Your brain weighs, on average, a mere three pounds, yet it controls all the senses and functions of the body. It has a memory capacity capable of holding more information than all the reference materials in your local library—an astounding accomplishment for something that weighs the equivalent of just a few books. It is capable of holding an enormous trove of knowledge.
In order to understand how to improve brain function—including sharpness—let’s take a closer look at how this sophisticated organ is structured and how it works with the rest of the body. Then we’ll see how your brain stacks up with a simple self-test or two, and what kind of cognitive testing and other assessments you might find valuable, particularly if you’re trying to determine if what you’re feeling, brain-wise, is normal aging or something else.
Most likely you’ve seen cartoonish depictions of the brain in movies—think of Frankenstein, or other films, with the odd-looking, rounded, rippled organ suspended in a giant jar of liquid. Or perhaps you’ve watched a science documentary or seen high-resolution images of an actual human brain (which does resemble Frankenstein’s after all). What is all that squiggly, wrinkled stuff, and what does it do? Let’s take a tour of the brain to answer just those questions, so set aside the images—the ones you have stored in your brain, of course.
The brain is composed of a complex network of more than 100 billion neurons (also called nerve cells). Between every pair of neurons is a point of connection, called a synapse. Information travels from synapse to synapse through chemical neurotransmitters, naturally occurring chemicals that serve as nerve system messengers, like dopamine (the feel-good chemical released during moments of pleasure) and serotonin (which can control everything from appetite to mood). Each neurotransmitter is made from a specific amino acid through a series of steps that require specific nutrients, called cofactors.
There are trillions of synapses in the brain, and the brain’s speed and sharpness depend upon these biochemical connections. The messages being sent along this route can be anything from “stop eating, you’re full” to “hit the brakes” to “remember to call the plumber”—virtually all our thoughts and deeds travel across these channels. Because our body’s biochemistry, which we can alter with diet, keeps this neuron-synapse-neuron assembly line moving, it shouldn’t be surprising that nutrition plays a substantial role in brain performance.
The human brain experiences much of its growth after birth, reaching about 80 percent of its adult size by age two. But though its physical growth may level off early on, the brain’s cognitive function continues to grow and improve throughout childhood and well into adulthood. (By contrast, a chimpanzee generally reaches its cognitive function by age three or four, consistent with when it becomes self-sufficient.) Your ability to process information quickly and to remember facts improves gradually from birth until age thirty.
At our peak, the brain’s total memory capacity is amazing and exceeds that of a computer. Each year after thirty, most people have a natural, gradual drop in mental speed. This is normal, but it isn’t always noticeable because as we gain experience and retain memories, we make up for it with knowledge. As you age (particularly after forty), it is almost as if you have to work with a slightly slower computer, but with experience, you don’t need to rely as much on that computer.
Memory and attention also decrease over time, but these functions should decline more slowly than processing speed does. Many people are capable of maintaining their memory and attention into their eighties and nineties, even if it takes them more time to access the information; the knowledge may still be in their brains—it just requires a little longer to pluck that book off the shelf, so to speak, and look up the fact. Losing memory isn’t a balanced process: typically we lose the ability to recall a name or fact before we lose the ability to recognize. Hence we are likely to forget someone’s name before we forget who they are.
Executive function or mental sharpness is different from memory—it is the ability to problem-solve and jump from one task to another. The better your executive function, the more complex work you can accomplish in a given amount of time. (For patients in my clinic, executive function seems to be the most important aspect of cognitive function that makes them successful in their work and personal lives; we’ll look at how it impacts productivity shortly.) If your executive function is sluggish or impaired, however, your memory will underperform as well.
The brain and its functions can be divided into three major parts: the forebrain, the midbrain, and the hindbrain.
The hindbrain, which some scientists call the reptilian brain, is the primitive part of the brain that controls the basic “automated” body functions we don’t think about every time they occur: the beating of our hearts, breathing, and blood circulation. The hindbrain, which all animals have, evolved from the brains of our earliest reptilian ancestors—hence its name.
Higher on the evolution tree is the midbrain, which regulates what we sense and controls basic instincts, such as seeking food and reproducing—aspects related to basic survival. It has a broad range of duties as it regulates motor control, hearing, vision, body temperature, thyroid and adrenal function, fertility, libido, and our wake and sleep cycles. It controls involuntary processes, such as coughing, swallowing, sneezing, and vomiting. An alligator has only a mid- and hindbrain (though at least it moved beyond its original reptilian brain). When it sees food, it eats. When it sees danger, it flees.
The midbrain doesn’t compel you to think about whether the food is healthy or junk (the alligator definitely won’t stop to think); it wants you to eat to avoid famine, period. The midbrain has another important responsibility: it sends us into survival mode. When we are stressed, this part of the brain tends to take over, whether we’re escaping from a burning building or are sleep deprived and juggling multiple deadlines at work.
