Sugar is often portrayed as an absolute evil in health discussions, but it's actually a vital source of energy for the brain. However, as with many other substances, it all depends on the amount, type, and context of consumption. Psychology Today explains how different types of sugar affect the brain and why stable blood glucose levels are critical.
What is sugar in food and in the blood?
Dietary sugar is not just the white sugar we put in our tea. It includes molecules like sucrose, fructose, and lactose, which are found in fruits, dairy products, and processed foods. The most dangerous are added sugars, such as syrups and concentrates, which significantly increase blood glucose levels.
Glucose is the main “fuel” for the brain. However, its excess in the diet or sudden fluctuations in blood levels can disrupt brain function.
How does sugar affect the brain?
Foods with a high glycemic index (sweets, sodas, white bread) quickly raise blood sugar levels. This can cause:
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insulin resistance, which makes it difficult for glucose to reach the brain;
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Inflammation in brain tissue is one of the risk factors for depression, stroke, and dementia;
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oxidative stress due to the formation of advanced glycation end products that damage cells.
So-called “Western diets,” rich in added sugars and ultra-processed foods, are associated with an increased risk of cognitive impairment and Alzheimer’s disease.
Why is stable blood sugar important?
As we age, the brain's access to glucose becomes less efficient. This partly explains the decline in cognitive function and the development of neurological diseases. Studies show that type 2 diabetes increases the risk of dementia by 60%. Even minor disturbances in insulin function can reduce memory, concentration and speed of thought.
How to keep your brain in good shape?
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Limit added sugars: candy, cookies, sodas.
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Eat minimally processed foods rich in fiber (vegetables, legumes, whole grains).
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Maintain regular physical activity — it improves insulin sensitivity.
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Get quality sleep and manage your stress levels — these factors affect hormonal regulation of appetite and glucose levels.
A sensible attitude towards sugar consumption is not only a matter of figure, but also a guarantee of a healthy and clear mind in the future.
