HOW TO PREVENT CANCERS

The CNiC cooking team is fortunate to have numerous wonderful resources to draw on when looking for healthy recipes that incorporate the cancer prevention principles that make up our 8 Ways to Prevent Cancer. When talking to others about these approaches, I'm often asked how much extra time and effort is required to cook this way. Thanks to New York Times columnist Mark Bittman, I don't even have to answer that question myself anymore - Bittman explains it all - accurately, honestly and with great perspective, in his new cookbook - The Food Matters Cookbook.

Bittman's book is full of solutions to make the choices easier - like how to substitute the herbs you have in the house for the ones in a recipe so you aren't spending $25 a week on fresh herbs to add flavor to food without lots of meat, dairy, or calories. There are also great suggestions on protein substitutions, vegetable substitutions and substitutions to make recipes vegan. The recipes aren't fussy - Bittman's style is simple yet flavorful.

There is a role for all kinds of eating in Bittman's cookbook - it is based on his personal approach to eating and he is a food writer after all!

If you are thinking about making some changes to your diet - incorporating more whole grains, eating more fruits and vegetables, eating less meat and getting your protein from other sources, cutting back on processed foods - this cookbook provides all the tools you need.

Related CNiC Posts
Recipes
Diet
Weight

Related Links
Your Disease Risk - Risk Assessment
Cancer Prevention - Google Knol
8 Ways to Stay Healthy and Prevent Cancer (PDF)
Mark Bittman (blog plus)

Recently, there’s been a lot of chatter on the blogosphere about sneaking vegetables into kid’s food. This practice gained notoriety a few years back with the publication of cookbooks by both Jessica Seinfeld (wife of Jerry) and Missy Lapine (“The Sneaky Chef”) and came back into the conversation with the publication of another cookbook by Ms. Seinfeld. Plenty has been said about the potential merits and potential harms of this practice - from mom chefs/bloggers like Stacey at one hungry mama to nutrition powerhouses like Marion Nestle.

Why does this matter for cancer prevention? Because eating vegetables matters for cancer prevention. Eating fruits and vegetables is one of our key 8 ways to prevent cancer. Some fruits and vegetables have specific benefits for specific cancers – like tomatoes and prostate cancer. But fruits and vegetables are also important for healthy weight management – they provide lots of fiber (bulk) without a lot of calories – that means you feel full without taking in a lot of calories. That’s why most weight management programs encourage eating lots of them and focus on counting the other items you are eating. Those other items are the calorie high ones that add up.

Dr. Nestle points to some other alternatives for encouraging kids to eat vegetables that don’t involve deception based on behavioral economic principles and the research of Dr. Brian Wansink. She also points out that parents have the responsibility to decide what kids eat.

There are some really great strategies at work among the CNiC families – many of which have been written about or suggested elsewhere – having kids help grow the vegetables increases their interest in eating them; serving fruits and vegetables at every meal; giving kids a role in choosing which vegetables to eat, but not whether vegetables are consumed; focusing dessert on fruit not processed baked goods; including fruits and vegetables in other dishes in an open and transparent manner; making meals colorful using fruits and vegetables.

What do you think? Is there a role for deception or sneakiness in a health promotion/disease prevention diet to boost fruit and vegetable consumption? What strategies do you use to get kids to eat fruits and vegetables?


Related CNiC Posts
Recipes
Diet
Weight

Related Links
Your Disease Risk - Risk Assessment
Cancer Prevention - Google Knol
8 Ways to Stay Healthy and Prevent Cancer (PDF)

Last week new data were released adding to the evidence on the harmful effects of hormone therapy on breast cancer incidence and mortality (story). This timely report released in October when so much media attention focuses on breast cancer detection, treatment and prevention, brings further evidence to show how hormones cause breast cancer. Here I put these results in some perspective of findings from studies over the past 20 years.

