Researchers say there are certain lifestyle measures we can take to reduce our risk of developing Alzheimer's disease and dementia, including being physically active, eating a healthy and balanced diet, maintaining good cardiovascular health, and exercising the brain.
The Alzheimer's association says we need more scientifically based large-scale studies to back up some of the proposed measures, but research so far has been promising.
The incidence of dementia, including Alzheimer's is expected to grow as lifespans increase. A study carried out by the RAND Corporation and published in NEJM (New England Journal of Medicine) (April 2013 issue) reported that the economic burden of dementia in the USA could double by 2040. This rising rate of dementia and Alzheimer's has fuelled efforts to find prevention strategies.
Experts from the University of California, San Francisco, said that over 50% of all Alzheimer's cases may be prevented through lifestyle changes. This involves reducing important risk factors, including:
- not smoking
- being physically and mentally active
- combating low education
- properly treating or preventing chronic diseases and conditions, such as hypertension (high blood pressure), high blood cholesterol, diabetes, obesity in mid life, and depression.
Canadian expert, Dr. Kenneth Rockwood of Dalhousie University in Halifax, Nova Scotia, explained in the journal Neurology that if you pay attention to health factors not traditionally linked to dementia, such as vision, hearing, or how well dentures fit, you may also reduce the risk of developing dementia.
If it is good for your heart it is good for your brain
Several studies have shown that the risk of developing Alzheimer's disease or vascular dementia is higher among people who have diseases and conditions that damage cardiovascular health, i.e. the health of the blood vessels and the heart. Examples include hypertension (high blood pressure), atrial fibrillation, high cholesterol, heart disease, stroke, diabetes, and high cholesterol. We know that bad heart habits reduce brain volume.
The Alzheimer's Association says that up to 80% of autopsies on people who had Alzheimer's disease show that they also had cardiovascular disease.
Experts are not sure why some patients with the hallmark Alzheimer's plaques and tangles never developed Alzheimer's symptoms while they were alive. Perhaps in these cases symptoms only appear if the patient also has some kind of vascular disease.If this is the case, and most experts believe it probably is, controlling cardiovascular risk factors could be one of the best ways to protect patients from developing Alzheimer's disease or dementia.
High cholesterol raises Alzheimer's risk - a team led by Kensuke Sasaki, MD, PhD, from Kyushu University in Fukuoka, Japan, demonstrated a close association between high cholesterol levels and senile plaques, which are common among people with Alzheimer's disease. The study was published in Neurology (September 2011 issue).
Women with metabolic syndrome are more likely to develop dementia, researchers from the University of California, San Francisco reported in JAMA (Journal of the American Medical Association).
Metabolic syndrome refers to a cluster of conditions, including obesity, high blood pressure, high cholesterol, and high blood sugar levels - they all occur simultaneously and increase the risk of stroke, heart disease and diabetes.
Metabolic syndrome can be treated with good diet, exercise, weight loss and some medications. People with metabolic syndrome who are able to reach their ideal weight, bring down their blood pressure and cholesterol to healthy levels, and control their blood sugar will not only reduce their risk of diabetes and cardiovascular events, but also dementia and Alzheimer's disease.
Obesity in old age undermines male cognitive function - a study of 3,000 elderly men and women found an association between obesity and poorer thinking and memory skills among the obese males, but not the females.
Obesity in middle age raises dementia risk later on - Dr Annette L Fitzpatrick of the University of Washington, Seattle, found that 75 year-old people who were obese when they were 50 had a higher chance of developing dementia. However, they also found that being underweight when elderly increased the likelihood of dementia.
Diabetes considerably increases risk of dementia - diabetes is a risk factor for dementia, researchers from Kyushu University in Fukuoka, Japan, reported in the journal Neurology (September 2011 issue).
Senior author, Yutaka Kiyohara, MD, PhD, said "Our findings emphasize the need to consider diabetes as a potential risk factor for dementia. Diabetes is a common disorder, and the number of people with it has been growing in recent years all over the world. Controlling diabetes is now more important than ever."
The team found that patients with diabetes had double the risk of developing Alzheimer's and other dementias, including vascular dementia. Other studies suggested that patients with the best diabetes control had the lowest risk of dementia. If you have diabetes and wish to minimize your risk, follow your treatment regimen carefully. However, one study suggested that intensive blood sugar control in type 2 diabetes does not slow cognitive decline.
