Genetics and cancer prevention

The Times today reports that the genome (http://nyti.ms/9CqHdl) has deepened understanding of human genetics and opened up the potential for new approaches to treatment of disease. The potential pay off has not yet arrived, however. As the Times story notes, a family history of disease provides a good summary of risk, and also identifies those for whom prevention may offer substantial benefits.

In the same decade that we invested heavily in this scientific enterprise, (3 billion dollars in the Human Genome Project), we also have made progress understanding prevention of chronic diseases. For example, additional insights have been gained on the role of exercise and weight loss in reducing risk of breast cancer (see Maruti et al, 2008 - JNCI - and my presentation http://bit.ly/d2SY2s). Studies show that higher levels of activity from onset of menstrual periods in young girls through to their 20s and 30s, results in prevention of one quarter of premenopausal breast cancer. This is most important since our treatment approaches for premenopausal disease have not progressed as rapidly as for postmenopausal breast cancer. In addition to exercise, we see growing evidence that high fiber diet and higher soy intake in childhood and adolescence reduces risk of breast cancer throughout life.

We should not sit in awe waiting for genome sciences to produce a miracle cure but we should act on what is already known. The Susan G. Komen for the cure, for example, spent 3% of its funds on prevention research between 1982 and 1996, and in 2008 to 2009 they spent 7 percent of the research portfolio on prevention. Clearly like other organizations funding research and prevention of chronic disease, they too await or hope for a miracle cure.

The benefits of healthy childhood and adolescence are not limited to breast cancer prevention. Avoiding excess weight gain during childhood and adolescence can prevent the onset of diabetes. Healthy diet and exercise have numerous pay-offs through the adult years but prevention begins in childhood.
Reorienting our priorities to prevention could substantially reduce the burden of cancer, heart disease, diabetes, and other chronic conditions. Growing attention to salt in the diet points has identified population-wide strategies that can reduce blood pressure. We need to engage as a society to make the changes that will reduce the burden of chronic disease and hence save many future expenditures that are driven by the diseases caused by our lifestyle including lack of exercise, obesity, and poor diet.

Leaving on a Jet Plane: Making Healthy Choices on the Road

This is a month packed with travel to meetings for me. It coincided with giving a talk to a group that spends a lot of time on the road planning and organizing meetings about making and offering healthy choices.

This got me thinking about the things I’ve learned about healthy eating while making my way from concourse to concourse on trip after trip. I don’t have all the answers, but I used to travel by plane weekly and I continue to travel with some frequency, so I at least bring some hard fought experience.

Travel can be physically and psychologically draining so when I’m on the road, I try to make healthy choices as much as possible. Doing so also helps alleviate guilt I might feel indulging in a local specialty that might not make a healthy choice list, like I did on a recent trip to Chicago when I got to dig into one of my all time favorites - Sweet Mandy B's red velvet cupcakes. (As a New Yorker, I don't get excited about Chicago-style pizza.)

Making healthy choices on the road actually begins at home. Airports are full of junk food so I try to pack things at home that I can toss in my carry-on bag. Here are a few of my favorites

Nuts – I usually toss a bunch in a Ziploc bag and then I have them as a snack in my hotel room too. The other option I recently discovered are packaged mini-bags of roasted almonds that Trader Joe’s sells. I love these for when I’m running late and don’t have time to assemble a whole snack pack. They’re also great in my desk drawer when I’m in the office and to keep in the car – they’ve saved me from grabbing a candy bar or a fatty spongy blueberry muffin a few times!


Dried fruit – on its own or mixed in a baggie with the dried nuts.
Packets of plain instant oatmeal. Sure, steel cut is better, but this is a much better option than a fat and calorie laden Danish or muffin. The dried fruit does double duty here as a mix-in.

Recently, food companies have begun to make some healthier pre-packaged snacks targeted to kids. The great news for those of us over 8 is that the “anything in a shiny package” concept that appeals to kids often means a travel friendly food for us. This is a danger zone as well so tread carefully. Yogurt is a great snack but many yogurt-containing foods (including the organic kind) have as much sugar as a candy bar! One recent favorite of mine are squeezable applesauce and carrot-applesauce. I’ve found them at Trader Joes and Whole Foods.


I have mixed feelings about snack bars – in a pinch, many make better choices than a traditional candy bar or certainly the cookies and cakes sold in airport coffee shops. But they nearly universally aren’t a healthy food the way that nuts, fruit and plain yogurt can be. The best source I’ve found for reviews and evaluations of these is the Snack Girl website – so rather than reinventing the wheel, I suggest you head over there for her thoughts. For example, she gave the Kind bars a good review and when I checked them out, I agreed. Pretty tasty with a limited ingredient list that is basically fruit and nuts. In general, you want to watch for the calorie content - many don’t count as a snack – they pack as many calories as a meal. And don’t be fooled by “grams of protein” or other label tricks. The more ingredients you recognize and can pronounce, the healthier the choice likely is.