Numerous studies that have evaluated trends in breast cancer over time consistently show that since the result of the Women’s Health Initiative were published in 2002 rates of breast cancer have declined in parallel with the drop in use of combination estrogen plus progestin (Prempro). Combination therapy, estrogen plus progestin, causes breast cancer and is classified as a carcinogen by the IARC (International Agency for Research on Cancer 2007). Strong evidence that use of hormone therapy can act as a late promoter of cancer in women comes from evidence relating unopposed estrogen and endometrial cancer. With the acknowledgment of this cause and effect relation in the 1970s, a sharp drop in estrogen prescribing led to a parallel rapid decrease in incidence of endometrial cancer (Austin and Roe 1982). Uptake of estrogen plus progestin therapy was somewhat slow, and epidemiologic data in the US were limited in their ability to separate effects of combination therapy from that of unopposed estrogen. However, by 1995 prospective data from the Nurses’ Health Study indicated that estrogen plus progestin therapy was not protective against breast cancer and the increase in risk may be greater than for estrogen alone (Colditz, Hankinson et al. 1995). Furthermore, mortality from breast cancer was significantly elevated in women who had used hormones prior to diagnosis. Estrogen alone remained the treatment of choice for women without a uterus. Between the mid-1970s and the mid-1980s, incidence of estrogen receptor-positive tumors increased an average of 131% in the population-based tumor registry of Kaiser Permanente in the United States (Portland, OR), perhaps implicating hormonal factors in the rising incidence of breast cancer (Glass and Hoover 1990).

Epidemiologic studies (Ross, Paganini-Hill et al. 2000; Schairer, Lubin et al. 2000) during the 1990s show that combination E&P therapy significantly increased risk, and that this was most evident among leaner women who would have lower starting estrogen levels prior to use of postmenopausal hormone therapy. Recommendations based on these findings were for women to avoid progestins if possible (Willett, Colditz et al. 2000). A broad range of epidemiologic studies continue to support the causal relation between combination E&P and total breast cancer. Meanwhile, some investigators focused on the increase in lobular cancer (Li, Weiss et al. 2000; Li, Anderson et al. 2003) – these tumors are predominantly estrogen receptor positive and so would reflect a signal from hormone therapy more precisely than the more common form of breast cancer, ductal cancer, that is estrogen receptor positive only about 70 percent of the time. Overall, studies of receptor positive tumors show that combination therapy clearly increases risk (Glass and Hoover 1990).

In 2002, the Women’s Health Initiative confirmed the epidemiologic findings relating combination hormone therapy to increased risk for breast cancer. In this trial there was substantial non-adherence to therapy, which would reduce the ability of the study to detect an effect. In fact some 40% of the women randomized to take estrogen plus progestin (PremPro), stopped taking the drug. The independent Data Safety Monitoring Board stopped the trial early due to the adverse effect of therapy on breast cancer (Rossouw, Anderson et al. 2002). The results were consistent with the HERS trial and epidemiologic data showing an increase in risk of breast cancer in the initial 2 to 5 years of use. Importantly, risk increased significantly with duration of use; the longer a woman used hormones the greater her risk of breast cancer.

Based on data from the San Francisco mammography registry, prescribing of E&P peaked in 1999. Before publication of HERS the use of hormone therapy was increasing at 1% per quarter, but declined by 1% per quarter after the publication (Haas, Kaplan et al. 2004). This decline in prescribing continued until the publication of the WHI in 2002, at which point a more substantial decline of 18% per quarter was observed. The peak and decline through 1999 to 2002 is concordant with the HERS report (Hulley, Grady et al. 1998) in 1998 showing a significant increase in CHD in the first year of therapy among women with prevalent coronary disease, and in addition, no long-term benefit in reducing CHD (Grady, Herrington et al. 2002). The growing epidemiologic evidence published since 2000 on the adverse effects of combination therapy on breast cancer added further evidence against the use of this therapy. Bases on the level of use of combination hormone therapy in California, Tina Clarke and colleagues estimate that 11 percent of all breast cancer was being caused by use of hormone therapy (Clarke, Purdie et al. 2006). Since risk increases with duration of use, this estimate of the proportion of cancers caused by hormone therapy is likely conservative.