The forebrain (also called the neocortex) is what makes humans different from animals. It is responsible for processing sensory information from vision (eyes), smell (nose), sound (ears), taste (tongue), and touch (skin). The forebrain’s frontal lobes allow humans to process complex information and problem-solve, while the temporal lobes hold memories and process language.
The neocortex also allows you to inhibit impulses. When someone puts food in front of you, this part of the brain can say, “Stop, I don’t need to eat now, and I certainly don’t need to eat junk.” That is under normal circumstances. But when stress is introduced, the brain reacts accordingly. When you are stressed, it’s as if an internal alarm goes off; blood is shunted away from the inhibitory neocortex to the midbrain so “survival mode” can kick in. For example, if a lion is chasing you, you want to divert blood flow and energy to the midbrain and hindbrain, which helps you to escape.
Diverting blood supply from the neocortex fires up your midbrain appetite center. If there is food around, unless you’re running from a beast, you’ll eat it. This is how chronic stress results in prolonged impulsive eating. Willpower resides in the forebrain, and you need peace and calm for willpower to overcome survival mode.
When we’re really stressed out, it’s easy to settle for the quick-and-easy fix, particularly if we’re on the go and racing from one crisis to another. That’s when we’re most likely to hit the drive-through or reach for candy, pretzels, or even a “healthy” granola bar (which is likely just a candy bar with healthy-sounding packaging).
For every food action, there is a brain reaction. When we eat the wrong foods, hormonal shifts blunt our satiety—that important sense of feeling satisfied and full so that we put the fork down—and appetite-regulating hormones (like leptin and ghrelin) ultimately go haywire, which make us instantly hungry. This powerful, hormone-induced hunger message sends an alert to the midbrain (“avoid famine, store calories!”), which in turn creates cravings as blood is shunted from the forebrain to mid- and hindbrain.
Cravings win out over willpower. This is one of the reasons calorie counting is so ineffective. Eventually, the longer we are stressed, the more the midbrain will dominate over the forebrain, and we’ll be overwhelmed by hunger. Now that you know what abnormal blood sugar is capable of doing to the brain, you can appreciate why managing stress is so important. (When we discuss foods to eat and to avoid, I’ll focus on those that prevent hormonal swings, provide satiety, and prevent hunger, even when you follow a partial fast.)
When our more thoughtful forebrain is running the show, we make healthier decisions (not just about what we eat) and are less stressed. For instance, when researchers examine MRIs that capture images of the brain during meditation, they can actually see the increased blood flow to the neocortex, a healthy circulation pattern that makes us less impulsive. When we’re less impulsive, we think before we act and make better choices about how we treat our bodies. It becomes a positive feedback loop. So reducing stress and learning to manage it effectively, such as with some form of daily meditation, is an important part of the Better Brain Solution.
The male and female brains are nearly identical in structure, but certain hormones can impact behavior and even cognitive function. (I’ll explore this more thoroughly in Chapter 9.) One interesting midbrain difference between men and women affects the choices we make when we’re stressed. When men are stressed, the midbrain takes over to “feed and breed.” They’ll eat and have sex even if disaster is looming. That’s because men don’t have to be concerned about being pregnant, giving birth, and lactating. When women become stressed, it’s yes to feed but no to breed. If a famine is coming, a woman doesn’t want to become pregnant. This ancient survival mechanism has a modern application as a clear incentive for men to keep their female partners happy, not stressed.
Memories begin when an experience is imprinted on the brain. That experience can range from learning how to cook or drive a car, reading a newspaper or book, meeting a person and learning their name, or going on a vacation and taking in the sights. All these experiences, great and small, are ultimately stored in our brains as memories, information that we can access at will when our executive function is working properly.
Memories are scattered in different parts of the brain. Memorized facts are typically processed first in the frontal lobe cortex and then encoded in a region of the temporal lobe called the hippocampus, which is often referred to as the brain’s memory center. Hippocampus is the Greek word for “seahorse,” so named because its structure has a seahorse-like shape.
Habits and motor skills, like riding a bicycle, are stored in the basal ganglia and putamen of the midbrain. Emotional memories, like fear of a snarling dog or joy in celebrating a special holiday, are stored in the amygdala, also in the temporal lobe and near the hippocampus. The amygdala also acts as the fight-or-flight center and, in response to a high degree of fear, can generate instantaneous unrestrained responses. In Greek, amygdala means “almond,” and this part of the brain has an almond shape. Thus with a stroke or a head injury, different types of memories may be lost or retained, depending upon the location of the damage itself.
When you see a word (think of when you learned to read the word cat), you perceive the image in the back of the eye along the retina. Then information is transmitted to the midbrain, processed in the frontal lobes, and stored in the temporal lobe memory center. Thousands of neurons are involved in this type of simple task.
