Power Foods for the Brain (3 page)

What if your memory is sputtering and misfiring? What if you’re having lapses more frequently than normal?

If that is happening to you, it is important to know that there is a surprising range of things that can derail your memory and cloud your thinking—problems that are often easy to identify and treat. Sometimes it is as simple as correcting your sleep habits. Many people are chronically sleep-deprived, often without realizing it, with noticeable effects on their memory function.

Other times it’s a question of looking at medications you may be taking. As we will see in
chapter 8
, common medications can throw a wrench into your gray matter. Sometimes a medication causes no problem when used by itself but causes all manner of problems when prescribed in combination with other drugs.

There are many medical problems that affect the brain, too, from vitamin deficiencies to thyroid problems. So you’ll want to have a medical evaluation, and I’ll show you what you need to look out for so you can correct the problem.

If memory problems continue and no cause can be spotted, your doctor would label the problem
mild cognitive impairment
. This term refers to a situation in which you are doing fine in other respects—you’re able to socialize, take care of yourself, and enjoy life—but your memory and thinking are not as sharp as they were. You might be a bit slower when it comes to paying bills or balancing your checkbook, and you might forget to pick
up your dry cleaning. You may have trouble with names and words. You may also have trouble solving problems, planning ahead, or focusing your attention.

How can you tell whether mild cognitive impairment will turn into something more serious? The answer is, you can’t at first. Only as time goes on does the picture become clearer.

Your doctor will want to track how you are doing over time. He or she is likely to give you some simple tests, such as asking you to memorize a name and address—John Smith, 103 Orchard Street, Springfield—and to recall it a few minutes later. Or he or she might show you three common objects—a pen, a stapler, and a book, for example—and place them around the room, asking you to remember each object and its location later on. What your doctor is looking at is your ability to learn and hold on to new information, because that is an indicator of how likely it is that more serious problems lie ahead.
¹

These quick tests sometimes are followed by more formal testing, which can be repeated as often as needed. Some researchers add special examinations to try to predict who might be headed for Alzheimer’s disease. Drawing a sample of spinal fluid, they would look for two proteins, called
beta-amyloid 42
and
tau
.
²
A low level of beta-amyloid 42 suggests that beta-amyloid, which is linked to Alzheimer’s disease, has been deposited in the brain. A high level of tau protein suggests that neurons have been damaged.

Using an MRI or other scanning methods, they can look for brain shrinkage (particularly in a part of the brain called the hippocampus), reduced brain activity, or signs that amyloid has been deposited in the brain.

If you have mild cognitive impairment, you’ll want to use each of the steps in the following chapters to regain function if you can and to prevent further loss.

Frances and her younger sister Mary Lou were born in Milwaukee, Wisconsin, and have lived there all their lives. They inherited a large grocery store from their parents and worked there throughout their careers, making a comfortable living.

Both reported that around the time they turned sixty, they felt less sharp than before. For Mary Lou, that meant memory problems, which worsened over time. She found that she would often draw a blank for names and sometimes could not remember the words for common objects. She also found that she was no longer the math wizard she had been as a youngster, and she was not as able to keep her attention focused. In part as a result of these problems, she retired from her job. As the years went by, she found these problems annoying, and her doctor labeled them mild cognitive impairment. However, the condition never deteriorated into Alzheimer’s disease, and she still lives in the same house she has been in for the past four decades.

Frances’s situation was different. She, too, noticed that it often took a bit longer to remember names, but she observed no other problems at all, and even her difficulty with names did not get any worse. She is now in her mid-eighties and still works in the same job in the family store.

Later on, we will look at what may have made the difference in these two women’s experiences.

Not everyone with mild cognitive impairment progresses to Alzheimer’s disease, but many do. As we’ve seen, Alzheimer’s is extremely common among older folks. But the fact is that we are now at a turning point in Alzheimer’s disease research, with
the emergence of what appear to be powerful tools for reducing the likelihood that you will develop it. Unfortunately, treatments for people who already have Alzheimer’s are not at all what they should be, but research studies suggest an effective preventive strategy, which I’ll lay out for you in the next several chapters.

When Alzheimer’s disease takes hold, it attacks your brain’s centers for learning, memory, reasoning, and language.
³
Here are the common symptoms:

• Difficulty learning and remembering new things.
  You might misplace personal belongings more frequently than normal. You might ask the same questions repeatedly, or get lost on what had been a familiar route.
  
• Poor reasoning, judgment, or problem solving.
  It becomes harder to make decisions, plan activities, handle routine finances, or take the usual steps to protect yourself (e.g., looking out for traffic before crossing a street).
  
• Poor visuospatial abilities.
  You might have trouble recognizing faces or using simple objects, or find it harder than it should be to do routine things like putting on your shoes or doing up buttons.
  
• Losing language skills.
  Words may elude you, and reading and writing can be more difficult.
  
• Personality changes.
  You could become irritable, agitated, or eventually just apathetic.
  

Alzheimer’s is different from mild cognitive impairment in that cognitive problems are no longer just a nuisance; they are now interfering with your day-to-day activities. To reach the diagnosis, a doctor would look for at least two of the above symptoms. Typically these changes come on insidiously, unlike
the more sudden cognitive problems caused by a stroke, trauma, or infection.

