Smoking Lowers Your IQ, Study Suggest

by Dr Antonio Howell, MD

in Blog

The 3 Week Diet

Numerous studies have long warned us of the harmful effects of smoking, and just recently, new research suggests that smoking could also lower your IQ.

Paperwork OverwhelmAccording to the study, young adults who smoke recurrently are more likely to mark lower intelligence scores than non-smokers. That is, the more cigarette they smoke, the lower their IQ becomes. Those who smoke 20 cigarettes or more a day showed an average IQ score of 7.5 lower than their non-smoking counterparts. Meanwhile, smokers aged 18 to 21 scored an IQ of 94, while non-smokers of the same age bracket scored an average of 101.

Heavy smokers, or those who smoke more than one pack of cigarettes a day scored very low at 90 points. The normal intelligence IQ score varies from 84 to 116 points. The research, conducted by the Sheba Medical Center at the Tel Hashomer Hospital in Israel, included 20,000 volunteers.


The researchers also discovered that even brothers scored differently subject to whether or not they smoke. Regardless of the similarity in the environment, non-smoking brothers scored higher IQs than their smoking siblings.


However, researchers are still inconclusive whether smoking directly causes the decline in IQ level or whether less intelligent people are more likely to be susceptible to smoking.

IQ scores are noticeably lower in young male smokers than their non-smoking counterparts, and in siblings who smoke in contrast to their non-smoking siblings. The IQs of young adults who started smoking between at the age of 18 to 21 are significantly lower than those who do not smoke.

According to the head researcher, it seems that people who have lower IQs are those who are more likely to choose to smoke, regardless of their socioeconomic standing.

He added, that the result could strengthen previous convictions that people who have lower IQs are more likely to make poor decisions concerning their health – like take drugs, exercise less, or eat unhealthy foods. The study can also help prevent smoking in teens by zeroing those who have lower IQs.

Statistics suggests that 28 percent of male adolescents smoke one or more sticks of cigarette a day, 3 percent disclosed to have smoked in the past, while 68 percent never tried smoking.

A 2004 research by the University of Aberdeen first discovered the potential relation between smoking and abridged mental function.


In another study conducted by the Scottish Mental Survey, smokers who retook the test after 53 years performed worse compared to those who retook the test who stopped smoking and those who never smoked.

However, experts cannot yet decisively provide details on the relation between reduced lung function and mental aging but it has been advocated that smoking can cause oxidative stress to the brain which can cause DNA damage.


Previous post:

Next post:

Click here to subscribe to my mailing list