There is a clear link between your dietary choices and your brain and mental health. What you put in your mouth has everything to do with what goes on in your head. Of course, there are no guarantees. Unfortunately, sometimes vegan, marathon runners develop Alzheimer’s and fast-food eating couch potatoes don’t.
However, your lifestyle habits are the best bet you have for preserving your brain health, and diet is a big factor. Growing scientific evidence indicates that diet plays a critical role in cognitive function and mental well-being and preserving both as you age.
Weight and Brain Function
According to the most recent National Health and Nutrition Examination Survey (NHANES), 18.5 percent of children and nearly 40 percent of adults qualified as obese in 2015–2016 in the United States. These are the highest rates ever documented by NHANES. Globally, the World Health Organization (WHO), found that 13 percent of the world’s adult population was obese in 2016. The worldwide prevalence of obesity nearly tripled between 1975 and 2016.
As your waist expands, your brain actually shrinks. Numerous studies have documented that as a person’s weight and BMI (body mass index) increase, their brain shrinks in size. Excess weight often leads to obesity and diabetes. These conditions destroy synapses, wither blood vessels, batter neural pathways, and kill neurons in your brain. The result is a smaller brain.
One study found that the brains of obese people looked 16 years older than their healthy counterparts while the brains of overweight people looked 8 years older. Researchers classified this as ‘severe’ brain degeneration with serious implications for aging, including a heightened risk of Alzheimer’s. Other research found obesity to be linked with mild impairments in several areas of cognitive function, including short-term memory, attention, and decision-making.
Diet and Alzheimer’s
According to Miia Kivipelto, one of the chief researchers on the groundbreaking FINGER study, a randomized control trial that investigated the effects of lifestyle changes on risk of dementia, if you make changes to your diet, along with other lifestyle changes, the risk of dementia can be reduced by as much as 30 percent.
A specific diet, the MIND diet, which is a combination of the Mediterranean Diet and the DASH Diet, lowered the risk of Alzheimer’s disease by as much as 53% in participants that followed the diet rigorously and a 35 percent reduction for those who followed it moderately well. The Mediterranean diet has been the go-to diet for brain health for the most part because of its focus on fish, green vegetables, fruits, olive oil, and red wine. The DASH (Dietary Approaches to Stop Hypertension) diet has been recommended to reduce the risk of cardiovascular disease. The MIND diet combines the benefits of both.
Science has shown that your dietary habits over the course of your life play a crucial role in determining whether or not you develop Alzheimer’s disease. Research has proven the MIND diet as a way to help you avoid this fate.
Diet and Depression and Anxiety
Research analyses looking at multiple studies support that there is a link between what you eat and your risk of depression. One analysis concluded:
A dietary pattern characterized by a high intake of fruit, vegetables, whole grain, fish, olive oil, low-fat dairy and antioxidants and low intakes of animal foods was apparently associated with a decreased risk of depression. A dietary pattern characterized by a high consumption of red and/or processed meat, refined grains, sweets, high-fat dairy products, butter, potatoes and high-fat gravy, and low intakes of fruits and vegetables is associated with an increased risk of depression.”
In the article, “5 Dietary Habits connected to depression and anxiety“, the authors write:
In February 2019, researchers in Korea published a study in the Journal of Nutrition and Health, showing a connection between diet and mental health.
The researchers recruited over 3,500 participants for their study, all of whom were over the age of 65. They then analyzed their dietary information, addressed their anxiety and depressive states, and split them into two groups: those with anxiety and depression and those without.
They made quite a few findings as they compared diet and mental health between the two groups.
- Men who ate alone were more likely to have depression and anxiety than those who ate with others.
- Women who ate the evening meal less frequently were more likely to have depression and anxiety.
- Men who ate less—particularly less fish, shellfish, seaweed, mushroom, oils/fats, and seasonings—were more likely to have depression and anxiety
- Men who had poorer nutrient intake generally were more likely to have depression and anxiety
- Women and men who ate less dietary fibre, riboflavin (B2), niacin (B3), potassium, iron, and vitamin C were more likely to have depression and anxiety.
This is one more study among a growing body of research showing a connection between what we eat and our mental health.
So, What Should You Be Eating?
