Heavy Smokers, Drinkers, Develop Alzheimer’s Disease Earlier

A number of cigarettesBoth heavy smoking and heavy drinking lead to the development of Alzheimer’s disease at an earlier age according to a study presented at the annual meeting of the Academy of Neurology held in Chicago between the 12th and 19th of April.

The study involved 938 people aged 60 or older who had been diagnosed with Alzheimer’s disease. The researchers looked at three potential risk factors: heavy cigarette use, heavy alcohol consumption and the presence of a particular allele of the ApoE gene which is known to increase the risk of Alzheimer’s disease.

The research team found that 20% of the patients diagnosed with Alzheimer’s disease had been heavy smokers (20 or more cigarettes smoked per day), 7% were heavy drinkers (more than two standard drinks consumed per day), and 27% had the ApoE allele that is known to increase Alzheimer’s risk.

The researchers determined that consumption of more than two standard drinks of alcohol a day led to Alzheimer’s disease developing 4.8 years earlier than in people who consume less than two standard drinks a day. The researchers also found a link between heavy smoking and Alzheimer’s disease with heavy smokers developing the disease on average 2.3 years earlier than those who did not smoke heavily.

Those who had a combination of all three risk factors studied developed Alzheimer’s disease at the average age of 68.5 which was 8.5 years earlier than for individuals with none of the risk factors.

The authors of the study admit that there is some controversy over the link between heavy drinking and Alzheimer’s, especially in regard to how “heavy” drinking is defined and the type of alcohol that is consumed. Some studies have found that light to medium consumption of alcohol, in particular wine, can actually reduce an individuals risk of developing Alzheimer’s. It is generally accepted however that consumption of more than three standard drinks a day, especially in the form of hard liquor, damages the brain and increases the risk of dementia.

The link between heavy smoking and Alzheimer’s disease risk is thought to be more clear cut with several studies demonstrating a link between the two. A 1997 study published in the journal Lancet found that smokers had a 2.2 times greater risk of dementia, and a 2.3 times greater risk of Alzheimer’s disease compared to people who had never smoked. That study also found that smoking had the greatest impact on people without the high risk ApoE gene and had little impact on people with the high risk variant.