Thursday, January 27, 2011

Smoking, Breast Cancer, and One More Reason to Keep up the Fight Against Tobacco

It may not fall into the "shocking" category, but a new Harvard study by our colleagues at the Nurses' Health Study has provided further insight into the links between smoking and breast cancer (study).  To date, many studies have had waffling results on the subject.  Some showing smoking raising risk; some showing it not affecting risk at all; and some even showing it lowering risk.

This new study by Xue et al is a longer followup to an earlier Nurses' Health Study report and included over 110,000 women who were tracked over a 30 year period.  The main finding from this study was that smoking likely has some affect on breast cancer risk, but even with heavy smoking, the risk isn't as high as with other cancers linked to smoking (like lung, oral, and esophageal cancer, to name just a few). Greatest risk came from heavy smoking before giving birth to a first child, which raised risk by about 18 percent compared to never smoking.  The broad analysis comparing those who have ever smoked  to those who have never smoked showed a small six percent increase in risk.

Not surprisingly, heavy smoking after menopause showed a small protective effect against breast cancer.  After menopause, blood estrogen levels drive a lot of breast cancer risk, and for multiple reasons, smoking stems estrogen levels, which in turn could lower risk after menopause. Increases in risk, though, from smoking before menopause outpaced any small drop in risk from smoking afterward. 

So what do these results mean?  While there are still some open questions about the link between smoking and breast cancer, they certainly add one more reason to avoid smoking and to support policies that lead to that end.  Adding breast cancer to the list, there are no fewer than 12 different cancers caused by or directly linked to cigarette smoking.  Heart disease, diabetes, stroke, chronic bronchitis, emphysema, osteoporosis, and a number of other important conditions belong on the list as well.  With the decline in US smoking rates stalling - leaving just over 20 percent of the population regular smokers (previous post) - it's important that we keep our guard up against tobacco use.  It's been a long fight, and we've gained a lot of ground, so it's easy to feel that we've done what we can and move on to some new health promotion venue.  But, really, smoking still deserves a great deal of attention. The potential health gains from further lowering smoking rates are huge and should not be downplayed just because we've made some strides and have been working on the issue a long time.

Tuesday, January 25, 2011

Tossing out hypotheses?

It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.
-Konrad Lorenz

This week's news brought a story that remind me that sometimes, the best science involves letting go of previously held hypotheses.

Access to quality, health food, particularly fruits and vegetables, is something that has occupied a good deal of news space in recent years. And with good reason. If people can't get healthy food, all the health education in the world telling them to eat it isn't going help. The result has been a lot of attention on food deserts - the lack of supermarkets in certain neighborhoods. How pervasive are these food deserts and what do the food options look like in these areas? Jim Griffioen takes a powerful look at this in his hometown of Detroit over at Urbanophile. He shows, in great detail, the incredible depth and breadth of quality locally owned food purveyors within Detroit. He also points out that a quick Google search locates a number of smaller chain grocery stores. Does Detroit have a Whole Foods or Super Target? No, but Griffioen argues they don't need one. I have been reading his personal blog for some time and one of my favorite series has always been his photos of the family's "haul" from Detroit's Eastern Market. The photos highlight an incredible diversity of delicious looking produce and food that is locally grown or produced. Kudos to Griffioen for pushing journalists and researchers to examine these questions in more detail - and draw new conclusions when the data indicates it.

Thursday, January 20, 2011

Canada needs to get moving, physical activity report shows

A new report released by Statistics Canada yesterday shows that the level of physical activity in the Canadian population is far lower than previously estimated (see report).

While Canada has used self-report to monitor the level of activity in the adult population and seen high levels of reported physical activity – in the new report barely one third of the population reached the target of 10,000 steps per day measured by pedometer. Many of us use a pedometer to monitor our daily level of activity – in this setting it was one of the measures to more directly assess the activity in the population.

Overall these data suggests that Canadians are not as active as national targets recommend for health benefits. Many benefits accrue from higher activity, including weight control, lower risk of heart disease, diabetes, and cancers of the breast and colon, to name a few.

With the New Year upon us, increasing our daily activity to achieve at least 10,000 steps per day gets us towards achieving some of these health benefits. It is never too late to begin being more active. As we have written previously, we have many tips to help you move towards these goals.

