Impacting Dread Dementia by Healthy Lifestyle

"The lifestyle factors we chose to study in this project are totally dependent on individuals so they can change them immediately if they want."
"We were expecting to find a protective effect of these factors on dementia risk. But we were surprised by the magnitude of the effect."
Dr. Klodian Dhana, Rush University Medical Center, Chicago

"The core message from these findings is that whatever their genetic risk, people may be able to benefit from a healthy lifestyle."
"It’s really reassuring in a way, since people say, ‘my parents had dementia so I probably inherited bad genes."
"It’s important that people don’t fall into the trap of thinking that depending on your genes, dementia is inevitable. We found it’s not an all or nothing thing. The overall pattern of healthy behaviors and a healthy lifestyle can make a difference."
David Llewellyn, the University of Exeter Medical School, Great Britain

"A healthy lifestyle was protective, even for the people who had a bad luck of the draw with their genetic inheritance."
"[There are a number of theories as to why peoples' risk of dementia has been diminishing in recent years], but big ones are that we’re doing a better job of controlling cardiovascular risks, people have given up smoking and people are better educated at older ages than they used to be."
Dr. John Haaga, U.S. National Institute on Aging

While the number of people at risk of dementia, because of age, is growing rapidly as the population ages, a person's individual odds of getting dementia have been going down. Photo by Getty Images

Two recent studies presented at  an annual Alzheimer's Association International Conference reached very similar conclusions, offering hope to people with regard to a dread disease for which no protocol reaching toward a cure -- much less amelioration of symptoms to break the disease's slow march to death -- gives assurance that despite genetic inheritance weighing toward Alzheimer's onset, people with those genes are still able to offset the chances of having Alzheimer's through altered lifestyle values.

Dr. Dhana's team of researchers followed 2,500 subjects for close to a decade, tracking a number of lifestyle factors inclusive of diet, smoking, leisure physical energy, alcohol consumption and cognitive exercises engaged in. The finding concluded that those who reported a life dedicated to a healthier lifestyle with a low-fat diet, non-smoking, a minimum of 150 minutes of exercise weekly, moderate alcohol use, and cognitive activities engaged in, came with lower levels of Alzheimer's dementia.

The greater attention to a healthy lifestyle had the effect of lowering onset risk, it was established. in comparison to others who maintained none, or only one type of behaviour linked to a healthy lifestyle. Study subjects engaged in two or three healthy lifestyle factors succeeded in reducing their personal risk of developing Alzheimer's dementia by 39 percent; those who routinely engaged in four to five healthy behaviours saw a reduction in risk of 59 percent.

The two studies were published in JAMA Neurology, establishing that it is not inevitable that as people age they will be stricken with dementia. Nor is it inevitable that those whose genes are heavily influenced for Alzheimer's onset will succumb to Alzheimer's. Researchers in Britain followed close to 200,000 people to discover that those with a high genetic risk for dementia yet do not smoke, exercised on a regular basis, drank moderately and ate a Mediterranean-type diet had a full third-lower risk of dementia.

The UK Biobank study was the source of 195,383 study subjects, enabling the researchers to access an extremely large sample. All those included in the study were aged 60 and over, free of dementia at the beginning of the study period. They were genotyped (DNA analyzed for genetic features linking to dementia risk) and assigned a category group according to risk: high, intermediate, or low-risk. Scores were established for individuals, based on four recognized risk factors for dementia onset (smoking, physical activity, diet, alcohol consumption).

How much the study group smoked, how important fish was in their diet, how much red meat was consumed, how many servings of fruits and vegetables eaten daily, and how much alcohol was taken in a typical week, led to the risk-group assignments. Those with an identified high-risk genetically aligned with an unhealthy lifestyle were three times likelier to develop dementia in comparison to those with a low genetic risk and healthy lifestyle habits.

Good lifestyle habits tended to lower the risk of dementia onset irrespective of an individual's genetic predisposition. Those with a high genetic risk saw 1.13 percent with a healthy lifestyle developing dementia after eight years of follow-up versus 1.78 percent of those with less holistic lifestyle habits. Non-smokers, those limiting alcohol consumption (not exceeding one drink per day for women; two per day for men) along with those who ate at least three servings of fruits and vegetables daily and those who consumed relatively little red meat, scored highest on the lifestyle scale.

The study authors emphasized that full benefits of reduced chances of acquiring Alzheimer's dementia depended on adopting all four healthy lifestyle criteria, to protect the brain. Dr. Llewellyn explains the brain as requiring to be well nourished with a rich and constant supply of oxygen and glucose; that disruptions to the blood supply make the brain vulnerable to dementia.

Dementia is the only major cause of death in Western countries lacking effective treatment. Over 419,000 Canadians age 65 and more are diagnosed with dementia, women representing two-thirds of the total number. Published this week in the Journal of the American Medical Association, the study fails to prove cause and effect since lifestyle factors were self-reported, the follow-up period was only eight years and some dementia cases are not recorded in medical records or death registries.

"We can’t guarantee you’ll never get it. But you’ll delay it, you’ll reduce your likelihood."

"Lifestyle is really, at this point, where the biggest bang for the buck is in terms of prevention. We don’t have good pharmaceutical treatments that can really extend life out or prevent dementia, yet. But I think reducing cases by a third could have considerable impact."

Laura Middleton, associate professor of kinesiology, University of Waterloo, Ontario

Dementia is the only major cause of death in Western countries without an effective treatment.