Even genetics aren't set in stone when it comes to dementia, which is good news for America's more than 46 million seniors ages 65 and older. Choices do make a difference, with nutrition, exercise and sleep all playing a role in healthy aging. And it's never too late to start.
Dr. Timothy R. Jennings, board-certified psychiatrist, brain expert and author of "The Aging Brain: Proven Steps to Prevent Dementia and Sharpen Your Mind," says those who think dementia, disability and dependence are just part of growing old don't know there are strategies almost anyone can undertake to age well and maintain a healthy brain. "If you live a different way, you can live long without dementia."
The changes are simple, says Jennings, who is careful to explain the biology behind why his recommendations work. And you can start right now, at whatever stage you've reached in life, to make a difference to your future.
We asked Jennings, who's also a lecturer, master psychopharmacologist and clinician in Chattanooga, Tennessee, for some simple advice. This interview has been lightly edited for clarity and length.
The big overview is physical exercise, healthy lifestyle and food choices. The two diets that have been shown to correlate with better brain volume, better cognition, better memory and reduced dementia rates are the plant-based diet and the Mediterranean Diet.
Then mental stress management — learning how to unwind and relax. A lot of things correlate: healthy families, learning how to resolve conflict well and not hold grudges, how to forgive people who have done you wrong, weekly sabbath rest experiences, meditation on a regular basis. All of them work in the same vein, learning how to turn off the brain's stress circuitry.
Breaks from the rat wheel have a profound healthy effect on us. And also sleep. Sleep is a physical requirement along with food, water and air. It is important to manage sleep well and get unmedicated sleep.
That point would be late-stage dementia. Multiple studies have shown benefits for people with mild cognitive changes who do not meet criteria for dementia but have symptoms that are measurable — forgetfulness or being slower at cognitive tasks.
If those people start exercise; a diet that moves away from being an oxidative diet (the junk food, the fat food, the high-sugar diet, fried foods) and toward more plant-based diet; do stress management; and get sleep — if they do all those things, those people will not progress to dementia. At worst, they maintain. Some of them even improve.
If I had a patient who couldn't walk, I would refer them to a physical therapist or their primary care doctor, send them to work with a trainer, get them into a pool of water, do something with their arms with weights or other types of activities that their bodies can handle. Very few can't do something.
Regular exercise increases blood flow to the brain so you get better circulation, better oxygenation, better nutrients. It turns on all the proteins in the brain that stimulate the brain's new growth, so you get new connectivity, new neuronal growth. It causes insulin sensitivity so it reduces insulin resistance. That's critical to brain health. Not only does it reduce diabetes type 2 issues, but in the brain, insulin is essential for clearing amyloid (the toxic protein that builds up in Alzheimer's dementia). People who have insulin resistance in the brain have higher rates. Exercise helps reduce the buildup of amyloid by resensitizing the insulin receptors.
They are just separate manifestations of an underlying process, and that is oxidative stress on the body, which drives insulin resistance. The underlying pathology is a chronic inflammatory state either from chronic worry, negative thinking, running the rat race, not getting enough sleep, unhealthy food choices — all of it really fuels the same path in our body.
Type 2 diabetes increases your risk of Alzheimer's dementia because of the underlying pathology that drives it. Obesity increases your risk. The brain of an obese person at 70 has 8 percent less brain volume and looks 16 years older than a normal-weight person at 70. There are a variety of reasons for that, too. It's not just obesity. Why is the person obese?
Adipose tissue produces more oxidizing molecules. Cut an apple, leave it and come back 30 minutes later, it's brown. That's oxidation. Rust is oxidation. It's oxygen interacting with molecules, damaging them.
Our bodies have a series of antioxidant pathways and molecules to help protect us. Obesity produces oxidizing molecules and interferes with the body's own anti-oxidant enzymes. Additionally, people who are obese tend to not exercise as much, so they lose the good circulation in their brains. They tend to have sleep problems, so they don't get normal sleep cycles and sleep is critical because during sleep the brain clears the byproducts and metabolites out of the brain. They tend to eat unhealthy food, so they are ingesting a lot of oxidizing and inflammatory substances through their diet. Obesity is a marker to somebody who's generally living a lifestyle that's unhealthy.
Some factors are genetic. So if a person is obese but eats a plant-based diet and has good sleep and no sleep apnea or it's being treated, walks 20-40 minutes every day, has good stress management and rest, they will still benefit from all these healthy things even if their weight never changes. They will have a lesser chance of dementia.