In general, a healthy diet that benefits your brain will also benefit your heart and overall health. In Max Lugavere’s book, Genius Foods: Become Smarter, Happier, and More Productive While Protecting Your Brain for Life, he shows how the food you eat directly affects your ability to focus, learn, remember, create, problem-solve, and maintain balanced mental health and mood. He recommends the ten foods listed below for optimal brain health.
Extra-virgin Olive Oil
Studies show that olive oil reduces brain inflammation but most importantly activates something known as autophagy. Autophagy is the process by which cells break down and clear out intracellular debris and toxins, such as amyloid plaques and tau tangles – classic markers for Alzheimer’s disease. Olive oil contains a compound called oleocanthal, a type of phenol that has powerful anti-inflammatory properties.
Not all olive oil is the same though. For the most benefit, the BrainHQ article, Getting the Most Out of Olive Oil, recommends:
- Always use olive oil labeled “extra virgin”
Oils labeled “virgin” or “light” may have undergone a chemical process that strips away the nutritional benefits, or they might even be blended with other types of less-healthy oils.
- Make sure the olive oil is fresh
Olive oil is a perishable product, and when it goes rancid, the brain-healthy antioxidants, omega-3 fatty acids, and polyphenols go right along with it. Check harvest and sell-by dates on the bottles: if you can’t find those, you may want to consider another brand.
- Keep an eye on the temperature
For the most health benefits, only use olive oil in raw or low-heat dishes. Above about 350 degrees, the beneficial compounds in olive oil begin to degrade, and at high heats can turn into potentially harmful substances.
- Store it correctly
An unopened bottle of olive oil can last for about 2 years if stored in a cool, dark place. Once opened, the 2 main enemies of olive oil are light and heat – so try to store it in a dark bottle and away from heat (meaning, not on the back of your stove or on a windowsill.) Don’t store it in the fridge; it will crystallize and may change the texture.
- Check the brand to see if it’s the real deal
Researchers at UC Davis recently found that almost 70% of olive oils labeled “extra virgin” were, in fact, not purely extra virgin olive oil. Unfortunately, it’s not always easy to tell the real from the fake. Among the ones that UC Davis found did not match the extra virgin olive oil standards were Bertolli, Carapelli, Colavita, Filippo Berio, Mazzola, Mezzetta, Newman’s Own, Pompeian, Rachel Ray, Safeway, Star, and Whole Foods. The brands that did meet or exceed the standards were Corto Olive, California Olive Ranch, Kirkland Organic (Costco), Lucero (Ascolano), and McEvoy Ranch. For more on this, you can check out the information from UC Davis.
Avocados are rich in monounsaturated fat, which contributes to healthy blood flow. This helps every organ in your body, particularly the brain and heart. The human brain is approximately 60 percent fat. To function optimally, your brain needs to maintain around this level of fat. Eating the right kind of fats can have a tremendous impact on your brain and overall health.
From brain function to metabolism to cardiovascular fitness, good fat is an absolutely essential macronutrient for your entire body. Monounsaturated fat decreases LDL cholesterol, the bad cholesterol, and increases HDL cholesterol, the good cholesterol, preventing hardening of blood vessels. Healthy blood vessels allow healthy blood flow which reduces the risk of stroke.
Because they’re rich in potassium, avocados help lower blood pressure. High blood pressure can impair cognitive abilities. Avocados also contain folate, which is essential for brain health and the maintenance of cognitive function, including memory.
Research shows that berries can prevent age-related neurodegenerative diseases and improve motor and cognitive functions. Berries also modulate signaling pathways involved in inflammation, cell survival, and neurotransmission and enhance neuroplasticity. The neuroprotective effects come from the phytochemicals and antioxidants in them.
Blueberries are among the most nutrient-dense berries. The most abundant flavonoids in blueberries are anthocyanins which have been shown to cross the blood-brain barrier, enhancing signaling in parts of the brain handling memory.
In animal studies, the antioxidants in blueberries positively impacted learning and memory. This effect on cognition is thought to be due to the direct interaction of berry polyphenols with aging neurons, reducing the impact of stress-related cellular signals and increasing the ability of neurons to continue functioning properly with age.
