Boost Your Brain (15 page)

Green tea, meanwhile, has other benefits too, thanks to epigallocatechin gallate (EGCG), a polyphenol and antioxidant. One animal study showed EGCG promotes neurogenesis in the hippocampi of adult mice,
²⁸
while another animal study showed it revved up mitochondria in diabetic mice and improved their glucose metabolism.
²⁹
Black and green tea also contain quercetin, another antioxidant.

Tomatoes

Tomatoes are a gold mine of vitamins and antiplatelet ingredients that ease flow in blood vessels, thus increasing oxygen supply to the brain. A recent study by researchers in Finland followed 1,031 men for twelve years and showed that those with the highest blood levels of lycopene, derived from tomatoes, were 55 percent less likely to suffer a stroke than those with the lowest levels of lycopene.
³⁰
Add tomatoes to your diet, and don’t forget tomato juice as a smart snack choice.

The Vitamins Your Brain Needs

We know from Dr. Bowman’s study that higher levels of vitamins B, C, D, and E in the bloodstream are associated with better cognitive performance and a bigger brain. We also know, from numerous studies, that low levels of certain vitamins are associated with cognitive decline in old age. Key vitamins that affect brain performance are:

Snack Attack

Between meals, snacking can actually offer benefits that go further than merely quieting that tummy growl. A well-timed, carefully selected snack can give you an energy boost and help reduce overeating.

My favorites are:

Nuts:
Try a palmful of pistachios, walnuts, or other nuts. One caveat, though, is to watch your portions. Overindulging in nuts can tack unneeded calories onto your daily total.

An Apple:
Relatively low in calories (a medium apple has about 81 calories), apples offer vitamins A and C, plus L-theanine, quercetin, and other nutrients.

Cherry Tomatoes:
Pop a handful of these (half a cup has just 15 calories) for a sweet, juicy treat. Tomato juice also offers brain benefits.

Vitamin B12

One of eight B vitamins, B12—along with folate—is vital to the function of the central nervous system as well as the nerves that run to your toes and fingers. Among other things, B12 and folate are important for the formation of the myelin lining that insulates the branches of nerves. When B12 and folate levels fall, this protective lining shrinks. As a result, signals aren’t passed as efficiently from neuron to neuron, resulting in reduced cognitive function and slowed thinking. Low B12 levels are also associated with fatigue and depression.

Low levels of these vitamins have another side effect: both B12 and folate are essential for converting the amino acid homocysteine. When B12 and folate levels are too low, homocysteine isn’t converted and blood levels of this amino acid rise. The result is an increased risk of heart attack, stroke, and inflammation of the blood vessels. Studies have also found that people with Alzheimer’s disease and vascular dementia have high homocysteine levels, compared to their healthy peers, but we don’t yet have proof that one causes the other.
³¹

We do know that high homocysteine is tied to a smaller hippocampus. One study of 1,077 cognitively healthy elderly people between sixty and ninety years old found that elevated plasma homocysteine levels were associated with shrinkage in the hippocampus.
³²
Another study found that high homocysteine levels were associated with a significantly smaller hippocampus and a high rate of hippocampal atrophy over a two-year period.
³³
The bottom line is that high homocysteine goes hand in hand with a smaller hippocampus, and since B vitamins and folate are key to keeping homocysteine in check, it’s critical to ensure you’re getting enough B12 and folate in your diet or through supplementation.

It’s important to note, too, that homocysteine levels tend to rise with age, in part because the elderly tend to have a harder time absorbing nutrients. Hence, it becomes harder as you age to get enough B12 and other vitamins through your diet. In fact, as you age you may only absorb 30 to 40 percent of the B12 that you need for optimal health.

Vegetarians and those who’ve had certain gastrointestinal surgeries need to be particularly careful to ensure they’re getting enough of these vital nutrients in their diets or through supplementation.

The good news is that a simple blood test can determine your B12 level, and it’s easy to supplement with B12 if needed. For most, that means taking a B12 supplement. For those with severe B12 deficiency, however, monthly shots of B12 may be necessary. Just one note of caution: most laboratories consider a B12 level of more than 200 pg/mL to be normal, although for cognitive health I consider the optimal level to be 500 pg/mL or more. Therefore, you might be told your B12 is normal and still benefit from supplementing or increasing the B12 through dietary changes.

