Quit smoking to keep your brain healthy
Publication Date:10/06/2008
Giving up smoking, even late in life, may help keep your memory sharp as well as improve your physical health, according to a new study.
It suggests that smoking isn't just bad for your body. People who smoke have a worse memory in middle age than people who've never smoked. But giving up smoking, even in late middle age, may help.
What do we know already?
Previous studies have suggested that older people are more likely to get dementia if they smoke. Doctors think that may be because smoking damages blood vessels, including those that supply oxygen to the brain.
Now researchers have looked to see what difference smoking made to the mental abilities of people in middle age.
What does the new study say?
The study found that that people who smoked had poorer mental ability in several ways. For example, smokers did worse on memory, ability to reason, vocabulary and fluency in speech. However, smokers in the study were also older, tended to be less educated and poorer and were likely to do less exercise and drink more alcohol. All these things could have affected their mental abilities.
When the researchers made allowances for these things they still found that smoking was linked to poorer memory, although not to other poorer mental abilities. Smokers were about one-third more likely to have poor memory, compared to non-smokers.
More hopefully, it also showed that people who make healthy changes in middle age, like giving up smoking and exercising more, seem to have better mental abilities.
Tell me more about the study's findings
The researchers tested people's mental abilities twice during the study, five years apart. But because the study lasted 20 years, not everyone who started the study was around to have their mental abilities tested during the last five years of the study. Researchers found that smokers were less likely to still be in the study, because more of them had died. This means the study may underestimate the effects of smoking on mental abilities.
People who'd smoked at the start of the study, but gave up during it, did at least as well as non-smokers on tests of mental ability. The study also showed that they were more likely to improve their diet, exercise more and cut down on the amount of alcohol they drank.
Where does the study come from?
The study was jointly carried out by researchers from University College London and Universite Paris in France. It was published in the Archives of Internal Medicine, a medical journal owned by the American Medical Association.
How reliable are the findings?
This was a very big study, looking at the health of more than 10,000 civil servants over a 20-year period. It was carefully carried out.
But it's very hard to prove that one thing, like smoking, causes something like poor memory. So many other things can also affect your memory, like your age, your education, or your overall health. The researchers did their best to take account of these, but they can't be dismissed.
It's also hard to know which is cause and which is effect. To put it bluntly, do people have worse mental abilities because they carry on smoking, or do they carry on smoking because they have poor mental abilities?
The results definitely show that smokers have on average poorer mental abilities in middle age. But we can't be completely sure that smoking causes all these problems.
What does this mean for me?
If you smoke, you'll already know it's bad for your body. But this study shows it could be bad for your mind, too. It also tells us that it's never too late to give up smoking. Giving up, even in late middle age, may help keep your brain sharp.
What should I do now?
If this study has encouraged you to quit smoking, there are lots of places you can get help. There are many products that can help you give up. Your pharmacist or GP will be delighted to help.
From:
Sabia S, Marmot M, Dufouil C, et al. Smoking history and cognitive function in middle age from the Whitehall II study. Archives of Internal Medicine. 2008; 168: 1165-1173.
To read more about the best ways to give up smoking, see our information on nicotine addiction.
News Archive
© BMJ Publishing Group Limited ("BMJ Group") 2007. All rights reserved
This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.
