What Causes Lewy Body Dementia?

Lewy body dementia is caused by protein deposits, called Lewy bodies, in parts of the brain involved in thinking, memory, and movement. The disease is characterized by a progressive decline in mental function, causing visual hallucinations and changes in alertness and attention along with Parkinson's disease-like movement problems.

Exactly what causes Lewy bodies to accumulate is not fully understood. And until recently, the only known risk factor for developing Lewy body dementia was older age. In recent years, however, scientists have identified other factors that appear to contribute to the risk of this common and rapidly progressing form of dementia.

This article looks at nine risk factors for Lewy body dementia—the second most common cause of dementia in the United States after Alzheimer's disease.

Older Age

According to research from the U.S. Department of Health and Human Services, the typical age for developing Lewy body dementia is between 50 and 85, although it can occur outside this age range.

A 2013 study from the Mayo Clinic concluded that the peak age range for Lewy body dementia is between 70 and 79.

Lower Education Levels

Higher levels of education correspond to a reduced risk of Lewy body dementia. Interestingly, the opposite appears to be true in people who develop Parkinson's disease, a condition so closely linked to Lewy body dementia that they, together, are sometimes referred to as Lewy body disease.

Depression and Anxiety

For reasons not entirely clear, a history of depression and anxiety is linked to an increased risk of Lewy body dementia.

What remains unclear is whether depression and anxiety contribute to the onset of Lewy body dementia or if they are early signs of the development of the disease.

Low or No Caffeine Intake

A history of high caffeine intake is associated with a lower risk of Lewy body dementia. Research has suggested that the benefits increase in tandem with the amount of caffeine a person drinks per day and may reduce the risk of Lewy body dementia by as much as 29%.

Family History

Genetics and heredity appear to play a role in the risk of Lewy body dementia. Generally, if you have a first-degree family member (such as a parent or sibling) with Lewy body dementia or Parkinson's disease, your risk of Lewy body dementia increases.

Several specific gene mutations have been closely linked to Lewy body dementia, including mutations of the SNCA, SNCB, GBA, and APOE 4 genes.

Even so, having these mutations does not mean you will get Lewy body dementia or Parkinson's disease. At the same time, the majority of cases of Lewy body dementia develop spontaneously in people with no family history of the disease.

Attention-Deficit Hyperactivity Disorder (ADHD)

According to a 2011 study in the European Journal of Neurology, roughly half of the participants with Lewy body dementia had adult attention-deficit/hyperactivity disorder (ADHD).

Subsequent research published in 2017 questioned whether ADHD may be an initial sign of Lewy body dementia or if, conversely, Lewy body dementia has been misdiagnosed as ADHD during the early stages of the disease.

Biological Sex

The general consensus among current studies is that males have double the risk of developing Lewy body dementia compared to females.

Even so, the relationship between Lewy body dementia and biological sex is not cut and dry. Some studies have reported that certain types of Lewy body dementia are predominant in males, while certain types may be more predominant in females.

Stroke

Some studies have suggested that a prior stroke is associated with an increased risk of Lewy body dementia. This is particularly true with regard to ischemic strokes caused by the massive obstruction of the blood supply to the brain rather than the rupture of a blood vessel.

Other serious brain traumas appear to increase the risk of Lewy body dementia, including massive head injuries and hydrocephalus ("water on the brain").

Metabolic Disorders

Hypertension (high blood pressure) is linked to an increased risk of Lewy body dementia. The incidence of hypertension among people with Lewy body dementia is roughly 65%. Having high blood pressure, in turn, increases the risk of Lewy body dementia by 60.5%.

Type 2 diabetes, a form of diabetes strongly linked to lifestyle, is associated with a 25% increased risk of Lewy body dementia.

Hyperlipidemia, commonly referred to as high cholesterol, also increases the risk of Lewy body dementia by roughly 25%.

A Word From Verywell

If you have a family history of Lewy body dementia or Parkinson's disease, it's understandable to be concerned about developing Lewy body dementia. Like other types of dementia, there is no guaranteed way to prevent Lewy body dementia.

Clearly, there are some factors for Lewy body dementia you can change and others that you can't. And it's not entirely clear if any related changes can prevent or slow the progression of the disease—mainly because the exact cause of Lewy body dementia is still under investigation.

Even so, making positive lifestyle changes (like lowering your cholesterol and blood pressure) is in your best interest and may have a positive influence on your long-term risk of dementia.