A new study shows that regularly doing puzzles and reading books could be linked to a decreased risk of Alzheimer's disease. It says that these activities reduce the accumulation of harmful proteins in the brain.
In the study, older adults who said they engaged in mentally stimulating activities throughout their lives had fewer deposits of beta-amyloid, the hallmark protein of Alzheimer's. The findings were true regardless of the participants' gender or years of education. The study was published online Jan. 23 in the journal Archives of Neurology.
The researchers asked 65 healthy, cognitively normal adults ages 60 and over (the participants' average age was 76) to rate how frequently they participated in such mentally engaging activities as going to the library, reading books or newspapers, and writing letters or email. The questions focused on various points in life from age 6 to the present. The participants also completed tests to assess memory and other cognitive functions, and received positron emission tomography (PET) scans using a new compound that was developed to visualize the amyloid protein. The brain scans of the older adults were compared with those of 10 patients diagnosed with Alzheimer's disease and 11 healthy people in their 20s.
The researchers found a significant association between higher levels of cognitive activity over a lifetime and lower levels of in the PET scans. Older adults with the highest reported amounts of cognitive activity over a lifetime also possessed levels of amyloid comparable to young people. In contrasts, older adults with the lowest reported amounts of cognitive activity possessed amyloid levels comparable to patients with Alzheimer's disease. The new study involved the use of an imaging agent known as Pittsburgh Compound B or PiB, which works with positron emission tomography, or PET scanners. This chemical sticks to and highlights deposits of beta amyloid.
The William Jagust, a professor at the University of California, Berkeley's Helen Wills Neuroscience Institute and study researcher notes that cognitive therapies that stimulate the brain may slow the progression of the disease, if applied before symptoms appear. Authors add that Alzheimer's is a complex disease that likely has more than one cause. In addition, other lifestyle factors not accounted for in the study may influence the link.
“We're not talking about the brain's response to amyloid. We're talking about the actual accumulation of amyloid,” Dr. Jagust said. “It's a brand new finding.”
“What our data suggests is that a whole lifetime of engaging in these activities has a bigger effect than being cognitively active just in older age,” said study researcher Susan Landau, also of UC Berkeley. She said amyloid probably starts accumulating many years before symptoms appear, so by the time memory problems start, there is little that can be done. “The time for intervention may be much sooner,” she said in a statement. However, the researchers said there was no downside to stimulating the brain later in life.
The researchers note that the buildup of amyloid can also be influenced by genes and aging — one-third of people age 60 and over have some amyloid deposits in their brain — but how much reading and writing one does is under each individual's control.
Dr Anne Corbett, research manager at the Alzheimer's Society, said, “This is an interesting initial finding that echoes the results from previous studies. However, the research involved only a very small number of people and we do not know if they went on to develop dementia. It is too early to say whether keeping your brain active can reduce your risk of developing dementia, or how this might work. However, we would encourage anyone who enjoys cognitively stimulating activities such as reading, writing and playing games to keep it up. The best way to reduce your risk of dementia is to exercise regularly, eat a healthy diet, don't smoke and get your blood pressure and cholesterol checked by your GP.”
Dr Simon Ridley, head of research at Alzheimer's Research UK, the UK's leading dementia research charity, said, “The authors of this small study suggest that there may be benefits to keeping an active mind throughout life, not just in old age. Whilst the study found an association between cognitive activity and the levels of amyloid protein in the brain of healthy elderly volunteers, we cannot conclude that one directly causes the other. It would be important to follow these healthy participants and see whether those that reported higher cognitive activity were less likely to develop Alzheimer's in the long run. With 820,000 people in the UK living with dementia, it is essential that we understand the factors that can lower our risk, so we must invest in more research.”
An estimated 5.4 million Americans live with Alzheimer's disease, and between 2000 and 2008, deaths from the disease increased by 66 percent. Currently, there are no drugs that can prevent Alzheimer's disease, which scientists now think begins 10 to 15 years before memory problems set in. Alzheimer's Disease International estimates there are now 36 million people with the disease worldwide. As the population ages the number will increase to 66 million by 2030, and to 115 million by 2050. Last week, the U.S. government released draft recommendations for a national Alzheimer's plan that calls for finding effective treatments or prevention strategies by 2025.
One weakness is that the study relies on people's memory of their mental activities, Jagust said.
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