Unhealthy Foods for Your Brain

What are the worst foods for brain health | 3 min read

The brain is the most crucial organ in your body. It keeps your heart beating, lungs breathing and all the systems in your body functioning. Therefore, it is best to look after it and keep it working in optimum condition by being mindful of what we eat. Certain foods adversely affect mood and the brain and might increase the risk of dementia. A worldwide estimate predicts that dementia will affect more than sixty-five million people by 2030. To help reduce this risk, fight inflammation, and promote brain health, consider cutting the following foods from your diet:

Sugary drinks

A high sugar intake and sugary drinks like soft drinks, sports, energy drinks, and fruit juice increase the risk of dementia and Alzheimer’s disease. The primary ingredient, high-fructose corn syrup – can cause brain inflammation and impair memory and learning. Good alternatives to sugary drinks are water, unsweetened iced tea, vegetable juice and unsweetened dairy products.


Refined carbohydrates

Eating refined carbohydrates (sugars and highly processed grains like white flour) with a high glycaemic index and glycaemic load results in poor memory, decreased mental alertness, and increased risk of dementia. It is due to the inflammation of the hippocampus, a part of the brain that affects aspects of memory. Inflammation is a risk factor for degenerative diseases of the brain. Healthy alternatives include vegetables, fruits, legumes, and whole grains.

Foods high in trans fats

Trans fats occur naturally in meat and dairy products but produced trans fats – hydrogenated vegetable oils – are the most harmful. These artificial trans fats can be present in margarine, frosting, snack foods, ready-made cakes, and pre-packaged cookies. It can have a detrimental effect on brain health and is associated with impaired memory and the risk of Alzheimer’s. Cutting out trans fats entirely and increasing omega-3 fats in your diet by choosing fish, chia seeds, flax seeds, and walnuts is a good strategy.

Highly processed foods

Processed foods are high in sugar, added fats and salt – e.g., chips, sweets, instant noodles, microwave popcorn, store-bought sauces, and ready-made meals. These foods cause weight gain that contributes to excess fat around the organs, associated with a decline in brain tissue. Eat fresh, whole foods such as fruits, vegetables, nuts, seeds, legumes, meat, and fish. A Mediterranean-style diet has shown protection against cognitive decline.


Aspartame is an artificial sweetener of phenylalanine, methanol, and aspartic acid readily added to soft drinks and sugar-free products. Phenylalanine can cross the blood-brain barrier and might disrupt the production of neurotransmitters. Additionally, aspartame is a chemical stressor and may increase the brain’s vulnerability to oxidative stress. Its use has been linked to behavioural and cognitive problems, though it is considered a safe product. Instead, try to cut excess sugar and artificial sweeteners from your diet altogether.


While moderate alcohol intake can have positive health effects, excessive consumption of alcohol can have detrimental effects on the brain, leading to memory loss, behavioural changes, and sleep disruption. High-risk groups include pregnant women, teenagers, and young adults. Chronic alcohol use reduces brain volume, metabolic changes, and disruption of neurotransmitters, which are chemical messengers the brain uses to communicate with the nervous system.

Fish high in mercury

Mercury is a heavy metal contaminant – a neurological poison that can be stored for long periods in animal tissues. Mercury is, therefore, particularly harmful to developing foetuses and young children. The primary source of mercury in the diet is sizeable predatory fish. Pregnant women and children should avoid or limit high-mercury fish, including shark, swordfish, tuna, king mackerel and tilefish. 

Other harmful foods to avoid or cut back on are fried foods, salty foods, processed meats and cheeses, and takeaways.


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