Risk factors

Many factors can eventually contribute to dementia. Some factors, such as age, can't be changed. Others can be addressed to reduce your risk.

Risk factors that can't be changed

• Age. The risk rises as you age, especially after age 65. However, dementia isn't a normal part of aging, and dementia can occur in younger people.
• Family history. Having a family history of dementia puts you at greater risk of developing the condition. However, many people with a family history never develop symptoms, and many people without a family history do. There are tests to determine whether you have certain genetic mutations.
• Down syndrome. By middle age, many people with Down syndrome develop early-onset Alzheimer's disease.

Risk factors you can change

You might be able to control the following risk factors for dementia.

• Diet and exercise. Research shows that lack of exercise increases the risk of dementia. And while no specific diet is known to reduce dementia risk, research indicates a greater incidence of dementia in people who eat an unhealthy diet compared with those who follow a Mediterranean-style diet rich in produce, whole grains, nuts and seeds.
• Excessive alcohol use. Drinking large amounts of alcohol has long been known to cause brain changes. Several large studies and reviews found that alcohol use disorders were linked to an increased risk of dementia, particularly early-onset dementia.
• Cardiovascular risk factors. These include high blood pressure (hypertension), high cholesterol, buildup of fats in your artery walls (atherosclerosis) and obesity.
• Depression. Although not yet well-understood, late-life depression might indicate the development of dementia.
• Diabetes. Having diabetes may increase your risk of dementia, especially if it's poorly controlled.
• Smoking. Smoking might increase your risk of developing dementia and blood vessel diseases.
• Air pollution. Studies in animals have indicated that air pollution particulates can speed degeneration of the nervous system. And human studies have found that air pollution exposure — particularly from traffic exhaust and burning wood — is associated with greater dementia risk.
• Head trauma. People who've had a severe head trauma have a greater risk of Alzheimer's disease. Several large studies found that in people age 50 years or older who had a traumatic brain injury (TBI), the risk of dementia and Alzheimer's disease increased. The risk increases in people with more-severe and multiple TBIs. Some studies indicate that the risk may be greatest within the first six months to two years after the TBI.
• Sleep disturbances. People who have sleep apnea and other sleep disturbances might be at higher risk of developing dementia.
• Vitamin and nutritional deficiencies. Low levels of vitamin D, vitamin B-6, vitamin B-12 and folate can increase your risk of dementia.

• Medications that can worsen memory. Try to avoid over-the-counter sleep aids that contain diphenhydramine (Advil PM, Aleve PM) and medications used to treat urinary urgency such as oxybutynin (Ditropan XL).

  Also limit sedatives and sleeping tablets and talk to your doctor about whether any of the drugs you take might make your memory worse.