Although Alzheimer's Disease and vascular dementia have traditionally been viewed as distinct disorders, it is now generally agreed that the two rarely occur in isolation. Both types of dementia share many risk factors and pathologic features with atherosclerosis. In addition, the presence and severity of cerebrovascular pathologic findings appear to increase the risk and stage of AD for any given level of AD neuropathologic findings Thus, the modification of vascular risk might reduce the risk of dementia regardless of type.
Traditional cardiovascular risk factors such as hyper-tension, dyslipidemia, and diabetes appear to increase the risk of developing dementia in old age, with several possible mechanisms... Promising Strategies for the Prevention of Dementia
A full-court press controlling the factors that (over the long-term) increase the risk of ischemic heart attacks and strokes will also reduce the risk of developing dementia.
A key point that is often missed in the popular press is that a person can lived with "plaque" closing a large percentage of their heart's arteries for a very, very long time. It becomes an acute problem when a clot starts to form. The current thinking seems to be that inflammation is a major trigger for clot formation which then becomes a self-perpetuating phenomena that snowballs. Look out when the clot detaches from the blood vessel's wall and goes downstream.
If this is an accurate model, then a robust approach is to take steps to ensure minimum plaque build-up and steps to minimize inflammation.
These items are listed roughly in the order of how quickly they will be effective in reducing risk from dementia.
Talk to your doctor before doing anything crazy, but that daily 81mg of aspirin is both an anticoagulant and an anti-inflammatory.
Inflammation, exercise: Inflammation is linked to excessive blood-sugar levels. Exercise builds muscle and nothing can strip excess glucose out of the blood stream faster than muscle. Most people are aware that glycogen (who the body stores glucose or blood-sugar) is stored in the liver but for most people, five-times as much glycogen is stored in the muscles. Even modest increases in muscle mass greatly increase your body's ability to buffer blood-sugar spikes regardless of your status as diabetic or non-diabetic.
The majority of current research supports the belief that exercise has a beneficial effect on inflammation (even though specific muscles and joints will hurt in the short-term).
Inflammation, diet: The majority of the research suggests that increased sugar increases inflammation. Ditto for trans-fats and fried foods, and large quantities of starchy foods and/or alcohol. The research is divided with Keto-good while "red meats, cured meats and over-cooked meats and Omega-6 fats" bad.
The advice Paul gave to Timothy is worth following: All things in moderation.
Inflammation, infections: Oral hygiene is your friend. If you have an ear-ache, attend to it. Don't bite your fingernails. If you lack sensation in your feet, get a mirror and do daily checks. Always wear substantial footwear when outside. Any additional advice in the comments from the medical profession will be much appreciated.
Inflammation, diabetes: Many of the pathological manifestations of diabetes (poor circulation, blindness, infections) are due to damage to capillaries from high blood sugar. You can add increased risk of dementia to the list of manifestations. One more reason to watch your diet and blood-sugar like a hawk.
Inflammation, obesity: Obesity is a tough nut to crack because body-weight does not change overnight. Realistically, body-weight will take care of itself if you burn an additional 200 Calories a day via increased exercise and eliminate almost all of the empty calories in your diet, your body weight will take care of itself.
Graphic from Daily Mail. While the contents of this post mostly repeats this information it is presented in the context of a structure that shows how they are connected
Social contact: Regular social contacts is generally recognized as slowing the onset of dementia or reducing the likelihood of getting dementia. Some of the causal mechanisms that have been proposed seem to be a bit of a stretch. Personally, I recognize that guys are stubborn and sometimes we need a kick in the backside to seek professional, medical help; whether it is to see a dentist or an audiologist or to visit a sleep clinic.
Smoking: If you smoke, then be deliberate about it. Some people smoke on auto-pilot. Just saying that if you are going to smoke then be sure that you enjoy it and it isn't automatic. I will not be a nag because there is nothing I can say that you have not already heard 100 times before.