HOW TO PREVENT CANCERS

Despite some pretty timid headlines, like “Sigmoidoscopy May Reduce Deaths From Colorectal Cancer,” the results of a UK-based randomized controlled trial seemed pretty resounding and further confirm the importance of regular colon cancer screening tests between ages 50 – 75 (USPSTF recommendations).

The studied appeared early-online this Wednesday in the Lancet (study) and tested the hypothesis that a single flexible sigmoidoscopy screening between 55 and 64 years of age could substantially reduce colorectal cancer incidence and mortality. Just over 170,000 eligible men and women were randomly placed either in the intervention group and offered screening with a flexible sigmoidoscope, or in the control group and not contacted further. Participants were followed for colorectal cancer incidence and morality.

Screening significantly reduced mortality from colorectal cancer among those in the screening group. Mortality was reduced by 33%, a significant reduction compared to the control group. The screened group also had a lower incidence of colorectal cancer compared to the control group – presumably as a result of removal of premalignant polyps detected on the initial screening test.

Regular screening is the single best way to lower the risk of colorectal cancer. Along with sigmoidoscopy, other recommended tests include colonoscopy and fecal occult blood tests. Together with their doctors, patients can choose which one of these is best suited to them.

Our related material
Your Disease Risk – Colon Cancer
You Can Prevent Colon Cancer – a Knol
Cancer Prevention – a Knol

Last week, the Institute of Medicine (IOM) called on the US Food and Drug Administration (FDA) to mandate a maximum level of sodium in food (IOM report). They did this because high sodium intake contributes to high blood pressure, which is a contributor to heart disease and stroke.

The average person in the US takes in more than double the recommended amount of sodium. And for most people, the salt shaker on the dinner table isn’t the main culprit. It’s processed foods, which are often very high in sodium, even for foods one wouldn’t expect to be “salty.” A graphic in last Sunday’s New York Times shows this nicely (Graphic: Funny, they don’t taste salty). Two Eggo brand waffles have over a quarter of the daily recommended sodium intake, as does a half cup of some brands of cottage cheese.

If sodium is such a problem and such a contributor to high blood pressure, shouldn’t we just identify the folks with high blood pressure and have them lower their sodium intake? This is in fact, the approach our health system has used for the past decade or so, and without much success. Rates of high blood pressure in the US have remained largely steady since the late 1990s (Ostchega, et al. 2008). Taking a broader approach to the issue, by lowering sodium intake across the population can have a larger and more sustained impact.

Why? The answer can be a bit detailed and has to do with the science of prevention. But it’s well-established that making small, healthy changes across an entire population can have a much bigger impact on health than trying to greatly lower the risk in a small percentage of “high-risk” people who already have a condition. This “population-approach” runs counter to the way much of the US health care system works, which focuses so much on one-on-one care for people who already have a disease or a condition, like high blood pressure. Yet, while it’s important to continue to treat people who get sick, establishing small population-wide changes can greatly reduce or delay the number of people who actually do go on to get sick.

The biggest obstacle with the population approach, though, is figuring out how to affect such small changes across an entire population. Though people often know a lot of the steps they should take to improve their health – say, be more active, eat more fruits and vegetables, or lower their salt intake – enticing most people into doing these things can be difficult.

The sodium recommendation from the IOM is one effective way. Processed foods make up about 70 percent of the American diet, and so changing their composition would impact the health of most Americans, and in such a way that they don’t even have to think about it.

In an analysis by colleagues (Cook, Cohan et al. 1995) at Harvard Medical School, researchers compared whether they could more effectively lower rates of heart disease and stroke by taking a healthy lifestyle population approach or by offering medical treatment to all individuals whose diastolic blood pressure exceeded 95 mm Hg. What they found was that the population-based approach resulted in fewer cases of heart disease and stroke than the high-risk treatment approach.

The Harvard study found that even better than either approach alone was the combination of the two approaches, where the entire population was ‘treated’ through the food supply, and high-risk individuals received medical attention. This is what would happen if the FDA took up the IOM recommendation. The government would be facilitating a population shift in sodium intake and physicians would continue treating those with high blood pressure. Similar results have been reviewed by UK based researchers (Frost, Law et al. 1991).

