Brain Rules for Aging Well: 10 Principles for Staying Vital, Happy, and Sharp

by John Medina

Researchers noticed years ago that fit seniors seemed smarter than sedentary seniors, even when wading into the deep end of the statistical pool. Especially powerful were results linking aerobic exercise to changes in executive function. If you survey a large number of studies (called a meta-analysis) looking at aerobics and EF, you see really impressive numbers. Elderly individuals who regularly exercised scored higher, sometimes stratospherically higher, on executive function tests than sedentary controls (effect sizes, which are measures of correlation, were almost seven times greater with exercisers than with couch potatoes). It is quite rare you get such clear numbers in work of this kind.

One study got a 30 percent boost in executive function scores after a skimpy three-month exercise program consisting of an even skimpier “walking regimen.” Some studies show much greater improvements. And the boosts appear to be long-lasting.

Harvard’s Frank Hu have said: “The single thing that comes close to a magic bullet, in terms of its strong and universal benefits, is exercise.”

not all parts of executive function are susceptible to exercise. The ability to focus, for example, seems impervious to exercise. The effects of exercise on working memory are also mixed. Some studies show a boost if the workout is aerobic; others show no effect at all.

People who do aerobics bulk up their hippocampal volume by a whopping 2 percent. In contrast, people who just do stretching exercises show a decrease of 1.4 percent. People who do nothing, just letting nature take its course, lose 2 percent.

Connectivity increases, enabled by the neural cell bodies in gray matter. One study showed an 8 percent increase in global gray matter for seniors who exercised. And the effect was as durable as a tax increase. Nine years later, the exercising group still had more gray matter than sedentary controls. Astonishingly, this elevation reduced their risk for dementia twofold.

Exercise stimulates a process called angiogenesis (literally “vessel creation”), and the protein responsible for it is called VEGF—pronounced “vedg-eff,” as in vegetables. It’s actually short for a tongue twister: vascular endothelial growth factor. It does for blood vessels what BDNF does for neurons. It makes them grow.

By exercising, you are not just slowing age-related decline. Your brain actually gets better at its job.

Research into human nutrition is ridiculously hard—and surprisingly expensive—to do well. Food is complex stuff: even a simple sandwich is composed of hundreds of biomolecules.

It’s been observed for centuries that people who eat less seem to live longer—and are oddly happier—than those who gorge themselves. This has striking confirmation in the laboratory, at least if you’re a rodent. Severe calorie restriction can lengthen life expectation in certain animals by a whopping 50 percent compared with typically fed controls. The incidence of their many age-related diseases (cardiovascular disorders, numerous types of cancers, neurodegenerative disorders, cancers, diabetes, etc.) goes down—way down—with calorie restriction. The earlier they start, the better the numbers become. Lengthenings have been shown in virtually every animal tested—even fruit flies.

Another unexpected result is that dieters slept better. They had more energy (weird, because they were actually consuming less energy) and were in a better mood (even though they were probably hungry all the time).

eating southern European food was associated with cardiovascular health, the most interesting result was discovering a big-time arrest of cognitive decline, not associated with cardiovascular issues at all.

Nutritional epidemiologist] Martha Clare Morris has found that the so-called MIND diet—which is rich in berries, vegetables, whole grains, and nuts—dramatically lowers the risk of developing Alzheimer’s.

“Eat food. Not too much. Mostly plants.”

Both calorie restriction and plant-based diets exert their anti-aging effects through hormesis, at least in lab animals, and there’s increasing evidence of similar mechanisms at work in humans, too. These repair mechanisms fix everything from faulty proteins to leaky cell membranes. They allow extra calcium into nerve cells, strengthening their activities. Certain growth factors become stimulated, such as neuron-loving BDNF (which, as you recall, does many positive growth-related things for the brain’s neural constituencies). Dietary restriction stimulates hormesis by convincing the cells that their owner is starving. If calorie reductions are continuously experienced, the repair mechanisms are continuously activated.

researchers show that experiencing such restrictions only five days a month confers the age-related benefits; more than that and you risk negative physiological effects.