Imagine how many times that has happened over a lifetime, second by second, in an organ that weighs barely three pounds. Now consider the astonishing level of neuron and synapse activity that goes on in your brain when you’re engaged in complicated problem solving, courtesy of your executive function. Is it any wonder that the human brain requires 20 percent of the total energy we obtain through the food we consume? (All the more reason to feed it the right food.)
Entire books have been written on brain structure, and neurologists and other brain experts train for years to learn about every nook and cranny of this complex and nuanced organ. The brain and its many functions is a fascinating topic, and I highly recommend you dive into it and learn more, if you’re so inclined. Researchers are constantly uncovering new facts about neurological structure and performance.
What you’ve just read is by no means a comprehensive guide, but it is meant to provide you with some brain basics, so that you can better understand how lifestyle choices can impact your cognitive function, for better or worse. Now that you have a grasp on what parts of the brain control various aspects of cognitive function, let’s turn to some ways to measure its performance.
It would be wonderful if all of us could take a single test that would accurately measure brain health and cognitive function, taking into account factors like age and overall wellness, predicting problems and noting risks, and highlighting areas that require improvement. We can take blood samples, listen to the heart, perform MRIs, and do other diagnostic testing and preventive screening, but unfortunately, there is no single, fail-safe way to precisely measure normal brain function.
That is, in part, because the most common brain testing tools focus on end-stage memory loss, when it’s too late to reverse damage and strengthen cognition; tools that assess greater levels of function are less standardized and are used infrequently. How best to measure brain function is a controversial topic among experts. The controversy is compounded by the fact that our current health care system focuses on diagnosing and treating diseases, not on improving brain function and performance or taking preventive measures against memory loss. Furthermore, medical insurance usually will not cover the handful of tests that do measure function.
Today the most common tool in use to detect memory loss is the Mini-Mental State Examination, known as the MMSE.
The Mini-Mental State Examination, used extensively in clinics and hospital settings, is essentially a thirty-point questionnaire. It is used so widely that nearly everyone in the health care field understands its scoring system. It takes only five to ten minutes to perform, and it doesn’t require any fancy equipment.
The primary function of the MMSE is to screen for dementia, which turns out to be a disadvantage for some people. It is not designed to distinguish between being mentally sharp and being mentally dull, and it likely won’t identify the very first signs of cognitive loss. Sample questions include
• “What is the year? Season? Date? Day? Month?”
• “Where are we now? State? County? Town/city? Hospital? Floor?”
• “Count backward from 100 by sevens.” (93, 86, 79, 72, 65…)
• “Repeat the phrase: ‘No ifs, ands, or buts.’ ”
If you have an elderly parent or other relative or friend with dementia and have accompanied them on doctors’ appointments, perhaps you’ve been with them when this type of test was administered. Given the types of questions, it’s obviously most useful for screening for dementia, and in fact by the time some patients take (and sadly fail) it, they are often mentally disabled and have become dependent upon others for care.
On the 30-point MMSE scale, a score greater than 27 is generally considered normal, although it may reflect subjective cognitive impairment. Depending upon one’s education, many scientists would consider a score of less than 26 or 27 as mild cognitive impairment, and a score below 23 to 25 as dementia.
There is another concern with using the MMSE. A person who is hearing-impaired or has another physical disability may score low on the MMSE, even though their cognitive function is healthy. The MMSE is not designed to account for such variables and is a guide only for dementia diagnosis. It must be combined with clinical savvy. A health-care professional should not make a diagnosis of dementia based solely on the MMSE.
Though it is widely administered—and it may well be the test you are given if you go to your own physician concerned about memory loss—the MMSE is of little value to someone experiencing the onset of reversible memory loss, or simply wanting to know How sharp is my brain?
For the last decade, if a patient in my clinic has early symptoms of cognitive dysfunction, we use our own Brain Symptom Score questionnaire. It is a far less standardized tool (it hasn’t been used on hundreds of thousands of patients by thousands of doctors, like the MMSE). But it aims to assess whether a person is suffering not from dementia or mild cognitive impairment but rather from cognitive dysfunction fairly early on in the process, To take our test, ask yourself the following questions.
1. Do I lose things (keys, pens, cellphone, glasses) more often?
2. Is it harder to find my car in a big parking area?
3. Is it difficult to remember a bank password and enter it, or a seven-digit phone number and dial it?
4. Do I find myself writing lists to help my memory more than I used to?
5. Am I forgetting names of movie and sports stars or other well-known figures I once knew well?
6. Is it easier to remember an event from twenty years ago than two days ago?
7. Do I have trouble dealing with everyday math problems, like reviewing personal finances, working with numbers at my job, calculating percentages for tipping, and performing household measurements?
8. Am I challenged when I have to learn a software program or assemble a piece of furniture?
9. If I’m in a meeting at work or listening to a detailed lecture, does my mind start drifting sooner than it used to?
10. When I’m working on a project, do I find it hard to get back into the groove after being interrupted by a phone call, text/e-mail, or an office visitor?
How did you do? Score your responses based on the number of questions you answered yes to.
