Book Excerpt: The Brain’s Way of Healing
Dementia is the most feared of afflictions and a true hardship on even the most loving of families. Here, in an excerpt from his latest groundbreaking book, The Brain’s Way of Healing, brain guru Norman Doidge suggests 5 ways to help stave off the disease.
The question inevitably arises: if walking can turn back Parkinson’s symptoms and can delay the onset of Huntington’s, both degenerative diseases, might it have a role to play in the commonest degenerative disease of the brain—Alzheimer’s disease?
The question is especially important because there are no effective medications for Alzheimer’s. Yet Alzheimer’s and Parkinson’s have similarities. Dr. Mark P. Mattson, chief of the National Neurosciences Laboratory at the National Institute on Aging, National Institutes of Health, has shown that many of the cellular processes that cause problems in Parkinson’s also occur in Alzheimer’s but in different brain areas.
In Parkinson’s, the substantia nigra [which releases neurotransmitters that help control movement and co-ordination] begins to malfunction first. In Alzheimer’s, degenerative changes begin in the hippocampus (which turns short-term memories into long), which starts to shrink, so that its victims lose short-term memory. In Alzheimer’s disease, the brain literally loses its plasticity and its ability to make connections between neurons, many of which die.
In 2013 that pressing question about walking and Alzheimer’s was answered. Walking was a key contributor to a very simple program that reduced the risk of dementia by a staggering 60 per cent. If any drug could do that, it would be the most popular, talked-about treatment in medicine.
The breakthrough study was done by Dr. Peter Elwood and a team from the Cochrane Institute of Primary Care and Public Health, Cardiff University, United Kingdom, and released in December 2013.
Results showed that if the men did four or five of the following behaviours, their risk for cognitive (mental) decline and dementia (including Alzheimer’s) fell by 60 per cent:
1. Exercise (defined as vigorous exercise or walking at least two miles a day, or biking 10 miles a day). Exercise was the most powerful contributor to decreased risk of both general cognitive decline and dementia.
2. Healthy diet (as measured by eating at least three to four servings of fruits and vegetables a day).*
3. Normal weight (as measured by having a body mass index between 18 and 25).
4. Low alcohol intake (alcohol is often a neurotoxin).
5. No smoking (also a case of avoiding a toxin).
All five factors promote the general cellular health of neurons and glia [the cells surrounding neurons]. All factors require that a person live closer to the ways our hunter-gatherer ancestors lived and thus use the body as it evolved to be used. All these behaviours are basically subtractive: don’t do things we didn’t evolve to do, such as sit all day and travel sitting in cars; don’t eat processed food, inhale smoke or drink too much.
One of the reasons this work hasn’t received more attention is that the scientific community has been so focused upon “curing” Alzheimer’s by coming up with a drug for it or thinking of it in terms of genetics. Of course, if “it is all in your genes,” most people assume there is nothing they can do about it, except pray for “genetic breakthroughs.”
Another breakthrough study, in 2011, shed important light on the cognitive effects of exercise. J. Eric Ahlskog, of the department of neurology at the Mayo Clinic, and his team reviewed all 1,603 studies to date of exercise and cognitive impairment with a focus on dementia. Ahlskog did what is called a meta-analysis, examining all studies of high quality and selecting out the best, including randomized, controlled trials.
The 29 randomized, controlled studies that were selected documented that exercise—mostly aerobic—was helpful in improving cognitive functioning in adults without dementia, in terms of memory, attention, processing speed, and ability to form and act on plans. Typical doses in most studies are 2.5 hours of aerobic exercise a week.
A recent randomized, controlled trial by the Mayo group shows that those (without dementia) who did aerobic exercise for a year showed significant hippocampal enlargement, compared with sedentary adults. These changes last, too. Another study showed that adults who walked had hippocampal enlargement nine years after they began their exercise program. Ahlskog also found that even those with dementia made some modest improvements with exercise.
Will incorporating these behaviours defer dementia indefinitely? We don’t yet know. Right now, 15 per cent of people over 70 have some dementia, and that number radically increases by age 85. But it isn’t inevitable in a long life: some people live to very advanced years without Alzheimer’s.