Plant-based diets exert their effects because they are filled with so-called phytochemicals, which endlessly tell your brain cells that they are, well, vegetables. These phytochemicals somehow persuade those antioxidant armies we discussed earlier to come out of retirement and start taking out the trash, free radicals and all. Combined with the way exercise boosts blood flow, critical for waste removal, you’ve got a powerful maintenance crew. Phytochemicals also persuade nerves to make more BDNF, jump-starting the process of making new neurons. That the body might think of eating vegetables as an irritating stressor is not lost on this author. But as long as you continue annoying your cells, you also stimulate their life-extending molecules.

SUMMARY MIND your meals and get moving • Executive function—a suite of cognitive gadgets enabling emotional regulation and cognitive control—tends to fade with age, as the brain’s repair mechanisms break down. • Greater physical activity means greater intellectual vigor (improvements in executive function) regardless of age. • Though it is only 2 percent of your body’s weight, your brain consumes 20 percent of the calories you eat. • Cutting caloric intake has been shown to reduce chemicals associated with age-wrecking inflammation, improve sleep and mood, and boost energy level—all findings associated with longer life. • Diets rich in vegetables, nuts, olive oil, berries, fish, and whole grains (such as the Mediterranean diet or the MIND diet) have been shown to improve working memory and lower the risk of Alzheimer’s.

No one looks back on their life and remembers the nights they had plenty of sleep. —Anonymous

I’ve reached the age where happy hour is a nap. —Anonymous

Sleep must involve energy restoration, right? Wrong. Or at least partly wrong. Bioenergetic analysis shows the energy savings during sleep is only about 120 calories, the same as a bowl of soup. And your brain is mostly to blame for this. It’s the power hog of the body, taking 20 percent of the energy you consume and required to remain active 24/7 to keep you alive.

You need to sleep not to rest but to learn. Nighttime is the perfect time for it, when there’s little competing information bombarding your brain for attention. As research continues, it has demonstrated that sleep aids other functions, from digestion to keeping your immune system humming along. Slowly, we’re beginning to understand why you need to sleep. It’s not because you need to rest. It’s because you need to reset

sleep to look for patterns, and they summarized their findings this way: “Maintaining good sleep quality, at least in young adulthood and middle age, promotes better cognitive functioning and serves to protect against age-related cognitive declines.

Here’s the bottom line: you need to get between six and eight hours of sleep every night, no more and no less.

He suggested people get rid of their alarm clocks. He encouraged insomniacs never to try to sleep, declaring it just makes them more aroused. And he recommended people keep track of their sleep habits the way some people keep track of their diets. His ideas were eventually codified into the book No More Sleepless Nights. It was for years the go-to book for treating insomnia.

1. Pay attention to the afternoon. Getting a good night’s sleep starts with paying attention to what you’re doing four to six hours before you go to bed. No caffeine six hours prior. No nicotine. No alcohol, either. Alcohol, legendary for inducing drowsiness, is actually a biphasic molecule possessing both sedating and stimulating properties. Drowsiness occurs initially; the stimulating effect much later. When you drink, you spend less time in REM and SWS, especially in the terminating night hours. Exercise has a profoundly positive effect on your ability to sleep, but you want to do it earlier in the day.

2. Create a sleep “terrarium.” Designate a place in your house where the only activity is sleep. That’s going to be the bedroom for most people. Don’t eat there, don’t work there, don’t have a TV there. Just sleep.

3. Watch the temperature. People fall asleep ideally around 65 degrees. Make sure the room you just designated as Sleep Central is cool.

4. Create a stable sleep routine. Go to that cool single-use bedroom of yours at the same time every night. Wake up at the same time every day. No exceptions. If you’re unable to fall asleep in time to get six or seven hours of sleep at first, continue to wake up at the same time, to reset your routine.

5. Pay attention to your body’s cues. If at all possible, don’t bed down until you’re tired. And if you wake up during the night, don’t turn the experience into an Olympic toss-and-turn fest. If you can’t fall asleep after thirty minutes, don’t stay in bed. Get up and read a dead-tree (non-electronic) book. Especially one that’s boring.