• 0 questions: You’re doing great! I’d suggest you ask yourself this battery of questions yearly.
• 1–2 questions: You’re likely fine, but you should watch for further cognitive loss. Some people have never been good with names or finding their car in a large parking lot. Others may work in an environment that’s chaotic beyond their control. If your company is about to be sold and everyone is constantly interrupting you with the latest gossip, it is probably difficult to return to what you were doing. Not being able to remember names, find objects, or refocus on a task isn’t worrisome, unless these blips are new and worsening with time.
• 3–4 questions: This would be a cause for concern. Check in with your doctor.
• 5 or more questions: Clearly, further mental function testing guided by your doctor would be suggested.
Don’t be discouraged if you scored higher than you’d hoped. The Better Brain Solution can help you improve your results over time. And if you scored zero, that’s a perfect reason to preserve your cognitive function!
In addition to the Brain Symptom Score questionnaire, my clinic uses a tool called Central Nervous System Vital Signs (CNS VS). It is a computerized tool to assess memory, brain speed, attention, and executive function. It takes about thirty minutes to perform. I use it with my patients every year or two to monitor their cognitive function over time. I’ve occasionally repeated this test after four to six weeks when the person scored poorly and has a major medical issue such as poorly controlled blood sugar.
Another cognitive testing system that also includes brain training is BrainHQ. This system is used worldwide and its developers have published results showing an improvement in cognitive function over time.
The aim with my patients, and now with you, is to identify a drop in cognitive performance ten to twenty years before it becomes significant and to try a variety of interventions to prevent that decline. Some of my patients love the challenge of taking this test, and honestly, some of them dread it and ask to skip it. Sometimes I have to remind them that the point is to identify and prevent cognitive decline, as it becomes harder and harder to reverse the loss, and the earlier we identify the process, the easier it is to get better and prevent further loss.
Ask your physician about the CNS VS, particularly if you’re concerned about your score on the test above. Medical insurance generally does not cover tests for optimal cognitive performance, but ironically testing such as I do in my clinic is often covered only if you have real symptoms of memory loss and a medical diagnosis for some type of cognitive dysfunction. The CNS VS test provides a detailed picture of cognitive function and is vastly more useful than the MMSE.
Unhelpful Reminders
For people with established, advanced dementia, a challenging cognitive test like the CNS VS is far too complicated. It can bring people to tears, a frustrating reminder to them of their mental decline. There is little point in subjecting a person already diagnosed with disabling memory loss to such a comprehensive test.
This brings me to another point. A person with dementia doesn’t want or need to be told that they can’t remember things. Such reminders from friends, family members, or caregivers may be done with the best intentions, but telling someone, “You already asked me that question—don’t you remember the answer?” or “I’ve already told you that four times,” verges on cruelty. If they truly have established cognitive impairment, there is no sense in responding this way to their condition. They may no longer be able to remember things, but at a certain fundamental level, they know that their brain function is in deep decline, and it’s extremely painful for them. As my loving mother-in-law Joy once said, “I know I’m losing my memory, but I want to maintain my dignity. Please don’t point out that I’m forgetting things. It’s humiliating.”
Cognitive testing shows that after age forty, brain speed and reaction time gradually decrease. Attention and memory also typically decrease but at a slower rate. Like graying hair or perhaps weakened vision, some of this slowdown is a normal part of aging. Accelerated cognitive loss, however, is different.
One of the first symptoms of accelerated or advanced cognitive loss is a drop in short-term memory. You remember things from years ago clearly, but you can’t quite remember what happened in a meeting one hour ago. I was supposed to do three things when I walked out of the conference room, you think. First, call John…but what were the other two? Sound familiar? Maybe you didn’t get enough sleep last night, or you were distracted during the meeting, but if such episodes are becoming a familiar pattern, that is worrisome.
Another sign of accelerated cognitive loss is that it takes you longer to react to and process information—because your brain speed has decreased. Let’s say you’re driving on the highway and check your rearview mirror. You see a truck is coming up behind you at a fast speed. If your brain is working normally, you instantly know to switch lanes. But if you’re experiencing cognitive loss, it takes longer for you to register the need to take immediate action and to move to the other lane—and that’s a problem. On a more mundane level, perhaps you find yourself rereading a piece of information before you finally comprehend its meaning. In addition, you’re slower to jump from one task to another, an ability that is a marker of executive function. If you work in an environment where you’re required to do just that, accelerated cognitive loss will throw you off your game.
When a Work Slowdown Isn’t on Purpose
Accelerated cognitive loss can impact job performance in a significant, quantifiable way. Take the average high-level professional who might be interrupted by a random thought, phone call, or office mate up to 120 times per day. Each time she is interrupted, it might take her, on average, an extra 15 seconds to get back to work and fully engage with her tasks. That’s 15 seconds × 120 interruptions = 1,800 seconds, or 30 minutes every day, potentially lost. Now suppose she is also experiencing accelerated cognitive loss and functions only at half-speed for the first minute after being interrupted and therefore loses another 30 seconds. That’s an additional 30 seconds × 120 interruptions = 3,600 seconds, or 60 minutes every day. She is losing up to 90 minutes of work time; over a week, that is practically a full eight-hour workday. Let’s make sure this doesn’t happen to you.
