Can You Prevent Alzheimer’s Dementia?

Multiple surveys of people over age 55 show the medical condition most feared, more than cancer, is Alzheimer’s dementia. Women are two-thirds of Americans living with Alzheimer’s, and it’s not just because we live longer. Women’s brains appear more vulnerable to Alzheimer’s disease (AD). What can you do to prevent Alzheimer’s dementia? Is there a test to screen for Alzheimer’s dementia?

Why are women at higher risk of Alzheimer’s?  We don’t know. Amyloid is a protein deposited in abnormal levels in the brain of AD patients and women have more amyloid than men. Other theories for the increased risk in women are: hormonal differences (testosterone vs. estrogen), the fact that women carry two X chromosomes instead of one, or perhaps something to do with childbearing. 

Is Alzheimer’s the most common cause of dementia? Yes. The second most common is vascular dementia, resulting from the same risk factors as stroke and heart disease. Other causes of dementia are frontotemporal, Lewy body, and mixed. 

Can you get a test to screen for Alzheimer’s?

Sort of. A referral to neuropsychological testing is the place to start. Memory changes from Alzheimer’s dementia are distinct from age-related memory changes, and neuropsychological testing will sort this out.

What about a blood test for AD? Less than 5% of AD patients are early onset, which affects people less than 65 years. A genetic cause may explain the early-onset form, so testing for folks with a family history of early-onset AD is an option. The three genes identified as contributing to early-onset AD are amyloid precursor protein, presenilin, and presenilin 2. For late-onset AD, by far the most common type, the most firmly established risk factor is Apo protein E4. If there is a history of early AD in your family, discuss genetic testing with your doctor. 

What about imaging tests to screen for Alzheimer’s dementia?


Amyloid PET scanning is commonly used in Alzheimer’s patients. PET works by an injected tracer that latches onto the amyloid allowing us to see areas of amyloid deposits. The use of amyloid PET as a screening test for Alzheimer’s is an area of interest, but amyloid deposition is seen in “normal” brains. Ten percent of 50-year-olds and 44% of 90-year-olds without dementia have a positive amyloid PET. Additionally, a negative amyloid PET doesn’t mean you can’t develop AD in the future. It is useful in folks with dementia where a negative amyloid PET pretty much rules out AD and suggests another form of dementia. 

What are the risk factors for Dementia?

  • Genetics: The ApoE e4 allele at birth
  • Less education in early life
  • Hearing loss, high blood pressure, and obesity in midlife
  • Smoking, depression, physical inactivity, social isolation, and diabetes in later life. 

What can you do to prevent dementia?

unsplash/Edgar Castrejon

Always remember that what’s good for the heart is good for the brain.

  • Exercise. Simply put, exercise can reduce your risk of dementia. Brain-derived neurotrophic factor (BDNF) is released during exercise and acts as a “fertilizer for the brain.” 
  • Diet and the Mind The Mediterranean diet reduces the risk of AD. The beneficial effect is likely an abundance of antioxidants and anti-inflammatory agents. As one example, olive oils and nuts are rich in phenolic compounds that enhance B-amyloid clearance, which reduces the risk of Alzheimer’s disease. 
  • Turmeric. Stay tuned here. The active component of Turmeric, Curcumin, dismantles plaques and tangles in the brain. Clinical studies that aim to show whether Curcumin can help prevent AD are ongoing. 
  • Any other supplements? Supplements including omega-3 fatty acids, vitamin E gingko biloba, and selenium have had disappointing results and are not effective for preventing dementia. Sadly, no over-the-counter supplement studied has shown usefulness for preventing memory impairment or Alzheimer’s dementia.

Dr. O.