Coffee-drinking associated with a reduced risk of death in women

Generally, people tend to have quite firmly established ideas about weather a food is healthy or not. And they may even have some idea about which conditions a food is supposed to protect against or promote. So, for instance, when asked to comment on red meat, most people will express the view that this food is inherently unhealthy, and will often qualify this by mentioning its supposed link with heart disease and colon cancer. And when many people think of sugary soft drinks, their mind will tend to go rapidly to problems such as tooth decay and weight gain.

Another foodstuff that tends to labour under an unhealthy image is coffee. Yet, when I ask individuals what it is about this drink that is so unhealthy I find the answers can be very vague indeed. Some may mention caffeine but be unable to say what the problem might be here. Mostly, though, individuals are unable to say what it is about coffee that makes it a supposedly undesirable beverage.

One reason for this is that there isn’t actually much evidence that coffee is unhealthy. In fact, there is a fair body of evidence suggesting quite the reverse. Not so long ago one of my blog posts looked at some of the evidence linking coffee consumption with a reduced risk of certain conditions including diabetes and cardiovascular disease (such as heart attacks and stroke).

Some have suggested that the apparent health-giving properties of coffee may come, at least in part, from the ‘antioxidant’ substances it contains (including so-called ‘polyphenols’ that are found in other foodstuffs such as tea, cocoa, onions and apples).

With this background in mind, I was interested to read about a study published this week which looked at the relationship between coffee-drinking and risk of death in a group of about 86,000 women and 42,000 men. Men in this group were monitored for 18 years, while women were monitored for 24 years.

The researchers who conducted this study, from the Harvard School of Public Health, in Boston, USA, looked at the relationship between different levels of coffee consumption and overall risk of death in both men and women. In women, compared to drinking less than one cup of coffee per month, drinking at least 5-7 cups of coffee per week was associated with a statistically significant reduction in overall risk of death. In particular:

Drinking 5-7 cups of coffee per week was associated with a 7 per cent reduction in risk of death

Drinking 2-3 cups of coffee per day was associated with an 18 per cent reduction in risk of death

Drinking 4-5 cups of coffee per day was associated with a 26 per cent reduction in risk of death

Drinking 6 or more cups of coffee per day was associated with a 17 per cent reduction in risk of death

For men, no statistically significant results were obtained. However, there was a trend for increasingly lower risk of death as coffee consumption increased. Specifically:

Drinking 2-3 cups of coffee per day was associated with a 3 per cent reduction in risk of death

Drinking 4-5 cups of coffee per day was associated with a 7 per cent reduction in risk of death

Drinking 6 or more cups of coffee per day was associated with a 20 per cent reduction in risk of death

This study showed that the reduction in risk of death was, essentially, due to a reduced risk of deaths due to cardiovascular disease. So-called epidemiological studies of this nature cannot be used to prove that coffee can reduce the risk of death. However, in women at least, this study supports the notion that coffee may have real benefits for health and longevity.

One weakness of this sort of epidemiological study is that it’s not coffee drinking per se, but factors associated with coffee drinking (so-called confounding factors) that may be the real reason behind an association with this dietary habit and disease. For instance, coffee-drinking may be more prevalent among younger people, and it might be their relatively young age that is the reason for why coffee-drinkers appear to be at a reduced risk of cardiovascular disease. In this study, certain confounding factors (including age, smoking and other risk factors for cardiovascular disease) were accounted for, which strengthens its findings somewhat.

All-in-all, this study seems to provide further evidence that coffee does not deserve its quite unhealthy reputation. It also supports the idea that coffee might even have some significant benefits for health.


Lopez-Garcia E, et al. The Relationship of Coffee Consumption with Mortality. Annals of Internal Medicine 2008:148(12);904-914

12 Responses to Coffee-drinking associated with a reduced risk of death in women

  1. Cybertiger 18 June 2008 at 1:41 pm #

    John Briffa says,

    “However, in women at least, this study supports the notion that coffee may have real benefits for health and longevity.”


    My fiancé is called Tinkerbell. Tinkerbell drinks a lot of coffee while Tiger drinks copious cups of tea. I am very pleased to learn that my strong belief in fairies … is soundly evidence based.

  2. Jonathan Swift 18 June 2008 at 5:10 pm #

    “One reason for this is that there is actually much evidence that coffee is unhealthy”

    Should that read “isn’t” or have I read it wrong?

  3. Dawn 19 June 2008 at 9:15 am #

    Did the study look at how the coffee was prepared? Was it instant or freshly brewed. Caffeinated or decaffeinated? Was milk included…seems there are a lot more questions than answers!

