by Marion Nestle

Currently browsing posts about: Cancer

Jun 12 2019

Bayer defends glyphosate

This is the second full-page ad like this I’ve seen in the New York Times.  This one is from June 4.

As far as I’ve been able to tell, ads like these cost on the order of $85,000 or so.

Bayer, you may recall, bought Monsanto some months ago along with all its baggage (some of which is increasing doubts about the safety of glyphosate for human health).

The ad quotes the EPA as saying that glyphosate is “not likely to be carcinogenic to humans, the agency’s most favorable classification.”

Perhaps, but other agencies—and the courts—come to quite different conclusions.  As the Financial Times explains, Bayer’s

weedkiller woes offer two cautionary tales. The first is the high reputational and financial cost of trying to distort the scientific record. Monsanto’s perceived attempts to game the literature prompted the jury to award punitive damages. Questionable practices allegedly included “ghostwriting” papers: persuading outside academics to put their names to internally written, more flattering research, then publishing in scientific journals.

The second cautionary tale has to do with glyphosate’s induction of weed resistance.

Bayer stocks are not doing well.  Its stockholders are complaining.

Bayer faces more than 13,000 lawsuits over cancers claimed to be caused by glyphosate.

Hence: these ads.

Dec 11 2018

Eat organics, reduce cancer risk?

I rarely post anything about agricultural chemicals, mainly because it’s so hard to find people who are not exposed to them, most people are exposed only to small amounts, and the industry that makes them is so fierce about casting doubt on the quality of any research demonstrating harm.

But here is a French study comparing the risk of getting cancer among people who consume conventional diets with those who mainly consume organic foods.  Organics are relatively free of the most potentially harmful pesticides and herbicides.

The key points of this study:

Question  What is the association between an organic food–based diet (ie, a diet less likely to contain pesticide residues) and cancer risk?

Findings  In a population-based cohort study of 68 946 French adults, a significant reduction in the risk of cancer was observed among high consumers of organic food.

Meaning  A higher frequency of organic food consumption was associated with a reduced risk of cancer; if the findings are confirmed, research investigating the underlying factors involved with this association is needed to implement adapted and targeted public health measures for cancer prevention.

The authors’ offer this as the most likely explanation:

…the prohibition of synthetic pesticides in organic farming leads to a lower frequency or an absence of contamination in organic foods compared with conventional foods46,47 and results in significant reductions in pesticide levels in urine.48

They also note that the International Agency for Research on Cancer finds certain agricultural chemicals (most notably glyphosate / Roundup) to be probable or possible carcinogens.

As for opposition, the American Council on Science and Health (ACSH), an industry-sponsored group that can always be counted on to defend chemicals in the food supply, offers this detailed critique of the study.

Yes, of course we need more research on this question, and the sooner the better.

In the meantime, this study provides another good reason for choosing organic foods whenever you can.

References

46. Barański  M, Srednicka-Tober  D, Volakakis  N,  et al.  Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses.  Br J Nutr. 2014;112(5):794-811. doi:10.1017/S0007114514001366

47. Smith-Spangler  C, Brandeau  ML, Olkin  I, Bravata  DM.  Are organic foods safer or healthier?  Ann Intern Med. 2013;158(4):297-300. doi:10.7326/0003-4819-158-4-201302190-00019

48. Science and Technology Options Assessment. Human health implications of organic food and organic agriculture. http://www.europarl.europa.eu/RegData/etudes/STUD/2016/581922/EPRS_STU%282016%29581922_EN.pdf. Accessed May 28, 2017.

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May 30 2018

Diet and cancer risk: the latest research evidence

The World Cancer Research Fund and the American Institute for Cancer Research have published their third compendium of information about diet and cancer risk.

By this time, their research base is so enormous that it takes them 12,000 pages to cover it.   The summary alone is more than 100 pages.

Consequently, they have created an online toolkit with a matrix for dealing with the information.

The matrix provides an interactive summary of dietary correlates .  Here is a clip from the section on factors that decrease cancer risk, convincingly or probably.

