We often think of good nutrition as a way to support the body. Vitamin D helps keep our bones strong, protein helps build and maintain muscle mass, and the antioxidants in fruits and veggies combat inflammation.
But optimal nutrition is just as important for brain health as it is for the rest of the body. What we eat matters for mood, memory, vitality, critical thinking, and more. At the same time, some foods and ingredients can be harmful to brain health, so what we don’t put into our bodies is just as important as what we do.
In this article, we’ll cover nutritional deficiencies that impact brain function, ingredients and foods that can be problematic for brain health, the gut-brain connection, and more.
Nutritional Deficiencies That Impact Brain Function
Nutrients get categorized as macronutrients and micronutrients, and you can be deficient in components of both.
Macronutrients
Macronutrients are nutrients the body needs in large quantities: protein, fat, and carbohydrates. The two most important considerations for brain health are adequate protein and healthy fat intake.
Protein
Protein provides the building blocks for neurons (nerve cells) and neurotransmitters, chemicals that help nerve cells communicate. Moderate protein intake has also been linked to a reduced risk or delayed onset for Alzheimer’s disease, the most common type of dementia.
Your protein needs will depend on your weight, activity level, age, and more. But a good rule of thumb is to get 0.5 grams of protein per pound of bodyweight per day if you’re minimally active and 0.8 to 1 gram per pound if you’re highly active.
Omega-3 fatty acids
Omega-3s are a type of healthy fat (polyunsaturated fatty acid, or PUFA) that combat inflammation. PUFAs are crucial for cognitive performance at all life stages. They aid in learning, memory, cognitive well-being, and blood flow. Aim for at least 1.1 grams or 1.6 grams per day for females and males, respectively. You can get omega-3s from nuts, seeds, and fatty fish.
Micronutrients
Micronutrients are the vitamins and minerals your body needs in smaller quantities. But deficiencies can cause big problems, including for your brain. Keep in mind that sometimes deficiencies result from inherited disorders, issues with absorbing certain micronutrients, and more. Here are a few micronutrients to pay particular attention to for brain health.
B vitamins
All the B vitamins are necessary for brain health. Here’s a look at what they do.
- B1 (thiamin) is important for nerve function. Deficiency, known as beriberi, can induce cognitive decline, including memory loss and confusion.
- B2 (riboflavin) helps facilitate energy production in brain cells and aids with synthesizing neurotransmitters involved in mood and brain function. Deficiency can result in neurological issues.
- B3 (niacin) is crucial for energy production and nerve health, and deficiency can drive depression, anxiety, memory loss, and more.
- B6 (pyridoxine) helps your body make neurotransmitters, and deficiency can bring about cognitive impairment, mood issues, and even seizures.
- B9 (folate) aids with neurotransmitter production and the formation of myelin, a substance that insulates and protects nerve fibers. Deficiency is linked to depression and dementia.
- B12 (cobalamin) is important for the synthesis of neurotransmitters that are involved in mood and cognitive function. Deficiency is linked to mental and physical fatigue, cognitive impairment, and mood issues.
Of these, a B12 and B9 deficiencies are most common, each affecting about 20% of adults in developed countries. Adults need 2.4 micrograms of B12 per day and 400 micrograms of dietary folate equivalent per day.
Vegans and vegetarians may need to take a B12 supplement, since the micronutrient is mostly present in fish and animal products, such as dairy, eggs, poultry, and red meat. However, some plant-based options include fortified foods, nutritional yeast, and red algae.
Vitamin D
Vitamin D helps maintain cognitive function, protects brain cells from damage and inflammation, and aids in the release of neurotransmitters important for mood. Deficiency is linked to Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis.
Adults need 15 to 20 micrograms (600–800 IU) of vitamin D. Foods that naturally contain it include fatty fish, egg yolks, mushrooms, and beef liver. Others are fortified, including milk and yogurt.
Iron
Iron, a mineral, is a key component of hemoglobin, the protein in our red blood cells that delivers oxygen from the lungs to the rest of the body, including the brain.
Without enough of it, your body can’t produce adequate hemoglobin, leading to iron deficiency anemia, which can cause fatigue and other symptoms. In the brain, iron aids with producing myelin for nerve protection, helps with neurotransmitter synthesis, and supports cognitive function.
Adults ages 19 to 50 need 8 and 18 milligrams for females and males, respectively. Older adults need 8 milligrams.
