Drinking or smoking heavily can speed up the development of Alzheimer's disease, according to a new study. Scientists found that drinkers developed the disease almost five years earlier and heavy smokers just over two years earlier, after studying 938 people aged 60 or more who had been diagnosed with Alzheimer's.
Ranjan Duara, of the Mount Sinai Medical Centre in Miami Beach, Florida, said the results were significant "because it's possible that if we can reduce or eliminate heavy smoking and drinking, we could substantially delay the onset of Alzheimer's disease for people and reduce the number of people who have Alzheimer's at any point in time". He added: "It has been projected that a delay in the onset of the disease by five years would lead to a nearly 50% reduction in the total number of Alzheimer's cases. In this study, we found that the combination of heavy drinking and heavy smoking reduced the age of onset of Alzheimer's disease by six to seven years, making these two factors among the most important preventable risk factors for Alzheimer's disease."
Researchers gathered evidence of drinking history from family members and also looked at whether the participants had a particular variant of the APOE gene, which predisposes people to get Alzheimer's earlier than normal. The results, presented yesterday at the American Academy of Neurology's annual meeting in Chicago, showed that 7% of the participants were heavy drinkers, defined as more than two drinks a day; 20% had a history of heavy smoking, defined as smoking one pack of cigarettes or more a day; and 27% had the Alzheimer's APOE gene variant.
Heavy drinkers developed Alzheimer's 4.8 years earlier than those who were not heavy drinkers. Heavy smokers developed the disease 2.3 years sooner than people who were not heavy smokers. People with the APOE variant developed the disease three years sooner than those without it.
The researchers also looked at combined risk factors, and found that people that came into all three risk areas developed Alzheimer's 8.5 years earlier than those with none of the risk factors.