The Mindspan Diet: Reduce Alzheimer's Risk, and Keep Your Brain Young - Softcover

Preston W. Estep is an esteemed genome scientist, who is Director of Collections and Director of Gerontology at the Harvard Personal Genome Project. He is frequently called to address professional and public audiences, and is often interviewed journalists on genetics and longevity. He is an adviser to many start-ups and non-profit organizations in the healthcare industry. He lives in Weston, Massachusetts.

1.

Mindspans on the Move

It ain’t so much the things we don’t know that get us into trouble. It’s the things we know that just ain’t so.

—Probably said first by Henry Wheeler Shaw (pen name Josh Billings), but also attributed to Artemus Ward and to Mark Twain

Our highest aspiration should be to make our mindspans soar—to maximize both longevity and mental performance. With our best possible minds we can confidently tackle the most challenging problems; we can better forecast and plan for the future; and we can live the fullest and happiest lives. In other words, we can experience and do everything better. Now, however, we face our days with less certainty and confidence.

According to recent polls, Alzheimer’s disease is the most feared diagnosis. Some of our uncertainty and fear about the future comes from the lack of scientific consensus on the most healthful path forward. There are all manner of claims, from hopelessly bleak to hopeful and inspiring. Some say nothing can prevent or substantially slow the decline. Others say cognitive decline can be stopped and even reversed by some implausible miracle cure. Both are wrong. I selected the Josh Billings quote to head this chapter because, of all the health-related information that inundates us these days, critical parts just ain’t so. They just ain’t. And, as Mr. Billings said, that gets us into trouble.

Choosing a Diet

I have seen and heard about countless diets over the decades. Most focus on weight loss, others on physical fitness or athletic performance, some on health. These are all laudable goals, but neglect what is most important: the long-term performance and health of your mind—and the minds of your loved ones. Think about being a caretaker for many years for someone you love as he or she slowly descends into the abyss of mental darkness we call dementia. Now reverse the roles and picture your loved ones caring for you as all of your memories and relationships fade one by one, leaving them to care for your progressively debilitated body and your ravaged mind. We want to remember the best of our loved ones, but it is difficult to disregard the repeated questions, odd behaviors, incontinence, and the like. The only reasonable goal in choosing a diet is maximum mindspan.

In recent years, both fatty foods and carbs have been vilified. Common assertions are that we’re being poisoned by our foods, we’re suffering from our bounty, and our diets and health are worse than ever. I agree generally with the first two of these claims, but not with the specifics. As for the state of our diets, in some important ways, they are better than ever. But that doesn’t stop the grim downpour of gripes and the rising tide of misguided solutions.

Some health gurus harken back to bygone days. They say if we could go back many millennia we’d see people living in pristine health. As we’d chat around the campfire with our cave kin, they’d be amazed by our descriptions of computers, cellphones, and routine airplane travel while being equally puzzled by our relatively recent ailments such as heart attacks, cancer, and dementia. These gurus are fascinated by our Paleolithic ancestors’ health, speculating as to why, for example, starches made up such a tiny fraction of their daily diet.

While our kin of millennia ago were leaner and far more active and diabetes was much less common, the juiciest parts of these stories—especially those used to justify currently popular Paleo diets—come from imaginations gone wild. Genetic evidence shows that over time humans have been evolving an increasing ability to digest starches and sugars. (Today, for example, we produce more than five times the amount of digestive enzymes needed to break down starches as chimps, our closest ape relatives.) The changes with the largest effect date to at least 50,000 years ago, which contradicts the belief that starch consumption is recent and therefore evolutionarily unimportant.

Scientists agree that diseases of older age such as heart disease, cancer, and dementia were less common many thousands of years ago—but primarily because old age as we know it was less common. In fact, mummies from around the world are found with cancer, atherosclerosis, arthritis, and other diseases, which appear to have been at least as common then as they are now when age is taken into account.

If we flash back to the turn of the twentieth century, we’ll see that the current ailments of old age were common. In fact, the age-adjusted rates of cardiovascular diseases—which remain leading killers today—occurred more frequently, as did age-adjusted rates of other deadly diseases, such as pathogenic infections.

