14 DAY TRIAL // Well, all smokers know that cigarettes are bad for their health, so here is a new thing, that probably most nicotine-lovers did not know: heavy smoking (two packs a day) doubles the risk of developing Alzheimer's disease and dementia.
A Kaiser Permanente study, using electronic records of 21,000 men and women for a period of 20 years, concluded that heavy smoking in midlife increases the risk of developing Alzheimer's by 157%, and the risk of vascular dementia by 172%.
The 21,123 people taking part at the study came from different ethnic populations and took part at the survey from 1978 to 1985.
The men and women were followed from midlife onward, for a period of 23 years, and the diagnosis of Alzheimer's disease, dementia and vascular dementia established in internal medicine, neurology, and neuropsychology, were collected from 1994 to 2008.
The researchers accounted for sex, age, education, race, marital status, hypertension, hyperlipidemia, BMI, diabetes, heart disease, stroke, and alcohol use.
The results showed that people having smoked over two packs of cigarettes a day, had over 157% risk of developing Alzheimer's disease, and 172% risk of vascular dementia during the follow-up period, compared to others.
The study's principal investigator, Rachel A. Whitmer, PhD, a research scientist with the Kaiser Permanente Division of Research in Oakland, California said that “the study shows that the brain is not immune to the long-term consequences of heavy smoking.
“We know smoking compromises the vascular system by affecting blood pressure and elevates blood clotting factors, and we know vascular health plays a role in risk of Alzheimer's disease.”
Study co-author Minna Rusanen, MD, of the University of Eastern Finland and Kuopio University Hospital in Finland, added that even if “we don't know for sure, we think the mechanisms between smoking and Alzheimer's and vascular dementia are complex, including possible deleterious effects to brain blood vessels as well as brain cells.”
Kaiser Permanente has published a series of studies focusing of better understanding the variable risk factors for dementia, and this is the latest.
Whitmer led other studies, that found that a large abdomen in midlife increases risk of late-life dementia, high cholesterol levels in midlife increase risk of Alzheimer's disease and vascular dementia, and low blood-sugar events in elderly patients with type 2 diabetes also increase dementia risk.
Also, another research carried out by Valerie Crooks of Kaiser Permanente in Southern California, found that having a strong social network of family and friends decreases the risk for dementia.
This entire research suggests that what is good for the heart is also good for the brain and even at midlife, it is not too late to start preventing dementia by adopting a healthy lifestyle.
This last study is the first study to look at the long-term consequences of heavy smoking on dementia, and it is published in the Archives of Internal Medicine.