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Exercise Tied to Lower Risk for Some Types of Cancer

well.blogs.nytimes.com

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Re: Exercise Tied to Lower Risk for Some Types of Cancer

#31

Post by ekianjo »

trhway wrote: post #20
methodover wrote: post #16

Earlier quoted context omitted.

Phew, 186 thousand cancers included out of 1.4 million participants? I knew cancer was not entirely uncommon but... man. That's a lot of unhappy news. Feels bad to think about. If it is true that exercising regularly reduces the risk of cancer, I wonder what the mechanism is? Exercise builds muscle mass, improves lung capacity... Why would that have anything to do with cancer?

>Phew, 186 thousand cancers included out of 1.4 million participants? I knew cancer was not entirely uncommon but... man. That's a lot of unhappy news. Feels bad to think about. 2 out of 5 will get cancer during their lifetime. http://www.cancer.gov/about-cancer/what-is-cancer/statistics

And close to 50 percent once uou cross the 80s. The biggest factor for cancer is aging.

Re: Exercise Tied to Lower Risk for Some Types of Cancer

#32

Post by ekianjo »

enraged_camel wrote: post #30
ekianjo wrote: post #29

20 percent less between super active folks and non active ones is not super convincing. If it diminished the risk by 80 percent instead it would make for a much better story

>>20 percent less between super active folks and non active ones is not super convincing. Do you mean "compelling"? Because it should definitely be convincing: it's well outside the margin of error.

Yeah, compelling is what I meant.

Re: Exercise Tied to Lower Risk for Some Types of Cancer

#33

Post by aortega »

wapapaloobop wrote: post #28
aortega wrote: post #8

I think it's pretty obvious. I believe that it is not that exercise helps, but sedentarism is poisonous. A sedentary 40 year old looks and feels 20 years older than a 40 year old athlete.

Agreed, but it can't be as simple as merely sitting down. For example, sitting down for meditation is considered healthy, and may in fact be so.

Healthy for the mind, sure. For you cardiovascular system? I doubt it.

Re: Exercise Tied to Lower Risk for Some Types of Cancer

#35

Post by ekianjo »

Someone1234 wrote: post #6
jimrandomh wrote: post #2

No. This study is confounded and provides no evidence of anything. The problem is that people's willingness to exercise depends on their health as much as or more than their health is affected by exercise. Because this study did not involve an intervention (it just pooled a bunch of surveys), it can't distinguish between exercise causing reduced cancer risk, or a third variable affecting both.

The same could be said of almost any study that tried to show this. It is unethical to design the study in the way you're suggesting (i.e. stop people exercising to see if they get cancer). They did however: > Body mass index adjustment modestly attenuated associations for several cancers, but 10 of 13 inverse associations remained statistically significant after this adjustment. So even for two thin people, exercise…

Statistically significant does not prove anything, and it does not mean the difference would be large either.

Re: Exercise Tied to Lower Risk for Some Types of Cancer

#36

Post by ekianjo »

jimrandomh wrote: post #9
Someone1234 wrote: post #6

Earlier quoted context omitted.

The same could be said of almost any study that tried to show this. It is unethical to design the study in the way you're suggesting (i.e. stop people exercising to see if they get cancer). They did however: > Body mass index adjustment modestly attenuated associations for several cancers, but 10 of 13 inverse associations remained statistically significant after this adjustment. So even for two thin people, exercise…

The correct study is one where some participants get an intervention to make them exercise more, and some are left alone. There's no ethical issue, but running such a study would be difficult and expensive. Adjusting for BMI does not solve the problem, because there are many things besides BMI (unmeasured confounders) which affect both cancer risk and willingness to exercise.

And BMI is a pseudo science measure anyway. Its been proven to be a poor indicator in about every disease many times before.

Re: Exercise Tied to Lower Risk for Some Types of Cancer

#37

Post by 0xcde4c3db »

methodover wrote: post #16
seizethecheese wrote: post #13

Results from the source study abstract[1]: " A total of 1.44 million participants (median [range] age, 59 [19-98] years; 57% female) and 186 932 cancers were included. High vs low levels of leisure-time physical activity were associated with lower risks of 13 cancers: esophageal adenocarcinoma (HR 0.58, 95% CI 0.37-0.89), liver (HR 0.73, 95% CI 0.55-0.98), lung (HR 0.74, 95% CI 0.71-0.77), kidney (HR 0.77, 95% CI 0.7…

Phew, 186 thousand cancers included out of 1.4 million participants? I knew cancer was not entirely uncommon but... man. That's a lot of unhappy news. Feels bad to think about. If it is true that exercising regularly reduces the risk of cancer, I wonder what the mechanism is? Exercise builds muscle mass, improves lung capacity... Why would that have anything to do with cancer?

It's conjectured that fasting kills (pre)cancerous cells by basically starving them when they fail to downregulate their metabolism under a calorie deficit. Perhaps exercise could have a similar effect in diverting energy from higher-cancer-rate cells (skin, digestive tract linings, endometrium, etc.) to lower-cancer-rate cells (muscle cells)?

Re: Exercise Tied to Lower Risk for Some Types of Cancer

#38

Post by nl »

azdle wrote: post #14

I don't have access to the actual paper, but my first thought on this is to wonder if they factored in the idea that people who specifically exercise are obviously interested in being healthy and may be doing other things that are "healthy" that would affect whether they get cancer or not. I wonder if it'd be possible to get data on people who are active, but not for the reason of being healthy, things like working c…

From the article: Encouragingly, the associations between exercise and reduced cancer risks held true even when the researchers factored in body mass. People who were overweight or obese but exercised had a much lower risk of developing most cancers than overweight people who did not move much.

Re: Exercise Tied to Lower Risk for Some Types of Cancer

#39

Post by wapapaloobop »

aortega wrote: post #33
wapapaloobop wrote: post #28

Earlier quoted context omitted.

Agreed, but it can't be as simple as merely sitting down. For example, sitting down for meditation is considered healthy, and may in fact be so.

Healthy for the mind, sure. For you cardiovascular system? I doubt it.

http://archinte.jamanetwork.com/article.aspx?articleid=41045...
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