Still, more than a hundred years later, it is clear we have some big problems, one of which is that many people have an unnecessarily high risk of cognitive impairment. It is very disturbing that as people and countries become wealthier, cognitive problems in later life become more common. But to see the best direction forward in dealing with such risks, we must get our facts straight.

Maximum Mindspan Means Optimal Health

Mindspan translates to longevity and performance of the mind, and it is the ultimate measure of overall long-term health. If the cardiovascular system is in poor shape, blood flow to the brain is impaired. Similarly, poorly functioning kidneys, lungs, or liver also impact mental performance. It is therefore unsurprising that a host of leading health problems, including diabetes and high cholesterol, are risk factors for mental decline. Optimal health and longevity of the body come baked into the overall recipe for achieving maximum mindspan. If you are eating a conventional diet—even one typically considered healthful—my dietary program will reduce your risk of all killer diseases.

Mindspan Rising, Mindspan Falling

First, the good news: We’ve made impressive headway in just the last few generations, both in overall longevity and in performance of the mind. Over the last 150 years, industrialized countries have achieved the greatest longevity increases in history. Improved prenatal care and reduced infant mortality have driven huge gains not just in overall life expectancy, but in adult years too. My great-grandparents were born just before the turn of last century. When they were children in the year 1900, a seventy-year-old woman living in the United States could expect to live about nine more years, a statistic that has increased to fifteen years today. And recent trends in record long life show accelerating growth. Between 2000 and 2010, the percentage of centenarians (age one hundred and up) of many populations increased dramatically—even more than doubling in some, including in Japan, which leads the world in longevity.

The realm of the mind has experienced similar gains. Modern mental testing didn’t become common until after the turn of the twentieth century; but once started and applied widely, testing showed gradual increases similar to those observed for longevity. The mental realm is highly complex and important changes are less easily measured than those in longevity, but measured gains in memory, IQ, and other cognitive functions are impressive: reportedly as high as 25 percent over the twentieth century. As with life expectancy, previous increases of this magnitude likely took many times longer.

While these gains are most often measured in children and adolescents, tests on adults show gains across the board, including in older adults (which is one of the important developments opposing the trend toward increased dementia as people live longer). In other words, it appears people are living longer than ever at about the highest-ever cognitive level. According to these mental test data, adults today are more intelligent than those of generations ago. The fact that these gains are both substantial and persist into later years shows they are at least as impressive as gains in overall longevity. Sensationalist headlines like “Aging Reversal Process Discovered!” aside, these two important types of gains are synergistic and together constitute increasing mindspan.

When we look deeper into the historical and global trends of rising mindspan, there is reason for hope . . . but also for serious worry. And unfortunately the bad news seems pretty grim. Mindspans of some developing nations are still on the rise, but there are alarming signs that mindspan growth has plateaued in developed nations. Most concerning, recent reports suggest that dementias and other neurodegenerative diseases such as Parkinson’s are already much higher in developed nations (comparing people of the same age), and might still be on the rise in the United States, Europe, and most other affluent nations of the world. Some of these reports suggest that many in higher-risk countries begin to develop memory problems as early as their forties.

According to a recent study, “deaths from Alzheimer’s disease and other dementias rose more than three-fold, and deaths from Parkinson’s disease doubled” globally between 1990 and 2010. It’s not just longevity driving this trend. These diseases appear to be increasing in frequency at every age, and in fact the age-standardized death rate from Alzheimer’s and other dementias doubled over just two decades.

However, even this alarming trend might seriously underestimate the magnitude of both current and future problems. Alzheimer’s disease is responsible for over 500,000 deaths annually in the United States, which is six times higher than the official estimate of the Centers for Disease Control and Prevention. This level of mortality makes Alzheimer’s disease the number three killer (maybe even number two) and suggests that it could become the number one killer in the near future. You may have been hearing for years of the coming wave of dementia as the baby boom generation ages, but this study—and others—shows that the worrisome wave is likely to become a devastating tsunami if this trend isn’t reversed very soon.

