Alzheimer’s disease, lifestyle and genetics: How to know if you’re at risk
We all know Alzheimer’s disease as the memory-loss condition. Perhaps you’ve seen the recent movie Still Alice, a true story about a linguistics professor who develops Alzheimer’s at just 50. Or maybe you joked that you had Alzheimer’s when you last forgot a birthday or an appointment.
The surprising fact is that although Alzheimer’s is a relatively well-known condition, and there are more than 310,000 Australians living with Alzheimer’s, what actually causes it isn’t as clear.
There are, however, certain risk factors that increase your likelihood of developing the disease, according to Associate Professor Michael Woodward, Director of Aged Care Research and the Memory Clinic at Austin Health.
Age is the key risk factor for Alzheimer’s
The greatest risk factor for developing Alzheimer’s disease is simply getting older. Assoc Prof Woodward says; the risk of developing the condition doubles every five years after the age of 65. A study published in the journal Science Advances in July 2019 found that tau proteins, a hallmark of the disease, spread more easily in the ageing brain.
A small number of people who develop Alzheimer’s – about 3 per cent – do so due to a single gene that runs in their family. Having the APOE4 gene is the strongest genetic risk factor for Alzheimer’s disease.
A family history of Alzheimer’s also increases the risk of developing the disease, Assoc Prof Woodward explains. Family history doesn’t just mean parents and siblings, however. As March 2019 research published in The American Academy of Neurology found, having an extended family member with the disease may also increase the risk of Alzheimer’s.
Lifestyle and health factors in Alzheimer’s
Other Alzheimer’s cases can be traced back to lifestyle factors. Assoc Prof Woodward explains that health issues such as high blood pressure, high cholesterol and diabetes can increase the risk of developing Alzheimer’s. Smoking has also been identified as a risk factor, as is being inactive or overweight.
Studies have shown that both lifestyle and dietary treatments can more generally slow the rate of decline in cognitive skills as a person ages. For example, the Mediterranean diet that’s rich in fruits, vegetables, olive oil, beans, wheat and rice, and limited in red meats and poultry can maintain brain power and delay many symptoms associated with Alzheimer’s.
Foods rich in omega-3 fatty acids, B vitamins and antioxidants are also known to contribute to better brain health. Eating, for example, salmon, cod or tuna twice a week can be beneficial to memory, as can a daily serving of leafy green vegetables.
Experiencing severe hearing loss, disrupted sleep or depression also increase the risk of developing the disease, Assoc Prof Woodward adds. Studies suggest older people who have less sleep have higher levels of the brain protein tau, which can lead to an increased risk of the disease.
Some studies indicate that having concussions and other traumatic brain injuries may increase the risk of developing Alzheimer’s earlier in life, while others have linked gum disease with Alzheimer’s, although these are only indicated no conclusions can be drawn.
Managing Alzheimer’s risk
Of course, some risk factors – age and genetics – can’t be controlled, Assoc Prof Woodward notes, but others can be managed to reduce the risk of developing Alzheimer’s as much as possible.
“The main risk factors that we can’t do much about are age and family history, but the factors we can do something about are … our lifestyle, diet, mental activity [and] social activity.” he says. “If we deal with all of those things, we have a significant chance of reducing our risk of developing Alzheimer’s.”
At the same time, though, he cautions against taking seriously every fad said to protect against Alzheimer’s disease. Instead, the geriatrician recommends simply eating a Mediterranean-style diet and exercising regularly – even if that exercise isn’t as vigorous as it might’ve been in the past.
Assoc Prof Woodward adds that mental stimulation is also vital, but ticking that off is more arduous than many people might imagine. “That’s more than doing the daily crossword,” he says. “You may want to learn a new language, or [a] musical instrument.”