risk of depression.
Also, research found that people who consume a lot of sugar are 23% more likely to get a mental disorder compared to those who consume less sugar.
5. Sugar slows down brain powers
High blood sugar damages blood vessels. This damage is the main cause of blood vessel problems in diabetes, leading to more issues like damage to vessels in the brain and eyes, causing retinopathy.
Studies on long-term diabetic patients show gradual brain damage, andthis can cause problems in:
-
learning.
-
reaction.
-
memory.
-
Cognitive functions.
Also, constant exposure to high glucose levels lowers mental ability. High HbA1c is linked more to brain shrinkage.
Besides that, in people without diabetes, eating lots of sugar is tied to lower scores on cognitive tests. This seems to be from a mix of high blood sugar andhigh blood pressure andinsulin resistance and high blood cholesterol levels.
Additional research shows that following a diet high inadded sugars reduces the production of brain-derived neurotrophic factor BDNF, which is a chemical in the brain needed for forming new memories, learning, and higher thinking, and low levels of BDNF are also linked to dementia andAlzheimer's disease.
In the end, any kind of sugar added to food is a risk to the brain, and these risks can be avoided by getting sugars naturally from fresh fruits and whole foods.
