Having a grandparent or even a cousin with Alzheimer’s disease may raise your risk of getting it.
Many people who have lost a parent to dementia have the nagging fear they may have inherited the condition. But a study now suggests less closely related relatives with Alzheimer’s disease could be a warning sign.
Someone with two grandparents diagnosed with the condition has a 25 percent higher risk of getting it, researchers found. Two cousins with Alzheimer’s disease can raise someone’s risk by 17 percent.
The risk from ‘second-degree’ family members like grandparents and uncles and ‘third-degree’ relatives like cousins being diagnosed with Alzheimer’s was found in a study of more than 270,000 people.
Those with two dementia-suffering grandparents has a 25 percent higher risk of getting it, researchers in Utah found. Two cousins with Alzheimer’s disease can raise someone’s risk by 17 percent
More than half of people with Alzheimer’s have a specific gene that triples the risk of getting it, and other genes passed down through families are also thought to lead to the condition.
However it is not inevitable that the condition will run in families, as someone can slash their risk of getting it through lifestyle changes like losing weight and reducing high blood pressure.
Dr Lisa Cannon-Albright, who led the study from the University of Utah, said: ‘Family history is an important indicator of risk for Alzheimer’s disease, but most research focuses on dementia in immediate family members, so our study sought to look at the bigger family picture.
‘We found that having a broader view of family history may help better predict risk. These results potentially could lead to better diagnoses and help patients and their families in making health-related decisions.’
It is well known that having a parent or sibling with Alzheimer’s disease can raise someone’s risk of getting it themselves in old age. But people may want to look more widely at their family tree, based on the latest results.
It can double your risk of getting Alzheimer’s disease if three or more second-degree relatives have had it. These relatives include grandparents, blood-related aunts and uncles and half-siblings.
Someone’s danger of the memory-robbing condition also leaps 43 percent when three of their third degree relatives have had it. That means cousins, great-grandparents, great uncles and great aunts.
Among 5,320 people in this category, 148 people had the disease when researchers would have expected 103 to be diagnosed.
The results come from analyzing medical records and death certificates for 270,800 people in the US, looking at four generations in each case.
They show someone with a parent or sibling with Alzheimer’s disease, plus a second-degree relative like a grandparent, could see their risk of being diagnosed rise 21 times.
However some results were based on small numbers of people and the authors stress that people who change their lifestyle can slash their risk of getting Alzheimer’s disease by a third.
Responding to the study, published in the journal Neurology, Dr James Pickett, head of research at Alzheimer’s Society, said: ‘Although this study does suggest that a family history, including extended family such as great-grandparents, is linked to an increased risk, it doesn’t mean people with a family history will definitely go on to develop dementia.
‘Alzheimer’s risk is complex, with many factors at play. By following good lifestyle advice, even people with a strong family history could significantly reduce their risk.’