NUTRITION
March 28, 2011

Feed Your Head

Some foods can help you feel, think and remember better. You may know about blueberries, but curcumin?

We may spend a lot of time thinking about the health of our hearts, bones, skin, and even our intestines — with good cause. They are critical to our general health and wellbeing. But how often do you think about how to nourish our body's most important organ — the human brain? The brain is the seat of our consciousness. It governs our capacity to think, learn, reason, and remember; it’s also the control center for virtually every other bodily process that we have. And, not surprisingly, it’s an organ that requires excellent nutrition to function at top capacity.

Most of us probably spend more time thinking about whether our food contains enough fiber for our GI tracts than we do about whether we’re getting enough B vitamins for our brain cells.

There’s a lot of evidence to suggest that what we do for the brain now can have a big impact on how it functions in the years – and decades – to come.

Keeping the brain healthy and well-nourished is a task that should be high on our to-do list. There’s a lot of evidence to suggest that what we do for the brain now can have a big impact on how it functions in the years – and decades – to come. Eating well in the present, along with other healthy lifestyle choices we make today, can keep the brain hopping along well now and stave off age-related problems in the future, like cognitive decline and Alzheimer’s disease.

When you feel mentally sluggish, foggy, unable to concentrate, and just plain tired, there is a good chance that what you have or haven't eaten is to blame. It is all too easy to be deficient in some of the nutrients the brain needs to work at top capacity, especially if we are dieting, or under stress, or eating on the go. These deficiencies can affect us mentally, leading to a number of cognitive problems and even to states like Anxiety and depression.

So it's a good idea to become familiar with the brain-friendly nutrition provided by omega-3 fatty acids, the B family of vitamins, vitamin D, and the now-famous phytochemicals, which are plant-derived compounds that often act as antioxidants. These compounds provide a laundry list of health benefits to the body and brain. In particular, we’ll discuss two types of phytochemical. One is the flavonoid family, which includes compounds found in berries and fruits. The other is a compound you may not have heard of – curcumin, which is found in a common Indian spice and offers major protection to the aging brain.

The Omegas' Brain-Boosting Powers

The healthy fats, omega-3s and omega-6s, are excellent – and necessary – for brain health. Fatty acids play a big part in cardiovascular health. What many people don’t know is that they also play several essential roles in brain function.

These deficiencies can affect us mentally, leading to a number of cognitive problems and even to states like anxiety and depression.

The two chief omega-3 fatty acids are docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and an essential omega-6 is linoleic acid (LA). Omega fatty acids are essential building blocks for the cell membrane of brain cells. They can affect the permeability of the cell membrane at the synapse, the point where brain cells – or neurons – interact with one another and exchange neurotransmitters. The synapse is the heart of neural communication, and, very likely, human thought. When omega-3s and -6s enhance permeability at the synapse (so that compounds are more easily transferred from brain cell to brain cell), they can have a big effect on cognition.

Lightening Mood
Gordon Parker, MD, PhD, is the executive director of the Black Dog Institute in Australia, a research center that studies and treats exclusively mood disorders like depression and bipolar disorder. Dr. Parker’s research focuses on how omega fatty acids affect our mental health and how their deficiency may lead to mood disorders. Omega-3 fatty acids help the brain communicate using the neurotransmitters serotonin and dopamine, powerful players in the regulation of mood. (Selective serotonin reuptake inhibitors like Prozac are common antidepressants and work by helping keep serotonin more available to the brain and nervous system.)

The omegas seem to reduce inflammation in the brain – just as they do in the rest of the body.

Another way omega-3s may act in the brain is to enhance the production of bone-derived neurotrophic factor (BDNF), which, through a cascade of events, ultimately stimulates the cell processes that are central in learning and memory. Finally, omegas seem to reduce inflammation in the brain – just as they do in the rest of the body, which Dr. Parker says is especially important since brain inflammation has been linked to depression.

So what happens if your diet does not contain enough omega-3 fats? Since the body is not very good at manufacturing the chief omega, DHA, it’s possible to become deficient in this compound. On the more severe end of the spectrum, DHA-deficiency is associated with disorders like depression, ADHD, bipolar disorder, dyslexia, and schizophrenia. It can also lead to fatigue and problems with memory.

