Alzheimer’s disease (AD) is an irreversible, progressive brain disorder that slowly destroys memory and cognitive skills. In later stages of disease, patients eventually loose the ability to carry out the simplest tasks. Most people with AD develop symptoms in their mid-60s. It is currently ranked as the sixth leading cause of death in the US. More recent estimations indicate, that this neurological disorder may rank third, just behind heart disease and cancer, as a cause of death of elderly people.
AD is one of the types of dementia. We wrote about the research of different types of dementia previously, here. Today we will look at the research effort made in discovering the causes of AD. Why? Because scientists estimate that more than 135 million people will have dementia by 2050. And the most common form of dementia, which accounts for 60%–70% of cases, is Alzheimer’s disease. What are scientifically most observed life-style related factors increasing the occurence of AD in polulation?
From the figure above, we can see that the broadest research is carried out on the incidence of AD in diabetic patients. Co-occurrence of AD a diabetes is not surprising, as both diseases cause millions of deaths globally every year. In 2013, researchers reported a strong correlation between AD and hyperglycemia. The study found that people with high blood sugar levels, as those linked to type 2 diabetes, had a dramatic increase in a protein toxic to brain cells. But it goes both ways. The AD patients are also likely to develop diabetes because AD affects the insulin pathways. If you would like to read more into current research on AD and diabetes co-occurrence, the scientist with the biggest contributions in this field of is Christian Hölscher.
High blood pressure is considered as another cause of AD. It can damage small blood vessels in the brain, affecting parts of the brain responsible for thinking and memory. Recent studies have shown that some antihypertensive medications are connected with a significant reduction in the incidence of AD. However, it remains uncertain whether antihypertensive drugs may have a preventive effect on cognitive decline in patients with AD. There are 1002 papers about the hypertension which causes AD. As we can see on the figure below, 52 of them were published in Journal of Alzheimer’s disease : JAD, 18 in Neurology and 16 in Journal of the neurological sciences. If you are interested in this topic, those are the sources to go to.
Results of currently well-developed research paradigm are consistent with the observation, that smoking increases the risk of AD. However, findings suggest that among previous smokers who quit smoking, there may be a slight reduction in the risk of AD. The most cited article for this topic is “The influence of smoking on the risk of Alzheimer’s disease.” with 29 citations. If you want to read something from the recent research on smoking-AD relationship the most recent well-received study is called: “Capillary dysfunction: its detection and causative role in dementias and stroke.”
Do you want to start with research on AD and push the paradigm a bit further? Well, great place to start is currently hot topic of alcohol-consumption impact on risk of AD. There are 108 studies on alcohol consumption-AD relationship, but their findings are rather opposite. Some of them suggest that alcohol has a positive effect on the onset of AD, because of the positive effect on cardiovascular system. Others don’t agree. We need further studies and broader systematic approach to research in this paradigm, to find out, what threat the alcohol consumption bears to AD patients.
AD is a devastating disease marked by cognition and memory decline, affecting the elderly population. Many of the people have the genetic predisposition for this illness. The scientist are currently trying to find the genes responsible for AD and a way to influence this genes. Meanwhile, we can try to maintain a healthy lifestyle and train our brains to avoid AD for as long as possible.