WATCH: This Disease Is A Massive Looming Threat To Public Health.......Alzheimer's is going to be one of the biggest public health threats in the coming decades (VIDEO)

Alzheimer's is going to be one of the biggest public health threats in the coming decades, according to Dr. Murali Doraiswamy, M.D., of the Duke University Institute for Brain Sciences. And not because the disease is being diagnosed in any greater magnitude, but simply because we are living longer.

Thanks to advancements in treatments of potentially-fatal diseases like heart disease and cancer, the aging population is bigger than it once was, he said in an appearance on HuffPost Live in Davos, Switzerland, where the 2014 World Economic Forum annual meeting is taking place, on Wednesday.

Currently, about 5 million Americans have Alzheimer's, he said. By the year 2050, 150 million people worldwide will have the disease. And it affects more than the people with it and their caretakers: We spend about $600 billion on Alzheimer's, according to Doraiswamy. If Alzheimer's were a national economy, it would rank at number 17 worldwide, he said. more