Consuming ultra-processed foods, alcohol, and fish with mercury may negatively impact your ability to think. While you don’t have to avoid these things completely, it’s a good idea to limit them.
Your brain is the most important organ in your body. It comprises over
The brain plays a key role in almost every physical, psychological, and emotional bodily function, such as moving, sensing, learning, processing information, and memory, among many others.
Eating certain foods may help boost brain health, while other foods and ingredients may have a negative impact. Research suggests that diet may also play a role in managing your risk of dementia.
Keep reading to learn more about 7 types of foods and ingredients you may want to limit to help protect your brain.
Sugary drinks include beverages like soda, sports drinks, energy drinks, and fruit juice.
A high intake of sugar-sweetened drinks may increase your risk of diabetes, heart disease, and cavities, as well as negatively impact your brain.
For instance, a small 2023 study found that participants who consumed the most sugar were two times more likely to develop dementia than those who ate the least.
This may be due to the high consumption of simple sugars like fructose and glucose. A primary component of many sugary drinks is high-fructose corn syrup (HFCS), which consists of 55% fructose and 45% glucose.
Some animal and human studies found that a high intake of HFCS, particularly from sugar-sweetened drinks, can negatively impact the hippocampus. This is the part of your brain responsible for learning and memory. Over time, this could also increase the risk of developing cognitive conditions like dementia.
Some alternatives to sugary drinks may include:
- sparkling water
- unsweetened tea
- vegetable juice
- unsweetened dairy products
Refined carbohydrates include sugars and highly processed grains, such as white flour. These carbs generally have a high glycemic index (GI), so your body digests them quickly, causing a spike in your blood sugar and insulin levels.
When eaten in larger quantities, these foods often have a high glycemic load (GL). This refers to how much a food raises your blood sugar levels, based on the serving size.
Foods that are high GI and high GL have been found to impair brain function.
For instance, some research suggests that long-term consumption of refined carbs may impact the hippocampus and prefrontal cortex, which play a role in memory, learning, decision making, and social behavior, among more.
Refined carbohydrates may also affect the gut-brain axis and cause inflammation in the body, including the brain. These effects have been shown to affect your ability to think and increase the risk of anxiety and depression.
Common examples of refined carbs include:
- pastries
- cookies
- white bread, wraps, and bagels
- white rice
- some breakfast cereals
Instead, consider eating whole grains and high fiber foods.
Trans fats are a type of unsaturated fat that may negatively impact brain health.
While trans fats occur naturally in animal products like meat and dairy, these are not a major concern. It’s industrially produced trans fats, also known as hydrogenated vegetable oils, that are a problem.
Artificial trans fats can be found in:
- shortening
- margarine
- frosting
- snack foods
- ready-made cakes
- prepackaged cookies
Some older research suggests that consuming higher amounts of trans fats may negatively impact memory and word recall in people younger than 45 years old. Trans fats may also increase inflammation, insulin, and cholesterol, which can impact the brain.
However, it’s important to note that the
What about saturated fats?
Some animal research suggests that saturated fats may negatively impact memory, learning, and spatial awareness. A
However, it’s important to note that not all fats are bad.
Consider eating foods high in omega-3 fatty acids, which may help protect against cognitive decline and Alzheimer’s disease. Omega-3s increase the secretion of anti-inflammatory compounds in the brain and can have a protective effect.
Ultra-processed foods are typically high in added sugars, fats, sodium, and other preservatives. There are many ultra-processed foods available, but some common ones include:
- chips
- sweets
- deli meats, hot dogs, and chicken nuggets
- instant noodles
- microwave popcorn
- store-bought sauces
- ready-made meals
- frozen pizzas
Some research found that getting more than 19.9% of total daily calories from ultra-processed foods over a period of 8 years increased the risk of experiencing negative impacts on executive functioning and the ability to think.
If your diet consists of 2,000 calories, this means that 400 or more calories come from ultra-processed foods.