You can get iron from both heme and non-heme foods. The body can more readily absorb heme iron—found in meat, poultry, and fish—compared to non-heme iron found in plant foods, such as leafy greens, nuts, seeds, and legumes.
Zinc
Zinc, another mineral, protects brain cells, regulates neurotransmitters, and aids with memory and focus. It also plays a role in our ability to learn and adapt. Deficiency can cause cognitive decline and nerve cell death.
Adults need 8 and 11 micrograms per day for females and males, respectively. You can get zinc from meat, poultry, fish, beans, nuts, seeds, and whole grains.
Magnesium
Magnesium is a mineral and electrolyte that helps with nerve and muscle function. It’s crucial for communication between brain cells, protecting the brain from harmful substances, reducing inflammation, supporting cognitive function, and aiding with relaxation and sleep quality.
A deficiency can lead to symptoms of fatigue, tremors, and twitching and put you at an increased risk for Alzheimer’s, Parkinson’s, and multiple sclerosis.
Adults need at least 310 and 410 micrograms per day for females and males respectively. You can get magnesium from legumes, nuts, seeds, whole grains, leafy greens, and some dairy products.
Foods & Ingredients That Can Negatively Impact Brain Health
Getting adequate macro- and micronutrients is crucial for brain health, but some foods and ingredients can also cause trouble. These include ultra-processed foods, refined carbohydrates, added sugar, and alcohol.
That doesn’t mean you can never have a sweet treat or your favorite packaged snack, but minimizing intake of these items can help reduce your risk for worsened brain health.
One rule of thumb is to eat as much whole foods as possible—whether raw or cooked. This will help you naturally reduce intake of some of the following foods that can harm brain health.
Ultra-Processed Foods
Ultra-processed foods (UPFs) are those that bear little resemblance to foods in their natural form. UPFs are generally packaged foods that are loaded with additives, including excess sugar, excess sodium, artificial dyes, preservatives, and other chemicals that make them tasty to eat, so much so that they can drive cravings for more.
But these foods and their ingredients are linked to cognitive impairment and stroke. They might also contribute to mental health concerns, such as depression and anxiety.
Added Sugar & Refined Carbohydrates
Eating added sugar can drive up your blood sugar, which puts you at risk for prediabetes and Type 2 diabetes. Added sugar can be sneaky, as it can show up in salad dressings, condiments, and seemingly healthy foods such as yogurt. So read ingredient lists thoroughly.
Refined carbohydrates include things like white bread, pasta, rice, and more. Rather than containing the whole grain, refined carbohydrates have been stripped of certain beneficial nutrients such as most of their protein and fiber. Whole grains, on the other hand, maintain these nutrients.
Refined carbs also drive up blood sugar, increasing the risk for prediabetes and Type 2 diabetes. Type 2 diabetes can increase your risk for Alzheimer’s disease, which is now sometimes called Type 3 diabetes.
Prediabetes and Type 2 diabetes develop over time. But even in the short term, these foods that cause high blood sugar can impact cognitive health. Large blood sugar spikes can cause what’s called postprandial reactive hypoglycemia, where your blood sugar plummets as the body overcorrects from the spike. Blood sugar crashes can tank your energy level and focus, and increase anxiety.
Alcohol
Newer research has revealed that “no amount of alcohol is safe” for health. Booze and its metabolites alter brain structure and function. If you drink, limit how much you imbibe. If you don’t partake, avoid starting.
The Gut-Brain Connection
Finally, no discussion about the brain would be complete without mention of the gut. The digestive tract and brain communicate via the gut-brain axis, with the health of each system affecting the other. If your gut health is impaired, it can contribute to brain fog, anxiety, depression, and more.
The good news is that you can influence your gut health by feeding your gut microbiome (the microbes that live in your gut). If you eat a wide variety of fruits and veggies, you will feed the beneficial microbes, which love fiber, and help reduce the negative ones that try to take over. Just one more way to influence your brain health for the better.
About The Author: Jennifer Chesak, MSJ
Jennifer Chesak is an award-winning author, science and medical journalist, editor, and fact-checker, and her work has appeared in several national and international publications, including the Washington Post and BBC. Recently her debut nonfiction book on women’s health was awarded the IBPA Benjamin Franklin silver medal. Chesak earned her master of science in journalism from Northwestern University’s Medill. She currently teaches in the journalism and publishing programs at Belmont University, leads various workshops at the literary nonprofit The Porch, and serves as the managing editor for the literary magazine SHIFT. Find her work at jenniferchesak.com and follow her on socials @jenchesak.