With long-term cognitive decline, brain cells are not only functioning more slowly; they are dying. Over time the brain shrinks in volume. Once it has shrunk dramatically, I don’t know of any realistic way to bring it back to normal. That’s why the Better Brain Solution is so important, because it gives you the tools to optimize your current performance and slow or prevent further cognitive decline.
Start by making an appointment with your own physician, who knows you and your medical history. This book can’t and shouldn’t try to replace that relationship, but let’s focus on areas of testing that you and your doctor should consider.
Many physicians will look at standard factors that clarify your risks for developing Alzheimer’s disease. To use the table, see if you have any of the conditions listed, then check to see how much they increase your risk and discuss your concerns with your doctor.
Note that one of the greatest risk factors listed here—diabetes—is also highly preventable, particularly if you follow the Better Brain Solution.
If you don’t have any of these risk factors or signs of cognitive decline and don’t need or want testing, jump ahead to Part II and get started with the plan.
If you have any of these risk factors, read on for an overview of testing that you and your doctor should consider.
When I started medical training back in the 1970s, we didn’t have much ability to scan brains. We were forced to use a physical exam to determine various neurological diseases. The reality is that we can still identify a variety of neurological problems with just a detailed examination. Testing for balance, light touch sensation, vibratory sensation, fine motion and tremor, strength, and agility tells a capable physician a great deal. Such testing often will identify a critical nutrient deficiency: a decreased sense of vibration, for example, is a sign of B12 deficiency, which can cause irreversible nerve injury and memory loss. A detailed conversation—the doctor asking questions and listening to what a patient has to say, from the straightforward yes-no responses to the more nuanced answers—can also provide much helpful information.
Sadly, as the demands of our insurance industry force many physicians to see more and more patients per day, these conversations about a person’s medical history and current state of mind are becoming a lost art. I love seeing only one or two patients a day and having time to chat with them and learn about their lives. Doctors can’t do this when they see thirty to fifty patients per day. In many ways, I’m old school. I still like to try to figure out what might be going on by taking a detailed history and doing a comprehensive physical examination before I jump to imaging and laboratory testing.
Depression is one of the most common medical problems that primary care providers encounter. The combination of chronically high stress levels, limited activity, a low-fat diet, and poor nutrient intake are a perfect storm for causing depressed brain function, which leads to clinical depression. (Yes, I said low-fat—and I’ll explain why in Chapter 3.)
Depression can mimic the signs and symptoms of memory loss and cognitive decline, and it is a major risk factor for memory loss, increasing the risk for dementia 200 percent for women and 400 percent for men.
Certain assessment tools are very helpful, such as the Beck’s Depression Inventory, which you can ask your doctor about. Asking some basic questions, such as the following, can suggest a true medical form of depression with depressed brain chemistry. If a number of these conditions are occurring every day for at least two to four weeks, that could indicate depression.
1. Do you have trouble sleeping? Can you not get to sleep or are you constantly sleepy and can’t wake up?
2. Do you have trouble with concentration?
3. Do you have decreased energy and drive for exercise, sex, and work?
4. Do you have feelings of sadness and pain?
5. Do you lack enjoyment? Do you go about your daily activities and do things with others because you should, but nothing feels like fun anymore?
Depression is easily confused with memory loss, but it’s not the same. Still, if it’s not properly identified and effectively treated, it becomes a risk for dementia. (I’ll offer recommendations for avoiding and reversing depression in Chapter 9.)
Just one incident of serious head trauma can increase a person’s risk of Alzheimer’s by 450 percent. As adults grow older, the effect of even a single traumatic brain injury is cause for concern. In one study researchers compared data from patients in their seventies and eighties who had suffered a traumatic brain injury with others who had been injured (such as a leg fracture) as a result of falling, an unfortunate but common accident among elderly people with balance issues. Those who had traumatic brain injury had a 26 percent higher risk for dementia than those who had other fall-related injuries. A broken hip, arm, or leg is difficult enough, but hitting one’s head is particularly dangerous and puts cognitive function at risk. That is a compelling reason for people to maintain fitness—and balance—especially later in life.
Chronic traumatic encephalopathy (CTE) is a degenerative brain disease that eventually can lead to dementia and death. It is brought on by a history of repetitive brain trauma, including concussions, both with and without symptoms. Athletes who engage in hard contact sports taking blows to the head, such as boxers, as well as football and hockey players, have succumbed to CTE, but this disease is not limited to them. Any person who sustains repeated head trauma is at high risk for CTE. Yet just a single head injury is enough to cause concussion, which has also been linked to dementia.
