Hot Dogs, Processed Meat & Colon Cancer Risk: Are Nitrates Responsible?

Last week, at the American Association of Cancer Research (AACR) conference, Dr. Sidney Mirvish presented data from a study which he interprets as strongly suggestive that nitrates are not the agent responsible for higher risk of colon cancer among those whose diets are high in processed meats like hot dogs.

Several in the media and the meat industry are hailing the data as casting doubt on the link between diets high in these foods and colon cancer.

Here’s our take, based on the comprehensive analyses of the global scientific literature found in the AICR/WCRF Expert Report, Food, Nutrition, Physical Activity and the Prevention of Cancer: a Global Perspective, and our 2011 Continuous Update Project: Colorectal Cancer.

AICR FACT CHECK: NITRATES AND COLORECTAL CANCER

1.  Nitrates are only one possible reason for the observed increased risk associated with diets high in processed meats like hot dogs, cold cuts, bacon and sausage.  You can find more information in this AICR leaflet.

2.  The findings of an individual, as-yet-unpublished study cannot change the clear and convincing evidence that AICR and WCRF have evaluated, which shows that diets featuring processed meat increase colorectal cancer risk.

3.  We at AICR welcome the kind of research that seeks to identify the agent or agents in processed meat responsible for the increased risk. Once this study, and others like it, are published and peer-reviewed, they will be added to our Continuous Update Project (CUP) — the largest scientific database on diet and cancer risk in the world — and contribute to our understanding of this issue. They may even ultimately lead to development of processed meats that can be enjoyed without cancer concerns.

4.  In the meantime, however, hot dogs and other processed meats remain foods to reserve for special occasions.


Are Hot Dogs as Bad as Cigarettes?

Citing the conclusions of WCRF/AICR’s expert report and its recent updates, the pro-vegan advocacy group called the Physician’s Committee for Responsible Medicine (PCRM) has launched a pitched campaign to raise awareness that regular consumption of hot dogs and other processed meats increase risk of colorectal cancer.

PCRM’s campaign is certainly arresting: A billboard ad that depicts hot dogs poking out of a cigarette pack has received a great deal of media attention.

Although AICR is not affiliated with PCRM or this campaign, the ad’s claims are based on WCRF/AICR’s Continuous Update Project (CUP), which built and continuously maintains the world’s largest research database on diet, physical activity, weight and cancer. A CUP report on colon cancer risk was released earlier this year, which confirmed the recommendations of an independent, international 21-member expert panel convened by WCRF/AICR.

Among those recommendations: Limit consumption of red meat to 18 ounces per week. But according to the expert panel: “The evidence on processed meat is even more clear-cut than that on red meat, and the data do not show any level of intake that can confidently be shown not to be associated with risk.” Processed meat includes hot dogs, bacon, sausage and lunchmeat.

Specifically, the CUP report concluded that, if a person eats 3.5 ounces (the size of one jumbo hot dog) of processed meat every day, their risk of colorectal cancer will be 36% higher than someone who eats no processed meat. If they eat 7.0 ounces of processed meat every day (49 ounces per week), their risk will be 72% higher, and so on.

That’s why we recommend saving processed meats for special occasions, such as a slice of ham at Easter or a hot dog at a ball game.

But let’s put that extra risk in context.

Take the example of a person eating one jumbo hot dog a day, every day. The fact that his risk for colorectal cancer is 36% higher than someone who doesn’t eat processed meat is a real cause for concern. But note that a 36% increase, while substantial, is not anywhere near the risk associated with cigarette smoking.

Smoking doesn’t simply increase risk for lung cancer, but multiplies a person’s risk by as much as 20 times, according to the CDC.

The increased risk associated with diets high in processed meat is much, much smaller than that. Even a person who eats 7 ounces, day in and day out, increases his risk by 72% — in other words, his risk doesn’t even double, let alone multiply by a factor of 20.

Here’s the bottom line:  An occasional hot dog will not cause colon cancer. What the evidence does show, however, is that making processed meats an everyday part of the diet, as many Americans do, poses clear and serious risks. That is why AICR continues to recommend avoiding processed meats.

And that’s also why finding convenient, healthful alternatives to hot dogs, bologna and other school lunch staples is so important.


An Apple a Day? Pesticides in the News

An apple.You may have seen headlines yesterday about fruits, vegetables and pesticide residues — headlines which have prompted serious questions in many people’s minds about the issue. Questions like:

1. Is there legitimate cause for concern here?

2. Should you avoid fresh produce out of concern for your and your family’s health?

The answers, respectively, are:

1. Yes, and

2. Emphatically no.

Some background: The consumer advocacy organization Environmental Working Group (EWG) released its annual Shoppers Guide to Pesticides in Produce. The Guide ranks pesticide contamination for many fruits and vegetables based on EWG’s analysis of tens of thousands of tests conducted by the USDA and the FDA.

The EWG’s Guide lists 12 produce items that contained the highest concentration of pesticide residues (“The Dirty Dozen” includes potatoes, spinach, peaches, strawberries, celery and — coming in at number one — apples).  EWG also ranked produce items that tested lowest in pesticides (“The Clean Fifteen” includes sweet potatoes, watermelon, mangoes, asparagus, pineapples, corn and — the cleanest of the bunch — onions).

What’s the Bottom Line?

EWG isn’t advocating avoiding produce. Their take-home message — which didn’t make it into much of the more sensationalist press coverage, alas — is very clear:

“Eat your fruits and vegetables! The health benefits of a diet rich in fruits and vegetables outweigh the risks of pesticide exposure. Use EWG’s Shopper’s Guide to Pesticides to reduce your exposures as much as possible, but eating conventionally-grown produce is far better than not eating fruits and vegetables at all.”

On this, AICR and EWG agree.  Our expert report on cancer prevention, and its updates, make clear that everyone’s priority should be on getting more vegetables and fruits into the diet — get them fresh, canned or frozen, get them organic or conventional, but get them.

If you can afford organic, and are concerned about pesticide residues — or opt for organic for other reasons such as issues of land and water use — do so. If you can’t, know that the cancer protection you’re getting from eating a variety of vegetables and fruits outweighs the potential risks associated with pesticides.

This is a notoriously difficult area to study. There is evidence linking high doses of pesticides to cancer in the laboratory, and to cancer in farm workers and others who are professionally exposed to high levels of pesticides over many years. But we still lack evidence from human studies that pesticides cause cancer at the levels they exist in US diets – a country where pesticide use is regulated.

Watch this space – we’ll know more as methods of studying this hot topic improve. In the meantime, get your vegetables and fruits however you choose to, rinse them thoroughly … and don’t shun that Red Delicious.