You may think of Alzheimer's and dementia as things that suddenly appear when you're in your 70s or 80s. Well, think again.

A study published in The Lancet Regional Health – Americas reveals that important risk factors such as cardiovascular issues and blood biomarkers (tau protein and amyloid tangles) can start showing up in your 20s and 30s, paving the way for clinical symptoms and impairments decades later.

This focuses a light on the importance (as a young adult) of protecting your heart health with good nutritional choices — no red or red processed meats, added sugars, or highly processed foods, along with plenty of fruits, vegetables, and fatty fish.

It also reveals the importance of putting down your screens and getting daily physical activity.

Two studies drive the point home. One found that exercise may play a more crucial role in preserving brain health than we've guessed, especially for people with liver conditions (that's about 100 million Americans). The most effective type is endurance exercise — such as moderate-to-intense 10,000 steps a day.

A second clinical trial shows that when older people at risk for Alzheimer's do low or moderate-to-high-intensity exercise three or four times weekly for a year, their cognitive function remains stable — in sharp contrast to what's expected.

For more help, check out my book "The RealAge Workout."

And consider the new way (at any age) to get rid of brain-damaging old proteins in your blood: therapeutic plasma exchange. See a review of the procedure for fighting for Alzheimer's and cognitive decline at LifespanEdge.com.