"People with dementia may experience increased levels of pain 16 years before their diagnosis, according to research," reports the National Institute on Aging.

"Although many people who have dementia also have chronic pain, it is unclear whether chronic pain causes or accelerates the onset of dementia, is a symptom of dementia, or is simply associated with dementia because both are caused by some other factor.

"Several conditions known to increase the risk of cardiovascular disease — such as high blood pressure, diabetes and high cholesterol — also increase the risk of developing Alzheimer's," reports the Alzheimer's Association.

"Some autopsy studies show that as many as 80% of individuals with Alzheimer's disease also have cardiovascular disease….Regular physical exercise may be a beneficial strategy to lower the risk of Alzheimer's and vascular dementia.

"Several prospective studies have looked at middle-aged people and the effects of physical exercise on their thinking and memory in later life," reports the Alzheimer's Society.

"Combining the results of 11 studies shows that regular exercise can significantly reduce the risk of developing dementia by about 30 per cent.

For Alzheimer's disease specifically, the risk was reduced by 45 per cent." You can do aerobic exercise for 20–30 minutes a day.

One study found that the risk of Alzheimer's disease can be reduced by daily physical tasks such as cooking and washing up.".

"The Bronx 20-year longitudinal Aging Study found that self-reported crossword puzzle use was associated with a 2.54 year delay in dementia onset, which suggests that similar to education, mentally stimulating activities may help delay the onset of symptoms, but on their own they cannot prevent dementia," reports Cognitive Vitality.

"A variation of this, called MIND (Mediterranean–DASH Intervention for Neurodegenerative Delay) incorporates the DASH (Dietary Approaches to Stop Hypertension) diet, which has been shown to lower high blood pressure, a risk factor for Alzheimer's disease."

"It is known that smoking increases the risk of vascular problems, including via strokes or smaller bleeds in the brain, which are also risk factors for dementia

In addition, toxins in cigarette smoke increase oxidative stress and inflammation, which have both been linked to developing of Alzheimer's disease," says the Alzheimer's Society