Bronwen Zilmer has three generations of Alzheimer's disease in her family. She hopes not to be the fourth.
Her great-grandmother and grandmother had Alzheimer's disease. Her father's illness was diagnosed at 56, and he died at 63. She's now 35.
After her father's death, the Highland Village, Texas, resident and mother of two began running half marathons, taking fish-oil supplements and eating more fish in hopes of avoiding the memory-robbing illness.
"People are desperate to avoid it and desperate to find some kind of treatment or cure," she says. "If somebody told me, 'Do these 10 things and I'll assure you that you won't get Alzheimer's disease,' I would do it."
Researchers agree that the causes of Alzheimer's have some genetic links, but they aren't sure exactly what causes the disease or how it progresses. Although a growing number of studies examine how lifestyle choices may affect a person's risk of Alzheimer's, medical professionals disagree over the strength of the evidence.
A National Institutes of Health independent consensus panel rejected a definitive scientific link between lifestyle habits and risk reduction in a 2010 report that said the amount of evidence and its quality was low. The panel called for more large-scale, randomized studies.
"Currently, firm conclusions cannot be drawn about the association of any modifiable risk factor with cognitive decline or Alzheimer's disease," the report said.
That hasn't kept Americans from taking up brain teasers or buying supplements in the hopes of staving off the disease.
Some books, such as "The Alzheimer's Prevention Program" by Dr. Gary Small of the UCLA Longevity Center, promote a proactive approach, much like exercise or diet programs. The book includes a seven-day regimen of foods to eat and mental and physical exercises to do.
"It's a weak argument to say, 'I'm going to wait here until we have conclusive proof,' while we have so much compelling evidence already," Small said in an interview.
"We are not saying you can guarantee you'll never get Alzheimer's disease," he says, "but what we're saying is there is a possibility that we can delay the onset of symptoms through the healthy lifestyle approach."
Dr. Bill Thies, chief medical and scientific officer for the Alzheimer's Association, a nonprofit organization and a large funder of research, says some basic health habits are associated with lower risk.
Physical exercise and good vascular health have the most scientific evidence as possible Alzheimer's fighters - and they come with the added perk of lowering risk of stroke, diabetes and heart disease.
A diet that's lower in fats and higher in vegetables seems to be preferable, but little is known about an Alzheimer's link to specific foods or whether there is one.
Thies cautions against adopting a specific diet or regimen: "The more prescriptive the books, the less it's supported by scientific research."
"The weakest data exists around mental activity itself," Thies says. Instead of doing solitary activities like crosswords or Sudoku, he suggests staying socially active and connected, which may keep the brain humming late in life.
Dr. David Knopman, a medical doctor and professor of neurology at the Mayo Clinic in Rochester, Minn., echoes the view. He says people should strive for a lifetime of brain-healthy habits rather than seek out a quick fix later in life.
"Going out and spending hundreds of dollars on some computer program that claims to improve your mind is probably not a very good investment," he says. Instead, he suggests reading books, joining a club or doing other activities that keep a person connected.
While researchers look for answers, Zilmer has added healthy activities to her daily routine.
"I am going to exercise and eat healthy, and if that gives me more time without Alzheimer's, then perfect," she says.
She can't help but examine her father's life for clues, but it's also difficult for her to identify any lifestyle choice that could have increased his chances. He exercised, ate healthy and held down a good job.
"I could guess all day," she said. In the end, it was probably just genetics.
REDUCE YOUR RISK OF ALZHEIMER'S
While experts don't agree on the links between lifestyle factors and diagnosis, there are some habits that have been associated with risk reduction. The Alzheimer's Association recommends these strategies:
Stay physically active. Exercise helps keep blood pumping to the brain and wards off heart disease, diabetes and stroke - other risk factors for Alzheimer's.
Eat a brain-healthy diet. Fill your meals with low-cholesterol, low-fat foods - especially fruits and vegetables.
Stay connected to others. Being social may help the brain cells by reducing stress.
Stay mentally active. Challenging your brain daily can strengthen existing brain connections and build new ones.