The most recent report from the Women’s Health Initiative, addressing mortality from breast cancer, shows that risk is elevated among the women who took estrogen plus progestin therapy (study). Investigators followed participants for 11 years. Among the 16,000 women in the study those randomized to estrogen plus progestin had twice as many deaths from breast cancer as seen in the women who took placebo. This, of course, is counter to the substantial marketing effort by the manufacturers who have been shown to have ghost written articles for gynecologists to advocate for hormone therapy as safe since it only causes “good cancers” that respond adequately to treatment. This literature and the academic physicians paid to write for the industry are summarized by Dr. Fugh-Berman and is available online (article). She summarizes evidence from industry documents showing how the pharmaceutical company Wyeth used ghostwritten medical journal articles to mitigate the perceived risks of breast cancer associated with hormone therapy. The WHI results published last week confirm previous epidemiologic data on the mortality effect of hormone therapy and rule the reassurance from the industry as only a marketing ploy not a truthful message for women.

With the evidence at hand, use of hormone therapy for menopausal symptoms should be extremely limited, if used at all. Combination therapy is more harmful than unopposed estrogen and is not indicated for women who do not have a uterus. As we have noted previously, hormone levels within a woman after menopause are directly related to risk of breast cancer. Weight loss through energy restriction and increase in physical activity is the best natural way to reduce these hormone levels and significantly reduce risk of breast cancer (related post).

This story from the New York Times on what health promotion items get tax breaks is sure to spark some heated comments, and it should (story).

The IRS has ruled that Americans can get tax breaks on denture adhesive and acne cream, but not on breast pumps and other nursing supplies because "breast-feeding does not have enough health benefits."

As we have noted here before, breast feeding is associated with lower risks of breast and ovarian cancers. And we didn't even get into the numerous benefits for the child that the Times mentions, which might include a lower risk of breast cancer in female children.

Despite calls for health care reform to focus on prevention, there is clearly work to be done in improving the quality of the evidence base supporting it. What do you think? Should breast pumps be covered?

Related CNiC Posts
Breast Cancer
Health Policy

New evidence has emerged that adds further insight into the risks and benefits of aspirin for prevention of colorectal cancer. Aspirin has been extensively studied in observational epidemiologic settings that address duration of use, dose, and magnitude of risk reduction. The observational evidence is consistent with evidence from randomized primary prevention trials, which have shown that use of at least 300 mg of aspirin per day for at least 5 years is effective in preventing colon cancer, reducing risk by about 25% (Flossmann and Rothwell 2007). A latency of about 10 years is observed. Like all chemoprevention strategies, risks and benefits must be balanced (Glasziou and Irwig 1995). To date, the risk-benefit considerations of cardiovascular disease, bleeding complications, stomach pain, and heartburn have precluded recommendations for aspirin use as a widespread prevention strategy (Gralow, Ozols et al. 2008; Cuzick, Otto et al. 2009).

In the Lancet, a new study combining data from four randomized trials of aspirin versus control in both primary and secondary prevention of vascular events evaluated risk of colorectal cancer over 20 years (study). A fifth trial compared doses of aspirin. After combining the data on individuals in these five trials the investigators observed that aspirin use reduced the 20-year risk of colon cancer but not rectal cancer. Risk of cancer was reduced by 25% and colon cancer mortality was reduced by 35%. Similar to previous reports, benefit of aspirin use increased with duration of use indicating that aspirin use operates early in the pathway to colon cancer and leading to long-term therapy as the necessary approach for prevention of colon cancer. This study, in contrast with previous evidence suggests that the benefit for colon cancer prevention is obtained with as little as 75 mg per day.

Importantly, this study separately evaluated colon cancer rectal cancers. We have previously shown that the risk factors for these two cancers sites vary substantially (Wei, Giovannucci et al. 2004). The evidence for aspirin adds further support for strategies to be specific to risk, particularly among those who are at increased risk, as is the case for family history.

Chalk another one up for the power of prevention.  While it's easy to give in to the "heredity is destiny" mindset when it comes to diseases like breast cancer, new research from the Women's Health Initiative suggests that women can take positive steps to lower their risk of breast cancer even if they have a family history of the disease.

The study, released early in the journal Breast Cancer Research (link) and reported yesterday on futurity.org (link), followed over 85,000 postmenopausal women who were part of the federal Women's Health Initiative Observational Study.  Researchers classified women by family history - those with a first degree relative (sister, mother) who had breast cancer after the age of 45, and those without - and by health behaviors - those who maintained a healthy weight, exercised regularly, and drank less than one alcoholic drink per day, and those who did not.