Related CNiC posts

Sunday, January 16, 2011

Embracing "You are what you eat!"

There is an impressive density of research on the role of diet in cancer prevention, leading to numerous reports, such as that from the American Cancer Society or the World Cancer Research Fund, but only relatively recently has the research community turned to study the role of lifestyle, including diet, in cancer survivors.  Despite this, there is a solid body of quality research on lifestyle in survivors, such that evidence based guidelines are available for numerous behaviors including diet and exercise .

The challenge always comes in implementing these guidelines, and unfortunately, despite the wealth of data showing dietary choices matter for health (not just cancer, but heart disease and diabetes, as well as weight), many hospitals still have cafeterias populated with too many deep fried choices and salads comprised mainly of sad-looking white lettuce.

It was my great delight, then, to open Sunday's New York Times and read about the great lengths the culinary staff at Memorial Sloan Kettering Cancer Center goes through to provide food that is both tasty and nutritious to their patients.  What is truly remarkable, tough, are the efforts Chef Pnina Peled and her team go through to provide food that meets the preferences and cravings AND dietary restrictions of the cancer patients at the hospital. Kudos to all of them and may they serve as an example to hospitals everywhere

Wednesday, January 12, 2011

Diet after breast cancer and survival

More data have come to light reinforcing messages we have summarized in previous posts on lifestyle changes for cancer survivors. Following more than 4,400 women with breast cancer and assessing dietary intake after diagnosis, Beasley and colleagues report that higher saturated and trans fat intake are both associated with higher total morality 1. 135 women died from breast cancer during follow-up. A total of 390 women died from other causes. As we have noted previously, addressing the lifestyle factors that drive chronic diseases in general is a high priority among cancer survivors. These data add further support.

See our recommendations and tips for healthy lifestyle changes after a diagnosis of cancer. Finding the key to health as a cancer survivor: a new 8 ways

Literature cited
1.            Beasley JM, Newcomb PA, Trentham-Dietz A, et al. Post-diagnosis dietary factors and survival after invasive breast cancer. Breast Cancer Res Treat. Jan 1 2011.

Tuesday, January 11, 2011

Obesity, insulin resistance, and poor breast cancer survival

Several new studies published in the Journal of Clinical Oncology provide strong evidence for poor outcomes among women with breast cancer who are obese. In the largest study to date, Ewertz and colleagues followed 18,967 women who were treated for early stage breast cancer between 1977 and 2006. Evaluating recurrence and mortality, the investigators observed that the risk of developing distant metastases was significantly elevated by 46% 10 or more years after diagnosis among both overweight and obese women. Risk of dying from breast cancer was significantly elevated by 38% and from other causes by 31% among obese women 1.

The pathways by which obesity drives recurrence, metastases, and mortality is summarized in an accompanying editorial (see pathway figure). Obese women produce more estrogen from their fat cells, have insulin resistance, and have decreased adipokines and increased IL-6 impacting cell survival 2. The persistent adverse outcomes for breast cancer even in the face of modern treatments has been described previously but is now reinforced by these data. Importantly, the excess morality from other causes attests to the need for more aggressive management of obesity among women with breast cancer.

In other papers published in this issue, the role of insulin resistance in survival after early stage breast cancer was also reported.  Duggan and colleagues followed 527 women with stage I to IIIA breast cancer. Using HOMA as a measure of insulin resistance they show that risk of breast cancer mortality and all cause mortality increased significantly with increasing insulin resistance 3. A measure of insulin section, C-peptide, also related to increased breast cancer mortality and total mortality during follow-up of 604 women with breast cancer 4.

These data together support the pathways summarized by Sinicrope and Dannenberg 2 and clearly support ongoing trials funded by NCI that are evaluating lifestyle interventions to promote physical activity and sustain weight loss among breast cancer survivors. In the mean time, given the proven benefits of sustained weight loss and increased physical activity for prevention of diabetes and improvement of quality of life, it's time for action to bring these benefits to all women with breast cancer. 