Australian researchers have applied a similar model to shifting BMI and such an approach could be applied to numerous other risk factors for cancer and other chronic diseases. In the Australian study, Wendy Brown and colleagues reported that a middle of the road approach may be best. If a high-risk approach is taken where individuals in the top 20 percent are targeted for a large intervention to reduce their BMI by three units (about a 20 pound loss for someone 5’10”), diabetes is reduced by 17 percent and high blood pressure by seven percent. By shifting the whole population’s BMI by one unit (a typical prevention approach and the equivalent of altering the population’s sodium intake without also treating those with high blood pressure), they estimated diabetes would be reduced by 13 percent and high blood pressure by 10 percent. But, if a middle of the road approach is used, where those in the top 50 percent of BMI are shifted two units, diabetes decreases by 23 percent and hypertension by 12 percent -- the best scenario for both outcomes (Brown, et al. 2007).

What becomes clear from all these studies and all these data is that a population-based approach when used alongside the usual high-risk approach can have a huge affect on the health of a nation. When it comes to high blood pressure, and the burden of diseases it's associated with, it’s time to look beyond the usual and try something new. Reducing sodium in processed foods may just be the missing ingredient we need.

Related web resources:
Strategies to Reduce Sodium Intake in the United States - APHA webinar, May 4, 2010

It seems like everywhere you turn these days products are touting how much soy protein they have. In some ways this is understandable as more and more evidence shows that soy can have important health benefits, like lowering the risk of breast cancer, prostate cancer, and heart disease as well alleviating symptoms of menopause.

Unfortunately, such labeling can also be misleading because the soy sources linked to these benefits are not those in highly processed food products, rather they are in less processed sources like tofu, tempeh (a sort of soy bean patty) and plain soybeans themselves.

On their own, soybeans make a great snack and are easy to prepare and mix in other dishes (like salads and pasta).

Never had them? Don’t know where to find them? Here’s a quick guide.

Cooking up soybeans is one of the easiest snacks or side dishes around. In most grocery stores you find them in the freezer section, where they are labeled as “edamame” – the Japanese word for baby soybeans. I found this bag at my big box shopping store in their small grocery section freezer.


They are soybeans still in the pod.


You can also find them frozen and shelled, which may be easier if you intend to just toss them into a salad or pasta dish. The process of cooking them is really simple (think boiled peanuts if you’re in the south!)

Get a pot and boil some water. You don’t need as much as if you are making pasta. When the water is boiling, add a bit of salt (this part is optional, I omitted it when my kiddo was small).


Now toss in your edamame/soybeans.


When the water returns to a boil, let those cook for about 5 more minutes and then drain.


They are HOT. Be careful. At this point, if you want them to taste like they do at a Japanese or sushi restaurant, toss with more salt. I’ve never found this necessary and would rather not have such a high salt intake, so I skip it.

Pour into a bowl, and when they are cool enough to touch, just pop the pod open and eat the beans inside.


*note for parents – my toddler loved these – pureed when she was very little, and then as an early finger food. Now she shells them herself.

A new study in this month's Archives of Dermatology suggests that indoor tanning can be addicting in young adults (study) (1).  While the study was relatively small, with just over 400 participants surveyed, the results seem to bolster the need for moves toward greater regulation of the indoor tanning industry, especially through policies that curtail use by youth (related post).

The release of the study seems particularly well timed with the signing of the new health care reform bill, which institutes a 10 percent tax on all indoor UV tanning services (related post).  Raising the price point of risky items has proved a particularly effective approach in limiting certain high risk behaviors in youth.  The classic example of this is tobacco (study) (2).  As excise taxes on - and therefore the prices of - cigarettes go up, the use of cigarettes by youth go down.  Keeping smoking rates low in youth means fewer will go on to develop lifelong smoking habits.

Though tanning bed use is not as destructive, nor likely as addictive, as tobacco use, it is an activity that can have serious lifelong consequences.  Much of the melanoma (and other skin cancer) risk related to UV exposure comes  from unprotected exposure in youth and young adulthood.  Taking a cue from the tobacco control playbook and raising the cost of tanning should help a good percentage of young people decide that it's just not worth it.  And they'd be right.