The brain is 2 to 3 percent of body weight but uses 20 percent of the body's energy. It's highly metabolic, burning a lot of fuel. And it has a lot of waste products or byproducts to be cleared. If waste products don't clear, they become inflammatory and oxidizing molecules that cause damage. During sleep, the neurons of our brain expel the byproducts of metabolism to be cleared out of the brain.
If we have chronic sleep deprivation — night in, night out not getting enough sleep — it's clear that increases our risk of dementia as we age. According to the Centers for Disease Control and Prevention, 30 percent of Americans are chronically sleep-deprived.
Many think normal sleep is you go to bed at a particular time and wake up seven or eight hours later. That's not normal sleep.
Normal sleep, you go into a light stage followed by deep slow wave sleep where your heart rate slows down, your blood pressure falls, your body temperature falls. That's followed by REM rapid eye movement sleep, where you do all your dreaming. Then you wake up, go back into another light stage, deep sleep, REM cycle and this happens all night. From the time you enter the light stage until you exit the REM is anywhere from 70 minutes to 120 minutes, so if you are waking up every hour or two hours over the night but you're able to get back to sleep, that's normal.
You need five of those cycles a night, seven-and-a-half or eight hours sleep. If you get that perfectly normal sleep, you don't need medication. Many of my patients come to me distressed, and when I have them describe what they are actually doing, they describe normal sleep. They are remembering wake-ups.
When people turn to medications, almost all of them cause memory problems and interfere with the normal sleep architecture. Using medication, even over-the-counter medication, usually makes things worse.
The best thing you can do is eat a plant-based diet. Lots of colors and berries, carrots, yams, greens. The more colors, the better. The closer to its natural state, the better. Steam rather than microwave, those types of things. When you sear food at very high temperatures or fry things, you cause advanced glycation end-products, where glucose binds to molecules it shouldn't bind to, and those become oxidizing and damage body tissues.
One is hemoglobin A1C, a hemoglobin molecule bound to a glucose molecule, which becomes a damaging molecule that increases aging.
If you have high glucose like diabetics do, you get more hemoglobin A1C because your glucoses are too high. This is one reason diabetics get retinal problems, peripheral nerve problems, kidney damage and have higher rates of dementia.
Glucose can bind to different things. When you cook in certain ways — fried foods, seared foods, grilled foods — it produces those molecules and your body will absorb 30 percent of whatever the load is. Diets high in those types of oxidizing foods accelerate aging.
Pressure cooking and steam cooking are fine. Microwaving doesn't produce events like these end-products, but can disrupt important vitamins and nutrients that you would otherwise get. Sometimes you are cooking in certain plastics and other things that might be producing different molecules you don't want.
One food I like to recommend is oily fish. There are good studies on walnuts reducing Alzheimer's risk. Multiple studies show 100 percent pomegranate juice helps. I do that every day. The pomegranate clears amyloid.
Exercise can be nothing more than walking. We're looking to try to get 150 minutes a week.
One of the keys is it needs to be something you enjoy. If you exercise but your mindset is 'I hate this, it's miserable,' you're slogging through it, that actually activates in your brain, which kicks up inflammatory cascades. You get stress hormones going and it undermines the benefit you get from the exercise. Pick an exercise you enjoy and an activity where exercise is a byproduct you're not really focused on: bike riding for instance, or walking with a friend where you're talking and not really focused on the walking.
People with a family history of late onset Alzheimer's disease likely have an APOE gene. If you get two copies, it increases your risk 60 percent. But it is only a risk, not a certainty. A study at the University of Washington found people with two copies of the gene had less amyloid in their brain and it did not progress to Alzheimer's dementia if they had a history of exercise.
Hormone replacement therapy has been shown to be beneficial if initiated within five years of menopause. After five years, it can cause problems.
Then stress. Many people are so busy they never take time to rest. Some work five days a week, then yard work and housework the other two. But the data shows if you take one day a week off where you actually decompress, where you unwind with family, maybe go to church or out in nature, that has a remarkable, remarkable inflammatory-lowering cascade. It turns off your amygdala, it alters gene expression in healthy ways and promotes longevity.
The healthiest worldview is believing in a benevolent God who is compassionate, forgiving, gracious and 'for' you, to heal and protect you. The next healthiest is a godless but compassionate humanistic worldview where you are altruistic and care for others. The least healthy worldview is believing in a god who is authoritarian, punishing, that causes you to live in fear of being punished and causes you to seek to punish other who are not living according to the way you think God would have you live.
The other key is new learning. Not word puzzles, which are repetition of what you can do. Study something that takes you down trails to comprehend or assimilate new knowledge. One good thing, if you don't already know how, is ballroom dancing. Bible study that is not repetitious, but that has you investigating and thinking outside the box is good. Learning a new langauge would be brilliant.