While this may seem like a lot, these foods are usually high in calories and low in other nutrients. Calories, fats, and sugar could add up very quickly. For instance:
- one can (370 grams [g]) of regular cola contains
155 caloriesTrusted Source - one portion (22 chips, 28 g) of lightly salted potato chips contains
149 caloriesTrusted Source
Ultra-processed foods may also increase systemic inflammation and decrease the size of the hippocampus and total gray matter volume in the brain, which is associated with thinking, memory, and emotions.
Lastly, some animal research from 2017 suggests that ultra-processed foods may also impact the blood-brain barrier. This is a membrane between the brain and blood supply for the rest of the body that protects the brain by preventing some substances from entering.
Eating ultra-processed foods from time to time won’t have long-term effects on your brain. But it’s best to eat a diet that mainly consists of nutrient-dense whole foods.
Aspartame is an artificial sweetener made of phenylalanine, methanol, and aspartic acid. It’s an
Aspartame is widely considered safe when consumed at about 18 to 23 milligrams (mg) per pound of bodyweight (40 to 50 mg per kilogram [kg]) or less.
According to these guidelines, a 150-pound (68-kg) person should keep their aspartame intake under about 3,400 mg per day, at the maximum.
For reference, a packet of sweetener contains around 40 mg of aspartame, and a regular 12-ounce (340-ml) can of diet soda contains around 125 mg. Amounts may vary depending on the brand.
However, some research suggests that consuming too much aspartame may be associated with behavioral, emotional, and cognitive problems, such as:
- learning difficulties
- irritability
- anxiety
- stress
- depression
This may be due to several factors.
For instance, in high doses, phenylalanine could cross the blood-brain barrier and might disrupt the production of neurotransmitters.
Additionally, aspartame is a chemical stressor that may impact the gut-brain axis and increase the brain’s vulnerability to oxidative stress.
Consuming aspartame in moderation is unlikely to have any major impacts on brain health, but regularly consuming high levels might.
When consumed in moderation, alcohol can be an enjoyable addition to a nice meal.
However, drinking any amount of alcohol may disrupt neurotransmitters in the brain, which are chemicals the brain uses to communicate. As such, alcohol may have short-term and long-term effects on the brain, especially when consumed at higher levels over time.
In the short term, drinking too much alcohol may lead to memory impairment, or “blackouts.” During these periods, a process known as
Chronic alcohol use may cause brain atrophy (shrinkage), structural and functional changes, and cell damage. This may affect several parts of your brain, including:
- prefrontal cortex
- cingulate cortex
- insula
- striatum
- cerebellum
- corpus callosum
These parts of the brain are associated with many different functions, such as thinking, planning, judgment, memory, decision making, balance, emotional processing, integration, and social processing, among others.
According to the
- 2 drinks or less per day for men
- 1 drink or less per day for women
Mercury is a
It’s most commonly found in some long-lived predatory fish that live in salt water,
- shark
- king mackerel
- tilefish
- swordfish
- tuna
For this reason, the primary food source of mercury in humans is seafood, particularly wild varieties.
After a person ingests mercury, it spreads all around their body and can penetrate the blood-brain barrier. In people who are pregnant, it also concentrates in the placenta and fetus.
Mercury may then disrupt the central nervous system and neurotransmitters and stimulate neurotoxins, possibly resulting in damage to the brain.
However, it’s important to note that when eaten in small quantities, mercury is mostly absorbed in your digestive system and doesn’t reach the brain.
For
Most fish are not a significant source of mercury. In fact, fish is a high quality protein and contains many important nutrients, such as omega-3s, vitamin B12, zinc, iron, and magnesium.
The
Some fish to consider eating include:
- salmon
- anchovies
- sardines
- Pacific oysters
- trout
- tilapia
- shrimp
- catfish
- crab
- flounder
Recommendations may differ from country to country, depending on the types of fish in your area, so it’s always best to check with your local food safety agency for the recommendations that are right for you.
Your diet has a big impact on your brain health, which can impact everything from your physical, emotional, and psychological health.
Ultra-processed foods, alcohol, and foods high in sugar, trans fats, and artificial sweeteners may affect different parts of the brain. These may negatively impact memory, learning, and executive function, and possibly increase the risk of dementia.
If you’re unsure how your current diet may be affecting your brain health, consider speaking with a healthcare professional or registered dietitian. They can help develop a diet plan for you.
