A recent study suggests that the single biggest risk factor leading to Alzheimer’s in the US is lack of exercise. Twenty-one percent of all instances of the disease, or 1.1 million cases, could be prevented if more people exercised regularly, according to the researchers. The single biggest risk factor worldwide, though, is lack of education.
Getting old scares the heck out of most of us. Not only do we dread the possibility that we’ll become weak and decrepit, but even more, we fear that we’ll start to lose our marbles. A British study of 2000 individuals earlier this year found that most people fear dementia more than they fear death, with 35 percent of the subjects naming cognitive decay as their number one anxiety.1 Given that fear is such a great motivator and that scientists project that the incidence of Alzheimer’s Disease will triple worldwide by 2050, one would think that a new study recently released by the University of California in San Francisco indicating that we can cut our risk of Alzheimer’s in half by modifying lifestyle factors should certainly be of interest to most people.2
The study suggests that the single biggest risk factor leading to Alzheimer’s in the US is lack of exercise. Twenty-one percent of all instances of the disease, or 1.1 million cases, could be prevented if more people exercised regularly, according to the researchers.3 Depression causes another 15 percent, says the study, smoking 11 percent, hypertension eight percent, obesity in midlife and low education each trigger seven percent, and diabetes correlates to three percent. All of these factors may be modified by lifestyle changes — people can quit smoking, eat better and exercise more to combat depression, hypertension, and diabetes — and reducing the prevalence of the risk factors by even 10 percent could prevent a million new cases of Alzheimer’s each year worldwide, the researchers say. Incidentally, the key risk factors differ in other parts of the world, with lack of education the number one factor in the world at large, followed by smoking.
The scientists emphasize that the study doesn’t prove that these factors cause Alzheimer’s. Rather, it validates the correlation between each of the risk factors and incidence of the disease. In other words, the study did not conduct fresh experimental trials but rather culled existing research, and no study to date has actually proven that exercising will prevent Alzheimer’s or that lack of exercise will cause it, per se. Still, the existing studies do show that an increased percentage of people who don’t exercise do, by the way, get Alzheimer’s.
“These things are not definitive,” said study author Dr. Kristine Yaffe.. “We’re assuming that these are sort of causally related to the risk of dementia and Alzheimer’s, but unless you have a great trial, you just don’t know.” That’s sort of like saying you can’t accuse the kid of finishing off the chocolate chip cookies unless you catch him with his hand in the jar, even though he has crumbs all over his face and chocolate all over his hands. On the other hand, there have been occasions where apparent causal relationships revealed in studies ultimately turned out to be less than imagined. Nevertheless, in this case, the evidence is strong enough that it ought to encourage the lazy among us to get on the treadmill or go to the yoga studio, especially considering that lack of exercise also correlates to killers like heart disease and diabetes.
That’s the thing: lack of exercise has been implicated in virtually every major disease, including some diseases that cause other diseases like Alzheimer’s. Depression, for instance, is the second leading cause of Alzheimer’s, and exercise combats depression. I’ve written before about studies showing that exercise outperforms antidepressants in combating depressive disorder. So exercising not only directly cuts Alzheimer’s risk, it also alleviates the second major risk for Alzheimer’s. Or are they one and the same thing. Perhaps a future study will let us know. And of course, exercise also has a healing effect on hypertension, diabetes, and obesity, three of the other major Alzheimer’s risk factors. So you kill many birds with one jog.
The same principal applies to diet. The researchers didn’t include diet as a risk factor in their study because they didn’t think there’s enough solid evidence that diet triggers Alzheimer’s Disease to assume a causative relationship. But that’s just their opinion. In fact, there are scores of studies that show that poor diet contributes to obesity, hypertension, diabetes, and depression. If these conditions are all Alzheimer’s risk factors, and if eating better reduces these conditions, it makes sense that improving diet will cut Alzheimer’s risk dramatically. Anyway, in the past few months alone, several studies have come out tying diet to Alzheimer’s, including one published in the June Archives of Neurology that found that a low-fat, balanced diet reduces the biomarkers associated with Alzheimer’s.4 Meanwhile, in May, a panel convened by the National Institutes of Health concluded that to avoid Alzheimer’s, it’s probably a good idea to follow a Mediterranean Diet high in fruits, vegetables, and healthy fats.5
In other words, when it comes to minimizing your risk of Alzheimer’s disease, it’s the same old song. Exercise every day, eat a Mediterranean-style diet, supplement with an L-carnosine based formula to reduce beta amyloid plaque in the brain, and stay positive. There are no guarantees that following this approach will prevent the disease, but doing so sure gives you a better shot at eluding it. The study authors write, “Public health campaigns targeted at increasing the amount of physical activity on a societal level could have a profound effect on future AD prevalence.” What a nice alternative to the usual recommendation to put more people on medication sooner and longer!
1 Rogers, Lauren. “We fear dementia more than death – study finds.”. 9February 2011. EDP24. 11 August 2011. <http://www.edp24.co.uk/news/health/we_fear_dementia_more_than_death_study_finds_1_796350>
2 Curley, Chris. “Cut Your Alzheimer’s Risk by Reducing These Risk Factors.” 21 July 2011. Well Being Wire. 11 August 2011. <http://wellbeingwire.meyouhealth.com/physical-health/cut-your-alzheimers-risk-by-reducing-these-risk-factors/>
3 Belluck, Pam. “Grasping for Any Way to Cut Alzheimer’s.” 25 July 2011. The New York Times. <http://www.nytimes.com/2011/07/26/health/26alzheimer.html?_r=1&ref=health>
4 “Study: Low-Fat Diet May Reduce Alzheimer’s Risk.” 16 June 2011. CBN.com. 12 August 2011. <http://www.cbn.com/cbnnews/healthscience/2011/June/Study-Low-Fat-Diet-May-Reduce-Alzheimers-Risk/>
5 Curley, Bob. “Exercise, Diet and Alzheimer’s: A Healthy Heart Equals a Healthy Brain.” 11 May 2011. Well-Being Wire. 12 August 2011. <http://wellbeingwire.meyouhealth.com/physical-health/exercise-diet-and-alzheimers-a-healthy-heart-equals-a-healthy-brain/>