If you have had one or more serious head injuries, it is essential that you take steps to protect and nourish your brain. When you discuss concerns about memory and cognitive function with your physician, make sure he or she is aware of any head trauma history, even if the injury happened years ago.
If you aren’t depressed but are having troubles with memory and cognitive function, some useful laboratory tests can identify problems that are generally treatable. If such issues are missed, some of them can result in permanent memory loss.
A chemistry profile (also called Chem 20, or CMP) blood test is a good start. If it’s done while you are fasting, it will give you a fasting blood sugar (glucose) level, which is absolutely essential. Given the connection between abnormal blood sugar and dementia, you should know your own fasting blood sugar level, and I hope it is less than 95 mg/dL. This test can also identify low sodium, which impacts memory, liver and kidney disease, and other basic illnesses that impact cognition.
In addition to fasting blood sugar, if I’m assessing for cognitive decline or assessing elevated blood sugar, I will also measure a fasting insulin level, to identify people with insulin resistance who still have normal blood sugar levels. A level greater than 5 μIU/mL suggests early signs of insulin resistance, and clearly an insulin level greater than 10 μIU/mL shows signs of insulin resistance. Some laboratories don’t consider insulin to be elevated until the levels exceed 20 μIU/mL, but that is for diagnosing diabetes, a disease, rather than looking for signs of insulin resistance.
Thyroid testing is essential to identify a treatable cause of cognitive dysfunction, as low thyroid function can be effectively addressed with the right medication. Most endocrinologists suggest a simple thyroid-stimulating hormone (TSH) test to assess basic thyroid function, but I’m concerned that it misses up to 20 percent of people with low thyroid function. In my clinic, for someone with cognitive dysfunction, I always include, in addition to a TSH test, free T3 and free T4 thyroid hormone levels and sometimes thyroid antibodies as well.
I always want to assess inflammation, and the easiest test is for high-sensitivity C-reactive protein (hs-CRP), a marker for systemic inflammation. A major limitation is that if you have been injured or sick thirty days prior to an hs-CRP test, the results won’t be valid, as hs-CRP will be appropriately elevated short term. You should be well and fully healed for at least thirty days before taking this test, to get an accurate result.
Adequate nutrient levels are essential for protecting brain health, but during a regular physician evaluation, nutritional needs are often not addressed, and nutrient levels are not tested. I’ll discuss these specific nutrients in detail in Chapter 5, but keep in mind that vitamin D deficiency will increase your risk for memory loss. Vitamin B12 deficiency can cause serious, irreversible dementia and neurological problems. Omega-3 fatty acids are essential for proper brain function. And homocysteine is a marker for B vitamin deficiencies and predicts an increased risk for dementia.
Testing for toxins is an essential part of cognitive function testing. In particular, lead and mercury can impact brain function.
The tragic events in Flint, Michigan, made lead poisoning a national issue, not only for children but for the whole population. Even in minute quantities, lead is a brain toxin, causing permanent harm. If you live in a house or work in an office that was built prior to 1978, lead paint may have been used that can contaminate the building. Lead pipes, another common source of lead exposure, were used through the 1960s. I recommend lead testing for all children and adults who live in a home or work in an office built before 1978, especially those who have any symptoms of cognitive dysfunction. Your lead level should be zero. (Lead is discussed in more detail in Chapter 8.)
Mercury toxicity is far more common and is associated mostly with large-mouth fish intake. Rising up the food chain from plankton to tiny copepods, to shrimp, to small fish, to bigger fish, to large-mouth fish (like tuna, grouper, bass, kingfish, and swordfish), mercury levels increase exponentially. The larger and older the fish, the higher the mercury levels. Still, seafood, safely consumed, is an excellent source of brain-healthy nutrients, especially omega-3 fatty acids, and it should be a part of your diet. If you eat more than three to four servings of big-mouth fish per month, ask your doctor to measure your mercury level with a “whole blood” mercury test, not just a serum level. I’ll lay out the relationship between fish consumption, mercury levels, and cognitive function in Chapter 8, including how to reduce your risk of mercury exposure.
The final laboratory testing I consider for people with cognitive dysfunction is sex hormone testing, looking at DHEA-S and total and free testosterone for men, and total testosterone, estradiol, progesterone, and DHEA for women. Women going through menopause can have major brain fog, though it is different for every woman. Men going through andropause can have depression, anxiety, and decreased cognitive performance when their testosterone levels drop, and how they feel varies significantly. I’ll discuss assessment and treatment issues for menopause and andropause in detail in Chapter 9.
As you know by now, brain health and cardiovascular health are strongly connected. If you are growing plaque in your arteries, your brain is likely shrinking too. In 2014, I published a paper in The Journal of the American College of Nutrition based on my patient database, to show how cardiovascular risk factors impact cognitive function. My coauthors and I noted that several cardiovascular risk factors—including fitness, and dietary intake of fiber, B vitamins, and fish oil—impacted cognitive scores. By far the strongest predictor of cognitive function was carotid intimal media thickness, which can be determined through carotid IMT testing (see Chapter 1). If you are growing plaque in your arteries, your cognitive function is declining.