Human studies have also yielded promising results. In one small study, nine older adults with mild cognitive impairment consumed blueberry juice every day. After 12 weeks, they experienced improvements in several markers of brain function. In another larger six-year study involving over 16,000 older individuals, blueberries and strawberries were linked to delays in mental aging by up to 2.5 years. Research has also found that in addition to reducing the risk of cognitive damage, blueberries can also improve a person’s short-term memory and motor coordination.
Science has found chocolate intake to be associated with higher cognitive function. Cocoa, chocolate in its raw form, contains many compounds that act on the brain. One category of these, flavonoids, the same as in berries, have neuroprotective benefits. Cocoa also contains caffeine and theobromine, stimulants found in coffee and tea, which improve alertness and mood.
In one study, people who consumed medium and high amounts of cocoa flavanols every day for eight weeks had significant improvements on tests measuring attention, executive function, and memory. A similar study by researchers showed that daily consumption of cocoa flavanols was associated with improved thinking skills in older adults who already had mild cognitive impairment. Both studies found that cocoa flavanols were associated with reduced blood pressure and improved insulin resistance.
Before you go on a chocolate binge, it’s important to remember that the amounts of these chemicals depend on the cocoa concentration of chocolate. The amount of cocoa used in chocolate varies and flavanols are often destroyed in the production process. Lugavere cautions you to check the label to make sure it hasn’t been processed with alkali also known as Dutch processing. Milk chocolate is going to contain much less active ingredients than dark chocolate. Milk chocolate is also going to be high in sugar, which is not good for your brain.
The concerns about eggs having dangerous cholesterol have been debunked and the egg is back from exile. In fact, studies have shown that eggs actually boost brain function. The egg contains everything needed to grow a brain making it one of the most nutritious foods for your brain. They contain a little bit of almost every vitamin and mineral required by your body.
One reason they are so good for your brain is a little-known nutrient called choline. Eggs are packed with choline. Choline converts into acetylcholine, a neurotransmitter that helps brain cells communicate with each other and keep memories intact. Egg yolk contains lutein and zeaxanthin, two carotenoids, shown to protect the brain and improve neural processing speed.
Lugavere advises you to eat pasture-raised, omega-3 enriched, free-range eggs when possible. If your budget doesn’t allow that, conventional eggs are highly nutritious as well.
Beef is mainly known for its protein. However, it provides many other nutrients your brain needs. It’s a source of essential minerals like iron and zinc, packaged in a form readily available to your body. This is not as true with the iron from spinach or the zinc from legumes, for example.
Grass-fed beef is also a valuable source of omega-3 fats, vitamin B12, vitamin E, and other essentials, like creatine. Deficiencies in many of these nutrients have been linked to brain-related disorders, such as low IQ, autism, depression, and dementia. In fact, many evolutionary biologists believe that a diet rich in red meat eaten by our ancestors was responsible for the dramatic increase in the size of our brains compared to other plant-eating primates.
Factory-farmed beef that is raised according to current industry standards produces meat that is lacking in nutrients. It comes from stressed-out animals, given antibiotics and other drugs, and fed a highly unnatural diet of throwaway grains and other empty calories. Maybe you don’t want to eat red meat for ethical reasons. (I’m with you. I’m a vegetarian.) Here’s what Dr. Drew Ramsey has to say about that in the article Meat Is Brain Food:
A vegan diet centered on whole fruits, vegetables, nuts, grains and legumes is certainly healthier than the modern American diet of processed foods laden with sugars, salt and hydrogenated fats. However, veganism’s total exclusion of animal nutrients poses some serious problems for the human body. Meat, fish and eggs are our only concentrated dietary sources of vitamin D, vitamin B12, omega-3 fats (which play a huge role in brain health), heme-iron (which increases the absorption of iron from vegetables) and conjugated linoleic acid (CLA), which appears to fight cancer and heart disease.A healthier choice is to modify the vegan diet with a minimal amount of animal nutrients. Clinical research finds that people on vegan diets commonly suffer from a variety of nutritional deficiencies. One study, for instance, showed that more than half of vegans tested were deficient in vitamin B12, putting them at risk of mental health problems such as fatigue, poor concentration, decreased brain volume with aging and irreversible nerve damage.”
Lugavere advises you to look for humanely raised 100 percent grass-fed and grass-finished beef, ideally from organic and local farms. Note that organic beef unless it clearly states “100 percent grass-fed,” is usually from cows fed organic grain – not grass.
