The brain is an energy-intensive organ, using about 20% of the body’s calories, so it needs “fuel” to maintain focus throughout the day. This can cause cellular “wear”, since a high energy density is equivalent to greater oxidative stress, i.e. the production of oxidizing free radicals (ROS). Cellular oxidative stress and inflammation are linked to brain aging and neurodegenerative disorders, such as senile dementia. Therefore, the brain requires a variety of nutrients to stay healthy. Omega-3 fatty acids, for example, help build and repair myelin and brain cells. Some vitamins and antioxidants maintain the metabolic support functions of brain neurons. Particularly useful antioxidants for the brain are glutathione and lipoic acid.
This article explores some of the scientific evidence behind 10 of the best foods for metabolic brain health.
- pure cocoa
Dark chocolate is made from cocoa and contains procyanidins, a type of antioxidant flavonoid. Antioxidants are especially important for brain health, as the brain is highly susceptible to oxidative stress, which contributes to age-related cognitive decline and brain disease. Cocoa flavonoids appear to be good for the brain. According to a 2013 review, they may encourage the growth of neurons and blood vessels in parts of the brain involved in memory and learning. They can also stimulate cerebral blood flow.
Some research also suggests that the flavonoid component of chocolate can reverse memory problems in snails. Scientists have yet to test it in humans. However, a 2018 study in men also supports the brain-boosting effects of dark chocolate. The researchers used imaging methods to observe activity in the brain after the participants ate chocolate with at least 70% cocoa content. They concluded that eating dark chocolate can improve brain plasticity, which is critical for learning.
2. Fatty fish
Oily fish is a good source of omega-3 fatty acids, which help build membranes around every cell in the body, including brain cells. They can, therefore, improve the structure of brain cells called neurons. A 2017 study found that people with high levels of omega-3s had increased blood flow to the brain. This is because they improve the metabolism of the vascular endothelium and stimulate the production of nitric oxide (*NO), a natural mediator that widens the arteries. Researchers have also identified a connection between omega-3 levels and improved cognition, or mental ability to calculate and organize. These findings suggest that eating foods rich in omega-3s, such as oily fish, can boost brain function. Examples of oily fish that contain high levels of omega-3s include: salmon, mackerel, tuna, herring and sardines. People can also get omega-3s from soybeans, walnuts, flaxseeds and other seeds.
3. Berries
Like dark chocolate, many berries contain antioxidant flavonoids. Research suggests that these may make berries good brain food. Antioxidants in berries include anthocyanins, caffeic acid, chlorogenic acid, catechins and quercetin. A 2014 review finds that the antioxidant compounds in berries have many positive effects on the brain, including improving communication between brain cells, reducing inflammation throughout the body, and increasing neuroplasticity, which helps brain cells recover. form new connections, increasing learning and memory. Antioxidant-rich berries that may boost brain health include: strawberries, blackberries but best of all blueberries, black currants and mulberries.
4. Nuts
Eating more nuts and seeds can be good for your brain, as these foods contain omega-3 fatty acids and antioxidants, such as resveratrol and zinc. A 2014 study found that higher overall nut intake was linked to better brain function in older age. Nuts and seeds are also rich sources of vitamin E (antioxidant), which protects cells from oxidative stress caused by free radicals. As a person ages, their brain may be exposed to this form of oxidative stress, and vitamin E may therefore support brain health in later life. A 2014 review found that vitamin E may also help improve cognition and reduce the risk of Alzheimer’s disease. Nuts and seeds with the highest amounts of vitamin E include: sunflower seeds, almonds and hazelnuts.