And here is a clip from the section on dietary correlates of increased cancer risk.

On the website, you can click on the bubbles to be directed to pages discussing the evidence for each of these factors.

The bottom line?  Eat your veggies.  Don’t gain excess weight.  Avoid excess alcohol and processed meats.  Be active.

Very handy, this.

The site also provides further information about these particular factors:

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Nov 2 2015

WHO clarifies meat-and-cancer report

The World Health Organization has issued a statement of clarification of the significance of its International Agency for Research on Cancer (IARC) report on the increased risk for colorectal cancer from eating processed and red meat (see my post on this).

The latest IARC review does not ask people to stop eating processed meats but indicates that reducing consumption of these products can reduce the risk of colorectal cancer.

Got that?

The New York Times explains the meaning of this increased risk.  To understand it, you need to know the risk of colorectal cancer among people who never eat processed or red meat.

The main problem with the public health messages put out by the W.H.O. is that the agency did a poor job of explaining what its risk-ranking system really means…it’s based only on the strength of the overall research, not on the actual danger of a specific product…Even the most strident anti-meat crusader knows that eating bacon is not as risky as smoking or asbestos exposure. Smoking raises a person’s lifetime risk of developing lung cancer by a staggering 2,500 percent. Meanwhile, two daily strips of bacon, based on the associations identified by the W.H.O., would translate to about a 6 percent lifetime risk for colon cancer, up from the 5 percent risk for people who don’t enjoy bacon or other processed meats.

My interpretation: Can processed and red meats be included in healthful diets?  Yes, of course.  But for many reasons, people and the planet would be healthier if these foods were consumed in smaller portions, less often.

Oct 27 2015

Some comments on the meat-is-carcinogenic report

Yesterday, the World Health Organization’s International Agency for Research on Cancer (IARC) issued a warning about the carcinogenic potential of processed and red meat.  This, as you might expect, caused a media flurry.  CNN News asked me for a written comment.  They titled it “The other benefit to eating less red meat.”  Here’s what I wrote:

The just-released report from the International Agency for Research on Cancer judging processed meat as clearly carcinogenic and red meat as probably carcinogenic has caused consternation among meat producers and consumers.

Meat producers do not like the “eat less meat” message. Consumers do not want to give up their bacon and hamburgers — delicious and also icons of the American way of life.

But these judgments should come as no surprise to anyone. Eating less processed and red meat has been accepted dietary advice since Ancel and Margaret Keys wrote their diet book for heart disease prevention, “Eat Well and Stay Well,” in 1959. Their advice: “restrict saturated fats, the fats in beef, pork, lamb, sausages …” They aimed this advice at reducing saturated fat to prevent heart disease. Federal committees and agencies have continued issuing such heart-disease advice to the present day.

Cancer entered the picture in the 1970s, when scientists began to link red meat — beef, pork, lamb — to the risk of cancers of the colon and rectum. Even after several decades of research, they had a hard time deciding whether the culprit in meat was fat, saturated fat, protein, carcinogens induced when meat is cooked to high temperatures or some other component.

In the mid-1990s, dietary guidelines committees advised eating lean meats and limiting intake of processed meats, still because of their high fat content. By the late 1990s, cancer experts said that red meat “probably” increases the risk of colorectal cancers, and “possibly” increases the risk of cancers of the pancreas, breast, prostate and kidney. The IARC report, based on more recent evidence, makes even stronger recommendations and favors carcinogens as the causative factors.

To put this in context: For decades, the meat industry’s big public relations problem has been that vegetarians are demonstrably healthier than meat eaters. People who do not eat red meat havemuch less of a chance of developing heart disease and bowel cancers than the average American.

More recently, the 2015 Dietary Guidelines Advisory Committee (DGAC) found diets “higher in red/processed meats…” to be associated with a greater risk of colorectal cancer, and it recommended dietary patterns and low in red and/or processed meats, but higher in vegetables, fruits, legumes, whole grains, lean meats/seafood and low-fat dairy — largely, but not necessarily exclusively, plant-based.