Related CNiC posts
Health Care Reform and Prevention of Cancer - April 7, 2008
More Blistering Truths About Tanning Bed Use by Youths - April 5, 2008 


Related media
Washington Post: Tanning beds may get closer scrutiny based on findings about skin cancer risk - April 20, 2010


Literature cited

1. Mosher, C., Addiction to Indoor Tanning: Relation to Anxiety, Depression, and Substance Abuse. Arch Dermatol, 2010. 146(4): p. 412-417.
2. Liang, L., et al., Prices, policies and youth smoking, May 2001. Addiction, 2003. 98 Suppl 1: p. 105-22.

Lately, with health care reform being the health topic de rigueur, much of the talk about technology in health has been related to electronic medical records. But, as the presentations at the 2010 Society of Behavioral Medicine (SBM) Annual Meeting demonstrate, there is a lot more to using technology to improve health than just electronic medical records. Many of these technologies focus on cancer risk factors like physical activity, diet and diabetes.

Pedometers
Pedometers (or step counters) have been around for decades, but lately thanks to some key technological advances, pedometers have gotten a big boost. Now you can seamlessly upload your pedometer data to the web and track your progress. The declines in the cost of some technologies has also meant that more sophisticated devices that measure both the amount and intensity of exercise (called accelerometers) are more affordable. These devices track both your total steps as well as the number of those steps that are aerobic, or more vigorous. This means those dilly-dallying steps I take when slowly walking my dog in the morning don’t count toward my aerobic goal, but the faster ones I take when I’m running late to a meeting do! The latest devices update seamlessly online and allow you to both track and share your progress.

Phone-based tracking
Smart phone applications (“apps”) to allow individuals to track and monitor health behaviors are getting lots of buzz these days. Unfortunately, there aren’t a lot of data on their effectiveness yet, but expect to see that coming soon. These applications allow you to track your food intake in a real time diary (evidence does show that people who keep food diaries do better at losing weight and maintaining a healthy weight). There are also programs in the works to allow you to use the camera in your phone to track your food and caloric intake! Similar programs for physical activity diaries are also available, and we expect to see more and more advances that will link smart phones with pedometers. There are even apps (many of which are free) that let you use your iPhone as a pedometer or a GPS tracking device that can show you how far you’ve gone, how fast, and even how much up and down you’ve traveled! Most of these applications haven’t been evaluated in a research setting, but the principles that underlie them have been.

Web tools
One of the most intriguing things presented at SBM last week was on the use of social networking websites to build support in young adult populations for improving health. In particular, some promising results were presented from a team at Vanderbilt on their use of a website for adolescents with diabetes to improve management of symptoms and improving health behaviors. Expect to see more and more of these sites for kids and adults going forward. Not only do they provide a place to track your progress, but you can get tips and support from others in a similar situation. And of course, if you want a personalized risk assessment, Your Disease Risk is a powerful validated tool that gives you YOUR risk for a host of cancers, heart disease, stroke, diabetes and osteoporosis.

In results widely reported this week, a new study has found strong links between the drinking behavior of young women and adolescent girls and their later risk of developing benign breast disease, a marker of future risk for breast cancer (study link) (1).

The study, published early online in the journal Pediatrics, surveyed close to 7,000 girls and young women aged 16 - 23 years in 2003 about their drinking behavior, then followed them through 2007, tracking health outcomes.  The researchers (which included CNiC's Dr. Graham Colditz) found strong links between regular drinking and a diagnosis of benign breast disease over that period.  Drinking once or more each week significantly increased the risk of benign breast disease compared to those who drank rarely or not at all.  Drinking 3 - 5 days each week was linked to three times the risk.  Drinking 6 - 7 days each week was linked to five times the risk.

Alcohol is a well established cause of breast cancer (2).  So while the link between alcohol use and a possible increased risk of cancer later in life isn't necessarily surprising, these findings are important because they show that  behaviors in the youth and young adult years likely play very key roles in the pathways that lead to cancer. Studies of soy and fiber intake early in life show similar results (related post) (3, 4) . This growing body of evidence points to the need to boost disease prevention efforts in youth while at the same time further explore the science behind early life choices and the impact this can have on later cancer risk. 