Getting a Grip

Our genes haven’t changed in the past two or three decades, but our foods, diets, and lifestyles have—radically. But I believe we can reduce risk to far below what it was even before then. Why? Because many independent strands of solid scientific evidence tell us that we have substantial control over mindspan. Dietary and lifestyle factors in developed countries have contributed negatively to dementia rates, yet certain stealth factors have produced the opposite effect. The Rolling Stones famously lamented that “you can’t always get what you want,” but I say sometimes you get more of a good thing when trying to get something else. Some of the gains in longevity and cognition have come from a focus on comfort and quality of life. As discussed at length in later chapters, coffee, tea, and red wine are flavorful ways to improve energy and mood, and certain modern pain relievers like ibuprofen reduce inflammation, but they also reduce dementia and produce other benefits. People seeking immediate mood or energy tweaks or relief from the pain of a bad back or balky knee have achieved long-term cognitive side benefits without intending to.

Other factors that have produced increased mindspan as side benefits include improved sanitation, water and food abundance and quality, and a range of other public health measures. But while these gains may have come easily, we’ve probably reaped most of the benefits we can from them. If we want to make more headway, we need to look for new sources. Even greater future mindspan gains are possible, but going forward, we need to apply key scientific knowledge and technologies more thoughtfully and precisely.

Eating Better as You Age

The second half of life is regarded somewhat differently across cultures, but one universal among them is that older means wiser, and thus we tend to entrust older people with more responsibility. Here in the United States, where we have a law that restricts the office of the presidency to people thirty-five and older, the average age at the start of all presidential terms is fifty-five, and our youngest president—John F. Kennedy—was just shy of his forty-fourth birthday when he took office. Even in countries without such laws, ultimate responsibility is almost always given to someone well into the second half of life; in the United Kingdom between 1800 and today, for example, the average age a prime minister first took office is about fifty-six.

People begin to slow down physically before this peak in wisdom and leadership (some have even theorized that this physical slowdown is an essential part of the rise to emotional and mental maturity). The technical term for this slowdown is senescence. But we don’t just get slower, our needs actually change. We respond differently to food, drink, exercise, and sleep, among other things. Over the decades of the second half of life, these changes add up, as do the benefits or costs of our choices. The importance of this change is underscored by focusing on the leading risk factors for Alzheimer’s disease.

Mainstream science has identified the most important genetic contributors to Alzheimer’s disease (which we’ll discuss in detail in chapter 5). The medical community has pursued treatments to correct the problem caused by one of these genes. Yet most experts don’t realize that the interaction of this gene with a ubiquitous environmental trigger negatively impacts cognitive functioning in virtually all older people.

Alzheimer’s disease is diagnosed in less than 10 percent of Western populations, but according to the Alzheimer’s Association, less than half of Alzheimer’s sufferers or their caregivers are told of their diagnosis (possibly because so many believe nothing can be done anyway). It’s also widely believed that an additional 10 to 20 percent of people suffer from other lesser or unrelated forms of dementia. Some estimates using relaxed criteria say more than 40 percent have some impairment. But even this figure underestimates the extent of age-dependent cognitive compromise. As chapter 5 explains in detail, most cases of Alzheimer’s disease and dementia have the same primary genetic cause, and it is not an uncommon genetic variant. In fact, this root genetic cause is so common it is nearly universal.

All forms of dementia also have common environmental causes, such as the ingredients in our foods. The public remains unaware of these dangers despite being assaulted by them every day. At the moment it is impossible to prove which influence cognition more, genetic or dietary factors, but my belief is that diet has a substantial and possibly greater capacity to either increase or decrease mindspan. Many dietary factors act as volume controls to turn the level of genes up or down or as switches to turn them on or off. In fact, iron is a primary dietary risk for neurodegeneration and dementia because it turns up the volume on this key gene that increases the risk of Alzheimer’s disease.

Diet: The Mindspan Maximizer

Currently we cannot change our genes, but we can change how they behave with a few potent factors: exercise and physical activity, sleep, drugs, and even our state of mind. But diet exerts the most profound and lasting effect. The critical role of diet isn’t very surprising, given that a typical person will eat about forty tons of food in a lifetime.

An outstanding dietary and lifestyle pattern reduces risk of heart attack, stroke, and other cardiovascular complications by 90 percent or more. The Lyon, France, heart study produced a 76 percent reduction in all-cause mortality by boosting the Mediterranean components in the diets of people already eating typical French diets—which are better and result in fewer cardio...