Things That Raise Your Chances of Dementia

Age

Alzheimer’s disease is the most common form of dementia. About a third of people 85 and older show signs of the disease. The genes you get from your parents play a part at this age, but so do things like diet, exercise, your social life, and other illnesses. Dementia isn’t a normal part of getting older.

It could lead to a heart attack or stroke, which makes dementia more likely. Heart disease is usually caused by plaque buildup in arteries around your heart (atherosclerosis). That can slow blood flow to your brain and put you at risk for stroke, making it harder to think well or remember things. And many things that cause heart disease — tobacco use, diabetes, high blood pressure, and high cholesterol — also can lead to dementia.

An English study found older adults who lived in areas with the highest yearly concentration of air pollution were 1.4 times more likely to get dementia than people who lived in places with cleaner air. Nitrogen dioxide (NO2) and particulate matter (micro-particles in the air you might not see but can inhale) caused the most harm.

Doctors aren’t sure exactly why people with diabetes get dementia more often. But they do know that people with diabetes are more likely to have damaged blood vessels. This can slow or block blood flow to the brain and damage areas of the brain, leading to what’s called vascular dementia. Some people may be able to slow brain decline if they keep diabetes under control with medicine, exercise, and a healthy diet.

Older people who have trouble identifying odors are more than twice as likely to have dementia as those with a sharp sense of smell. Almost half of people in an American study who’d been diagnosed with dementia had had olfactory dysfunction 5 years before. A simple smell test can flag a need for early treatment.

High Cholesterol

High levels, especially in middle age, are linked to obesity, high blood pressure, and diabetes. All of these raise your risk of dementia, but it’s not yet clear if the cholesterol by itself adds to the problem. Some research shows that high cholesterol in midlife could raise your chances of Alzheimer’s disease later in life, but the exact link isn’t clear.

Herpes simplex virus 1 (HSV1), or oral herpes, usually appears as blisters or sores on or around your mouth. But the virus can also get into and infect your brain. A recent study linked HSV1 with a decline in some mental functions, but not to dementia. However, lab studies on a realistic brain model showed HSV1 triggered major Alzheimer’s signs, including swelling and clumps of protein in the brain tissue.

If you have depression, or have had it in the past, you may be more likely to get dementia. Scientists aren’t yet sure that it’s a cause. It may simply be an early symptom or a sign of other causes like Parkinson’s disease or Huntington’s disease. Talk to your doctor or a therapist if you feel down for more than 2 weeks, and right away if you think of harming yourself. Therapy and medication can help with depression.