Dr. Parker also found that "when rodents are deprived of dietary omega-3s we see reduced synapse formation, impaired learning ability, and increased aggressive, depressive and anxious behaviours." Omegas also seem to ward off the cognitive decline that often comes with age. Whether they also protects against more severe forms of dementia like Alzheimer’s is still debatable, but research continues to be done in this area.

Luckily, once we’re aware of the importance of the omegas, it’s fairly easy to consume them in the diet or by taking supplements. Omegas are found in fatty fish like salmon and sardines, which Dr. Parker says we should eat at least two servings of per week.

Vegans May Be Deficient
Another important omega-3 is alpha-linolenic acid (ALA), which is found mainly in non-animal sources like walnuts, flaxseeds, soybean oil, spinach, and kale. Getting enough of this omega is also usually not a problem. However, since the omega-3s are mainly found in fish, supplements may be necessary for strict vegetarians and vegans. As Dr. Parker sums it up, "[f]ats often get a bad rap in terms of dietary implications, but some fats, particularly the omega-3 and omega-6 fatty acids are absolutely required for good physical and mental health."

The B Vitamins

Vitamin B12
The B vitamins – particularly B12, B6, and folate – are brain vitamins. The three vitamins all play central roles in molecular reactions, some of which lead to the production of DNA or RNA.

B12 is required for a cell process called methylation, a basic chemical process that all cells, including brain cells, require to thrive. Many important processes in the nervous system require methylation: cell communication, the production of neurotransmitters that control many aspects of cognition, and the production of myelin, which acts as insulation for neurons to help them fire more efficiently (similar to how plastic coating on a wire improves its ability to transmit an electric signal).

Without enough B12, the communication between different parts of the brain is less efficient — like a sluggish internet connection.

Interestingly, the methylation reaction uses a compound called S-adenosylmethionine (SAM or SAMe), which you may recognize as a compound sold in drug and health food stores, marketed to boost mood. In fact, some evidence has shown that SAMe supplements may be an effective way of treating depression in certain people.

Because B12 is so fundamental to basic cell processes in the nervous system, any deficiency can lead to a number of symptoms including fatigue, shortness breath, diarrhea or constipation, problems concentrating, and pale skin.

Without enough B12, cell communication can be compromised — now and as we age. Researchers at the University of Oxford's Oxford Project to Investigate Memory and Aging (OPTIMA) have found that B12 protects against age-related atrophy of brain cells and against damage to the brain’s white matter (the "tracts" or "wiring" of the brain that allows cells to communicate with other another).

Dr. David Smith, the founding director of OPTIMA, explains that "B12 is also needed to keep the nerve tracts connecting different parts of the brain functioning normally. Without enough B12, the communication between different parts of the brain is less efficient " — like a sluggish internet connection.

Without enough B12 in the brain, Dr. Smith says, "eventually, memory impairment sets in and gradually gets worse, leading to dementia." He adds, however, that this occurs after one has been B12-deficient for a number of years. Keeping our B12 levels healthy in the present is the best way to protect our brains from deficiency in the future.

B12 comes almost solely from animal products like meat (especially liver), seafood, eggs, milk and cheese. So it may be necessary for strict vegetarians and vegans to supplement B12, since it can be difficult for them to get enough of the vitamin. The body is able to store B12 for years and uses relatively little of it. Nonetheless, supplementation may be very important for some people.

Vitamin B6 and Folate
Two other B vitamins, B6 and folate (B9), are also essential for brain function, though we tend to hear less about them. Many foods are fortified with folate because of its role in preventing neural tube defects during pregnancy. It is also found in leafy greens, citrus fruits, peas and beans. Vitamin B6 is found in the highest quantities in potatoes, bananas, chick peas, and oatmeal. Vitamin B6 and folate work with vitamin B12 by regulating a compound called homocysteine, which inhibits the methylation reaction, mentioned above, which is so important in the nervous system.

