Can't think straight? Lay off the cigarettes.
According to a new study, smoking "rots" the brain, and is worse for one's brainpower than having high blood pressure and being overweight, the BBC reports.
The study, by researchers from King's College London, examined 8,800 participants over the age of 50, and asked them to perform cognitive tests, such as learning new words or naming as many animals they could in a minute. The researchers tested the participants again four years later, and again after eight years.
BBC says they found a "consistent association" between smoking and lower cognitive test scores. Those who experienced the greatest cognitive decline were also at higher risk for heart attack or stroke.
The findings are believed to underscore the notion that what's bad for the body is also bad for the mind.
"Research has repeatedly linked smoking and high blood pressure to a greater risk of cognitive decline and dementia, and this study adds further weight to that evidence," Simon Ridley of Alzheimer's Research UK told the BBC.
In a 2009 study, researchers at the Indian National Brain Research Center found that a compound in tobacco provokes the immune response to attack healthy brain cells, leading to neurological damage.
And earlier this year, British scientists found male smokers' brain function resembled that of non-smokers who were 10 years older. The smokers exhibited early dementia-like cognitive difficulties even at age 45, according to Reuters.