People with HIV have a higher rate of Alzheimer’s disease, including the early-onset form, than those without the virus. However, according to a new analysis, antiretroviral (ARV) treatment appears to eliminate this excess risk.

Researchers analyzed data from people with private insurance to parse the risk of early-onset Alzheimer’s among people younger than 65.

The database included nearly 75,000 people with HIV who had been enrolled for at least one year during the study period and who were at least 50 years old at any time therein. Forty-four percent of the cohort members were not prescribed ARVs during the study period.

Among the group of people with HIV overall, 0.11% had Alzheimer’s, compared with a rate of 0.07% among those without the virus. A total of 0.16% of those with HIV had early-onset Alzheimer’s. However, the Alzheimer’s rate among those receiving HIV treatment was 0.07%—the same as the rate among those without the virus.

After adjusting the data to account for various differences between the cohort members, including age, sex and the presence of heart disease, hypertension and diabetes, the study authors found that having HIV was associated with a 56% increased risk of early-onset Alzheimer’s. However, ARV treatment cut the risk of Alzheimer’s by 50% among people with HIV.