This test is different from the typical carotid ultrasound performed in most hospitals and clinics. A carotid Doppler test measures flow through the carotid arteries; a high-velocity flow shows signs of arterial blockage, qualifying somebody for surgery. Long before we can note this advanced state with the Doppler test, we can measure the thickness of the lining of the artery with simple ultrasound testing. No radiation or needles are involved in a carotid IMT test—just a ten-minute procedure to measure the age of arteries. The challenge is that this type of testing is considered age management, not disease testing, so typically it isn’t covered by insurance. The vast majority of medical centers don’t offer this type of testing, but check the resource center at www.DrMasley.com/resources for more information on carotid IMT testing.
Aerobic fitness is one of the strongest predictors of better brain performance and executive function. The gold standard for testing aerobic fitness is to measure the maximum amount of oxygen that you can burn with peak exercise, usually on a treadmill or stationary bike. The resulting score is called your VO2max, as in maximum oxygen volume burn rate per minute per your weight in kilograms.
Much easier and more practical is to use a gym treadmill or elliptical machine to measure your metabolic equivalency (MET) level. If you belong to a gym, seek out an exercise physiologist on staff who does fitness testing and ask them to assess your maximum MET level achieved. Most people with proper training can increase their MET level by one or two points, which will decrease their risk of a cardiovascular-related death by 12.5 to 25 percent. The training also helps them improve mental sharpness and overall cognitive function.
I’ll go over the best activities to improve your brain performance—those that can actually cause the memory portion of your brain to grow in size—in Chapter 6.
As you age, you’ve likely noticed that you don’t feel as sharp after a poor night’s sleep. However, several other aspects of sleep also impact your mental performance, including how much time you spend in deep restorative sleep, such as REM sleep, and whether sleep apnea causes your oxygen levels to drop during the night. A lack of oxygen supply to the brain can lead to brain cell death. Clearly anyone with a history of waking up gasping during the night, having headaches in the morning, and sleeping during the day needs testing for sleep apnea. But most cases are not that dramatic. Key signs of sleep apnea are afternoon sleepiness, or a partner who says you stop breathing during the night. (Some people with sleep apnea are also very loud snorers because their breathing is obstructed.)
When people with poor sleep—whatever its cause—improve its quality, they see a big improvement in cognitive performance. We’ll explore more sleep issues in Chapter 7. If you are considering some form of a sleep study and are on the fence, note that many of my patients were not even aware, before their testing, that they had terrible sleep!
In the past, to have a sleep assessment and check for sleep apnea, you needed to spend a night in a hospital for overnight monitoring and observation. But now a simple device can be used at home—it consists of a headband with a recording feature. (We use it at my clinic.) If you have a mild case of sleep apnea, you can wear a mandibular device—basically a fancy mouthpiece—to keep the airway open at night. For more advanced cases, we recommend treatment with a CPAP, a machine that blows pressurized air into your mouth or nose to keep the airway open. It requires overnight testing at a hospital and careful adjustments to the pressure levels to ensure the open airway is maintained.
Computerized cognitive testing was originally designed for pharmaceutical studies that were treating such conditions as head injuries, attention-deficit hyperactivity disorder (ADHD), memory loss, or Parkinson’s disease. As the databases have grown, we now have far more applications to assess cognitive function. We can use these tests to assess response to a treatment and clarify whether brain processing or memory has improved. Many tools are available—CNS VS (this page) is an example of such a test. Clinics specializing in neurocognitive testing frequently offer these tests, but they are typically not available in a primary care medical office. The website www.BrainHQ.com also offers forms of cognitive testing and training.
• A simple brain scan, such as computed tomography (CT) or magnetic resonance imaging (MRI), looks at structure, not function. The images it produces can identify a blood clot on the brain, increased fluid in the brain, and other treatable problems. These tests are expensive, but if a person has real memory loss, the price of treatment and care becomes so astronomical that most insurance companies will cover some form of brain scan.
• Amyloid plaque brain scans are used primarily to assess for beta-amyloid plaque formation, which, as we have seen, is highly suggestive for Alzheimer’s disease. These scans (usually not covered by insurance) have been available since 2013–14. There is a major limitation in trying to draw conclusions from amyloid screening. Thus far, drugs that block amyloid production don’t seem to be working nearly as well as we had hoped and sometimes even cause harm. It may be that amyloid production is a marker for Alzheimer’s disease, such as protecting the brain from an infection, but not the cause of memory loss itself. Amyloid production might even be a protective adaption by the brain to avoid loss in volume and damage.
