Jan 032013
 

 

If the tooth fairy gave you 10,000 RMB every year in China that you could only spend on your health, what would you buy? Would you get an air purifier? How about a gym membership; an organic delivery service; a daily massage — what would you choose? Perhaps it’s best to rephrase the question, “what gives my health the most bang for the buck?” In order to answer that, one needs to know which lifestyle choices are harmless fun and which are unhealthy.

Air Pollution : A Lifestyle Choice? 

Many in China, both local and foreign, would instinctively say that air pollution is their greatest threat to health, but is it really? Let’s make a slight intellectual leap and say that exposure to air pollution is a lifestyle choice; in other words, a modifiable risk factor. I know that breathing is of course involuntary, but most of my readers do have a choice whether or not to live here in China. If you accept this admittedly disturbing assumption, you can then compare this always dreaded “risk factor” to much more mundane risks we all encounter — such as obesity, smoking, lack of exercise, poor diet and other lifestyle choices.

We can clarify lifestyle choices even further into what the American Heart Association calls the four ideal health behaviors:

  • not smoking
  • not being overweight (body-mass index (BMI) <25 kg/m 2)
  • physical activity at goal levels (>150 minutes a week of moderate exercise)
  • diet that includes three or more servings of fruits and vegetables daily.

The AHA also lists three ideal health factors, including total cholesterol <200 mg/dL, systolic blood pressure <120 mm Hg and diastolic blood pressure <80 mm Hg, and fasting plasma glucose levels <100 mg/dL.

How many of these seven metrics do you pass? Don’t feel too guilty, as only 1 percent of the AHA’s test group of 7,622 persons passed all seven. But here’s the clincher: compared with individuals who didn’t meet any of these seven measures, those with five or more had a 78% lower risk of all-cause mortality and an 88% lower risk of death from diseases of the circulatory system. That’s impressive, no? But it’s much more interesting to find out exactly which of these ideal goals is most efficiently beneficial. Plus, how do they compare to air pollution?

It’s All About The Relative Risks

I’m a data junkie, and I find hard numbers very comforting in the midst of my hectic “medicine is art” family medicine clinic. My favorite tool to compare health outcomes is the relative risk; this compares the ratio of a disease’s prevalence from a health exposure as compared to non-exposure. It’s simple division: divide numerator (exposure) by denominator (no exposure) and you have your ratio, your “RR”. Any RR over 1 signifies a positive risk, and under 1 is a “negative” risk, i.e. a benefit. Let’s use air pollution and smoking as initial examples. As I mentioned in my controversial post earlier this year, a day in Beijing is comparable to smoking 1/6 of a cigarette, which for many of my readers was scandalously low, almost heretical to their predisposed belief systems.  Sorry, true believers, but you can crunch the numbers yourself from Dr C Arden Pope’s sudy. From this study, we can calculate relative risks of lung cancer for air pollution, smoking and secondhand smoke:

  • Air pollution (from American Cancer Society and Harvard Six Cities studies): 1.14-1.21 relative risk
  • Air pollution in Beijing: 1.49 RR
  • Secondhand smoke victims: 1.21-1.28 RR
  • Smoking 3 cigarettes a day: 5.6 RR
  • Smoking half a pack a day: 7.7 RR
  • Smoking a pack a day: 12.2 RR
  • Smoking two packs a day: 19.8 RR

As the numbers show, “light” smoking of only 3 a day is far more deadly than living with Beijing’s air pollution. Since writing that article last winter, I’ve achieved a certain catharsis on this issue, and my personal obsession with air pollution has mellowed from debilitating to professionally curious. I’m now more concerned with the much less glamorous lifestyle choices that bedevil all developing societies, all eagerly latching onto the “Western” lifestyle and quickly picking up both the best and the worst of such lifestyle.

I’m particularly worried about obesity, the great pandemic of our times and an astonishingly pervasive crisis in my homeland, the USA. When I make my annual visit home on Boston’s south shore, I’m truly shocked just how large are the average American adult and child. Having spent six years outside of America, I can peer back with increasing impassivity and state that Americans simply don’t realize the true state of this public health disaster. One of my all-time favorite public health graphs, taken from data from a 1999 NEJM review article, shows the relative risks of increasing weight on coronary heart disease, diabetes, high blood pressure and kidney stones.

  27 Responses to “Which Lifestyle Choice in China Will Kill You First?”

  1. To clarify, the risk of LUNG CANCER alone, is equivalent to smoking 1/6 of a cigarrette per day.

    But what about all the other known health effects of air pollution?