Some researchers also feel that folate deficiency can lead to problems with cognition and even increase the risk for depression. For these reasons, keeping healthy levels of all of the B vitamins is extremely important. If you have any concerns about your B vitamin levels, it is a good idea to get them checked.

The Buzz about Blueberries: How Phytochemicals Like Flavonoids Can Protect the Brain

Phytochemicals are chemicals derived from plant sources. There are a number of types of phytochemicals, but a familiar and key group is the flavonoids, which the scientific community and the public alike have embraced as "must haves" for health and longevity. Flavonoids are found in plant-derived food and drink like blueberries, apples, citrus fruits, black and green tea, and in cocoa, beer, and wine (these last few consumed in moderation, of course). They are known to affect our cognitive prowess – now and in the future.

Some studies have found that extracts from blueberries, strawberries, spinach, and blackberries may reverse the normal cognitive changes and memory problems that accompany the aging process.

Flavonoids take part in multiple cellular processes, depending on the type of flavonoid. They are responsible for many aspects our brain function. Researcher Fernando Gómez-Pinilla, PhD, studies the effect of nutrition on the brain at UCLA. He explains that flavonoids play important roles in repairing damage in the brain. They do this by influencing how neurons "talk" to each other and by increasing levels of antioxidants and anti-inflammatory compounds that reduce damage to cells in the brain.

Some studies have found that extracts from blueberries, strawberries, spinach, and blackberries may reverse the normal cognitive changes and memory problems that accompany the aging process. They also seem to take part in cell functions that help the brain form memories in people of all ages. Flavonoids boost the brain’s ability to form new neurons, prevent brain cells from dying, and enhance what researchers call "synaptic plasticity", or the ability of neurons to form and reform connections with each another. These processes – particularly synaptic plasticity – are thought to be the bases for learning, memory, and for cognition in general.

There is also some evidence that flavonoids can stave off not only cognitive decline, but also brain diseases like Alzheimer’s. This may be because the compounds protect against oxidative damage by hydrogen peroxide, which has been linked to the beta-amyloid plaques that characterize Alzheimer’s.

Flavonoids boost the brain’s ability to form new neurons , prevent brain cells from dying, and enhance what researchers call "synaptic plasticity", or the ability of neurons to form and reform connections with each another.

Flavonoids (particularly the ones found in cocoa) help boost blood flow to the brain. This may help protect against vascular disease like stroke. The anti-inflammatory properties of certain flavonoids can also suppress inflammation in the brain, which helps reduce the risk of a variety of diseases. Parkinson’s and Alzheimer’s diseases may be a result of inflammation, and certain flavonoids may offer protection against the kind of neuroinflammation that accompanies them.

Considering the vast evidence that flavonoids can benefit the brain in so many ways, eating a diet rich in the compounds is likely a wise move. Dr. Gómez-Pinilla stresses the best sources of flavonoids is berries, which have been linked to the cognitive "decay" that comes with age.

Vitamin D: for Brain and Bones Alike

In addition to its role as a promoter of bone health, vitamin D serves important functions in brain health. The "sunlight vitamin" is synthesized in the skin when ultraviolet rays from the sun hit skin cells and is thought to protect the brain against cognitive deficits that come with age.

There are vitamin D receptors spread throughout many areas in the brain and the rest of the central nervous system (CNS). Vitamin D also influences certain proteins that aid in neuron growth and development, and it takes part in many other important aspects of brain function, like synaptic plasticity, learning, memory, the activity of neurotransmitters, and certain motor processes. According to UCLA's Dr. Gómez-Pinilla, "Long-term vitamin D deficiency in humans (several years) has been shown to be associated with cognitive and mood disorders".

The D and Depression Connection
Studies have found that vitamin D increases the self-reported "well-being" of people who took supplements. Low levels of vitamin D have been linked to depression, particularly seasonal affective disorder (SAD); in fact, some studies have found that SAD is associated with low levels of vitamin D and that it can ease the symptoms of people with the disorder. This makes sense when you consider that people are exposed to less sunlight during the winter months and are presumably more likely to have a vitamin D deficiency at this time of year.