5. Coffee (regular or decaf)
Coffee is a well-known concentration aid – many drink it to stay awake and encourage mental pursuits. The caffeine in coffee works by interfering with a mediator in the brain called adenosine, which causes drowsiness. In addition to increasing alertness, a 2018 study suggests that caffeine may also boost the brain’s ability to process information. Researchers have found that caffeine causes an increase in brain entropy, which refers to complex and variable brain activity. When entropy is high, the brain can process more information. Coffee is also a source of antioxidants, such as caffeic acid, quinic acid and trigonelline. One study has linked lifelong coffee consumption with a reduced risk of cognitive decline, stroke, Parkinson’s disease and Alzheimer’s disease. Caffeine can, however, affect a person’s sleep and doctors do not recommend caffeine consumption for everyone.
6. Avocado
As a source of beneficial unsaturated fats, avocados may support the brain. Eating monounsaturated fats (eg, oleic acid) can reduce blood pressure, and high blood pressure is linked to cognitive decline. Thus, by reducing high blood pressure, the unsaturated fats in avocados may reduce the risk of cognitive decline. Avocado is the only fruit known to naturally have the highest levels of vitamin E, which is needed for fertility, to protect red blood cells, but also to restore the antioxidant reserves of brain cells. Other sources of healthy unsaturated fats include: almonds, cashews, walnuts, flaxseeds and chia seeds, soybeans, sunflower seeds and fish.
7. Peanuts
Peanuts are a legume with an excellent nutritional profile. They contain a lot of unsaturated fat and protein (20g/100g) to keep a person’s energy levels up throughout the day. Peanuts also provide key nutrients and minerals to keep the brain healthy, including high levels of phosphorus, resveratrol and vitamin E. Resveratrol is a naturally occurring non-flavonoid antioxidant found in peanuts, grape seeds, mulberries and rhubarb. Evidence from several scientific reviews between 2010 and 2017 suggests that resveratrol may have protective effects, such as helping prevent cancer, inflammation and neurological diseases, including Alzheimer’s and Parkinson’s. Peanuts are also among the few natural foods with a certain amount of coenzyme Q. This cofactor is an antioxidant and supports muscle and nerve cellular health.
8. Eggs
Popular for breakfast, eggs can be an effective brain food. They are rich in lecithin (phosphatidyl-choline), an analogue of soy lecithin, which enters the structure of the membranes of nerve cells. They are a good source of protein and sulfur amino acids (cysteine and methionine), as well as vitamin B6, vitamin B12 and folic acid. Recent research suggests that supplementing with these vitamins may prevent brain shrinkage and delay age-related cognitive decline. Furthermore, sulfur amino acids can form part of both antioxidant molecules (glutathione derives from cysteine) or neuroprotective molecules (SAMe derives from methionine).
9. Broccoli
In addition to being a low-calorie source of dietary fiber, broccoli may be good for the brain. They are rich in compounds called glucosinolates. When the body breaks them down, they produce isothiocyanates. Isothiocyanates can reduce oxidative stress and reduce the risk of neurodegenerative diseases, as well as act as chemopreventives for certain types of cancer. Raw broccoli also contains vitamin C (90mg/100g, almost double that of strawberries) and flavonoids and these antioxidants can further improve brain health. Other cruciferous vegetables that contain glucosinolates include: Brussels sprouts, bok choy, kale, cauliflower, and turnips. Like broccoli, kale contains glucosinolates, and leafy greens also contain other antioxidants (luteolin, kampferol, quercitin), key vitamins and minerals. This is why many consider kale a superfood.
10. Soy products
Soy products are rich in a particular group of antioxidants called polyphenols. Soy polyphenols are called isoflavones and genistein is the best known. Analogues are daidzein, formonetin and baicalin. These substances have an estrogen-like action and have been demonstrated in the laboratory to be capable of activating cellular mechanisms of memory, similar to the cascades induced by the estradiol-dopamine dialogue. Research has linked these polyphenols with a reduced risk of dementia and improved cognition in normal aging processes. Daidzein and genistein may also act as indirect antioxidants, activating the cellular factor Nrf-2 pathway that regulates the expression of antioxidant proteins and enzymes.
- By Dr. Gianfrancesco Cormaci, PhD, specialist in Clinical Biochemistry.
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