Dementia risk factors

 Study identifies 10 factors linked to Alzheimer’s risk written by James Kingsland on March 1, 2022 — Fact checked by Hannah Flynn

A new study appearing in The Lancet Digital Health finds links between health conditions and Alzheimer’s risk. The study was an observational study that highlighted 10 medical conditions associated with a diagnosis of Alzheimer’s disease up to 10 years later.

The conditions include known risk factors for the disease, such as depression and hearing loss, and conditions with no links to the disease, such as constipation.

People with dementia experience a progressive loss of their ability to remember, think, and communicate effectively.

However, the changes in the brain that are responsible for dementia may begin decades before its effects on cognition and behaviour become apparent.

The World Health Organization (WHO) indicates that of the 55 million people worldwide living with dementia, 60–70% have Alzheimer’s disease.

Attempts to develop an effective treatment for Alzheimer’s have met with little success. Researchers are increasingly turning their attention to detecting the disease early.

The key to this strategy is to identify early, “modifiable” risk factors that doctors can target with drugs or other interventions.

Researchers at the Paris Brain Institute in France have now found statistical associations between 10 health conditions and a diagnosis of Alzheimer’s disease up to 10 years later. Major depression was the earliest condition to be associated with a subsequent diagnosis of Alzheimer’s, appearing at least 9 years in advance.

Other conditions that the study linked to a later diagnosis of Alzheimer’s included:

·        anxiety

·        constipation

·        abnormal weight loss

·        a type of arthritis called cervical spondylosis

·        reaction to severe stress

·        hearing loss

·        sleep disorders

·        They also showed that falls and fatigue had links to Alzheimer’s risk.

The next step will be to determine whether these conditions help cause the disease or whether they are early signs of changes in the brain that are already happening.

Some of the conditions, such as depression, hearing loss, and sleep disorders, are already known risk factors for Alzheimer’s. However, this study was the first to identify constipation as a possible risk factor. The link between the two conditions became apparent 7 years before the diagnosis of Alzheimer’s.

Interestingly, constipation is also associated with depression and is an established early sign of other brain diseases, such as Lewy-body dementia and Parkinson’s disease.

Another recent study also found an association between mental health conditions and dementia. In 2020, the Lancet Commission on dementia added three new modifiable risk factors: excessive alcohol consumption, head injury, and air pollution to its existing list, which includes:

·        hypertension

·        smoking

·        obesity

·        depression

·        physical inactivity

·        diabetes

The report concluded that modifying all the risk factors that researchers have identified could prevent or delay dementia in up to 40% of people.