  4. Dr John Briffa 19 June 2008 at 11:08 am #

    Thanks for that – corrected now.

  5. chainey 19 June 2008 at 11:18 am #

    One of the “unhealthy” elements of coffee is supposed (I don’t have proof) to be its effect on people who are prone to anxiety. Caffeine is allegedly able to induce panic attacks in sufficient quantity.

    Six cups of coffee a day sounds like a lot if we’re talking full strength “real” coffee. I’d be climbing the walls on more than 3-4.

  6. ross 19 June 2008 at 7:20 pm #

    Did the study account for other confounding factors such as socio-economic background, lifestyle etc?

  7. Sherrie 20 June 2008 at 3:02 am #

    Caffeine can also spike insulin in some people.

    I never seemed to have problems with caffeine myself though it may hit me now if I suddenly drank lots as I have been drinking decaff ever since I fell pregnant 4 years ago. Which reminds me I do recall a negative study regarding caffeine consumption during pregnancy but I don’t recall the details.

    Anyhow, regarding the comment on anxiety levels my partner has this problem. He used to drink lots of caffeine years ago and was always moody and anxious, then during a health kick dropped caffeine entirely and became much more pleasant, neither of us picked up on it. Then eventually caffeine had come back into his diet again but no where near the amounts that he used to drink and I was given my first coffee machine for Xmas. Anyway so off I went and made us a nice espresso and he went off the rails, I remember later we were in a shop being served and he practically bit my head off the lady was in shock, it was so unlike him. Thats when it dawned on us that he had a problem with caffeine.

    Ever since, time and time again when he lets caffeine slip back into his diet he gets really moody and anxious without fail.

  8. cycletrax 20 June 2008 at 8:38 am #

    It would be helpful to have some other perspective on coffee, for example, re caffeine, and the reputation this has for leaching calcium from the bones. Older people are presumably statistically more in danger from heart attacks, but they are also more at risk of osteoporosis than younger people.

  9. Liz 20 June 2008 at 9:57 am #

    Sherrie’s comments show that coffee doesn’t suit everyone.

    And if it doesn’t, don’t use it.

    But it’s nice to know that for some of us the coffee might actually be doing us good!

  10. Richard 20 June 2008 at 1:18 pm #

    Coffee drinking is associated with insulin resistance according to this:

  11. Susan 20 June 2008 at 7:08 pm #

    Isnt coffee supposed to be avoided by people with borderline or high blood pressure?

  12. Sue 22 June 2008 at 2:13 am #

    Some other possible benefits of coffee:

    Caffeine’s bronchodilator effect of opening the air-ways can be beneficial to people suffering from acute bronchial asthma. Caffeine acts as an analgesic (pain killer) and, when combined with ibuprofen, can bring faster and longer lasting relief from tension headaches. It is often prescribed for migraine headaches. Drinking two cups of coffee before breakfast has helped individuals suffering from dizziness and other effects caused by abnormally low blood pressure.

    Coffee ” New Health Food
    Consider this: At least six studies indicate that people who drink coffee on a regular basis are up to 80% less likely to develop Parkinson’s, with three showing the more they drink, the lower the risk. Other research shows that compared to not drinking coffee, at least two cups daily can translate to a 25% reduced risk of colon cancer, an 80% drop in liver cirrhosis risk, and nearly half the risk of gallstones.
    Coffee even offsets some of the damage caused by other vices, some research indicates. “People who smoke and are heavy drinkers have less heart disease and liver damage when they regularly consume large amounts of coffee compared to those who don’t,” says DePaulis.
    There’s also some evidence that coffee may help manage asthma and even control attacks when medication is unavailable, stop a headache, boost mood, and even prevent cavities.

    But you can get other benefits from coffee that have nothing to do with caffeine. “Coffee is loaded with antioxidants, including a group of compounds called quinines that when administered to lab rats, increases their insulin sensitivity” he tells WebMD. This increased sensitivity improves the body’s response to insulin.
    That may explain why in that new Harvard study, those drinking decaf coffee but not tea beverages also showed a reduced diabetes risk, though it was half as much as those drinking caffeinated coffee.
    “We don’t know exactly why coffee is beneficial for diabetes,” lead researcher Frank Hu, MD, tells WebMD. “It is possible that both caffeine and other compounds play important roles. Coffee has large amounts of antioxidants such as chlorogenic acid and tocopherols, and minerals such as magnesium. All these components have been shown to improve insulin sensitivity and glucose metabolism.”
    Meanwhile, Italian researchers credit another compound called trigonelline, which gives coffee its aroma and bitter taste, for having both antibacterial and anti-adhesive properties to help prevent dental cavities from forming. There are other theories for other conditions.

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