Food Cures (46 page)

N
o one has ever come to me specifically looking for nutritional help for a memory problem, but the topic comes up more often than you might think. For example, a client who has trouble recalling what she ate for breakfast the day she comes to see me might mention that she’s been noticing more and more memory lapses. Or sometimes, while making conversation in the course of session, a client will tell me about a “funny thing” that happened. Like the guy who couldn’t remember to put gas in his car and had to call AAA roadside assistance three times in a single month. Or the woman who was forever losing her cell phone, only relocating it when the ringing led her to the pantry…or the refrigerator…or the laundry hamper…or a basket of bathroom cleaning supplies.

Of course, memory changes aren’t always so obvious. They can be subtle, hardly worth mentioning…except when they interrupt the rhythm and flow of our daily lives. We waste valuable time looking for keys, the cat, or a matching pair of socks—or even questioning our skills and ability to function at work. Memory problems can infuriate and frustrate us when that elusive thought is on the tip of the tongue—or the tip of the brain, in this case—but we just can’t access it. And if we’ve seen a friend or family member descend into dementia, our own memory problems might trigger fear for our own future.

My absentminded clients are thrilled when they learn that there are nutritional and lifestyle strategies that may keep them from sliding down the slippery slope of memory loss. Every single suggestion listed here will also help improve overall health, so it’s win/win, with no downside. Better memory, and better health.

WHAT AFFECTS MEMORY?

Memory is a tricky thing. So many factors can affect how it functions, and on top of that, how well your memory works on any given day is purely subjective.
You
know when “brain freeze” happens, but with very few exceptions, there are no physical signs that doctors can look for to pinpoint the cause. Even the memory disorder people fear most—Alzheimer’s disease—can’t be definitely diagnosed except at autopsy after death (for more on Alzheimer’s disease, see Chapter 12). For the most part, physicians make educated guesses about the cause of memory loss based on your medical history, physical examination results, and lifestyle.

Memory is carried in a network of brain cells called
neurons
. These cells are generally shaped like the roots, trunk, and branches of an oak tree—a long central
axon
(like the trunk of a tree) with smaller branches called
dendrites
on both ends. Each of these branches connects with other neurons, which in turn connect with more neurons, and so on and so on. Memory depends on your total number of brain cells and their connections, the smooth flow of communication between neurons, and the health of all those cells. That means that it is relatively easy for something somewhere in the brain to go on the fritz. Among the biggest factors that can affect memory are:

VASCULAR HEALTH

Every cell in your body needs a steady supply of oxygen and nutrients in order to stay alive and work properly but brain cells are especially needy, like hungry infants that need to eat regularly and often. Because oxygen and nutrients are carried in the blood stream, anything that impedes blood flow will starve those all-important memory cells. The plain truth is that a healthy heart makes for a healthy brain.

When clients ask me about memory, the first thing I do is review their medical history. Specifically, I look for the following signs that they might have a blood flow problem:

High blood pressure (hypertension).
Physicians recommend that you maintain blood pressure at or below 120/80 mmHg. If your numbers are significantly higher than that, your health is generally at risk and your memory can suffer. High blood pressure damages the delicate lining of blood vessels and triggers the formation of plaque. Over time, plaque builds up on the inside of the vessels like leaves in a rain gutter, choking the blood supply everywhere in the body—especially the brain.

An ingenious study by researchers at the University of Pittsburgh showed how hypertension affects memory. The scientists compared people who had normal blood pressure with people who had high blood pressure on two different measures of memory. Verbal memory was tested by having the participants remember words, and spatial memory was tested by having the participants remember the position of items on a computer screen. While they were performing the tasks, the participants had their brains scanned to see where the blood was flowing. The results were surprising: the participants with hypertension had less blood flowing to the parts of the brain that controlled these types of memory
even though they performed equally as well on the tests
as the participants with normal blood pressure. The researchers predicted that, over time, too many neurons would be damaged and memory would be severely compromised. The lesson is that high blood pressure starts doing its damage even before you realize it, so it is hugely important to take action early.