… and that old childhood standby, peanut butter and jelly, makes a sandwich that travels easily if you’re going to be at the airport around meal time and can’t bear the thought of another fast food meal.


At airports, I can pretty consistently find a few healthy snacks; most have someplace that offers cut up vegetables – typically carrots and celery with maybe some broccoli. Go easy on the ranch dressing that typically comes with them and you’ve got yourself a healthy snack. Whole fruit is almost always available at at least one restaurant. Some even have cut up melon and grapes together. Of course, some of that stuff may have been sitting around for a while or be pretty bleak looking – which is why the dried fruit always comes in handy! That said, some research does exist that suggests pre-cut and packaged produce holds nutritional content reasonably well.

I haven’t been to an airport newsstand in ages that doesn’t have dried fruit and nuts if you didn’t get a chance to bring yours from home. I always try to have something in my bag before I get on a plane these days since delays are increasingly common and increasing in length.

As for the meal options – the rules you use when eating out while at home are the same here. Low fat dairy is hard to come by in this environment so I usually look for sandwiches without cheese or I remove the cheese if all the prepackaged sandwiches have them. I also look for sandwiches that don’t have mayonnaise on them or mixed in (like in tuna and chicken salad). Choose water over soda or juice to watch your overall calorie intake. In fact, while you can’t bring a full water bottle through security, you can bring an empty one – so I’ve started tossing my empty reusable water bottle in my bag and filling it up at a water fountain after I clear screening. If my flight gets delayed and I have time for a sit down meal, I look for salads that aren’t full of cheese, fried chicken or fried toppings like tortilla strips, croutons and the like.

Really, it’s all pretty simple once you get the hang of it. So while our carry-ons may all be overstuffed in this era of checked-baggage charges, we don’t need feel that way.

Progress for Heart Attacks and What This Means for Cancer Prevention

New data reported this week in the New England Journal of Medicine show a reduction in incidence of myocardial infarction and improved survival after heart attack (Yeh, et al). This population based study from Kaiser Permanente in Northern California highlights the relatively rapid effect that improvements in the managing of risk factors can have on cardiovascular disease. From 1999 to 2008 the proportion of patients with high blood pressure who were successfully treated to meet target levels increased from 40 percent to 80 percent. And the proportion meeting targets for blood cholesterol also increased.

The 24 percent decrease in myocardial infarction seen in this population in just ten years highlights just how important time frame is for prevention. Cardiovascular risk factors respond to interventions relatively quickly, and subsequently, the risk of heart attack drops quickly. Taking aspirin lowers the risk of heart attack within hours. Stopping smoking lowers risk significantly over the first year of quitting. Improvements in blood pressure have a similar effect.

In contrast, there’s cancer risk, where we do not have this ready range of intermediate markers that are either amenable to preventive interventions or show rapid responses. Some factors have relatively quick impacts on cancer risk – tamoxifen and raloxifene lower breast cancer risk within 1 – 2 years; smoking cessation lowers lung cancer risk by half within five years. And removal of colon polyps found by screening significantly lowers later risk of cancer. Yet, none of these is the hard and fast marker that high blood pressure or similar measures are for cardiovascular disease. And even though we know that estrogen levels in postmenopausal women are a very good marker of breast cancer risk – similar in magnitude to the link between unhealthy cholesterol levels and heart disease - we don’t currently use it as such.

For cancer, the long lag between lifetime exposure to a risk factor and cancer onset leads to many challenges in documenting the benefits of prevention. We know that high levels of activity reduce risk of breast and colon cancer and that obesity increases the risk of many cancers. How quickly risk responds to changes in these components of our modern lifestyle, though, is not clear. For smoking, the measurement of exposure is somewhat easier, and the event of stopping smoking is clearly marked in the minds of most smokers. This helps us document the benefits of quitting for cancer (Kenfield, et alCNiC Prevention Spotlight). Most cancer risk factors, though, don’t have such a clear cut beginning (or end) or have such a quick effect on risk, which makes assessing the specific timeline of cancer prevention difficult.

Despite such uncertainties, the balance of evidence shows that cancer is largely preventable and that many of the same lifestyle changes that boost heart health also lower cancer risk. The benefits may take longer to come around than for heart disease, but in the end they’ll be no less real and no less important.