Four Cups of Coffee A Day Cuts Risk of Oral Cancer 151
An anonymous reader writes "Coffee may help lower the risk of developing oral and pharyngeal cancer and of dying from the disease. The study, published in the American Journal of Epidemiology, was conducted using the Cancer Prevention Study II. The large cohort study began in 1982 by the American Cancer Society. Researchers were able to examine 968,432 men and women, none of whom had cancer at the time of their enrollment in the study."
Four or more cups a day lowered the risk of getting oral cancers by a whopping 49%.
Relative versus absolute risk (Score:5, Interesting)
I find that changing relative risk to absolute risk makes the wow factor of these studies go down considerably. The absolute risk is of getting oral cancers and dying from them can be derived from the abstract:
Among 968,432 men and women who were cancer free at enrollment, 868 deaths due to oral/pharyngeal cancer occurred during 26 years of follow-up.
So the 26-year absolute risk of death due to oral/pharyngeal cancer in this study was about 1 in 1,000 (one thousand). Assuming an even spread across the years, that's also about 1 in 30,000 for any given year.
Drinking greater than 4 cups of coffee a day has a relative risk of about 0.5, so that's about 1 in 2,000 over 26 years (a difference of 0.045%), or about 1 in 60,000 in any given year (a difference of 0.0017%).
Note that this risk reduction is associated with death due specifically to oral/pharyngeal cancer, not the cancer alone -- it does not follow from these results that drinking coffee reduces your risk of getting cancer. If you get oral/pharyngeal cancer, but die from being impaled by an angry unicorn, it doesn't count for the purposes of this result / association.
surely, there were other results... (Score:5, Interesting)
A 26 year study, following 968,432 people and these guys draw a conclusion revolving around coffee and a cancer involving 0.09% of the people in the study?
That's some serious barrel scraping on that data set.
That said, it's one more argument to use when my wife complains that I drink too much coffee. Go science!
Re:You Sure? (Score:2, Interesting)
This. There is a reason 2/3s~ of the human race don't get cancer. Hint, it isn't because they were lucky.
Most people develop and destroy minor cancers throughout their entire life, a little known fact that seems to be forgotten by the majority.
These people, even exposed to high numbers of carcinogens still don't develop full-on cancers.
That is a genetic reason and one we still don't fully understand yet, that is different even from diet. (but diet does increase your defences too)
No, Petri-dish tests aren't a human body. So don't say you can infect anyone with cancer straight-up. Biology doesn't work like that.
Research on cancer lines isn't exactly helpful, either, since those came from people who developed full-on cancers!
Re:Lurking variables... (Score:4, Interesting)
Neglects to mention that people who work in an occupation where they have an opportunity to get four cups of coffee a day are usually office or transport jobs.... not dangerous ones. Any thoughts?
I grew up in town where most people worked some sort of blue collar job, and I recall plenty of big coffee drinkers. I spent a summer working in a steel mill and it wasn't unusual to see guys arriving with large thermoses of coffee. Those that didn't bring it to work could purchase it from vending machines in the break rooms. A couple of cups before work, a couple during breaks or lunch, and by the end of the day they had had at least four cups of coffee.
Re:That's great... (Score:4, Interesting)
...but what does it increase the chances of? Well, besides drug (caffeine) addiction?
I'll bet the rate of cancer morbidity among heroin users is extremely low.
Probably just affects the flora in the mouth. (Score:4, Interesting)
Re:Relative versus absolute risk (Score:4, Interesting)
Note that this risk reduction is associated with death due specifically to oral/pharyngeal cancer, not the cancer alone -- it does not follow from these results that drinking coffee reduces your risk of getting cancer. If you get oral/pharyngeal cancer, but die from being impaled by an angry unicorn, it doesn't count for the purposes of this result / association.
Thank you! A beacon of logic in an attic of doubt and uncertainty.
In order to assess the risk, we need to compare the total risk of drinking coffee with the total risk of not drinking coffee. Just examining and comparing one aspect is not enough - we need to take everything into account.
I've been considering starting to drink coffee now that I'm getting older (>50 yrs), and have been doing a bunch of research on it. I've found a number of benefits in the literature to drinking coffee; for example, it lowers the risk of kidney stones (surprising, in my view).
I have not found any long-term health disadvantages to drinking coffee (setting aside obvious short-term effects), and the number of benefits is surprising. I'm not ready to consider coffee as "safe" quite yet, but so far as I can tell it's a good bet.
We need a study of the total risk associated with drinking coffee, in the manner that we have total risks associated with smoking and drinking.
Re:That's great... (Score:4, Interesting)
The catch is this is American style drip brewed coffee. I'd be curious to see if this same finding is true for French Press or Espresso, which previously have been found to contain oils that are cancer causing, but these are removed in filtered coffee. Perhaps they counteract each other. Also I'd be curious if they used teabags or a tea ball in their research (that didn't find results in favor or against), which would be similar to filtered vs unfiltered coffee.