When you consume too much sugar, your blood sugar spikes rapidly and then drops rapidly. This increases the risk of brain fog and irritability.

Side Effects of Eating Too Much Sugar

Nowadays, people try to avoid fried foods, fast food, and processed foods, but there's one ingredient used in almost every household that causes the most brain damage: sugar (especially white sugar and added sugar found in sweetened beverages). According to doctors and the latest research, consuming too much sugar daily increases the risk of brain fog, memory loss, depression, and even diseases like Alzheimer's. Let's learn more about it. 

According to a report in the Times of India, leading neurologist Dr. Austin Perlmutter (MD) says that it's not fried or refined carbs that are the worst for the brain, but rather the daily sugar intake (especially liquid sugar, i.e., sweetened beverages). 99% of people consume this daily in tea, coffee, cold drinks, juice, biscuits, or sweets.

How does sugar harm the brain?

• Blood sugar spikes and crashes: When you consume too much sugar, your blood sugar spikes and then drops rapidly. This increases the risk of brain fog and irritability, as well as a lack of focus. According to a 2025 Healthline report, sugar with a high GI can damage the hippocampus (the memory part of the brain).
• Increased inflammation: Excess sugar increases inflammation in the brain. A 2025 neuroscience study found that high-sugar diets reduce brain-derived neurotrophic factor (BDNF), which keeps neurons healthy. This impairs learning and memory.
• Insulin Resistance and 'Type 3 Diabetes': Doctors now refer to Alzheimer's as 'Type 3 Diabetes' because high sugar intake makes the brain insulin resistant. This increases the risk of memory loss and dementia. A 2025 study in The Lancet found that high sugar levels damage brain blood vessels.
• Addiction-like effects: Sugar stimulates the brain's reward system, similar to a drug. This increases cravings and makes it difficult to quit. According to the World Health Organization (WHO), free sugars should not exceed 5-10% of daily calories, but most people consume much more than this.
• Children at greater risk: Excessive consumption of sugary drinks in young children increases the risk of ADHD, attention problems, and lower IQ later in life. A 2025 Korean study found that children under the age of 2 who drank more than 200ml of sugary drinks daily were at higher risk of ADHD.

How to prevent it?

• Reduce or eliminate sugar in tea and coffee.
• Avoid packaged juices, soda, and energy drinks.
• Sweeten with fresh fruits. These contain fiber, which releases sugar slowly.
• Eat more home-cooked food, whole grains, nuts, and green vegetables.
• If you want something sweet, use honey, jaggery, or fresh fruit, but in small quantities.