A new study by researchers at the University of California, San Francisco, has concluded that up to half of Alzheimer’s cases worldwide and in the US may be attributable to seven risk factors that are potentially preventable through simple lifestyle changes, such as exercising, using your brain, quitting smoking and losing weight.
The new study, by Dr Deborah E Barnes PhD and colleagues at the University of California, San Francisco, is published online in the July 19, 2011 issue of The Lancet Neurology, a British medical journal. It was presented on July 19 at the Alzheimer’s Association International Conference in Paris.
In an introduction to their study report the authors note that, “At present, about 33.9 million people worldwide have Alzheimer’s disease (AD), and prevalence is expected to triple over the next 40 years.” “Given the current absence of disease-modifying treatments, as well as increasing awareness that symptoms develop over many years or even decades, there has been growing interest in identification of effective strategies for prevention of AD [Alzheimer's disease],” the authors wrote.
Their research showed that a 25% reduction in all seven risk factors they studied could potentially prevent as many as 3 million cases of Alzheimer’s worldwide over the next 40 years, the authors reported. A 10% reduction in these seven factors could prevent 1.1 million cases, they said.
The seven risk factors isolated by the researchers include:
- Physical inactivity
- Cognitive Inactivity or Low Educational Attainment
- Mid-life Obesity
- Mid-life High Blood Pressure
The Study and Its Principal Findings
In the study, the researchers reviewed previous research examining factors that predispose people to developing Alzheimer’s. Based on their review, they identified the seven factors listed above, which are potentially within a person’s control to change.
They identified the following three factors as the greatest contributors to development of Alzheimer’s Disease:
1. Cognitive Inactivity or Low Educational Attainment. They found that the factor contributing to the largest number of cases of Alzheimer’s worldwide was lack of mental activity or low educational attainment. They defined low educational attainment as not having completing higher education, having a low IQ or not participating in mentally stimulating leisure time activities. This factor contributes to 19 percent of Alzheimer’s cases, or 6.5 million cases worldwide, they reported.
The researchers said that enhancing mental activity could make the biggest difference toward preventing Alzheimer’s.
2. Smoking. The factor contributing to the second-highest number of cases was smoking. The research showed that smoking contributes to 14 percent of cases, or 4.7 million cases of Alzheimer’s worldwide.
3. Physical Inactivity. Physical inactivity, the study found, contributed to 13 percent of worldwide cases and was the third-largest factor worldwide. However, physical inactivity was the highest contributor to Alzheimer’s in the United States — contributing to 21 percent, or 1.1 million cases.
“What really mattered was how common the risk factors were in the population. In the U.S.A., about a third of the population is sedentary, so a large number of Alzheimer’s cases are potentially attributable to physical inactivity,” said Dr. Barnes, the study’s principal author.
“Worldwide, low education was more important, because so many people throughout the world are illiterate or are not educated beyond elementary school,” Dr. Barnes said.
Implications of the Study
The authors caution that it has not yet been proved that these factors actually cause Alzheimer’s. The cause of Alzheimer’s remains unclear; like heart disease, it may be caused by a combination of factors.
“Accumulated evidence from epidemiological research strongly supports a role for lifestyle and cardiovascular risk factors in the pathogenesis and development of dementia. However, none of these factors has been proven to have a causal relation specifically with AD,” wrote researchers Laura Fratiglioni, from the Karolinska Institute in Sweden, and Chengxuan Qiu, from the Stockholm Gerontology Research Center, in an editorial accompanying the new study in the July 19 issue of The Lancet Neurology.
However, the findings suggest “that preventive and therapeutic interventions have great potential,” they said.
The clear association of the seven lifestyle-related factors with cases of Alzheimer’s, as found by the study, gives hope that modifying them may reduce one’s risk of Alzheimer’s.
According to Dr. Barnes, the study’s principal author, “It gives us a little bit of hope about things we could do now about the epidemic that is coming our way.”
The study suggests that public health initiatives to increase physical activity levels throughout life as well as to help people quit smoking and lose weight could help dramatically in decreasing the number of Alzheimer’s cases. The findings indicate that Alzheimer’s cases could be reduced if people enhanced their mental activity, quit smoking, increased their physical activity, controlled their blood pressure and diabetes, and managed their obesity and depression.
“A 10 – 25% reduction in all seven risk factors could potentially prevent as many as 1.1 — 3·0 million AD cases worldwide and 184,000 – 492,000 cases in the USA,” the authors wrote.
Finding a way to reduce one’s risk of developing Alzheimer’s is increasingly significant. It has been reported that half of all people over age 85, an estimated 5.4 million Americans, now have Alzheimer’s or some form of dementia, and the numbers are increasing in epidemic proportions as the Baby Boom Generation ages. Nearly 15 million Americans are now caring for a loved one with Alzheimer’s Disease or another form of dementia, according to statistics released by the Alzheimer’s Association.
By the year 2050, Alzheimer’s cases are expected to rise to 106 million around the world. The disease has no cure, and at this time, no treatments exist to prevent the disease. As reported by the Alzheimer’s Association, every 69 seconds someone in the U.S. now develops Alzheimer’s, which is the 6th leading cause of death in the U.S., and the only one for which no effective treatment to cure the disease yet exists.
See our previous reports on:
See also HelpingYouCare™’s resource pages on
Alzheimer’s/ Dementia, including sub-pages on What is it; Causes; Symptoms & Diagnosis; Prevention; Treatment; and Caregiving; and
Copyright © 2011 Care-Help LLC