Power Foods for the Brain (19 page)

Overly high levels of thyroid hormone can affect memory,
too. Symptoms of hyperthyroidism include rapid heartbeat, palpitations, heat intolerance, weight loss, and menstrual irregularities. You could also have an enlarged thyroid and appearance of unusually prominent eyes, among other problems. Treatment usually consists of medications, radioactive iodine, or surgery, followed by thyroid hormone replacement.

Thyroid problems sometimes improve on their own, without treatment. You will want to consult with your physician to see whether treatment is necessary.

If the supply of oxygen to your brain is interrupted—even briefly—the results can be disastrous for the brain.

Perhaps the most dramatic situation is cardiac arrest. As the ambulance crew comes to your rescue and gets your heart beating again, your family breathes a sign of relief. But while your heart was stopped, your brain cells were on their own. There was no oxygen reaching them, and the result could be persistent memory deficits.

Similarly, heart bypass surgery is often followed by cognitive problems. While the finger of blame had first pointed to the heart-lung machine (cardiopulmonary bypass), memory problems occur even when the device is not used, suggesting that it may actually be due to some more fundamental problem in heart bypass surgery. The good news is that cognitive problems typically improve as the weeks go by.

Many kinds of infections can cause memory problems, so your doctor may think about several possibilities: Lyme disease, HIV, syphilis, and various kinds of encephalitis. The treatment is targeted to the specific organism.

Many people with migraines feel that their headaches do real mischief to their memory and ability to focus. And indeed, researchers have found that people with migraines have trouble with verbal memory, reaction time, and even just paying attention, both during and after headache attacks.
⁵
,
⁶

The good news is that treating the migraine gets your brain working again. Sumatriptan nasal spray (20 milligrams) rapidly restores cognitive function.
⁶

As I mentioned above, you will want to see if diet changes can knock out your migraines. They often do. Common migraine triggers include dairy products, chocolate, eggs, citrus fruits, meat, wheat, nuts, tomatoes, onions, corn, apples, and bananas. Some of these foods (such as citrus fruits) are perfectly healthy for most people. But just as people who are allergic to, say, strawberries need to steer clear of them, the same is true of any food that is triggering headaches. With a simple elimination diet (described in my earlier book
Foods That Fight Pain
), it is easy to check which of these foods might be your culprit, and then you’ll have power you did not have before.

Chemotherapy often causes cognitive problems, in addition to its many other side effects. Researchers at the University of Toronto found that about half of women undergoing chemotherapy for breast cancer had moderate to severe problems with memory and language skills.
⁷
They also tested women who had finished their chemotherapy treatments more than a year earlier and found that about half had continuing cognitive problems that were at least moderate in severity.

Their memory problems were not psychological. That is, it
was not that depression or anxiety was interfering with their concentration. The problem was physical. Their brain cells simply were not working as well as they had before.

The fact is, chemotherapy is terribly toxic, which is exactly why doctors use it. They are trying to poison cancer cells. Unfortunately, some common chemotherapy drugs may be even more toxic to brain cells than to the cancer cells they are targeting.
⁸
As a result of these observations, many people are more and more cautious about chemotherapy.

Allow me to add diabetes to the list of memory threats. It is not that diabetes hurts your memory directly. Rather, people with diabetes are at heightened risk for Alzheimer’s disease and stroke.

In 1988, Japanese researchers invited more than one thousand adults to have their blood sugar levels tested with a glucose tolerance test. They then followed them over the next fifteen years. Those whose tests showed them to be prediabetic—with fasting blood sugars that were above the normal range but not high enough for a diabetes diagnosis—were 35 percent more likely than other people to develop any sort of dementia. Those whose blood sugars were in the diabetic range were 74 percent more likely to develop dementia.
⁹

Our research team has developed the most powerful dietary program ever devised for diabetes. Many people have used it to bring their blood sugar under better control and to reduce or even eliminate their medications. The regimen includes three simple steps: following a low-fat vegan diet, avoiding added oils, and favoring low-glycemic-index foods, as we will see in more detail in
chapter 9
.

The conditions listed above are the most common problems affecting the brain. The list of potential problems also includes trauma, surgery, radiation, tumors, seizures, Parkinson’s disease, Huntington’s disease, and multiple sclerosis. In nonindustrialized countries, diets deficient in vitamin B
₁
(thiamine) or vitamin B
₃
(niacin) can also lead to serious memory problems, but these deficiencies are rare in developed countries, due to the widespread fortification of foods.

If you notice any change in your mental function, a check of the medicine cabinet and a good medical evaluation hopefully will identify the cause so that you can address it promptly.

N
ow that you know about the brain-protecting effects of healthful foods, exercise, and attention to the effects of medicines and medical conditions, let me invite you to walk with me from the laboratory to the kitchen. It is time to put that knowledge to work.

In the next chapter, we’ll trace out a brain-enhancing menu to give you optimal nutrition, along with a simple way to ease into it. We’ll break the process into steps that are so simple that I have never seen anyone who couldn’t follow them. Whether you like to cook or prefer to eat at restaurants—or even fast-food places—we’ve got you covered.

Next, we’ll tackle food cravings—those annoying times when less-than-healthful foods just won’t take no for an answer. I’ll show you what these foods are doing inside your brain and what to do about it.

Finally, we’ll arrive at a treasury of delightful recipes, devised by Christine Waltermyer and Jason Wyrick. Page through them, see which ones call out to you, and give them a try.

O
ver many years, researchers have demonstrated the power of foods to help our hearts, trim our waistlines, tackle diabetes, ease chronic pain, and improve many other aspects of our lives. To this impressive list, we can now add protecting and enhancing our brains.

