Power Foods for the Brain (10 page)

The same sort of diet pattern made less difference in a French study.
²⁴
Researchers tracked the health of 1,410 people in Bordeaux, finding that this sort of dietary pattern did not reduce the risk of Alzheimer’s disease or other kinds of dementia over the five-year study, although it did seem to slow decline in some cognitive tests.

For most of us, a “Mediterranean diet” pattern is a change in the right direction. It certainly beats the kind of diet I grew up with, and that may be true for you, too. But my assessment is that we can do better. In the same way that people following chicken- or fish-based diets do not do as well as people who avoid meats altogether when it comes to their weight, their diabetes risk, or their heart health, the same is very likely true for brain health as well.

So I would suggest taking the best of the Mediterranean pattern—the vegetables, fruits, beans, and grains—and skipping the fish and oil. We’ll talk about alcohol in the next chapter.

Avoiding fatty foods and emphasizing healthful plant-based meals brings you a couple of added benefits:

Trimming your waistline.
People who eat plant-based
diets are, as a group, much slimmer than people who eat animal products, including fish. Part of the credit goes to the fiber in vegetables, fruits, beans, and whole grains. Fiber satisfies your appetite with essentially no calories. In addition, plant-based diets also tend to slightly increase your metabolism in the after-meal period.
²⁵
As a result, you’ll discover that, even though you have not been counting calories or limiting carbohydrates—and even without adding exercise to your routine—a plant-based diet makes it a lot easier to fit into your jeans.
²⁵
,
²⁶
,
²⁷

In turn, that slimmer figure means you’ll have less risk of developing diabetes, heart problems, or high blood pressure. And slimmer people also have less risk of Alzheimer’s disease.
²⁸

If you are wondering if your weight is in the healthy range, you can check your body mass index. The BMI is a way of looking at your weight while adjusting for your height. This is important because 140 pounds is a healthy weight if you are five foot seven, but not at all if you are six foot five. You’ll find an easy online BMI calculator at
www.nhlbisupport.com/bmi/
. A healthful BMI is between 18.5 and 25 kg/m
²
.

If you have some weight to lose, let me encourage you
not
to bother with a typical calorie-restricted weight-loss diet. Instead, fill up on vegetables, fruits, whole grains, and legumes, and skip animal products and oily foods, and your weight will adjust itself much more easily. See
chapter 9
.

Lowering your blood pressure.
As you know, diet changes can lower blood pressure. The first step most people try is to reduce salt, which is smart, but usually only modestly effective. A much more powerful step is to avoid fatty foods, especially animal products.
²⁹
This reduces the
viscosity
(thickness) of your blood, so it is less like grease and more like water. That means your blood flows more easily and your heart does not have to work so hard to push blood along. Your blood pressure promptly falls.

And there’s more: Fruits and vegetables are rich in potassium, which tends to reduce blood pressure as well. And the weight loss you are enjoying will help bring your pressure down, too.

Together, these steps can have an enormous effect. In
chapter 9
, I’ll show the best way to put all these things together. It’s easier than you might guess.

Checking your blood pressure, your health-care provider records two numbers (e.g., 120/80). Here is what they mean:

• The first number is your
  systolic
  blood pressure. It is the wave of pressure that comes with each heartbeat.
  
• The second number is your
  diastolic
  blood pressure and represents the relaxation between heartbeats.
  

A blood pressure below 120/80 is considered normal. A pressure between 120/80 and 140/90 is called prehypertension, and higher values are called hypertension.

So far, we have mostly focused on things to avoid—toxic metals and “bad” fats in particular. But there are certain nutrients that you want to be sure to include in your regular diet—four vitamins that protect your health, including your brain function. In the following chapter, we’ll see how they work and where to find them.

A
void toxic metals and “bad” fats—sounds like an easy prescription so far. But we’re just getting started. There is a lot more you’ll want to do to protect yourself.

Certain critically important vitamins—nutrients that can easily be neglected—play vital roles in protecting your brain. Let’s take a look at four of them: vitamin E, folate, vitamin B
₆
, and vitamin B
₁₂
.

Vitamin E protects your cells. Specifically, it knocks out free radicals, those angry torpedoes that form, in part, due to copper and iron, as we saw in
chapter 2
. Vitamin E is an
antioxidant
. It neutralizes free radicals as they arise.

This is important for every part of your body. But it is critical for your brain. Skin cells and muscle cells can be replaced, and
red blood cells and white blood cells turn over so quickly, they practically have a sell-by date. But brain cells are forever. Your ability to regenerate new ones is very limited, and there just aren’t a lot of shiny new replacement parts ready to stand in for brain cells that have died.

Every brain cell, the axon that extends from it, and the synapses that link it with other cells are fragile. Like an old stone statue in a town square assaulted day after day by air pollutants and acid rain, each brain cell is nicked and pockmarked by the microscopic attacks of free radicals. Vitamin E is a key part of your antioxidant shield.

