While I am taking a brief break from clinics and other obligations (including daily blog posts), I will be reposting past articles, which I still believe to be relevant but may have escaped the attention of the 100s of new readers who have signed up in the past months.
The following was first posted on 04/22/08
Yesterday’s big news was the study by Kerry Courneya, professor and Canada Research Chair in Physical Activity and Cancer at the University of Alberta, published in CANCER.
I am not going to repeat the findings or the data here because this was nicely summarized by Sharon Kirkey from Canwest News Service in the Edmonton Journal.
The bottom line is that cancer survivors are apparently not exercising more or eating healthier than everyone else, and are therefore at least as, if not even more, likely to develop obesity than the average Canadian.
This is particularly true for survivors of breast and colon cancer, which are particularly likely to recur with lack of physical activity, unhealthy eating and weight gain.
The dramatic impact of weight on cancer risk is perhaps best demonstrated by the observation that obesity surgery, which on average reduces body weight by 25%, results in an almost 60% reduction in cancer mortality! (see Adams et al. for an example of such a study).
I guess it just goes to show that cancer survivors are no less susceptible to the consequences of our obesogenic environment, which certainly does not make weight control easy, even at the best of times.
That is of course, unless there is something special about surviving cancer that makes you more likely to gain weight - an interesting hypothesis pursued by other researchers here at the University of Alberta.
I can think of a number of reasons why surviving cancer could predispose to weight gain: “catch-up” fat, depression, “post-traumatic” stress, anxiety, susbtance abuse, “overfeeding”, immobility, medications, and perhaps a few others.
Whatever the reasons, it looks like we may now need intervention programs to specifically address weight gain and obesity in cancer survivors?
For one, educating cancer survivors about the links between excess weight and cancer would be a start.
My sense is that most people still don’t fully appreciate the close link between obesity and cancer - all the more reason to promote healthy eating and active living for all.
Obesity prevention (and treatment?) may well turn out to be the most effective cancer prevention strategy (short of smoking cessation) - looks like a whole new field for bariatric health professionals?
I guess we’d call them Bariatric Oncologists?
AMS
Edmonton, Alberta
In The News
August 11th, 2009 at 3:04 pm
Hi,
Thanks for the interesting article!
December 1st, 2010 at 4:13 am
Thanks for the link, but…. oh shit.
December 1st, 2010 at 8:41 am
I’ve given this some more thought since I first read it.
Firstly, it’s not clear from the article whether the cancer patients went into their illness either at a normal weight or at a lower weight than usual (e.g. were they suffering cachexia and so undergoing a dramatic weight loss?). So did the cancer patients subsequently become overweight or obese, or is it that they were those things to begin with and the cancer didn’t prompt them to lose? It’s not clear to me.
Let’s assume that the cancer patients were of normal weight, got ill and then got fat. Having just recovered from cancer myself, I can offer some explanations about why this might be that have nothing to do with “cancer wasn’t enough to motivate them”.
First and foremost, one of the biggest changes to chemotherapy regimes in recent years is the development of powerful and effective anti-emetics. It is much rarer these days for chemo patients to suffer nausea during treatment. Yet none of the literature given to cancer patients has been updated to reflect this. We are still exhorted to eat as much and as often as possible, and to have regular protein shakes and as much fat as we can tolerate. That was good advice back in the days when a chemo patient was vomiting 24 hours a day - it’s incredibly bad advice now.
Secondly, cortisone is used as part of many chemotherapy regimes. It is a very powerful appetite stimulant. It’s no easier to resist cravings on cortisone than it is to resist sleep after being given a sleeping tablet.
Finally, I note that breast cancer patients are mentioned. Well, the hormonal drugs that are given to breast cancer patients are also known to lead to weight gain. This is so well known and such a distressing side effect, that it’s mentioned in soothing tones in much of the feel-good literature that’s handed out to women suffering breast cancer. The idea is that they’re not supposed to worry about weight gain from hormones, because “it’s for the good of your health”. Sometimes these hormonal drugs are taken long term.
In fact, cancer forums are fall of bewildered people complaining about their weight gain, when they thought they were going to end up gaunt. So it’s a bit rich for researchers to suggest that cancer patients are cavalier about their health and well being, when in fact many of us are extremely distressed and anxious about the changes that these powerful, powerful drugs have had upon us.