Some researchers feel that vitamin D may play a role in depression by affecting the brain’s inflammatory response. Low vitamin D may also be linked to psychological stress and anxiety, again presumably though its role in reducing inflammation in the brain. At the more severe end of the spectrum, Dr. Gómez-Pinilla tells us, it has been linked to schizophrenia.

During the short days of winter -- and as more people avoid sun exposure -- people may become deficient in vitamin D: this is because it is largely made in the skin when the sun’s rays hit it. The best food source of vitamin D is fatty fish, like salmon and tuna, though it is also present in smaller quantities in beef liver, egg yolks, cheese, and mushrooms.

Some products are fortified with vitamin D, like milk (which was begun in the 1930’s to fight the bone disorder rickets) and some breakfast cereals. If you don’t eat many of these products, it may be necessary to supplement, particularly during the winter months, depending on where you live. If you are concerned that your vitamin D level might be low, have it tested by your doctor and discuss taking supplements if your levels are found to be low.

Curcumin, The Spice of (Mental) Life

One nutrient that you may not be so familiar with is the spice, curcumin. Even if you have never heard of it, it is likely that you have tasted it, for curcumin, from the root of the tumeric plant, gives curry its yellow color.

Indian populations suffer from Alzheimer’s disease much less than Americans. New research has outlined the mechanism by which curcumin actually fights the development of amyloid-beta plaques in the brain.

This polyphenol has many brain-protective powers, most impressively including against the harmful amyloid-beta plaques that form in the brains of Alzheimer’s patients. According to Dr. Gómez-Pinilla, curcumin benefits the brain by providing protection against neurological disorders a number of ways. "As an anti-oxidant, anti-inflammatory, and anti-amyloidal agent, curcumin can improve cognitive function in patients with Alzheimer’s disease."

Elderly people who regularly ate curcumin were found to do much better on tests of cognitive function that people who consumed it rarely or never, which Dr. Gómez-Pinilla says suggests "a strong capacity for curcumin to affect brain function." Indian populations suffer from Alzheimer’s disease much less than Americans. New research has outlined the mechanism by which curcumin actually fights the development of amyloid-beta plaques in the brain.

So, have a meal at your local Indian restaurant or add some curcumin – tumeric – to your own cooking to get a dose of this powerful polyphenol. It seems that some of the most interesting foods and flavors contain some of the most potent brain-boosting molecules.

Eating for a Healthy Brain

Add Good Fats; Reduce Saturated Fats
While it’s crucially important to add good fats (omega 3s and 6s) to the diet, it’s also important to cut down on the bad fats and other compounds that can negatively affect your brain (and the rest of your body, for that matter). Research has shown that when rats are fed high-fat, high-sugar diets, their ability to learn new spatial information is reduced. Other research has shown that simply eating too many calories can increase the amount of damaging molecules like free radicals that can build up in the brain. When these dangerous little particles become too numerous for the brain to remove, they can lead to problems in cognitive function.

Brains Need Fuel: Why No-Carb Is A No-Go
The brain needs its carbs. Nutrition gives the brain the tools and building blocks it needs to perform vital actions like thinking, making memories, and repairing cell damage. But the brain also needs the energy to do its work.

The brain’s energy comes from only one source: sugar. It relies on a steady flow of glucose to fuel it throughout the day and night, and it uses a lot of it. Even during sleep it is performing energy-consuming tasks like repairing damage, weeding out old connections, and forming new connections to retain all information that we’ve learned throughout the day. While the brain only makes up about 2% of our body-weight, it uses up to 20% of our body’s energy resources.

The brain’s energy comes from only one source: sugar. It relies on a steady flow of glucose to fuel it throughout the day and night, and it uses a lot of it.

Women who followed a low-carb diet had more problems during memory tests – particularly the more challenging tasks -- than did women on typical reduced-calorie diets (the kind supported by the American Dietetic Association). When carbohydrates were reintroduced into their diet, the women’s memory improved again, suggesting that it was indeed the lack of carbs that affected their cognition. Other studies have shown that people perform better on memory tasks, report better moods, and have less fatigue when they eat high-carb meals.

