This Is The Most Important Thing You Can Do To Prevent Alzheimer's (No Matter Your Age)

Alzheimer's is the fastest-growing epidemic in the world, and 5.7 million Americans are living with the neurodegenerative disease today.

While we haven't quite figured out what causes Alzheimer's, genetic and lifestyle factors likely play a role. And that's great news because it means there are steps we can take to protect ourselves earlier in life. Dr. Dean and Ayesha Sherzai are two of the foremost experts on how to optimize your routine to promote a healthy brain into the future. The husband-and-wife duo are the directors of the Alzheimer's Prevention Program at Loma Linda University Medical Center and authors of The Alzheimer's Solution—and they're officially calling this the "century of the brain."

We were lucky enough to pick their (probably very healthy) brains at this year's revitalize event and for an upcoming episode of the mindbodygreen podcast. And we bet you can't guess the No. 1 piece of advice they have for protecting yourself from Alzheimer's starting today.

You've probably been told to "find your purpose" at some point in life (and you've likely shrugged it off on more than one occasion), but the advice actually holds some real weight. According to Dean and Ayesha, nothing determines brain health quite as much as a sense of purpose.

That's because purpose—setting personal goals and taking small but steady steps to achieve them over time—strengthens neuron connections and challenges the brain to be proactive. Purpose also increases our levels of "good stress" as the Sherzais call it, and decreases bad stress—the kind of chronic and overwhelming worry that pumps the body full of cortisol and adrenaline. Purpose-driven stress, on the other hand, actually improves health and reduces inflammation. (You can learn more about the distinctions between good and bad stress here.)

While some might say that solving puzzles and reading tons of books are the best ways to give your brain a workout, Ayesha and Dean are convinced that it's these more action-oriented exercises that we really benefit from.

"The brain is the most active organ in our body—it consumes more than 25 percent of the body's energy in any given moment," Ayesha told a captivated crowd at revitalize. "When we sleep, the brain is getting rid of all the toxic by-products."

One recent study found that the sleep-brain connection is so strong that people who suffer from sleep apnea have a 70 percent higher risk of contracting Alzheimer's. And unfortunately, one night of poor sleep can significantly increase disease-promoting inflammation in the body. If you're having trouble consistently getting the sleep you know you should, here are some lifestyle tweaks that could help.

Did you know that strong legs mean a stronger brain? That's right: Muscle mass in the legs has been associated1 with a larger hippocampus, the part of the brain that processes memories. The Sherzais recommend partaking in strenuous activity 20 to 30 minutes a day for four to five days a week, focusing on those legs whenever you can.

The Sherzais say that greens, berries, nuts and seeds, and whole grains with lots of fiber are key.

Which foods might be causing your brain fog? Find out here.