What they found after over five years of followup was that a woman's family history had no significant affect on the benefits linked to a healthy lifestyle.  Women with a family history who did all three healthy behaviors (weight, exercise, alcohol) saw drops in their breast cancer risk compared to women with a family history who did none of the healthy behaviors.  The same relationship held for women without a family history.

While the results indicated that a healthy lifestyle didn't lower the risk directly linked to family history, they do show that leading a healthy lifestyle should be an important goal for all women, including those with a family history of the disease.

Breast health tips for all women include:

• Maintaining a healthy weight throughout life
• Exercising regularly
• Drinking only moderately (less than 1 drink/day), if at all
• Avoiding long-term use of postmenopausal hormones, especially those with estrogen plus progestin
• Getting screened regularly - clinical breast exams in 20's and 30's, with annual mammograms added in 40's.

To get an estimate of your breast cancer risk as well as personalized prevention tips, visit Your Disease Risk.

Fifteen years after its ground-breaking expose’ on the dietary train wreck that is movie theater popcorn, the Center for Science in the Public Interest has published results of a new study showing that little has changed when it comes to the cinema-show favorite “snack” (report). The popcorn choices carried by most major theater chains range from 400 – 1200 calories and are packed with salt and “essentially fried in one to three days’ worth of saturated fat.” Other standard snack choices fair little better, with CSPI concluding that the best movie-time snack choice is no snack at all. No argument here.

The problem with popcorn, though, is in the preparation, not the grain itself. Popcorn is actually a whole grain food – which isn’t widely known – and if it’s popped at home in an air popper or over the stove with a small amount of healthy oil like canola oil, it can be a very healthy and tasty snack. Add just a dash of salt (not too much) and you’ll feel like you’re in a darkened theater waiting for the previews - and without the calories, saturated fat, and sodium of three fast food hamburgers.

New research results out today suggest that 1 in 13 colon cancers may be missed on colonoscopy. There are a few reasons this may happen - some you can control and some you can't. Completing the colonoscopy prep is one you can control - having a clean, prepped colon reduces the changes that a tumor is missed during the exam. But the results also highlight that colon cancer screening is just one part of colon cancer prevention.

A study from Wei and colleagues showed that even among those who are compliant with colon cancer screening recommendations, other lifestyle factors (maitaining a healthy body weight, limiting red and processed meat intake, regular physical activity, taking a folate supplement) contributed to a significant risk reduction.


This means even if you get the "all clear" after a colonoscopy, you shouldn't sit back and think you've done all you can. You've taken a great first step, so use that momentum to make other healthy choices too.

Breast cancer prevention means taking action now. We talked about awareness earlier this week and have discussed drug strategies to reduce risk of breast cancer in high risk or postmenopausal women. But for every woman there are things to do now to lower risk.

1. be active - increase your level of physical activity
2. maintain a healthy weight
3. cut down on the amount of alcohol you drink

The LA Times has a provocative new article out that seems to rail against breast cancer awareness month.

What are the criticisms?
- Since the breast cancer awareness campaign started, age-adjusted rates have remained largely flat.



- Talking about "breast cancer" ignores all of the research done to date that shows there are many different types of breast cancers, with very different etiologies and treatment paths. In particular, screening likely has very different effectiveness for different types of breast cancers.

- Promoting early detction, as the campaign does, leads to unnecessary diagnostic testing and treatment. (it is interesting to note that the major sponsor of breast cancer awareness month is a chemotherapy drug maker)

So is it time for the message to be changed? We addressed this, to some extent, in a previous CNiC post - when we talked about the "campaign" to list your bra color on social networking sites to promote breast cancer awareness.

Instead of focusing on awareness of the second most common cancer among women, why not focus energies to something more specific - like increasing enrollment in research studies and clinical trials, as advocated by Dr. Love, Avon and their Army of Women, which has opportunities for breast cancer survivors, those without cancer but who may have an increased risk, and individuals with no cancer history. OR, by focusing on primary prevention of cancer - not just early detection.

And breast cancer is preventable -- maintaining a healthy weight, participating in regular physical activity, and avoiding excess alcohol intake all reduce risk. Research shows that losing weight reduces the risk of overweight and obese women, so it isn't too late to start.