Watching a family member experience the cognitive decline and other symptoms of Alzheimer’s disease can be very painful. Beyond the concern for your loved one, you may also wonder if your family history puts you at risk for developing Alzheimer’s. Understanding how family history factors into an Alzheimer’s diagnosis is important to get a clearer picture of what your future might hold.

“In general, we say the risk of Alzheimer’s is twice as high in people whose family members have Alzheimer’s,” says Paul Schulz, MD, director of the University of Texas Physicians Memory Disorders and Dementia Clinic and an associate professor of neurology at the University of Texas Medical School in Houston. “However, there’s more to it than that.” Dr. Schulz says that many other risk factors contribute to that higher risk, including diabetes and high blood pressure, and each person’s individual risk of developing Alzheimer’s depends on a combination of risk factors.

Understanding Early- and Late-Onset Alzheimer’s

One form of Alzheimer’s, called early-onset Alzheimer’s disease, affects people younger than age 65, and “there are very strong genetic associations with early-onset Alzheimer’s disease,” explains Joyce Fogel, MD, chief of geriatric medicine at Beth Israel Deaconess Medical Center in New York City. However, early-onset Alzheimer’s disease is relatively rare, found in just 4 percent of the 5 million Americans with an Alzheimer’s diagnosis.

With respect to late-onset Alzheimer’s disease, which sets in after age 65, researchers aren’t exactly sure how family history increases risk, but they have some clues. Currently, the most significant clue relates to a gene called APOE, which provides directions for making a protein called apolipoprotein E. “There are three versions of APOE — e2, e3, and e4 — and those who inherit the e4 form appear to have a higher risk of late-onset Alzheimer’s disease,” Dr. Fogel says.

A study done at Duke University that included 257 adults aged 55 to 89 years old, some with Alzheimer’s, some with mild cognitive impairment, and some with no memory issues, found that people with a family history of Alzheimer’s were more likely to have this variation in the APOE gene, which is linked to a greater risk and earlier onset of Alzheimer’s.

What does all of this really mean if you have a mother, father, brother, sister, or grandparent with late-onset Alzheimer’s disease?

Simply put, it means your risk is slightly elevated, but you shouldn’t panic, Schulz says. Genetic tests are available for APOE-e4, but doctors currently don’t recommend routine screening for it. Although having the gene means your risk for Alzheimer’s is elevated, it doesn’t mean you’ll develop the disease for sure.

“The main thing is to keep it all in perspective,” Schulz says. “Family history is something we can’t change. However, of the approximately 10 to 15 risk factors that we know about for Alzheimer’s disease, we can modify at least half of them. Focus on the positive, which is that there are things you can modify.”

Early-onset Alzheimer’s disease is a different story. “If someone with a family history of Alzheimer’s starting in his or her 40s or 50s is concerned, they may want to consider genetic testing,” says Barbara Messinger-Rapport, MD, PhD, director of geriatric medicine at the Cleveland Clinic in Ohio.

Taking Steps to Overcome Your Family History

For late-onset Alzheimer’s, the genetics are a little less cut and dried, but there are still some steps you can take to help prevent Alzheimer’s if you have a family history of the disease. For instance:

Watch out for symptoms of Alzheimer’s disease. People often lack insight into the signs of Alzheimer’s, Dr. Messinger-Rapport says. “Early symptoms of Alzheimer’s include issues with short-term memory, such as problems keeping appointments, managing medications, and keeping track of finances.” These early symptoms of Alzheimer’s are often not noticed by people themselves, but are noticed by family members or loved ones. As Alzheimer’s progresses, symptoms may include lack of attention to grooming, changes in mood or personality, or repeating questions. If you notice these signs in your loved one, you should speak up, she says.

Know the difference between symptoms of aging and symptoms of Alzheimer’s. “There’s a difference between not remembering where you put your keys and getting in the car and not being able to figure out how to start it,” Fogel says. “People with Alzheimer’s will be able to tell you what happened to them in kindergarten, but not remember what they had for breakfast.” Another classic symptom of Alzheimer’s is forgetting words. “So instead of ‘lettuce,’ the person may pause and say something like, ‘that leafy green head,’” Fogel explains. If you’re struggling with symptoms of Alzheimer’s, go to the Alzheimer’s Association Web site and check out “10 warning signs of Alzheimer’s disease.”

Keep your brain and body active. “We’re still learning about interventions that work to help prevent Alzheimer’s, but we do know that people who are socially engaged and who interact with others on a regular basis in church, book clubs, and senior centers are less likely to progress from early memory problems to dementia,” Messinger-Rapport says. She adds that people are even less likely to progress to dementia and Alzheimer’s if they combine activities that are both social and physical, like dancing.

Eat a Mediterranean diet. Research published this year in the journal Neurology found that eating a Mediterranean diet rich in omega-3 fatty acids found in fish and avoiding saturated fats, sugar, and dairy may help preserve memory and prevent Alzheimer’s. The research, which included 17,478 people, found that those who followed a Mediterranean-style diet were 19 percent less likely to develop problems with thinking and memory within a four-year span than those who did not.

Take good care of your heart. In addition to family history, heart health can affect your risk for developing Alzheimer’s. Conditions that damage the heart or blood vessels — such as heart disease, high blood pressure, stroke, diabetes, and high cholesterol — also increase the risk for Alzheimer’s disease. “These are all diseases of older age, so it’s very important to follow a healthy lifestyle to reduce your risk of developing these conditions,” Messinger-Rapport says. To manage these risk factors, keep your cholesterol and triglycerides at a normal level, control your blood sugar and blood pressure, exercise regularly, and don’t smoke.

If you or a loved one has a genuine concern about family history of Alzheimer’s, talk with your doctor. “Don’t hesitate to get it checked out,” Schulz says. “Some people are embarrassed if their testing turns out to be normal, but that’s a good thing in the end.”