    Alzheimer’s like changes in the brain, Depression and affect changes, and Cognitive and memory problems and Hippocampus degeneration, along with cellular cardiovascular changes that lead to heart disease… and this is just what I can remember offhand. So, please clarify all this in your post.

    The TOTAL HEALTH risk of air pollution in terms of cigarettes smoked per day has never been clarified.

    • To clarify even further, a day in Beijing’s air is similar to the PM2.5 from 1/6 of a cigarette. That “1/6″ number has nothing to do with lung cancer data — you’re thinking about relative risks from this PM2.5, which I’ve detailed in my previous posts extensively. In this article I mention the lung cancer risk only, that’s true. There are many, many other risks documented, especially heart disease. But the relative risk of heart disease from air pollution is even smaller than lung disease (RR around 1.3), which is why I didn’t mention here. Again, I’ve written dozens of posts about air pollution discussing health effects.

      Even with all this, I still don’t see any way how the total relative risks from air pollution could be anywhere near the risks from being obese, for example. Or just from having high blood pressure…

    • To clarify even further, a day in Beijing’s air is similar to the PM2.5 from 1/6 of a cigarette. That “1/6″ number has nothing to do with lung cancer data — you’re thinking about relative risks from this PM2.5, which I’ve detailed in my previous posts extensively. In this article I mention the lung cancer risk only, that’s true. There are many, many other risks documented, especially heart disease. But the relative risk of heart disease from air pollution is even smaller than lung disease (RR around 1.3), which is why I didn’t mention here. Again, I’ve written dozens of posts about air pollution discussing health effects.

      Even with all this, I still don’t see any way how the total relative risks from air pollution could be anywhere near the risks from being obese, for example. Or just from having high blood pressure…

      • I live in Chengdu which also has pretty bad air quality – typically PM2.5 of 150-200.
        A couple of months agao while I was teaching I gradually started to feel dizzy until it was so bad I couldn’t continue with my classes. I was also extremely tired. The dizziness continued for two weeks.
        After a few visits to the hospital I was diagnosed with vasoconstriction of the brain.
        I was suffering from quite bad cognitive impairment and memory problems.

        Since then I have stayed at home more with an air purifier and I have started exercising at home too. My gym always has its windows wide open and is right next to a busy road.
        Gradually my symptoms have improved.
        Yesterday, though, I went back to the gym and used the cycling machine. After I got home I felt pretty bad – quite fluey, headache and last night I had insomnia.
        Is it possible that the vasoconstriction and my symptoms are caused by the air quality? There have been quite a few studies that show vasoconstriction of the heart can be caused by high levels of PM2.5, but I’ve not seen any related to the brain.
        It’s quite worrying as I plan to stay in Chengdu for several years and wonder what the effects on my health will be if I’m perhaps quite sensitive to the poor air.

  2. By the way, Dr. Saint Cyr, I agree with you on several levels….first, living in fear and anxiety is known to affect all sorts of body systems negatively. I do not mean to scare anyone, just to state that there are interesting studies showing tons of various and surprising health problems resulting from Air pollution besides the “Lung Cancer” /cigarette analysis that was done. Other cancers are also an issue I should have included in the above comments too.

    I also agree with you that, overall, Weight, and Diet (I will just add Gut Health to the list!) have a hugely greater impact on adult illness and death. However, just because one risk factor is “off” does not mean we should not pay attention to other known risks.

    Especially for babies, I maintain that air filtration of the highest quality is a NECESSITY in Beijing, not a luxury. All the best, Liora

    • I agree with the baby issue. I do feel the evidence is strong enough to warrant every parent put a HEPA filter in their child’s bedrooms, at the very least. I also am a big supporter of schools’ air pollution action plans. I even think ISB’s new pollution dome is a great idea!
      Regards,
      Richard

      —————————-
      Richard Saint Cyr MD

    • I agree with the baby issue. I do feel the evidence is strong enough to warrant every parent put a HEPA filter in their child’s bedrooms, at the very least. I also am a big supporter of schools’ air pollution action plans. I even think ISB’s new pollution dome is a great idea!
      Regards,
      Richard

      —————————-
      Richard Saint Cyr MD

  3. Could an explanation be that the PM2.5 from cigarettes is just lower than we would think? Or that larger particles such as PM10, or the Tar, Nicotine and other chemical compounds in the tobacco are more “responsible” for lung cancer etc. than the PM2.5 component?

