Drugs designed to prevent organ rejection in transplant patients may also protect against the development of Alzheimer's disease, a new study has found.

Researchers from The University of Texas Medical Branch at Galveston who analyzed the medical records of 2,644 patients who received organ transplants — and were taking drugs to prevent rejection — were far less likely to develop dementia than the general population. In fact, only eight of the patients developed dementia — two younger than 65 years of age, five between 65 and 74, and just one over 75, Medical News Today report.

The findings, published in the Journal of Alzheimer's Disease, suggest anti-organ-rejection medications taken by transplant patients that block an enzyme known as calcineurin — which regulates communication between brain cells — also prevent dementia.

Past studies involving mice have linked the enzyme to the toxic effects of beta-amyloid oligomers, which build up in the brain and can cause Alzheimer’s disease. Elevated levels of calcineurin are also typically found in the nervous systems of people with Alzheimer's.

"These data clearly show that the prevalence of dementia and Alzheimer's in our transplant patient group is significantly lower, in fact almost absent, when compared to national data from the general population," noted lead researcher Luca Cicalese.

Alzheimer's is the sixth leading cause of death in the U.S.