So, does it work? Does vitamin E actually protect your brain cells? Dutch researchers analyzed the diets of 5,395 people, all of whom were fifty-five or older as the study began. They tracked how much vitamin E they were getting in foods, and they then followed them over the next decade. It turned out that those who got the most vitamin E cut their risk of developing Alzheimer’s disease and other forms of dementia by about 25 percent.
¹

Similarly, the Chicago researchers found that in older people followed over a four-year period, Alzheimer’s disease developed in 14.3 percent of those who had relatively little vitamin E in their diets,
but in only 5.9 percent of those who got the most vitamin E
.
²
Here is the math: Every 5 milligrams of vitamin E in a person’s daily diet reduced the risk of developing Alzheimer’s disease by 26 percent.
³

In the Dutch study, it did not matter if you had the APOE e4 allele—vitamin E was still helpful. But in the Chicago study, it seemed to work only in people who did
not
have the APOE e4 allele, for reasons that are not clear.

Two caveats: First, not all research teams have confirmed the protective effect of vitamin E for the brain. Second, don’t rush to the store and buy a bottle of vitamin E. Get it from foods
instead. Here is why: Most vitamin E supplements have only one form of the vitamin, called
alpha-tocopherol.
Foods provide it, too, but they also have a second form, called
gamma-tocopherol
, and others as well. These various forms of vitamin E work as a team. There is no need to bother with pills, and some evidence suggests that vitamin E pills are not effective against dementia.
⁴

What if you have Alzheimer’s already? Will vitamin E help? In 1997, a large research project found that vitamin E did seem to slow the decline of Alzheimer’s disease. Called the Alzheimer’s Disease Cooperative Study, the project enrolled people with moderately severe symptoms.
⁵
Their average age was seventy-three, and they had had Alzheimer’s disease for about five years. By taking 1000 IU of vitamin E (alpha-tocopherol) twice a day, they were able to delay further decline by nearly two years. “Decline” meant loss of the ability to perform activities of daily living, severe dementia, institutionalization, or death.

Unfortunately, this optimistic finding was not replicated by later studies, and the role of vitamin E in Alzheimer’s treatment remains a matter of debate. So, for prevention, vitamin E–rich foods do seem to be effective, but once dementia has begun, its benefits are uncertain.

The recommended dietary allowance for vitamin E for adults is 15 milligrams (22.4 IU) per day. The amount that helped in the Dutch study was around 18.5 milligrams (27.6 IU) per day. The amount that helped in the Chicago study was just 7.6 milligrams (11.4 IU) per day.

You’ll find traces of vitamin E in broccoli, spinach, sweet potatoes, mangoes, and avocados. And there is much more in nuts
and seeds, especially almonds, walnuts, hazelnuts, pine nuts, pecans, pistachios, sunflower seeds, sesame seeds, and flaxseed.

An ounce of typical nuts or seeds has about 5 milligrams of vitamin E. How much is an ounce? Pour some nuts or seeds into the palm of your hand and stop before they reach your fingers. That is about an ounce. If that’s part of your routine, it trims your Alzheimer’s risk by about one-quarter, if the Chicago findings hold.

While nuts and seeds are rich in vitamin E, they are also high in fat, which means they pack a lot of calories, not to mention some saturated fat. So I would suggest using them sparingly, focusing on the vitamin E–rich varieties mentioned above rather than peanuts or cashews, which have less vitamin E and more saturated fat.

If you have a tendency to overdo it with nuts and seeds—you tear open a pack and pretty soon you’ve eaten the whole thing—try this: Use them as an
ingredient,
rather than as a snack food that you might eat all by itself. Sprinkle them on your salad or into a sauce. That way you’ll be less tempted to go back for more.

Vitamin E is not the only important nutrient. Three other vitamins are being studied for their role in protecting the brain. Let me tell you what they do.

There is a small, destructive molecule that circulates in your bloodstream, called
homocysteine
(pronounced
ho-mo-SIS-teen
). At high levels, it is linked to risk for heart attacks and strokes. It also affects the brain. Exactly how it does its dirty work is not entirely clear, but some have suggested that, among other things, homocysteine works in combination with copper and cholesterol to damage brain cells.
⁷

Where does this nasty actor come from? Well, you don’t inhale it, you don’t drink it, and it does not come from food. It is actually created
within your body
. As your cells build protein, homocysteine is a temporary by-product made along the way.

That’s where vitamins come in. They help you get rid of it. Specifically, three B vitamins—vitamin B
₆
, vitamin B
₁₂
, and folate—work as a team to eliminate homocysteine. If you are low in any one of them, it will tend to build up in your bloodstream.

In the Netherlands, researchers conducted a study to see what folate supplements could do to boost memory and cognition overall.
⁸
They invited a group of volunteers to participate. They were healthy, between fifty and seventy years of age, and free of any major memory problems, but they all had high homocysteine levels on blood tests. Everyone was asked to complete some basic cognitive tests. For example, they were given a list of fifteen words and asked to recall as many as they could twenty minutes later. They were asked to name as many animals as they could think of in one minute. The researchers measured their reaction times.

Then, half the volunteers were given folate supplements of 800 micrograms per day. The other half were given a placebo—a dummy pill that had no folate in it at all. Every year for the next three years, they were tested again.

The placebo group ended up getting no benefits, needless to say. But for the folate group, homocysteine levels promptly fell, from around 13 micromoles per liter to around 10. Their memories improved, and they were thinking measurably more quickly compared to participants who did not get folate.