Diet to prevent Alzheimer's disease and dementia
Researchers have found that a healthy and well balanced diet helps brain health because of its impact on heart health. A healthy heart provides the brain with plenty of oxygen-rich blood. A study published in Neuron found that heart disease risk scores are closely linked to the likelihood of cognitive decline.
The Mediterranean diet protects aging brains - a diet which includes olive oil as the main source of fat, plus plenty of fruits, vegetables, pulses (legumes), a moderate-to-high amount of fish/seafood, low quantity of dairy products and red meat, and moderate amounts of wine has been shown to protect older people at risk of vascular dementia, scientists from the University of Navarra, Spain, reported. Vascular dementia occurs when blood vessels which provide the brain with oxygen are damaged - the brain becomes deprived of oxygen.
Their study was published in the Journal of Neurology Neurosurgery and Psychiatry (May 2013 issue). The authors added that the Mediterranean diet appears to be more effective in protecting the brain health of seniors compared to a low-fat diet, which is typically recommended for stroke and heart attack patients.
Eating too much bad for memory in seniors - researchers from the Mayo Clinic in Scottsdale, Arizona, showed that people over 70 years of age who ate in excess of 2,100 calories per day almost doubled their risk of mild cognitive impairment. Study author Yonas E. Geda, MD, MSc, said "We observed a dose-response pattern which simply means; the higher the amount of calories consumed each day, the higher the risk of MCI."
Diets high in omega-3 fatty acids and vitamins C, B, D, E improve mental ability - a study carried out by a team at Oregon Health & Science University in Portland demonstrated. Dr. Gene Bowman and colleagues also found that diets high in trans fats were more likely to encourage brain shrinkage.
Eating fish once a week reduces risk of Alzheimer's disease and mild cognitive impairment - the researchers, from the University of Pittsburgh School of Medicine, said that those who ate baked or broiled fish at least once a week "had better preservation of gray matter volume on MRI in brain areas at risk for Alzheimer's disease."
In this video below, Carl W. Cotman, Ph.D., explains how a diet rich in antioxidants and regular exercise may benefit the brain.
Exercise to protect from Alzheimer's disease and dementia
Being physically fit and doing regular exercise will most likely lower the risk of developing vascular dementia and Alzheimer's disease, experts say. This could be for a number of reasons, including a better blood and oxygen supply to the brain. Exercise protects cardiovascular health, which is known to reduce the risk of dementia.
A research team from The Cooper Institute, Dallas, Texas, reported in Annals of Internal Medicine (February 2013 issue) that people who are fit and exercise regularly during middle age are less likely to develop dementia later on.
Team leader, Laura F. DeFina, MD, said "Higher midlife fitness levels seem to be associated with lower hazards of developing all-cause dementia later in life. The magnitude and direction of the association were similar with or without previous stroke, suggesting that higher fitness levels earlier in life may lower risk for dementia later in life, independent of cerebrovascular disease."
Even a brief spurt of intense exercise boosts memory among both mentally "healthy" seniors as well as those with slight cognitive impairment, scientists from UC Irvine's Center for the Neurobiology of Learning & Memory reported.
As humans enter late adulthood, the brain's hippocampus starts to shrink, this leads to loss of memory and a higher risk of dementia. A team from the University of Illinois and Rice University found that just 12 months of moderate physical exercises can reverse shrinkage of the hippocampus and improve spatial memory. Their study was published in PNAS (January 2011 issue).
The hippocampus is part of the limbic system and sits deep with brain tissue; it plays an important role in several types of memory formation and spatial navigation.
Could exercise be more important than diet for preventing dementia? - Ayae Kinoshita and colleagues at the Kyoto University Graduate School of Medicine, Japan, suggest that exercise alone may be as effective in reducing β-amyloid formation (a defining characteristic of Alzheimer's disease) as exercise plus diet. Kinoshita suggested that "Based on the results in this research, exercise should be given priority to prevent Alzheimer's disease."
Even if you start late, exercise can protect from Alzheimer's - even if you start exercising after the age of 80 years, your risk of developing Alzheimer's will probably go down, researchers from Rush University Medical Center reported in Neurology (April 2012 issue).
