Risk factors
There is no sure way to prevent dementia. However, research has identified several risk factors associated with dementia. While there are some risk factors you can’t control, such as genetics or age, many risk factors can be managed through lifestyle changes or appropriate medical treatments. These dietary and lifestyle interventions cannot stop you from developing dementia but they may reduce your risk.
Many of the same risk factors for heart disease have also been shown to increase the risk of developing dementia – demonstrating that being heart smart is smart for your brain as well. Additionally, most of these risk factors are active all your life, so no matter what your age is, acting to change your lifestyle now may reduce your risk!
Family history and genetic risk
A family history of dementia – for example in your parents or siblings - increases your risk of developing dementia. However, many people with relatives with dementia do not develop dementia. Only one gene (Apolipoprotein E) has been associated with an increased risk of late onset Alzheimer’s disease, however, there are probably other genetic factors which have not yet been discovered.
Family history is one risk factor you can’t control. However, genetic risk factors like the ApoE4 gene do not act in isolation. There is evidence that you can decrease your risk of developing dementia in other ways, such as by living a healthy lifestyle and reducing other risk factors.
High blood pressure/hypertension
Untreated high blood pressure has been linked to an increased risk of both Alzheimer’s disease and vascular dementia. A long term study of Japanese-American men in found that men with uncontrolled high blood pressure in mid life were at increased risk of dementia in later life. Another study has indicated that high blood pressure in mid life increases the risk of developing dementia by 24%. This relative risk is drastically increased by other cardiovascular risk factors such as smoking, high cholesterol or diabetes. Some studies indicate that active treatment of hypertension, even in later life, can reduce the risk of developing dementia.
High cholesterol
Cholesterol is essential to the function of the brain and body. However, studies have shown that high cholesterol levels can increase the risk of Alzheimer’s disease. In a recent study of almost 9,000 individuals in Northern California, people who had high cholesterol levels in mid life had a 46% increased risk of developing dementia. Subsequent studies have indicated that cholesterol lowering drugs such as statins may lower the risk of developing Alzheimer’s disease -however - more research is needed to confirm these effects.
High homocysteine levels
Homocysteine is an amino acid found naturally in the blood, a by-product of the many metabolic reactions occurring in our body. Some studies have found that excessive homocysteine levels are associated with an increased risk of Alzheimer’s disease and other dementias, as well as with a higher risk of heart disease, stroke and other vascular disorders. Folic acid and vitamins B6 and B12 help break down homocysteine and ensuring adequate intake of these nutrients can help reduce high levels of homocysteine.
Stroke and cerebrovascular disease
A history of stroke can increase the risk of Alzheimer’s disease. This may be due to damage to the brain’s blood vessels, which can inhibit the flow of blood and oxygen to the brain. The risk is further increased if other cardiovascular risk factors are present, such as high blood pressure or diabetes. However, treatment of high blood pressure in individuals with cerebrovascular disease and a history of stroke has been shown to reduce their risk of subsequently developing dementia.
Obesity
A recent study has found that obesity in middle age drastically increases your risk of developing dementia in later life. Researchers studied over 10,000 people for 27 years. Those who were obese in mid life were 74% more likely to develop dementia and those who were overweight were 35 % more likely to develop dementia compared to those of normal weight.
Diabetes
A recent study found that having diabetes increases the risk of developing Alzheimer’s disease by 65%. This risk can be reduced by careful management of diabetes with medications that maintain blood glucose levels within a healthy range.
Hormone Replacement Therapy (HRT)
While some studies indicated that estrogen might slow or prevent the development of Alzheimer’s disease, other studies have not found this to be the case. The Women’s Health Initiative Memory Study found that women taking hormone replacement therapy (HRT) with estrogen and progesterone had an increased risk of developing dementia. Continued research is needed to resolve these findings.
