Older women are nearly twice as likely to develop Alzheimer’s disease as they are to get breast cancer, according to a new report from the Alzheimer’s Association. Approximately one in six women over age 65 develop the brain disease, compared to one in 11 men.

Alzheimer’s, which affects the brain and leads to significant memory and cognitive deficits, kills nearly half a million people each year and is currently the sixth-leading cause of death in the country. A recent report found that it may kill even more people than was previously thought, rivaling heart disease and cancer. Researchers expect that rates of Alzheimer’s will continue to rise, potentially tripling by 2050, due largely to an aging baby boomer population. Someone in the U.S. develops Alzheimer’s every 67 seconds.

The data in the new report was drawn from a survey of over 3,000 women. It showed that women are disproportionately carrying the Alzheimer’s burden, making up two-third of people with Alzheimer’s and over 60% of caregivers for the potentially devastating condition. There are currently 15.5 million caregivers in the U.S., many of whom provide unpaid round-the-clock care. The report stated that this care added up to to 17.7 billion hours in 2013 and would otherwise be valued at $220.2 billion – “nearly eight times the total revenue of McDonald’s in 2012.” Caregivers often face health tolls of their own, with 60% reporting their emotional stress as high or very high, and one-third reporting symptoms of depression.

Advancing age is the largest risk factor for Alzheimer’s, but genetic factors and family history (particularly a history in a parent, sibling or child) can also increase risk. While most people acquire the disease after age 65, there are currently about 200,000 Americans younger than 65 who have early-onset Alzheimer’s.