It's been long known that youth is a key time for laying the foundation for a healthy lifestyle.  Avoiding smoking, keeping weight in a healthy range, being regularly active, and eating a healthy diet are all behaviors that, when started in youth, are more likely to carry through to adult life as well.  Now, with the results of this and other studies, the importance of fostering healthy choices in youth and young adulthood are even more compelling and something we shouldn't wait to act upon.

Related Web links
8 Ways to Stay Healthy and Prevent Disease (includes tips for parents & grandparents) 
American Academy of Pediatrics - Policy Statement--Alcohol Use by Youth and Adolescents: A Pediatric Concern (free full text)

Related CNiC posts
Despite New Results - Keep Eating Your Fruits and Vegetables - April 8, 2010  
More Blistering Truths About Tanning Bed Use by Youths - April 5, 2008 
Adolescent diet prevents breast cancer - March 18, 2010


Literature cited

1. Berkey, C.S., et al., Prospective Study of Adolescent Alcohol Consumption and Risk of Benign Breast Disease in Young Women. Pediatrics, 2010.
2. Hamajima, N., et al., Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease. Br J Cancer, 2002. 87(11): p. 1234-45.
3. Wu, A.H., et al., Epidemiology of soy exposures and breast cancer risk. Br J Cancer, 2008. 98(1): p. 9-14.
4. Su, X., et al., Intake of fiber and nuts during adolescence and incidence of proliferative benign breast disease. Cancer Causes Control.

The headlines this week about fruits and vegetables doing little, if anything, to lower cancer risk may entice you to reach for a candy bar rather than a carrot (study), but there's still plenty of good reasons to keep working on your 5 or more each day.

Most importantly, there's still very good evidence that eating a diet rich in fruits and vegetables can significantly lower the risk of heart disease and stroke - two major killers in the United States.  One 2004 study that included over 70,000 participants from the Nurses' Health Study and over 35,000 participants from Health Professionals Follow-Up Study found that those people eating eight or more servings of fruits and vegetables per day had a 30 percent lower risk of cardiovascular disease than those eating less than 1.5 servings per day (study) (1).  On top of this, studies also strongly suggest that a diet high in plant foods can lower the risk of diabetes and high blood pressure (2,3), and help keep weight in check (4,5).

In terms of cancer risk, while it's true that the recent study out of Europe that included over 400,000 people followed over eight years found only a very small benefit from eating fruits and vegetables, it's important to keep some things in mind when looking at these results (6).

First, they don't rule out a benefit for specific cancers from eating specific fruits and vegetables.  It can get fairly complicated, fairly quickly, but the European study looked at links between overall cancer risk and overall fruit and vegetable intake.  Yet, there is good evidence that some certain types of fruits and vegetables may lower the risk of some certain types of cancer.  For example, diets high in tomato-based foods have been found in previous studies to lower the risk of prostate cancer and diets rich in yellow/orange vegetables have been found to lower the risk of lung cancer (7-9).  The broad approach of the European study could have washed out such targeted benefits.

Second, the study only looked at adult intake of fruit and vegetables.  One thing that's become clear over the years is that when a person is exposed to a factor can have important implications on how it affects cancer risk. The time frame for prevention matters.  Radiation is one good example, and one mentioned in the editorial accompanying the study (editorial) (10).  The younger a person is when exposed to a given amount of radiation, the greater the impact that exposure will have on later cancer risk.  Soy intake and breast cancer risk is another prime example, with studies showing that the reduced risk linked to high soy intake may be strongest for intake in childhood and adolescence (11). The relationship could be similar with fruits and vegetables.  Eating a diet rich in fruits and vegetables early in life could have a much bigger impact on lowering cancer risk than such a diet later in life.  Looking at diet so late and only a few years before cancer is diagnosed may be looking in the wrong place. (See related post).

The results of this new study are little surprise to the scientific community, who have seen the cancer benefits of total fruit and vegetable consumption dwindle as good evidence has accumulated over the past ten years.  Yet, the overall health benefits of a diet rich in fruits and vegetables aren't in question when you look beyond cancer to heart disease, stroke, diabetes, and weight control.