Although there have been some contradictory findings over the years it’s very clear from very large studies that smoking increases the risk for Alzheimer’s Disease and other dementias. There are probably many reasons why this is the case the most prominent of which is that chemicals in tobacco smoke are severely detrimental to blood vessels in the body including in the brain. Damage to brain vessels reduces the delivery of oxygen and glucose to the brain and increases local inflammation. We know from many studies that the pathological processes underlying Alzheimer’s Disease interact very negatively with those that underlie stroke. Consequently, these two diseases interact very harmfully together to produce the symptoms and signs of dementia in individuals who have both disorders. All possible measures to quit smoking should be adopted as the negative health consequences are so profound.
It has long been known in the scientific community that head injury or Traumatic Brain Injury [TBI] increases risk for Alzheimer’s Disease. Sportsmen and women who take part in activities that increase risk for TBI have a higher prevalence and incidence of cognitive impairment and Alzheimer’s Disease. Avoidance of such activities or at least minimization of such risk by wearing appropriate protective head gear [such as wearing a helmet when riding a bicycle, motorcycle or horse] is highly recommended. For our senior citizens falls at home or out are a common cause of head injury as are vehicle crashes. Simple home precautions like anti-slip mats in the shower or bath may prevent slips and falls. In addition various experimental interventions have been tried to reduce the number of falls in the elderly such as strength and balance training. As part of a physical exercise program such activity may have considerable benefit. The most important thing to remember is that multiple head injuries throughout life either from sport or other trauma and even single injuries as we age can be highly detrimental increasing our risk for Alzheimer’s Disease and related dementias.