Functional brain imaging reveals how well cells in various brain regions are working by showing how actively they use glucose or oxygen. Examples include positron emission tomography (PET) and functional MRI (fMRI), which measure glucose uptake in specific regions. Radiotracers are also used to detect cellular and chemical changes linked to specific diseases, as in single photon emission computed tomography (SPECT). The mainstream medical community is not ready to advocate these types of functional brain testing for everyday patients, and medical insurance generally does not cover them. But a variety of clinics provide these services, and some individuals will gain tremendous insight from this type of evaluation.
Genetic factors can increase your risk for memory loss, but they don’t determine whether it actually happens. Most genes are pleomorphic, meaning that lifestyle choices modify how and whether we express those genetic features. If your brain is a target, and your genes are the gun, your lifestyle is the trigger that may or may not fire the gun. Some genetic tests won’t change your outcome, like testing for the dreaded Huntington’s disease, which has no cure and, for the moment, no clear path to prevention. But some more common genetic testing options do have an impact and have action plans that should reduce your risk.
If you have a family history of dementia, or you are concerned about decreased cognitive function, then you should address at least two genes. The first is the ApoE gene; the second is the gene associated with converting folic acid into biologically active forms of folate.
Apolipoprotein E (ApoE) is a gene that has consistently been associated with longevity. It is a complex plasma protein that plays an important role in cholesterol metabolism and inflammation. In humans, ApoE has three major forms: ApoE2, ApoE3, and ApoE4. All early humans and primates had the ApoE4 gene; 220,000 years ago a mutation occurred and the ApoE3 gene emerged, and 80,000 years ago the ApoE2 gene occurred. Now, only 20 percent of people have the ApoE4 gene.
Each person has two of these genes, be they a double of E2, E3, or E4 or a mixture of E2, E3, and E4. Of these three, ApoE3 is now the most common. The ApoE2 genotype is associated with people living to one hundred, and ApoE4 has been shown to be associated with age-related diseases, including heart and Alzheimer’s disease. To clarify the different risk for Alzheimer’s disease based upon the ApoE4 genotype, consider that:
• For 80 percent of the population with either the ApoE2 or 3 genotypes, 9 percent get Alzheimer’s disease in their lifetime.
• For 75 million Americans (20 percent of the population) with a single ApoE4 gene (heterozygotes for the gene), 30 percent get Alzheimer’s disease in their lifetime.
• For 7 million Americans (2–3 percent of the population) with two ApoE4 genes (homozygotes for the gene), 90 percent get Alzheimer’s disease in their lifetime.
If you are among the 20 percent of the population that has an ApoE4 gene, your risk for Alzheimer’s disease increases threefold. If you have two ApoE4 genes, your risk is fifteenfold higher than someone who has ApoE2 and ApoE3 genes. A single ApoE4 gene also increases the risk for heart disease by 42 percent compared to people without it.
People with a single ApoE4 gene have increased inflammation pathways to fight infections, but decreased brain and artery protection mechanisms and decreased brain repair mechanisms, so it is absolutely critical that they follow an optimal-health lifestyle, like the one outlined here. (For those with the ApoE4 gene, see Chapter 10 for tips on lowering the risk of cognitive decline.)
Methylation is a process that helps repair damaged DNA. If you can’t protect your DNA with methylation, then you have an increased risk for memory loss, cancer, and heart disease.
Methylenetetrahydrofolate reductase (MTHFR) is a very important enzyme in the body, responsible for converting basic folic acid from our diets to a usable form of folate called 5-methylenetetrahydrofolate. If you don’t have this enzyme, you tend to form a toxic compound, homocysteine, that is an indicator of poor methylation.
Many foods, like flour, are fortified with basic folic acid, and many supplements contain it as well. The challenge is that nearly 40 percent of people have a genetic defect and lack this special enzyme, so they cannot make this conversion.
Genetic testing can clarify whether a person has the ability to make this folate conversion. For my own patients, I always recommend a multivitamin with activated forms of folate (including adequate 5-MTHF) instead of inexpensive folic acid; the genetic testing seems less important when one is already treating for this condition. Be aware that if you are taking a standard, inexpensive multivitamin from a pharmacy or grocery store; if you have a family history of dementia; or if you’re wondering if poor methylation might be a factor for you, you should discuss testing and treatment options with your doctor. (I’ll clarify how to find a multivitamin with the best forms of folate in Chapter 5.)
Educating yourself about tests like these is important. At the very least, start with a baseline physical exam, and then, depending on your history, ask your doctor about the value of these other assessments.
Whatever results you may get from all those lab reports, facts, and figures, the biggest takeaway remains this: controlling blood sugar, remaining or becoming active, stopping smoking, managing stress, reversing nutrient deficiencies, and eating the right foods can prevent up to 60 percent of all dementias. And since we can’t totally prevent dementia—it typically occurs at the end of life—simply delaying its onset by just five years could decrease its prevalence by nearly 50 percent.
Let’s begin with my easy-to-follow Better Brain Solution, the plan that will improve your cognitive function and prevent future memory loss.