This is good advice for anyone.

Eating less red and processed meats has two benefits: a reduced risk for certain forms of cancer,and a reduced effect on climate change.

The DGAC deemed eating less red meat to be exceptionally beneficial to the environment as well as to human health. The IARC report strengthens the health component of the recommendation. The secretaries of USDA and Health and Human Services, however, have refused to allow environmental concerns to be considered in the 2015 dietary guidelines.

I mention the dispute over environmental “sustainability” in the dietary guidelines because largely plant-based diets are appropriate for all kinds of health concerns — obesity, type 2 diabetes, coronary heart disease and now, especially, colorectal cancer — as well as environmental concerns.

By eating less red and processed meats, you promote both your own health and that of the planet.

At issue then is how much red and processed meat is compatible with good health. The IARC commission ducked that question, although it cites evidence that as little as 100 grams (a quarter pound) of red meat a day, and half that much of processed meats, increases cancer risk by 15% to 20%.

Will an occasional hamburger or piece of bacon raise your risk that much? I don’t think so. But the evidence reviewed by IARC strongly suggests that if you do eat meat, eat less when you do, don’t eat meat every day, save processed meats for rare treats and be sure to eat plenty of vegetables.

Fortunately, this advice leaves plenty of room for delicious meals — just with meat taking up much less room on the plate.

Other comments

Jun 18 2014

Time Magazine: “Eat Butter.” Maybe in moderation, please?

I love butter as much as the next person, but when I went to New York’s Food Fest yesterday, the butter makers were all proudly displaying Time Magazine’s provocative June 23 cover.

INTcover0623LR.jpg

The cover story is by Bryan Walsh.

It comes with an even more provacative video–one of those “everything you thought you knew about diet is wrong” things.

I’m quoted in his article, but I wish he had quoted more of my comments about context.

He says saturated fat consumption is down, but heart disease is still the number one killer of Americans.

Yes it is, but not nearly as much as it used to be (as I discussed in a previous post):

Americans must be doing something right.

The big problem is type-2 diabetes.  It’s going up in parallel with obesity: Fat calories and sugar calories contribute to obesity.

The dietary bottom line?  Eat your veggies, balance calories, and stay active.

Really, it’s not more complicated than that.

But that kind of advice will never make the cover of Time, alas.

Addition, June 20: David Katz on how easy it is to misinterpret studies of saturated fat (or sugars for that matter) and health.

Jan 22 2014

The latest cancer statistics

Every year, CA–A Cancer Journal for Clinicians publishes an annual review of cancer statistics.

The report has some good news: trends in the overall death rates from cancer show significant declines, for both men and women.

The overall incidence (new case) rates are holding steady or a down a little since 1990,but are still above the rates in 1975.

The incidence patterns differ for cancers at different sites:

Screenshot 2014-01-21 12.05.13

In men, lung cancers are down undoubtedly due to less cigarette smoking.  Prostate and colorectal cancers are down, perhaps due to favorable dietary changes.

In women, lung cancers have leveled off and colorectal cancers are down, but breast cancers don’t seem to budge.

As for the comparison to heart disease, that’s interesting too.  In 2005, cancer surpassed heart disease as the leading cause of death in people younger than age 85.

Plenty of good news here, but plenty more to be done.

Oct 23 2012

Multivitamins prevent cancer (maybe), sell supplements (definitely)

According to a new study in JAMA, multivitamins might reduce the risk of some cancers, although not by much.

But even a tiny benefit, restricted to skin cancers in healthy male doctors—but not prostate cancers, alas—is good news for the supplement industry.  Supplement sellers are eager to make sure you don’t miss this research.

The study results came out on October 18.  Pfizer, the maker of the Centrum Silver pills used in the study, placed this ad in the New York Times on October 19:

But that’s not all.  CVS pharmacy sent me this personal e-mail message:

Pfizer, of course, could not be happier.

Why do I think this is about marketing, not public health?