Lead author, Dr. Aron S. Buchman, said "The results of our study indicate that all physical activities including exercise as well as other activities such as cooking, washing the dishes, and cleaning are associated with a reduced risk of Alzheimer's disease. These results provide support for efforts to encourage all types of physical activity even in very old adults who might not be able to participate in formal exercise, but can still benefit from a more active lifestyle. This is the first study to use an objective measurement of physical activity in addition to self-reporting. This is important because people may not be able to remember the details correctly."
Exercising during pregnancy protects baby from Alzheimer's later on - the offspring of mothers who exercised during pregnancy are less likely to develop neurodegenerative diseases, including Alzheimer's, later on in life, scientists from University Hospital Esse, Germany, reported in The FASEB Journal.
Team member, Kathy Keyvani, M.D., said "This research provides an experimental rationale for the effects of beneficial behavioral stimuli experienced by the pregnant mother affecting the disease status of an as yet-unborn child.
"Epigenetic alterations (alterations in gene and protein expression caused by mechanisms other than changes in the underlying DNA sequence) provide a most probable mechanism by which mothers could have transferred their own behavioral experience to their progeny. A better understanding of the underlying pathways may provide novel treatment and/or prevention strategies for Alzheimer's disease and bring more insight into the fascinating link between brain and behavior."
Aerobic exercises cut dementia risk and also slow down its progress once it starts - according to a study published in Mayo Clinic Proceedings (September 2011 issue). Lead researcher, Dr J Eric Ahlskog explained that aerobic exercise is not just a gym workout, but includes walking, doing household chores, as well as raking leaves and shoveling snow.
Dr. Ahlskog said "We concluded that you can make a very compelling argument for exercise as a disease-modifying strategy to prevent dementia and mild cognitive impairment, and for favorably modifying these processes once they have developed."
Teepa Snow, MS, OTR/L, FAOTA, a dementia expert, talks about "Dementia: Risk Reduction and Exercise Tips."
Keeping the mind active to protect from Alzheimer's and dementia
Several studies suggest that the risk of cognitive decline is much lower if the brain is kept mentally active and people maintain strong social connections.
Retiring later reduces the risk of dementia - a team from the Bordeaux School of Public Health, France, found that the chances of being diagnosed with dementia went down for each year a person postponed retiring. The study found that employees who retired at the age of 65 were 14% less likely to be diagnosed with Alzheimer's compared to those who retired when they were 60.
Study leader, Carole Dufouil said "Our data show strong evidence of a significant decrease in the risk of developing dementia associated with older age at retirement, in line with the 'use it or lose it' hypothesis. The patterns were even stronger when we focused on more recent birth cohorts."
Writing, reading and engaging in brain-stimulating activities help preserve memory in old age, neurologists from Rush University Medical Center in Chicago wrote in Neurology (July 2013 issue). Senior author, Robert S. Wilson, PhD, explained that people who regularly took part in activities that exercised their brain had better results in tests that measured thinking and memory.
Dr. Wilson said "Exercising your brain by taking part in activities such as these across a person's lifetime, from childhood through old age, is important for brain health in old age."
Keeping the brain active reduces the risk of developing Alzheimer's - a team led by Susan M. Landau, Ph.D., at the University of California in Berkeley and the Lawrence Berkeley National Laboratory, reported in Archives of Neurology (January 2012 issue) that individuals who keep their brains active throughout their lives have lower levels of the the β-amyloid protein. The β-amyloid protein plays a major role in amyloid plaque buildup in Alzheimer's disease.
Examples of brain stimulating activities include playing games, reading and writing.
Being bilingual delays onset of Alzheimer's - if you speak two languages fluently, you will need to suffer twice as much brain damage before Alzheimer's symptoms start to appear, compared to people who speak only one language, rsearchers from St. Michael's Hospital, Canada, reported in the journal Cortex (October 2011 issue).
Study leader, Dr. Tom Schweizer, explained that bilingualism beats by far any medications in delaying the onset of Alzheimer's symptoms.
Mental exercise wards off dementia - anything that gets the mind and brain working can help protect from dementia, researchers at the Albert Einstein College of Medicine in New York found. Neurologist Joe Verghese suggested people play musical instruments, play chess, bridge, or get involved in anything that stimulates cognition.
