Stay Sharp to 100!

Dementia can impair your memory, thinking, and speech. Alzheimer’s disease is the most common cause of dementia.

“Dementia can sneak up on people because they don’t like to think about the possibility that something is wrong,” says Bredesen. “So, they write off the warning signs.” Plus, the symptoms of early-onset Alzheimer’s (diagnosed before age 65) may not be what you expect.

Later-onset dementia often starts as purely a memory problem and then spreads to other cognitive dysfunction, explains Bredesen. Worsening memory isn’t the only symptom you should be watching out for.

Genetics and risk

Several genes increase your risk for Alzheimer’s disease, but your genetics don’t determine your destiny.

“Scientific evidence shows that several lifestyle changes can reduce your risk of Alzheimer’s disease, regardless of your genetic predisposition,” says Demetrius Maraganore, MD, who leads the Tulane Healthy Brain Aging Initiative in New Orleans.

That said, genetic testing may help you and your health care practitioner better focus your prevention efforts.

“Consider getting genetically tested to see if you carry the apolipoprotein-e4 (APOE-e4) risk variant for Alzheimer’s disease,” says Maraganore. “APOE is one of the approximately 25,000 genes that you inherit—one copy from your mom and one copy from your dad.” The APOE-e4 variant is the strongest genetic risk factor for Alzheimer’s.

People with zero copies of APOE-e4, which is the majority of us, have a 10 to 15 percent risk of Alzheimer’s disease. But those with one copy of the gene variant have an estimated 25 to 40 percent risk, and those with two copies have a 40 to 55 percent risk of developing Alzheimer’s disease.

Your doctor can test you for APOE-e4, or you can use an at-home test kit, such as one from alzheimersorganization.org. For more information, visit apoe4.info.

Subtyping Alzheimer’s disease

You may think of Alzheimer’s disease as a single entity. But many different paths can lead to the condition.

Bredesen classifies Alzheimer’s according to the most likely underlying factors in a given individual, including

• increased inflammation due to APOE-e4 genetics
• high blood sugar and insulin resistance, as in prediabetes and type 2 diabetes
• hormonal disruption (such as thyroid issues) and nutritional deficiency
• toxicity due to factors such as air pollution and biological toxins from mold
• vascular disorders, such as heart disease and high blood pressure
• head injuries, such as those sustained in sports or car crashes

Other factors can also contribute to your risk, including obesity, smoking, excess alcohol intake, poor sleep, certain chronic infections, and impaired hearing. Generally, multiple factors are involved, so prevention should be multipronged.

Eat for your brain

“The importance of diet in preventing dementia cannot be overemphasized,” says Arnold Eiser, MD, adjunct fellow at the Center for Public Health Initiatives at the University of Pennsylvania. He says the Mediterranean diet appears helpful for reducing Alzheimer’s risk.

Mediterranean diet

The Mediterranean diet, which can also reduce your risk of obesity, heart disease, and diabetes—all risk factors for Alzheimer’s—helps brain function by providing protective antioxidants and reducing inflammation.

The Mediterranean diet features olive oil, fish, poultry, vegetables, fruit, nuts, and legumes. It limits highly processed foods, red meat, and sweets.

Ketogenic diet

The brain relies on glucose for energy, but this ability may be impaired for decades before symptoms of Alzheimer’s disease surface. Ketones are a workaround alternative fuel source. The ketogenic (keto) diet, which has been highly studied for brain function, is meant to shift the body toward using fat to make ketones.

The keto diet is a very low-carbohydrate, high-fat diet that, with good planning, can be nutrient-rich and healthy. Many aspects of the Mediterranean diet can be adapted to the keto diet (within carb limits).

Plant-based diets

Healthy plant-based diets have also been associated with a reduced risk of cognitive decline. Vitamin B12, a brain-supportive nutrient, should be consumed via fortified products or supplementation if no animal products are eaten.

Exercise regularly

Getting regular aerobic exercise—such as moderately paced walking, jogging, cycling, or swimming—may reduce your risk of developing Alzheimer’s disease.

In addition, aerobic exercise promotes ketone production to fuel your brain. It may also help your brain better utilize glucose for energy.

New research also suggests strength training (think using dumbbells or weight machines) helps protect brain function.

Optimize your sleep

“When you sleep seven to eight hours a night, it may reduce your odds of dementia by slowing the rate that beta-amyloid accumulates in your brain,” says Maraganore. Beta-amyloid plaque can interfere with brain function.

Sleep is important for “taking out the trash” that accumulates in your brain during the day. While you sleep, beta-amyloid and other debris are removed via the glymphatic system in your brain.

Be alert to the risk of sleep apnea, which impairs sleep quality and lowers the oxygen available to your brain, says Bredesen. Sleep apnea is associated with more beta-amyloid in the brain and increased risk of Alzheimer’s disease. Loud or frequent snoring is the most common symptom.

Reduce your toxin load

A recent scientific report from the Lancet Commission noted traffic exhaust, second-hand tobacco smoke, and fine particulate matter are among the sources of toxins linked with an increased risk of dementia.

Fine particulate matter consists of tiny inhalable particles, which include heavy metals (such as mercury) and mold. Mold produces toxins (mycotoxins) that can harm your brain.

Finland has the highest death rate from dementia in the world. Eiser says a combination of high exposure to mycotoxins (due to the cold, humid climate and well-insulated homes), mercury-polluted fish, and other toxins may contribute to dementia risk in Finland’s population.

Canadians are also commonly exposed to mycotoxins in their homes. Do-it-yourself tests, such as those from envirobiomics.com and immunolytics.com, can help determine if your home has a mold problem.

Sweat the toxins out

Eiser says working up a sweat, via exercise or in a sauna, can help with detox. To help limit your toxin exposure from personal care products, water, food, and more, he also recommends resources from the Environmental Working Group (ewg.org).

Bolster your brain

The more you build up your brain through education and challenging mental activities, the more resilience your brain has against dementia, says Bredesen.

Mental exercises for your brain

BrainHQ (brainhq.com) is a subscription-based online service offering interactive brain exercises designed by neuroscientists and tested to confirm they help with aspects such as memory and brain processing speed.

You can also exercise your brain with sudoku, crossword puzzles, and the like. Social activities can support healthy brain function, too.

Healthier brains ahead

An increasing number of specialty clinics now focus on Alzheimer’s risk assessment and early intervention. Free online resources, such as those at alzu.org, also emphasize prevention.

“We encourage people to get on prevention so that everyone can stay sharp to 100,” says Bredesen. For best results, keep in mind the many facets that can increase your risk of Alzheimer’s, rather than just one factor.