Ronald Reagan, Rosa Parks, Peter Falk, and Aaron Copland are four very different folks, but they all had one thing in common: Alzheimer's disease.

It’s estimated that 5.7 million Americans have the condition, and that number is projected to hit 16 million by 2050.

But maybe not. A study in the Journal of Neurology, Neurosurgery & Psychiatry analyzed current research and came up with the top 10 evidence-based risk factors for Alzheimer's that you can avoid with lifestyle changes and medical care.

The risks are: lack of education; insufficient cognitive activity; obesity late in life; depression; chronic stress; diabetes; head trauma; high blood pressure in middle age; elevated homocysteine level (it increases the risk for artery damage and blood clots, and usually indicates a vitamin B12 deficiency); and low blood pressure on standing, also called orthostatic hypotension, which can cause dizziness, weakness, and falls. 

If any of those risk factors applies to your, take these steps to regain control of your brain health:

1. Sign up for a class, challenge yourself with new interests.

2. Talk with your doctor to address excess weight and control your diabetes (or better yet, reverse it).

3. Always get medical attention for any head bump or bang.

4. Start treatment for any chronic stress or depression, and exercise 300 minutes a week. That eases depression and stress for many people.

5. Reduce high blood pressure with weight loss, nutritional changes, medication, and exercise.

6. Have a blood test to check your vitamin B12 level.

7. Adopt a Mediterranean diet.

8. Talk to your doctor if you have frequent lightheadedness or dizziness upon standing.