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The content of your diet is the most important, and flexible change you can make. Certain nutrients foster brain cell growth, synaptic plasticity, and neurotransmission. Other nutrients can damage brain cells and impair their functionality. Making these distinctions and adapting your diet to fit the research is vital.

It is common knowledge that eating high-fat foods is unhealthy. It increases your risk for cardiovascular disease, obesity, and diabetes. Many are not aware that high-fat diets are also bad for your brain. Research has demonstrated that high-fat diets impair hippocampus neurogenesis, and that males are more susceptible to this impairment.

A high-fat diet decreases the amount of brain-derived neurotrophic factor (BDNF) in your cells. BDNF is a protein that supports the survival of existing neurons, and encourages the growth and differentiation of new neurons and synapses. In other words, BDNF helps your brain grow new brain cells, improves their survival rate, and facilitates the creation of new synaptic connections between new brain cells. Lower levels of BDNF impede the first two drivers behind cognitive function.

But what exactly is a high-fat diet?

A diet is considered "high-fat" when over 25% of the calories come from fats. Analyze your diet and make sure no more than 25% of your caloric intake come from fats. However, you need to do more than limit your fat intake. There are different categories of fats, and it is important that your diet consists of the right category. The three categories of fats are:

  • Trans-fat
  • Saturated fats
  • Monounsaturated fats and Polyunsaturated fats (Omega-3 fats)

Of the fats you consume, none should be trans-fats, most should be polyunsaturated or monounsaturated fats, and the rest should be saturated fats. If possible, 0% of your daily caloric intake should come from trans-fats. If you only make one change to your diet, make this change.

Why are trans-fats so bad?

Believe it or not, our brain is composed largely of fat. Fatty acids comprise a significant portion of cell membranes, brain tissue, and myelin sheaths. These fatty acids protect neurons and without them, brain cells cannot function properly. Trans-fats can replace the "good fatty acids" in our brain and when this happens, neurons lose functionality. They lose their ability to communicate and eventually die.

Trans-fats are also terrible for your heart’s health as they contribute to coronary heart disease. This impairs cerebral blood flow (CBF), a term used to describe the amount of blood reaching your brain. Blood fuels the brain with oxygen and glucose which our brain needs to carry out all of its functions. If delivery of oxygen and glucose to the brain is compromised you will hinder not just the three drivers behind cognitive function, but all brain function.

Recall I referred to the brain as a super computer. Think of blood vessels as electrical cords that deliver it power and the heart as the battery connected to the cords. Trans-fats weaken the battery and interfere with the electrical cords. These effects accumulate over time, and can severely impair cognitive performance.

Foods high in trans-fats are easy to recognize. Such foods are processed and are rarely found in nature. For example most fast, frozen, and fried foods, and margarine are high in trans-fats.

Below is a list of changes you can make to limit the amount of trans-fats you consume:

  • Limit your intake of fast food and if you must indulge, do so rarely.
  • Stop eating microwaveable dinners and frozen foods, such as pizza. If you cannot avoid these products, compare packages and select food options with lower amounts of trans-fats.

Of the fats you eat, most should be polyunsaturated or monounsaturated fats.

Polyunsaturated and monounsaturated fats contain Omega-3 fatty acids. Omega-3 fatty acid is a good type of fatty acid, and is an “essential fatty acid” because it cannot by synthesized by our body, but is vital to our overall health. Omega-3 fats are the polar opposites of trans-fats. They help neurons function properly and improve cerebral blood flow. Instead of inhibiting the three drivers of cognitive performance like trans-fats, Omega-3 fatty acids facilitate them.

Omega-3 fatty acids are most commonly found in marine and plant oils. The best way to get Omega-3 fats is fish. Experts recommend you eat fish at least twice a week, enough to get an average daily intake of 250mg of Omega-3. Almost any type of seafood such as salmon, halibut, cod, shrimp, tuna, and krill are good sources. Plant based sources include cloves, soybeans, tofu, kale, collard greens, and winter squash. Below is an article that outlines different ways to get Omega-3 fats into your diet. You can also purchase Omega-3 supplements from any pharmacy or supermarket.

Some changes you can make include:

  • Consume at least one fish meal every week. I choose salmon because it contains a larger amount of Omega-3 fats compared to most other sea foods.
  • Add spinach and walnuts to your salads. They are a cheap and easy way to get more Omega-3 fats.
  • Make kidney or pinto beans as a side dish for dinner at least once a week.
  • Take an Omega-3 supplement. The most commonly purchased Omega-3 supplement is fish oil.

Saturated fats are considered "neutral" and will not help or harm brain function as long as your daily fat caloric intake is below 25%. Saturated fats only become harmful when they turn your diet into a high-fat diet. In summary, keep your diet low in fat, high in Omega-3 fats, and eliminate trans-fats.

Make sure you are getting enough fruits and vegetables.

Chances are you do not eat enough fruits and vegetables, especially if you are a college student. A diet balanced in fruits and vegetables likely will not boost cognitive function in the short term, but research has shown that insufficient amounts of fruits and vegetables can affect cardiovascular and cognitive health in the long run.

We have discussed how our heart’s health is related to our brain’s health. Not eating enough fruits and vegetables will weaken the heart overtime. As the heart weakens, it pumps less blood including glucose and oxygen to the brain.