6. Pay attention to light exposure. Expose yourself to bright light during the day, dim light during the evening. This mimics what our brains were used to experiencing d...

8. Visit lots of friends during the day.

9. Keep a sleep diary.

1. Subjects were to reduce the amount of time they spent in bed (six-hour minimum).

2. Subjects were to observe a strict adherence to a daily schedule, arising from bed at the same time—even if their previous sleep was of low quality.

3. Subjects were not to go to bed until sleepy, regar...

4. Subjects were not to stay in bed for long if they had not fallen asleep.

Fifty-five percent of the group who underwent the treatment showed no insomnia by the time they were finished. That’s complete remission, folks, from a formerly very sleep-troubled population.

SUMMARY For clear thinking, get enough (not too much) sleep • Scientists don’t actually know how much sleep you need per night. Nor do we fully understand why you need to sleep. • The sleep cycle is born of a constant tension between hormones and brain regions vying to keep you awake, and hormones and brain regions trying to make you go to sleep. This is called opponent-process theory. • Sleep, we are finding, doesn’t have as much to do with energy restoration as it does with processing memories and flushing out toxins in the brain. • As you grow older, your sleep cycle becomes more fragmented, particularly the part of the cycle during which toxins are flushed out of the brain. • Accruing good sleep habits by middle age (a stable sleep routine; no caffeine, alcohol, or nicotine six hours prior to going to sleep) is the best way to avoid sleep-related cognitive decline in old age.

“The participant’s score at age eleven can predict about 50 percent of the variance in their IQs at age seventy-seven.” That means performance measured at puberty can predict with astonishing accuracy performance six decades later. No other factor comes close: not external activities, not level of education, not physical activity, nothing.

All told, anywhere between 25 percent and 33 percent of the variance in life expectancy can be explained by how well you chose your parents.

GHR-KO 11C lived almost twelve more months, dying just short of its fifth birthday. If that animal had been human, it would have lived almost 180 years.

Researchers know how to extend the life of many familiar lab denizens now. One creature, a roundworm with the tongue-twisting name Caenorhabditis elegans, has met with especially spectacular success. Mutating a gene called age-1 can extend its life to more than 270 days. That’s amazing, considering it usually only lives about 21 days. If that animal had been human, it would have lived to almost eight hundred years.

The threshold beyond which a cell no longer is allowed to split is called the Hayflick limit.

The last bit of DNA tip is not replicated. This surrender is as constant as paper jams. It occurs on all chromosomes and happens every time a cell reproduces itself. Since some cells reproduce every seventy-two hours, the tips get shorter and shorter by the week. Researchers now know that this serial amputation serves as a kind of doomsday clock: when enough of the tips have been lopped off, the cell gives up and dies.

If telomerase were allowed to add back tips whenever it saw a stump, there’d be no “time’s up” signal. Cells would replicate in an unrestricted fashion and, as long as they were given enough food, never die. They’d be immortal. We have a name for cells that replicate uncontrollably. We call it cancer.

In the twisted logic of biochemical survival, death is nature’s way of keeping you from getting cancer.

You don’t have to rely on genetic engineering to compel sirtuins to overproduce. Ingesting exotic-sounding biochemicals like chalcones and flavones and anthocyanins and resveratrols also do the trick. The first three of these molecules are found in fruits and vegetables, the last in wine.

These mice, it seemed to Wyss-Coray, were getting younger. He wrote in a paper published in Nature Medicine: “Here we report that exposure of an aged animal to young blood can counteract and reverse preexisting effects of brain aging at the molecular, structural, functional, and cognitive level.”

SUMMARY You can’t live forever, at least not yet • Aging is not a disease, rather a natural process. People don’t die of old age; they die of biological processes that break down. • Genetics is responsible for between 25 percent and 33 percent of the variance in life expectancy. • The Hayflick limit is the threshold beyond which a cell can no longer divide, leading the cell to deterioration and, eventually, death.