Just choose your carbs carefully, favoring low-glycemic, complex carbs over simple carbs and sugars. Complex carbs like whole grains (oats, wheat, and brown rice) will help keep glucose levels steady and fuel your brain throughout the day without the crash connected to processed grains like those in white bread, cake and cookies.

You Can Undo Past Mistakes with Smart Food Choices and Exercise
More and more evidence suggests making changes to our nutrition can reverse the damage that’s been done from past blunders. Research shows that exercise and eating right can actually reverse the negative effects that a high-fat diet has on our brains. In one study, rats who were fed a high-fat diet for two months and allowed to exercise did not show the same memory problems as rats who did not exercise. (In this study, exercise also reversed decreases in BDNF that accompanied the high-fat diet.) The results showed that exercise alone can reverse – and prevent – the effects of the high-fat diet on cognition.

But even better than exercise alone is adding some good fats to the equation: Another study showed that the omega-3 DHA enhanced rats’ ability to learn new spatial information, and that this phenomenon was boosted even further when the animals were allowed to exercise. So it seems that exercise and fatty acids may work along the same pathway, molecularly-speaking, so that when we pair the two, our bodies and brains both benefit, and this combination may reverse damage caused by other less-than-healthy lifestyle choices.

Prepare for the Future — Keep Nutrient Levels High Now
How we eat now can dramatically affect our brain health in the future. More and more evidence shows that people who maintain good nutrition throughout life have less risk for cognitive decline and other brain diseases as they age.

Keeping healthy B12 levels now may help prevent the cognitive decline that comes with age. Older people who consumed omega fatty acids (from eating fish regularly) had less cognitive decline than people who consumed less.

Dr. Smith and his team at the University of Oxford have discovered that vitamin B12 plays a crucial role in the brain’s aging process: "B12 helps stop the brain from shrinking. Elderly people with low-normal levels of B12 showed a greater rate of brain shrinkage than those with higher levels." Keeping healthy B12 levels now may help prevent the cognitive decline that comes with age. Omega fatty acids have a similar affect on the aging process. Older people who consumed omega fatty acids (from eating fish regularly) had less cognitive decline than people who consumed less.The best way to preserve our mental health in the future is to nourish our brains in the present.

A Final Checklist

In general, eating a well-balanced diet, along with moderate amounts of exercise as you are able, is the best way to keep your brain healthy now and in the future. The vivid colors in natural foods come from the nutrients within them, so look for deeply colored fruits and vegetables. For example, sweet potatoes with deep orange flesh, purple grapes, dark leafy greens, and many types of berries offer a range of essential vitamins, minerals, and antioxidants. Again, taking supplements may be necessary if you have dietary restrictions, but check with your doctor first.

The vivid colors in natural foods come from the nutrients within them, so look for deeply colored fruits and vegetables.

Use common sense when it comes to brain food, always keeping in mind that the brain is as sensitive to the compounds you put in it as the rest of your body. It’s never too late to reverse some of the effects of poor nutrition — and the choices you make today will affect your body and brain in years to come.

  • Add healthy fats like omega-3 and -6s to boost brain power, while cutting the bad fats like saturated and trans fats that may harm the brain.
  • Eat moderate amounts of complex carbohydrates like whole grain rice, wheat, and oats to keep glucose levels steady throughout the day.
  • Eat lots of fruits and veggies with vivid colors for a full range of brain-healthy phytochemicals and antioxidants. Blueberries, strawberries, spinach, kale, oranges, sweet potatoes, eggplant, grapes, and some dark chocolate, are examples of nutrient-rich foods.
  • Drink coffee, tea, and red wine in moderation for added antioxidants.
  • To keep B12 levels high, consume high quality animal proteins, like lean meat and low-fat dairy. And to keep your strength and stamina up throughout the day, add some healthy plant-derived proteins like tofu, beans, nuts, and quinoa.
  • Talk to your doctor if you suspect you may be low in a nutrient. He or she can do a blood test to determine if any deficiencies exist and make suggestions about how to get your levels up if needed.
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