The need for Alzheimer’s prevention is growing. About 7 million people in the U.S. now live with the disease, with estimates climbing to 13 million by 2050. The estimated annual cost of care for Alzheimer’s and other dementias could rise from $360 billion to almost $1 trillion over that time period, according to the Alzheimer’s Association.One class of HIV drug shows promise in preventing Alzheimer’s disease, according to an article in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.Scientists arrived at the finding serendipitously. While studying how a class of drugs used to treat HIV works, researchers noticed that they also impacted mechanisms involved in the onset of Alzheimer’s disease.Analyzing HIV TreatmentOnce the researchers made that connection, they turned to two databases. They scoured them for patients being treated with a class of HIV drugs called nucleoside reverse transcriptase inhibitors (NRTIs), which prevent the HIV virus from replicating in the body. They searched decades of data for people who were both being treated with various HIV medications and were 50 years or older. They excluded people diagnosed with Alzheimer’s disease.They found more than 270,000 subjects who met those criteria from two sources: 24 years of patient data within the U.S. Veterans Health Administration Database and 14 years of data for commercially insured patients. Then they compared how many people developed Alzheimer’s between those taking NRTIs and people who were prescribed other HIV medication. Even after screening out factors like potential pre-existing conditions, they found the difference “significant and substantial,” according to the paper. In one set of patients, risk of developing Alzheimer’s decreased 6 percent every year the patients took NRTIs. In the other, the annual decrease was 13 percent.Potential Alzheimer's Prevention “Our results suggest that taking these drugs could prevent approximately 1 million new cases of Alzheimer’s disease every year,” Jayakrishna Ambati, a researcher with University of Virginia School of Medicine and an author of the study, said in a press release.The researchers note that patients taking other types of HIV medications did not show the same reduction in Alzheimer’s risk as those on NRTIs. Based on that, they say that NRTIs warrant clinical testing to determine their ability to ward off Alzheimer’s.This article is not offering medical advice and should be used for informational purposes only.Read More: The 4 Main Types of DementiaArticle SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.