  4. Could an explanation be that the PM2.5 from cigarettes is just lower than we would think? Or that larger particles such as PM10, or the Tar, Nicotine and other chemical compounds in the tobacco are more “responsible” for lung cancer etc. than the PM2.5 component?

  5. A wonderful read and has me less worried about the air pollution here. I think that government across the globe and their populations are not taking their weight seriously enough. There is far to much ‘love the body you have’ mentality. Facts are the weight, smoking and drinking are the biggest killers they are the things the we need to tackle before we start on the less serious risks (not saying we should ignore them just prioritise)

  6. Someone thinks this story is hao-tastic…

    This story was submitted to Hao Hao Report – a collection of China’s best stories and blog posts. If you like this story, be sure to go vote for it….

  7. It appears to me that you have presented numbers in a fashion that severely understates the health risks of Beijing’s PM2.5 pollution. You cite that having 5 out of seven of AHA’s ideal health behaviors/factors reduces people’s risk of death from circulatory system disease by 88%. That’s great! But putting your numbers into the Pope et al. paper you cite, one finds a 32% increased risk of dying from circulatory system disease just from living in Beijing. That’s not so great. On top of that, if you are trying to reduce your BMI with some aerobic exercise, you can easily increase the amount of air you are breathing by 4-5 times. “1/6 of a cigarette” is misleading.

    • There’s plenty of research to support the idea that exercise, even in the outdoors, is still far more beneficial than the risks. The relative risks aren’t even close (read my post on bicycling in Beijing). And you mention this 32% increased risk but ignore the far greater 125% risk from a BMI of 25? Or the 600% risk of diabetes from a BMI of 25? Or the 52-62% increase in cancer death from BMI >40? And is this 32% risk really that clinically/statistically different than the 21% risk from living in Paris, or the 19% risk from London?

      Subject: [myhealthbeijing] Re: Which Lifestyle Choice in China Will Kill You First?

    • There’s plenty of research to support the idea that exercise, even in the outdoors, is still far more beneficial than the risks. The relative risks aren’t even close (read my post on bicycling in Beijing). And you mention this 32% increased risk but ignore the far greater 125% risk from a BMI of 25? Or the 600% risk of diabetes from a BMI of 25? Or the 52-62% increase in cancer death from BMI >40? And is this 32% risk really that clinically/statistically different than the 21% risk from living in Paris, or the 19% risk from London?

      Subject: [myhealthbeijing] Re: Which Lifestyle Choice in China Will Kill You First?

  8. Hi Dr. Richard,
    I have been living in Beijing for a year and a half now, and although I was more than aware of the famous Beijing pollution all this time, I never really thought I’d do anything about it until we had the “airpocalypse” come down upon us. I am 24 years old, and there are more and more 20 to 30 somethings flocking to Beijing after graduating college in search of a dynamic lifestyle and exciting job opportunities. Most of us have not thought too much about wearing facemasks (how unfashionable and drab!), and definitely not getting in-home air purifiers (that’s for old people and babies!!). After airpocalypse though, many of us ran to the World Health Store to pick up the Techno brand “bane” mask – at the price range it wasn’t cheap but definitely an impulse buy.

    Buying air purifier, however, makes me sit back and think – do I really need this at my age? I think a lot of people my age that plan on being in China for at least 2 to 3 years would like to hear what your thoughts are on if we should take the plunge and get adequate air purifiers in our apartments. Keep in mind that many of us spend 2 to 3 nights a week going out to bars and being in closed apartments, surrounded by second hand smoke if not full blown smokers ourselves (I personally am not, though had a bout with it for about 6 months last year, about 3 cigarettes a day, have quit completely for 2 months…I’m also not overweight). Drinking alcohol more than one should comes with that of course.

    So, what do you think? Take all the rest of what I said as a control (i.e. we love to party!) What is an air purifier really going to do for us? Most of us are on a budget and don’t really want to fork over the cash for something that isn’t necessary. Thanks!

    Dan

  9. I am a doctor moving to stay in Beijing soon, it is really interest to read your blog to have another insight information of Beijing, especially, I am looking for school and house now, I really focusing on the air pollution only, however, you made a very good points other than air quality, we have a lot of health related issues. I want to add water quality as well, aside from air, this is the second most important element that we required. I believe that when most peoples are focusing on air quality, we also need to concern about the Beijing underground water quality as well.

  10. [...] also important to keep air pollution in perspective; it’s much more unhealthy to be obese, or to have high blood pressure, or to be smoking any [...]

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