Dr. Verghese emphasized that it is never too late to start. The team found that mentally active seniors could reduce their risk of developing dementia by up to 75%, compared to people who do not regularly challenge their minds.
In this video below, Teepa Snow, MS, OTR/L, FAOTA, talks about using your brain to reduce dementia risk.
Getting plenty of sleep reduces Alzheimer's and dementia risk
Often overlooked, getting plenty of good quality sleep can help significantly in protecting from dementia and Alzheimer's disease. In today's high speed world, sleep deprivation has become a growing problem for hundreds of millions of people.
In a presentation by Yo-El Ju, M.D., from the University School of Medicine, St. Louis, done at the American Academy of Neurology's 64th Annual Meeting in New Orleans (February 2012), he explained that the amount of sleep people get may later influence memory function and Alzheimer's risk.
Dr. Ju said "Disrupted sleep appears to be associated with the build-up of amyloid plaques, a hallmark marker of Alzheimer's disease, in the brains of people without memory problems. Further research is needed to determine why this is happening and whether sleep changes may predict cognitive decline."
Dr. Ju and team found that people who did not wake up often during the night were five times less likely to have amyloid plaque build-up compared to those who did not sleep well. Amyloid plaque accumulation predicts future Alzheimer's.
Dr. Ju added "The association between disrupted sleep and amyloid plaques is intriguing, but the information from this study can't determine a cause-effect relationship or the direction of this relationship. We need longer-term studies, following individuals' sleep over years, to determine whether disrupted sleep leads to amyloid plaques, or whether brain changes in early Alzheimer's disease lead to changes in sleep. Our study lays the groundwork for investigating whether manipulating sleep is a possible strategy in the prevention or slowing of Alzheimer's disease"
Smoking and dementia risk
The association between smoking, nicotine and cognitive decline has been shown in some studies, but contradicted in others. As already mentioned above, all risk factors for stroke and heart disease also raise the risk of developing dementia or Alzheimer's disease. Smoking raises the risk of heart disease and stroke, so it should logically also be more likely that a regular smoker develops dementia.
A study conducted at University College London and published in Archives of General Psychiatry (February 2012) demonstrated that regular male smokers are more likely to experience faster cognitive decline compared to lifetime non-smoking men. The authors added that smoking is becoming more and more accepted in the scientific community as a risk factor for dementia among seniors.
Séverine Sabia, Ph.D., and colleagues assessed the association between smoking history and cognitive decline during the transition period from midlife to old age. They gathered and analyzed data on 5,099 males and 2,137 females from the Whitehall II cohort, a health database of employees in the British Civil Service.
Dr. Sabia concluded "Our results show that the association between smoking and cognition, particularly at older ages, is likely to be underestimated owing to higher risk of death and dropout among smokers."
The team was surprised to find no link between regular smoking and cognitive decline in females.
Heavy smoking raises Alzheimer's risk by 157% and vascular dementia by 172%, a study carried out by experts at Kaiser Permanente and published in Archives of Internal Medicine (October 2010) found. The authors emphasized that the "heavy smoking" relates to when it occurs in midlife.
Lead researcher, Rachel A. Whitmer, Ph.D., said "This study shows that the brain is not immune to the long-term consequences of heavy smoking. We know smoking compromises the vascular system by affecting blood pressure and elevates blood clotting factors, and we know vascular health plays a role in risk of Alzheimer's disease."
Nicotine patches help patients with mild cognitive impairment (MCI) - scientists from Vanderbilt University School of Medicine in Nashville found that older patients with MCI showed improvements in cognition when given nicotine patches.
Study leader, Paul Newhouse, MD, said "People with mild memory loss should not start smoking or using nicotine patches by themselves, because there are harmful effects of smoking and a medication such as nicotine should only be used with a doctor's supervision. But this study provides strong justification for further research into the use of nicotine for people with early signs of memory loss.
We do not know whether benefits persist over long periods of time and provide meaningful improvement."
Conclusion: How to reduce your risk of developing Alzheimer's or dementia?
- Don't smoke
- Maintain a healthy body weight
- Eat a well-balanced diet that includes plenty of fruit and vegetales
- Keep your mind active
- Do regular physical exercise
- Get plenty of good quality sleep
- Follow your treatment guidelines if you have a chronic disease, such as diabetes
- Maintain healthy blood cholesterol levels
- Control your blood pressure