Related CNiC posts

Untapped Benefits of Physical Activity and Weight Loss in Breast Cancer Prevention

Priorities for prevention: breast cancer survivors

Literature cited

Friday, January 7, 2011

What can you really do in 4 hours?

Full disclosure: I haven't read "The 4-Hour Workweek" or "The 4-Hour Body." I tend to hear about the latest "best selling" health book and let it zip in one ear and out the other. My take on making healthy choices is that they take a little time (though not a lot as Mark Bittman admirabily reminds us about cooking) and a little work, but they are feasible. Quick fixes, gimicks (e.g., cleanses), shticks just aren't my thing.

But, since no less than 3 people have mentioned Tim Ferriss' book to me this week and the NY Times has a review today, it seemed a brief comment might be worth posting.

I'm going to take Dwight Garner at his word on the tips included in Ferriss' book. My sense is that the book takes scientifically sound ideas (e.g., self monitoring) and turns them on their head and takes them out to the extreme (e.g, weighing feces). No less than two colleagues of mine have had a similar take on the book - there are valid strategies buried in there, and they aren't new, but those strategies don't sell books. So, Ferriss has surrounded them with a bunch of gimmicks that make headlines (as surely his "humanitarian" efforts with the yoga instructor are meant to, and do).

For my money, I'd rather buy a pedometer, a bathroom scale and a notepad to track my activity, weight and diet.

How are those New Years' Resolutions?

If you needed another reason to lace up your sneakers and keep your New Years' resolution to be active, this week offered 2:

1) Our team published, in collaboration with colleagues at the American Cancer Society, research on the role of physical activity in colon cancer and colon cancer mortality. There is a strong and consistent body of evidence showing physical activity reduces colon cancer risk. This new study examined whether the consistency of physical activity matters.

We often get this question at CNiC - can I start now? Is it too late? What we found is that consistent physical activity does matter for colon cancer mortality. Does this mean if you haven't been active before now it is too late and you shouldn't bother starting? Absolutely not. It is important to look at this study in the context of the previous work and see the big picture -- physical activity matters for colon cancer risk and mortality. Starting earlier seems to be better, but it doesn't appear it is ever too late to start either.

And of course, the other thing to remember is that physical activity isn't just beneficial for colon cancer - it reduces risk of other cancers AND heart disease AND stroke AND diabetes AND osteoporosis. And physical activity improves the quality of life as well - you FEEL better.

2) Providing another reason to be active - colleagues of ours published a report on the benefit of physical activity after a prostate cancer diagnosis. Among men diagnosed with non-metastatic prostate cancer, those who were physically active after diagnosis were less likely to die and less likely to die of prostate cancer. Overall mortality risk was reduced with activity equivalent to 30 minutes a day of brisk walking. The study suggested more vigorous physical activity may be necessary to reduce risk of prostate cancer specific death.

When the days are short and the temperatures cold, it can be hard to find the motivation to be physically active, even for our team. As we've said before - anything that gets you up and moving is good - even short breaks. And if you think you don't have time, remember our tips. Physical activity is a place where you get enormous "bang for your buck!"

Monday, January 3, 2011

iMotivate: What's the Future of Gaming and Healthy Lifestyles?

We're not big gamers here at CNiC, but there was a fascinating episode of WNCY's radio program On the Media last week devoted solely to the topic, which had some very interesting, if also unsettling, things to say about the ways gaming culture may eventually impact the real-life choices we all make.

In one segment (embedded below), Carnegie Mellon professor, Jesse Schell, spent some time envisioning a time in the not-too-distant future where our lives could become one big game of racking up automatic points - 10 points for brushing our teeth, 100 points for walking to our next meeting (with a bonus for reaching target heart rate) - which could effect our insurance premiums and even tax credits. 

Clearly, it's a Big Brother scenario that smacks of the dark sides of Minority Report, but with a number of recent articles on "incentivizing" healthy lifestyles, most recently in the New York Times (story), it seemed to be a future worth thinking about.  Exactly where things will go 5, 10, or 20 years from now, no one knows.  But Schell's vision does not seem too far-fetched, so maybe it's worth a little energy to begin to think about how we could work to influence the positive aspects of such a future while minimizing its negatives.

Jesse Schell enters into the segment at 5:05.