Depression
There is a strong association between depression and cognitive impairment and differentiating between early symptoms of dementia and depression can be difficult. Several studies have indicated that depression may be a risk factor for cognitive decline and dementia. However, the relationship is not clear and it is not known whether treating depression has any effect on the development of dementia.
Head Injury
A study of World War II veterans indicated that moderate to severe head injury increased risk of developing Alzheimer’s disease and other dementias. Another study found that this risk is further increased if the head injury resulted in loss of consciousness.
Reducing risk
Although there is no proven way to prevent dementia, research indicates that a healthy lifestyle and engaging in physical, mental, and social activity may help to reduce the risk of developing dementia.
A healthy diet
Eating a well-balanced and healthy diet can help control risk factors for dementia such as high cholesterol levels, obesity and diabetes. A healthy diet includes reduced intake of saturated fat and cholesterol, and plenty of antioxidant rich foods such as dark skinned fruits and vegetables - kale, spinach, brussels sprouts, alfalfa sprouts, broccoli, beets, red capsicum, onion, corn, eggplant, prunes, sultanas, blueberries, blackberries, strawberries, raspberries, plums, oranges, red grapes and cherries.
Several studies have investigated whether vitamins may reduce the risk of developing dementia. While it has been suggested that vitamins C and E may reduce the risk of developing dementia, there is some conflicting evidence. It appears as though obtaining adequate vitamins through diet rather than supplements is more effective.
Food sources of vitamin E include wheat germ, almonds, peanuts, pistachios, green leafy vegetables, mango, kiwi, and vegetable oils such as corn, soybean and safflower.
Fish containing omega 3 fatty acids, including salmon, halibut, mackerel, trout and tuna, may also be beneficial if included in the diet. A 7 year long study examining dietary factors revealed that people who ate fish once a week had 60% less risk of developing Alzheimer’s disease than people who never or rarely ate fish.
Some studies have found that moderate alcohol (max 1-3 drinks per day) and caffeine intake may have a protective influence. However, it is important to emphasise that alcohol and caffeine also have other negative effects that may outweigh their potential benefit in delaying dementia.
Physical, mental, and social activity
A number of studies have reported that mental and social activities, such as reading, dancing, playing music or singing in a choir might prevent or delay the onset of dementia. It has been proposed that such activities may increase brain activity, stimulate new connections between brain cells and may even result in the production of new nerve cells.
Including social and mental activity and physical exercise in your life, even in later life, has been shown to improve cognition and reduce the risk of developing dementia. Additionally, these lifestyle choices promote longevity, better health, and may reduce the risk of other diseases.
A prospective 21 year study has shown that increased participation in leisure activities is associated with a decreased risk of both Alzheimer’s disease and vascular dementia. Leisure activities included reading, playing board games or musical instruments, and dancing.
Another study indicated that older men who walked more than two miles a day had a reduced risk of developing dementia compared to men who walked less than a quarter of a mile. Exercise may help manage cardiovascular risk factors, increase blood flow to the brain and stimulate nerve cell growth and survival.
Staying connected with your community and keeping active both physically and mentally are fun and easy ways of reducing your risk of developing dementia and other diseases.
Prevention Links
Alzheimer’s Disease: Prevention
Information on current prevention and risk reduction strategies provided by the Mayo Clinic.
Maintain your Brain campaign by the US Alzheimer’s Association
A public information campaign targeting risk reduction through physical activity, improved diet and healthier choices.
Mind your Head campaign by the UK Alzheimer’s Society
Information about reducing your risk of developing dementia.
Risk Factors and Dementia
Understanding risk factors and dementia provided by the UK Alzheimer’s Society.
Prevention Research
Research into the prevention of dementia provided by Fisher Center for Alzheimer’s Research Foundation.
Reducing the risk of dementia
Discussion of research findings into the effect of leisure activities, such as reading, board games, and ballroom dancing, on risk of dementia, provided by BUPA.
Prevention and Wellness News
Recent Prevention news from the Fisher Center for Alzheimer’s Research Foundation.
