Alzheimer’s disease, the most common cause of dementia, afflicts 10 percent of those over the age of 65. Now, researchers at Ben–Gurion University have learned what may trigger it.

The researchers discovered a specific protein – SIRT6 – is severely reduced in the brains of Alzheimer’s patients. SIRT6 is critical to the repair of DNA, the deterioration of which “is the beginning of the chain that ends in neurodegenerative diseases in seniors,” explains Dr. Debbie Toiber, lead author on the study and a member of the BGU Department of Life Sciences.

“We should be focusing our research on how to maintain production of SIRT6 and improve the repair capacity of the DNA damage that leads to these diseases,“ Dr. Toiber says.

Dr. Toiber’s lab research is focused on DNA damage as the cause of aging and age–related diseases. She and her team discovered that as a person ages the amount of the SIRT6 protein in the brain declines.

“In Alzheimer’s patients, it is almost completely gone,” she says.

Unfortunately, it is not enough to simply inject the protein into the brain to replenish its supply.

“There is a blood brain barrier that prevents things from passing into it,” Dr. Toiber explains. “But we are trying to find a way to increase the expression of the protein into the brain.”

DNA in each cell breaks down due to natural causes, such as metabolism and the usage of the DNA to produce proteins.

According to Dr. Toiber, we damage DNA just through normal living. “We repair it and continue going on. But the repairs are not perfect and some DNA remains unrepaired. As you get older unrepaired DNA accumulates.”

When the DNA is damaged, Dr. Toiber explains, it may lose important information. “If a cell feels it is too dangerous to continue with this damaged DNA, it may activate a self–destruct mechanism. If too many cells do this, the tissue with the dying cells will deteriorate, such as the brain.”

Dr. Toiber acknowledges that healthy habits like good diet and exercise might make a difference in our DNA health, but there is little we can do to avoid the effects of aging entirely.

“You have to remember that half of everyone over the age of 95 will get Alzheimer’s,” she says. “It is not something genetic or environmental. That may influence it a little bit, but when there is a 50–50 chance of getting Alzheimer’s, it demonstrates that it just happens over a lifetime.”

Still, Toiber is quick to point out that engaging in sports and even working past retirement can challenge the body in positive ways, preparing your cells to react more readily and thus be more likely able to repair themselves.