To separate Alzheimer’s disease from other brain conditions, your doctor will do a physical exam and laboratory tests, and will also test your ability to learn and remember and can check your language skills. Sometimes doctors check cerebrospinal fluid, drawn via spinal tap, for
beta-amyloid 42
and
tau
. Special brain scans can spot amyloid deposits in the brain or shrinkage or reduced function in certain parts of the brain.
⁴

But even with sophisticated testing, your doctor cannot be entirely sure of the diagnosis. If it looks like Alzheimer’s, the diagnosis will be called “possible” or “probable.” A definitive diagnosis relies on an examination of the brain itself.

If you were to look within the brain of a person with Alzheimer’s disease, you would not find normal, healthy brain tissue. Here and there between the brain cells are tiny deposits of beta-amyloid protein. Doctors refer to these deposits as
plaques.
They are microscopic, but they are not doing the brain any good. They are a sign of a disease process.

I should mention that “plaque” is a generic word that refers to any sort of unwanted deposit. So you could have plaque on your teeth, plaques clogging your arteries, or microscopic plaques in your brain. They have nothing in common, except that the same word is used in each case.

Scientists have teased these beta-amyloid plaques apart to see what is in them. After feverish research, we now have a good picture of what they are made of. What is actually inside those plaques is surprising. As we’ll see in the next chapter, we
can put this finding to use, starting today, to work toward preventing the buildup of these plaques in the first place.

Aside from the beta-amyloid plaques that lie between the brain cells, there is also something wrong
inside
the brain cells themselves. They contain what look like tangled balls of yarn.

Normally your brain cells have microscopic tubes—which scientists call
microtubules—
that maintain the cell’s structure and help it to transport various things from place to place within the cell. To stabilize these microtubules, your cells use
tau
proteins (
tau
is just the Greek letter that is the equivalent of our letter “T”). And it’s those
tau
proteins that are balled up in what neurologists call
neurofibrillary tangles.

In 1906, German physician Alois Alzheimer spotted these odd plaques and tangles in the brain of a patient who had died in her mid-fifties after suffering from memory loss and behavioral problems. Although Dr. Alzheimer dutifully reported the existence of plaques and tangles, he had no idea what had caused them, and for the past century, researchers have struggled to find out.

A person assaulted by Alzheimer’s disease has also lost brain cells, along with many of the synapses between brain cells—the connections they need to communicate with each other.

So where is all this leading? Ultimately, many people with Alzheimer’s disease die of pneumonia, often because the disease has affected their ability to swallow, and food particles end up in their lungs.

All of these problems are what we now aim to prevent.

Genes play a role in Alzheimer’s disease. Chromosomes 21, 14, and 1 hold genes that produce proteins (called
beta-amyloid precursor protein
,
presenilin 1
, and
presenilin 2
) that are involved in
making the beta-amyloid that ends up in plaques. Mutations in these genes cause aggressive forms of Alzheimer’s disease that can strike when people are just in their thirties, forties, or fifties.

Fortunately, these cases are rare. For the vast majority of people, the effect of genes is weaker.

The best-known genetic contributor is a gene called APOE. Located on chromosome 19, it holds the instructions for producing a protein called
apolipoprotein E
(which scientists abbreviate with small letters as
apoE
, to differentiate it from the gene). ApoE’s job is to help carry fat and cholesterol from place to place. It also repairs brain cells and builds connections from one neuron to another.

Here is what counts: There are three different common versions (alleles) for the APOE gene, called e2, e3, and e4. The e4 variant is the one that has raised concerns about Alzheimer’s risk. Compared with people who got the e3 allele from both parents,
those who inherit the e4 allele from one parent have about three times the risk of developing Alzheimer’s disease. People who get the e4 allele from both parents have ten to fifteen times the risk.
⁵
,
⁶

People with the e2 allele have less Alzheimer’s risk. But e2 has problems of its own, causing a higher risk of rare cholesterol problems and cardiovascular disease.

It is important to understand that genes work in many different ways. Certainly, some genes are dictators—the genes for hair or eye color, for example. If they call for you to have blond hair or brown eyes, that’s it. Those dictatorial genes won’t take no for an answer.

But the genes for Alzheimer’s disease are more like committees. They don’t give orders; they make suggestions. And research suggests that changes in diet and lifestyle—the steps you will read about shortly—can keep those genes from expressing themselves. Like dry seeds on the desert floor, they simply lie dormant. If you don’t water them, they’ll never sprout.

So even though the e4 allele is linked to increased risk of Alzheimer’s disease, some people who have the e4 allele—even from both parents—never get the disease. And at least one-third of Alzheimer’s patients do not have the e4 allele. Research suggests that food and lifestyle choices can help protect you, whatever genetic hand you’ve been dealt.

Alzheimer’s is not the only neurodegenerative condition. Here are other common types:

The blood vessels of the brain can be gradually damaged and narrowed. In the process, they no longer give the brain the oxygen it needs. Sometimes the narrowing is very much like that which occurs in the arteries to the heart. At these narrowed spots, blood clots can form, plugging the artery like a cork in a bottle. Clots and debris can also break free, passing downstream and plugging smaller blood vessels farther along. Sometimes arteries actually break open, leaking blood into the brain tissue.