Dark Leafy Greens
Dark leafy greens are low in sugar and packed with vitamins, minerals, and other phytonutrients that your brain needs. Leafy greens are an excellent source of Vitamin E, which helps to reduce inflammation in the brain as well as preventing the build-up of plaque on brain cells – associated with Alzheimer’s disease. Greens are also a great source of folate, which is an essential ingredient in your body’s methylation process. This process occurs ongoing in your body and is critical for detoxification and your genes to function properly.
One study found that eating at least one serving (half a cup cooked or one cup raw) of leafy green vegetables every day was associated with a slower decline in brain function. Another study showed that people who ate approximately 1.3 servings of dark leafy greens per day over five years had brains that looked 11 years younger on scans. The article, Kale and other leafy vegetables may make your brain seem 11 years younger, puts it this way:
Let’s say you and your neighbor are both 75 and similar in most every way: You both completed the same amount of school, take regular walks together, don’t smoke, and gather with friends over an occasional beer. But while you enjoy a little more than a bowl of greens every day, your pal barely touches the stuff. This long-running study would predict that at 75, your memory and thinking skills are a notch stronger than your neighbor’s. Over the next five years, hers will decline twice as fast as yours. By the time you’re both 80, a battery of exercises that test several types of memory, as well as the speed and flexibility of your thinking, may show that your mental age is typical of a 75-year-old’s. Meanwhile, your neighbor’s performance on the same cognitive tests may look more like that of an 86-year-old.”
Broccoli and other cruciferous vegetables, including Brussel sprouts, bok choy, cabbage, cauliflower, radishes, arugula, and kale, are especially healthy because they are a source of sulforaphane. Sulforaphane is part of a group of plant-based disease-fighting phytochemicals that play a role in the defense response of plants. Therefore, sulforaphane is only activated when the plant is damaged – as in chopped or chewed.
Raw vegetables have the highest levels of sulforaphane. One study found that raw broccoli had ten times more sulforaphane than cooked broccoli. Sulforaphane is not a vitamin or essential nutrient. In the body, sulforaphane stimulates the production of important enzymes that neutralize free radicals.
Research indicates that sulforaphane may offer a number of health benefits ranging from preventing and killing cancer cells, reducing inflammation, and combatting vascular disease to detoxifying the body. In the brain, sulforaphane has shown promise in treating certain symptoms of autism, protecting against brain damage and improving recovery and reducing mental decline after a brain injury.
Wild salmon is low in mercury, high in both EPA and DHA omega-3 fats and a powerful carotenoid called astaxanthin. Carotenoid gives salmon their pink color and comes from their main food supply, krill. Astaxanthin has health benefits for your entire body. Specifically, pertaining to your brain:
- Researchers found that supplementing with astaxanthin-rich Haematococcus Pluvialis (microalgae) extract lead to improvements in cognitive function in older individuals with age-related forgetfulness.
- Science suggests that astaxanthin could help prevent dementia, including Alzheimer’s.
- It helps to prevent neurodegeneration associated with oxidative stress research has found.
According to an article in the Alternative Medicine Review:
Astaxanthin improved cognition in a small clinical trial and boosted proliferation and differentiation of cultured nerve stem cells… Astaxanthin’s clinical success extends beyond protection against oxidative stress and inflammation, to demonstrable promise for slowing age-related functional decline.”
Shrimp, crab, and lobster are also high in astaxanthin.
Almonds are potent brain food for three reasons.
- The skins of almonds are prebiotics that increase good gut bacteria and reduce pathogenic populations. Your gut bacteria, or microbiome, greatly influence your brain and mental health.
- They are a rich source of polyphenols. Polyphenols are plant defense compounds which have antioxidant properties for both you and your gut bacteria.
- Almonds are an abundant source of the fat-soluble antioxidant, vitamin E, which supports neuroplasticity. Science found decreased levels of vitamin E to be associated with poor memory and supplementation has even been shown to slow Alzheimer’s.
In Genius Foods, Lugavere says that all nuts are nutritionally best consumed raw. If you prefer roasted, you’ll be glad to know that the benefits aren’t destroyed entirely in the roasting process. Just be sure to opt for the “dry roasted” nuts he cautions. “Roasted” almost always means deep fried in poor quality vegetable oil.