High LDL, low HDL cholesterol.
Cholesterol comes in two main varieties—the “bad” variety known as low-density lipoprotein (LDL) cholesterol, and the “good” kind known as high-density lipoprotein (HDL) cholesterol. LDL cholesterol is one of the components of blood vessel plaque—the higher your LDL cholesterol, the greater the chance your blood vessels are becoming narrowed. The optimal level of LDL cholesterol is below 100 mg/dL.

HDL cholesterol, on the other hand, acts almost like a plaque magnet, picking up the vessel-clogging cholesterol and carrying it away to the liver. So the higher your HDL levels, the better and healthier your blood vessels—and by extension, your memory—will be. HDL levels below 40 mg/dL are considered too low to be healthy.

High homocysteine levels.
This role of this natural amino acid in heart health is still unclear. Some experts believe that homocysteine damages the blood vessel lining and encourages blood clots. We know that high blood levels of homocysteine (anything over 10 micromol/L) could be a sign of an increased risk of heart attack and stroke. For these reasons, lowering homocysteine levels is considered critical for health. Although no one knows yet whether lowering homocysteine levels will improve blood flow to the brain, the “fix” is so simple that it would be crazy not to take advantage of it. The best treatment for lowering homocysteine is not a new drug, but folic acid, vitamin B
₆
, and vitamin B
₁₂
from food or supplements.

(For more on heart health, see Cardiovascular Disease, Chapter 7.)

AGING

Almost everyone over age 40 has experienced memory problems. Part of the reason has to do with changes in our general health. As we get older, more things can and do go wrong with our bodies. Heart and blood flow problems, type 2 diabetes or prediabetes (glucose intolerance), and some autoimmune disorders can cause memory to decline. But there are other possible reasons for age-related memory loss. Beginning in our twenties, we typically begin to lose brain cells, which means that we lose the very structures that hold our memories. In addition, older brains make less of certain brain chemicals necessary for memory encoding, so no matter how hard we try to commit something to memory, it may not stick. It would be like putting your keys in a briefcase that had a big hole in the bottom—you may think your keys are safe, but your storage system is leaky.

Some memory experts believe that older brains store information in a qualitatively different way than younger brains. Older brains have been around a lot longer and have built up a complex network of information and memories. Every new piece of information has to get wired into the existing network, and sometimes random bits of trivia get lost. This isn’t necessarily a bad thing—it may mean that we get better at distinguishing between relevant and irrelevant information—but it does tend to make it more difficult for older people to recall specific pieces of information, such as names or appointments. (See there, it’s not just you!)

Other big factors in age-related memory loss are exercise and nutrition. Good nutrition and an active lifestyle can protect your brain from aging the same way they can protect your body from looking dumpy before its time. Even though it sounds basic, a healthy diet goes a long way to putting the brakes on memory loss in middle and old age. Researchers at the University of California, Los Angeles, investigated whether adopting a healthy lifestyle can keep brains more youthful. Participants ate a more memory-healthy diet, exercised for cardiovascular training, learned relaxation strategies, and challenged their brains with memory games. After just two weeks, brain scans showed that their minds were working with greater efficiency, allowing them to remember with less effort. It’s not a far stretch to imagine that these same lifestyle changes could, over the long term, make our 60- or 70-year-old brains more like our 20- or 30-year-old brains.

STRESS

These days, stress seems like an unpleasant but inescapable part of life. Until stress causes insomnia, overeating, or illness, most of us don’t give it much thought, much less to its possible effects on memory. When you’re stressed, your brain releases a steroid hormone called
cortisol
, which can damage your brain. It doesn’t take long—just a week or so of ongoing stress can be toxic.

Chronic stress can also make you feel depressed or anxious, and these feelings can interfere with the way your brain processes memories. Every emotion, positive or negative, causes a shift in brain chemicals. For example, happiness is usually associated with increased levels of serotonin, and depression is associated with decreased levels of serotonin. Any time you change the chemical soup in your brain, you risk changing the way memories are encoded and retrieved. But the damage may be even more serious, leading to permanent memory disorders. For example, people who are clinically depressed throughout their lives have a greater risk of developing Alzheimer’s disease. (For more information on mood and stress, see Mood on Chapter 13.)

But these related factors can also affect memory for a much simpler reason—distraction. Stress, anxiety, and depression can take over your life, push all other thoughts out of your mind, and make everything seem less important. And whatever you don’t consider important, you won’t remember.