Luckily, you do not need one diet to bring you vitamins, a second to help you avoid “bad” fats, a third to limit iron exposure, a fourth for cholesterol control, and so on. One set of simple steps covers all these and more. This chapter puts it into action.

First, let me be clear about one thing: Nutrition is powerful. If you had imagined that a diet change might trim a few points off your cholesterol or help you lose a pound or two, it is time to think more boldly. Foods can change your life.

We have seen so many people who were hoping to just get their diabetes under a bit better control. They never suspected
they might be able to reduce or even stop their medicines or that the disease could essentially disappear. We have seen people who have been beaten up by one failed weight loss regimen after another, only to learn that the failure was in those poorly designed diets, not in them, and that a new focus on truly healthful eating gave them more control than they had imagined possible.

The same is true with brain health. A few years ago, I would never have guessed that foods could have much effect on brain function or that they could change your odds for staying mentally clear into ripe old age. That is exactly what we are now aiming to do.

This prescription is not just healthful. It is also wonderfully enjoyable and diverse. As a child, I ate from a typical American diet, which, in retrospect, was very limited. We ate roast beef, baked potatoes, and corn, night after night after night. Sometimes a pork chop took the place of the beef or peas took the place of corn. But we knew nothing of the culinary brilliance of other lands and never explored the range of foods that nature makes available to us. As I began to move away from a meat-heavy diet to a plant-based menu, it felt as if the doors to truly delicious foods were finally opening up. As you page through the recipes in this book, you will see what I mean.

Prior to 1990, most people thought modestly about nutrition. But that year, a page was turned. Dr. Dean Ornish, a young Harvard-training physician, showed that it is possible to actually
reverse
heart disease. Researchers had thought that artery disease was a one-way street. Narrowed vessels worsened over time, and surgery was the only way to reopen them. But, using a plant-based diet, along with other healthy lifestyle changes,
Dr. Ornish showed that, indeed, narrowed arteries can gradually reopen, reversing damage that had accumulated over decades.
¹
,
²

As revolutionary as Dr. Ornish’s discovery was for the heart, it is potentially even more important for the brain. As you’ll recall, about 20 percent of all the blood flowing from the heart passes up the carotid and vertebral arteries to the brain, carrying oxygen and nutrients in and carrying wastes out. Wide-open arteries are exactly what the brain needs.

Meanwhile, my research team tested the effect of a plant-based diet for obesity, diabetes, and cholesterol problems, all of which can harm the brain. It worked wonderfully. The participants slimmed down, their cholesterol levels dropped dramatically, their blood pressure improved, and many felt better than they had in years. Blood sugar control improved so much that some people with diabetes were able to stop their medications.
⁴

Perhaps the biggest surprise was how our research participants felt about the diet change. After all, they were making what many would have thought was an enormous shift—throwing out the meat, dairy products, eggs, and oily foods. But they adapted quickly. They found delicious choices at restaurants and interesting new products at food stores, and came to see food in a whole new light. Their energy rebounded, and they felt great. They liked their new way of eating and were eager to keep it going permanently.

Even so, there can be occasional missteps along the way. In a study testing a plant-based diet for weight loss, we asked volunteers to set animal products aside and keep oils low, and we provided weekly group meetings to help everyone stay on track. In one of the first sessions, one of our participants announced, “Dr. Barnard, I’ve found a treat that I can have on your diet!”

“Uh-oh,” I thought, running through the snack possibilities in my mind.

Opening her purse, she pulled out a big pack of red licorice.

“Twizzlers!” she said. “Read the label!”

Twizzlers are pencil-shaped candy twists sold at convenience stores all over America. And it’s true: If you look at the label, you―ll find no animal ingredients and no added oil—they are just starchy, sugary, artificially colored junk food. And she made sure that the whole group knew that they could eat all the Twizzlers they wanted in Dr. Barnard’s research study.

So my vegan, low-fat, Twizzler-fueled research participants set off on their path toward the unknown. Luckily, as the weeks went by, they lost weight. After fourteen weeks, the participants had lost an average of thirteen pounds.
³
And unlike the usual yo-yo effect seen with previous diets, weight loss became essentially a one-way street. Following them long-term, they were thinner after a year than when they began, and thinner at two years than at one year. Without counting calories, limiting portions, or even exercising, weight loss was easy and essentially permanent.

A plant-based menu that is powerful for physical health is no less powerful for the brain. It allows you to skip “bad” fats, cholesterol, and excess metals that are linked to memory loss, while providing abundant vitamins your brain needs.

Let me lay out the guidelines for a menu that shields your brain, and then we will look at delicious breakfasts, lunches, and dinners that put these guidelines to work.

It is best to avoid animal products
completely.
As you know by now, they contain saturated fat and cholesterol, increasing your cholesterol level and boosting your risk of Alzheimer’s disease
and stroke. While some people are tempted to include small amounts of meat, dairy products, or eggs here and there, those occasional animal products can easily stall your progress if you are aiming to lose weight, control cholesterol, and improve your brain health.

Some people use fish as a source of “good” fats, but fish also delivers cholesterol and a fair amount of saturated fat, as well as a surprising load of toxic pollutants in many species. As a group, fish eaters do not do nearly as well as people who focus on plant foods when it comes to weight, diabetes risk, and other health indicators.
⁵

In 2009, the American Diabetes Association published a comparison of five different diet patterns in a study including 60,903 adults.
⁵
Some of them ate meat every day; others steered clear of it completely. Some had dairy products and eggs, or perhaps fish, while others avoided these foods. The researchers measured everyone’s body mass index, which, as you will recall, is a measure of your weight, adjusted for your height (a healthy body mass index is between 18.5 and 25 kg/m
²
).