More Muscle Strength, Less Cancer

A 2009 study followed about 9000 men for 10-20 years. It found that strength (how much you can bench and leg press) measured at the start of the study was associated with likelihood of dying of cancer during the study. Men in the upper two-thirds of the study population in strength had 40% less cancer mortality. This might be the most surprising result:

Further adjustment for BMI, percent body fat, waist circumference, or cardiorespiratory fitness had little effect on the association. The associations of BMI, percent body fat, or waist circumference with cancer mortality did not persist after further adjusting for muscular strength.

In other words, muscle strength was a better predictor than several similar measures (BMI, etc.) and these other measures stopped predicting when corrected for muscle strength. Muscle strength is closely connected to something important.

Men who are stronger by and large exercise more, no doubt. Yet muscle strength is determined by resistance training, not aerobic exercise — and it is aerobic exercise (and to some extent walking) that have been promoted by countless experts since the 1960s and the invention of the concept aerobic. Jogging reduces how much time you have for resistance training.

These findings interest me because I do a lot of resistance training — stand on one leg to exhaustion several times per day — purely to sleep better. By improving something easy to measure (sleep), these data suggest I have also been improving something hard to measure (chance of dying from cancer). Not surprising, but reassuring.

My data also suggest two different possible reasons for the strength-cancer association. One is that men who exercise more sleep better as a result; better sleep, better immune function, less cancer. Another possibility is that strength is a marker for good sleep. Among men who do equal amounts of exercise, those who sleep better will be stronger.

From The Breviary.

11 Responses to “More Muscle Strength, Less Cancer”

  1. Charlie Currie Says:

    My father-in-law would be the exception…he had very strong legs and arms. He was an athlete in his younger days and worked labor intensive jobs prior to becoming a realtor. In his thirties he grew a large belly…solid, not flabby. Aerobic exercise was not on his to-do list.

    In his fifties he had high blood pressure, by sixty he had heart disease, T2 diabetes, required knee replacement (both) and was diagnosed with bi-polar syndrome. In his sixties he had quadruple by-pass surgery, in his seventies he developed throat cancer. He died at age 86 from complications from aspirating a piece of chicken. If not for excellent medical, and home care, he would have died much younger, either from his heart disease or cancer. I think the fact that he was never feeble was also a benefit and contributed to his multiple recoveries.

    Maintaining leg and arm/shoulder strength is excellent advise, but it may not prevent you from contracting life threatening diseases.

  2. Max Says:

    Another likely contributing explanation for the strength-cancer association: resistance training improves (reduces) HbA1c. Elevated HbA1c has been shown to be an independent predictor for cancer. Dr Richard Bernstein connected all these dots years ago, which is why his program includes serious strength training for T1 and T2 diabetics.

    (love the blog, thank you)

  3. Jake Says:

    Two reasons why muscles help prevent cancer:

    Active muscles produce myokines. Myokines reduces inflammation which reduces your chance of getting cancer.

    Muscles act as a glucose sink to reduce glucose and insulin peaks. These peaks are a major driver of cancer.

  4. Adam Says:

    “It found that strength (how much you can bench and leg press) measured at the start of the study was associated with likelihood of dying of cancer during the study.”

    This should read “was _inversely_ associated”.

    When I first read it, I thought you were saying the stronger you are the more likely you are to get cancer.

  5. aretae Says:

    I think there’s a reasonable chance that Muscle Mass is a generic health marker. Mark Rippetoe, who is the most interesting person in health that I haven’t yet started reading (linked often from Instapundit), has been saying things like this for a while: Muscle Mass is your basic measure of health. Beats almost anything else, at least for some groups (men?).

    You’re now the second person who’s said: No, really, muscle mass matters a lot. Beats the pants off fat. More muscle & more fat: Healthier. Less fat + less muscle = less health.. Fascinating.

  6. Bo Says:

    “These findings interest me because I do a lot of resistance training — stand on one leg to exhaustion several times per day — purely to sleep better.”

    I’m sorry, but standing on one leg isn’t really resistance training (at least not even for the average not-so-healthy individual). If you can stand on one leg for more than a few seconds (and after a few goes once you master balancing) it’s not really strength training. It’s strength-endurance at best, though I wouldn’t count on even that.

  7. John Smith Says:

    I would think that the strength of the will and the psyche, the level of determination, these are what form the basis of good muscle and good health.

    Many folk give up far too early…………..’I can’t’ they wail. Just watch them on the fat shows. Admittedly that strength of will needs to be developed just as one develops muscle and not just on the day of the TV shoot, so heavy people should not be expected to perform like a flyweight overnight.

    Those who believe they can, are usually right. Those who believe they can’t are always right.

  8. Justin Irving Says:

    A few years ago Art De Vany linked to a study (on his old subscription blog) showing that lean mass was the best/a top predictor of cancer survival. I guess that’s not shocking. Thanks for this post though, motivation for dead lifts!

  9. Charles Says:

    Well, strength requires muscle. Muscle building requires growth hormone, and I believe GH is released in sleep. So there could be a connection.

  10. aretae Says:

    Other point re: muscle mass/Strength.
    It seems to be substantially to hugely genetic. As with most things, putting 50% of variance as a lower bound for the genetic share seems reasonable.
    This makes me less convinced by your sleep hypothesis.

    Example, my teenager has much larger/more muscular legs than I do, despite my having been semi-seriously lifting for 1/3 of the last 15 years, and his being mostly a couch-potato.

  11. Paul N Says:

    Having more lean muscle mass also helps you live longer.
    This excerpt and graph from the book “bending the aging curve gives a good illustration.

    Further within that book (which I have not read, only seen excerpts), it talks about the decline of fast twitch muscle mass with age, while the amount of slow twitch remains roughly constant until the last decades.

    All this might have something to do with the fact that to retain your fast twitch fibres, you need to be doing lifts, sprints and power exercises

    At the other end of the scale, marathon runners die younger, so I know which group I’d rather be in