We also discussed the process of oxidation which takes place in your brain. Oxidation is a chemical reaction that produces a "free radical" by transferring an electron from a substance to an oxidizing agent. These free radicals then become the oxidizing agent, and cause a chain reaction. Limited amounts of free radicals are actually a good thing. They can destroy certain types of unwanted bacteria and are necessary for the communication of certain cells. But if free radical levels become too elevated, and the chain reaction is left unchecked, cells are injured or destroyed.

Many fruits and vegetables contain antioxidants. An antioxidant is a molecule which terminates the free radical chain reaction. There is debate as to whether supplemental antioxidants slow mental decline. One possible explanation is people consume too many antioxidants, and do not receive the benefit bestowed by low levels of free radicals. However, research has concluded that dietary intake of antioxidants may slow the cognitive decline associated with aging.

How many servings of fruits and vegetables are enough?

Web MD states: “You should have a minimum of five servings per day, but more is better.” Keeping close track of your fruit/vegetable intake is not as important as keeping track of your fat intake. But you should eat fruits and vegetables on a daily basis.

Below is a list of the changes you can make:

  • Keep fresh bananas, peaches, and apples in the house. Instead of opening a bag of chips when you get hungry, snack on fruit.
  • Eat a salad most days.
  • If you eat pancakes or waffles for breakfast, add blueberries or strawberries.

The bottom line is, fruits and vegetables are good for your overall health, including cognitive health and function.

Dietary Content Modification Summary:

  • Eliminate as many trans-fats as possible.
  • Consume as many Omega-3 fats as possible, and consider taking a Fish Oil supplement.
  • Consume more fruits and vegetables.

These three changes will have a dramatic impact on your overall and cognitive health. Failing to make these changes can impede the three drivers behind cognitive function. Do not forget, cardiovascular health is linked to brain health.

Below is list of the changes I made to my diet while following this regimen:

  • I substantially reduced the amount of fast food I ate. When I absolutely had no choice, I went to a restaurant specializing in low fat freshly prepared food.
  • Microwaveable dinners and frozen chicken nuggets are a thing of the past. I buy a lot more nitrate-free deli meat, chicken, pork, and beef that I prepare myself.
  • Instead of eating chips or ramen noodles as a snack, I switched to apples, peaches, and bananas.
  • I consume a fish meal every week. I usually eat salmon because it contains a larger amount of Omega-3 fats when compared to other sea foods.
  • I now add spinach and walnuts to all of my salads. They are a cheap and easy way to get more Omega-3 fats.
  • I make kidney or pinto beans a side to my dinner at least once a week.
  • I take started taking an Omega-3 supplement.
  • I eat a salad for lunch most days. This provides vegetables and keeps me from feeling lethargic during the day.
  • When I eat pancakes, I make sure they are blueberry pancakes.
  • I started to eat honey nut cheerios for breakfast every other morning instead of bacon and eggs.
  • I completely stopped eating chocolate and other sweets.

Below is a list of foods to consider as alternatives to unhealthy diet choices:

Blueberries - Research has shown blueberries contain powerful antioxidants. Studies show they protect the brain from oxidative stress and reduce the harmful effects of different forms of dementia such as Alzheimer's disease. Other studies have suggested blueberries can help slow age-related cognitive decline, and inhibit the growth of cancer cells. Blueberries contain the chemical Pterostilbene which provides additional health benefits.

Tea - Freshly brewed tea contains modest amounts of the two nootropics, Caffeine and Theanine. Tea also contains catchetins, molecules with powerful antioxidant properties. The nootropics caffeine and theanine are especially beneficial to cognitive health. They improve memory, focus, and mood. Both are discussed in the nootropics chapter.

Wild Salmon - Wild Salmon is renowned as an excellent brain food because it contains high levels of Omega-3 fatty acids. As explained, these fatty acids are extremely important for cognitive health. If you do not like seafood, fish oil supplements are a popular way to get Omega-3 fatty acids.

Cherries - While oxidative stress is a major cause of mental decline, inflammation also plays a role. Cherries contain cox-2 inhibitors. These inhibitors help reduce inflammation in the brain.

Sage - Sage contains compounds which help prevent the breakdown of the neurotransmitter acetylCholine. Two nootropics, Galantamine and Huperzine A, have been proven to improve cognitive performance in a similar way. If working sage into your diet does not sound appealing, you can purchase either Galantamine or Huperzine A to reproduce its benefits.

Beans - Often neglected, beans help stabilize blood glucose levels, and are an excellent source of glucose for the brain. The brain depends on glucose for energy.

Pomegranates - This fruit contains extremely potent antioxidants.

Nuts and Seeds - These are high in vitamin E, which has been shown to help prevent the cognitive decline that results from aging. Nuts and seeds that provide this benefit include almonds, cashews, peanuts, sunflower seeds, hazelnuts, and walnuts. Nut butters such as peanut butter are also a good source of vitamin E.

Pumpkin Seeds - While a rather obscure entry to the list, pumpkin seeds contain high levels of zinc. Just a dozen pumpkin seeds per day are sufficient to meet your daily recommended zinc intake.

Beets - A study performed at Wake Forest University showed that beets contain natural nitrates. These nitrates increase blood flow to the brain. Increased blood flow to the brain improves all three drivers of cognitive performance.