You can add B12 to your diet through dairy products, lentils, spinach, meat, poultry, and fish, which are all good sources. If your B12 level is less than 500 pg/mL you can also take a B12 supplement at a dose of 500 to 1,000 mcg per day.

Vitamin D

Vitamin D is probably best known for its effect on bone health, but it actually is involved in a number of chemical processes in the brain. Low vitamin D has been associated with neurological and psychological problems that range from fatigue and depression to schizophrenia, multiple sclerosis, and dementia. Low vitamin D has also been associated with low BDNF and a thinner cortex.

I check vitamin D levels in all my patients and find that about 20 percent have levels that are low. Fortunately, supplementation works well for increasing your level of vitamin D. Keep in mind, though, that people who have low vitamin D often also have low calcium levels, so simultaneous supplementation for both might be beneficial for overall health.

Vitamin E

An anti-inflammatory substance, vitamin E has many benefits for protection against heart attacks and inflammation in the brain. There’s evidence, too, that it may delay the onset and even slow the progression of Alzheimer’s disease. Some studies have emerged in recent years, however, to suggest that high doses of vitamin E can be harmful. More research needs to be done, so for now I don’t recommend high-dose supplementation for my patients. If you do choose to take a supplement, the ideal dosage is 200 to 400 IU per day, and it’s most effective when taken with vitamin C. Many multivitamins include vitamin E, so it’s important to check your multivitamin dose before you supplement with vitamin E. People who take Coumadin or other blood thinners shouldn’t take vitamin E because it increases the risk of bleeding.

The Jury Is Still Out

There are countless supplements that are touted for their brain-boosting potential but for which the evidence is contradictory or simply not yet available. Two that I often hear about are Ginkgo biloba and coconut oil.

Ginkgo Biloba

Though it’s received plenty of hype over the years, the truth about Ginkgo biloba is that, when it comes to science, the evidence is controversial. Some studies have shown it to be beneficial, but two placebo-controlled clinical trials failed to show any cognitive benefit. Since it may have harmful effects as well, I don’t recommend it for patients with brain issues.

Coconut Oil

Coconut oil in recent years has gained attention for its potential in helping to treat, and perhaps reverse, some of the effects of Alzheimer’s disease. The theory that’s been floated is that the brain cells in patients with severe dementia die in part because increased resistance to insulin has impaired their ability to use glucose for fuel (as normally happens in the brain). An alternative source of fuel for brain cells can be ketones; so coconut oil, which is metabolized to ketones, could potentially help fuel the brain when glucose can’t.

It may be true, but more study needs to be done. Given that it, too, may have harmful effects, I do not recommend it.

Add a Glass of Wine?

When I give lectures, I find that of all the things I say the one men remember most is this: alcohol in moderation is believed to offer neuroprotective benefits. Often people read that as license to hit the bottle on a regular basis. And maybe it is. Alcohol, after all, is thought to increase HDL, which is beneficial to heart health (and by extension, brain boosting).

But the key here is moderation. As you’ll read in
chapter 14
, alcohol abuse wreaks havoc on the brain. Moderation means one serving of alcohol per day for women and two for men. But you shouldn’t consider quaffing a glass of merlot with dinner to be sufficient for a bigger brain. I actually consider it an option that’s fairly low on the list of priorities. (A healthy diet, complete with DHA, is right at the top.) That’s because if you’re gobbling Ho Hos and gallons of soda, ending the day with a glass of merlot will barely make a dent in the damage.

There’s an important exception to the moderation rule, too. If you’re currently experiencing memory problems, you should avoid alcohol entirely.

A diet high in DHA, flavonoids, and vitamins and low in trans fats is associated with a bigger brain. The more you adhere to such a diet—and work to avoid being overweight—the bigger the brain benefit. For optimal brain growth, I recommend a diet rich in fruits, vegetables, grains, and fish, (with zero sugary junk food and sodas) along with a DHA supplement.

Brain-Boosting Foods

Your Rx

Track 1

If you’re currently consuming a highly unhealthy diet, with few brain-building nutrients, this is your track. First, you’ll need to detox, cutting the worst foods from your diet before you make any serious effort to add brain builders. Why? Your unhealthy diet is increasing your risk of being overweight or obese and of developing high cholesterol, high blood pressure, diabetes, and stroke, all of which are major brain shrinkers. Adding DHA or green tea to your diet won’t have nearly the effect that cutting major brain shrinkers will.