March 30, 2007 - “Breast Cancer is another reason to limit beef,” reads the headline on an MSNBC story dated March 16, 2007.
Similar headlines were featured in various newspapers in response to the release of a study analysis that suggested a link between red meat consumption and breast cancer. Researchers found no link between overall cancer rates, but when they looked at only those cancers that were dependent on estrogen and progesterone, they found that women who ate one to one and a half servings of red meat a day doubled their risk of developing breast cancer when compared to those who ate three servings or less per week. Most of the news articles advised replacing meat with plant foods in light of the findings.
The researchers offered several possible explanations to explain the link between red meat and cancer: high-heat cooking methods, high fat, and, of course, the universal scapegoat, saturated fat. Conspicuously missing from the list of suspects: the fact that meat producers routinely implant animals with hormones. Since it was only hormone-dependent cancers that showed a relationship to red meat, it seems like a no-brainer to check out that connection before pointing the finger of blame.It is illegal to use hormones in pork or poultry, but cattle can be implanted with natural and synthetic estrogen and progesterone from the time they are weaned until the day they are slaughtered.
The pharmaceutical companies advertise that hormone use will provide a return of five dollars for every dollar spent by promoting faster weight gain on less feed. Dairy cattle are injected with rBGH, a genetically engineered hormone, to boost milk production. (Don’t read the next two sentences if you are squeamish.) This is a question from the Q&A page of the Posilac® (rbST) Web site: “What about the increased "pus" in the milk from cows treated with rbST?” The answer: “These cells are necessary to fight infection, and the increase noted in some POSILAC-treated cows likely reflects the slight increase in mastitis incidence and mammary cells which slough off during infection.” (OK, you can come back now.)
The European Union refused to allow the use of rBGH because of health concerns about breast and prostate cancer. Most other countries have banned its use. The EU has also banned the importation of American beef since 1988 because of concerns that the extra estrogens would cause an increase in breast cancer and that hormone-laden animal waste in the run-off from farms would pollute streams and damage wildlife.Although little research has been done on the effects of hormone use in meat and dairy products, one recent study discovered a correlation between hormones in beef and infertility. The sperm count of a group of young men was found to be inversely related to the amount of beef eaten by their mothers when they were pregnant.
Read about the study from the March 28th Journal of Human Reproduction .
A second article in the same issue, titled Could hormone residues be involved?, brings up some troubling possibilities. The US and Canada based their approval of the use of such hormones primarily on research about the mutagenic activity of the hormones. The author suggests that exposure to hormonally active chemicals could work epigenetically rather than by DNA mutation to cause disruptions at much lower concentrations. Such changes could be inherited by future generations.
The FDA has actively sided with the pharmaceutical industry to prevent label disclosure of hormone use in dairy products. You may have noticed that when a label says “No artificial growth hormones,” it will also say: “FDA states: No significant difference has been shown between milk derived from rbST-treated cows and non-rbST-treated cows.”Label disclosure of hormone use in meat is not required. The FDA has taken the position that labels only have to tell us what we need to know; and they get to decide what that is. It has been estimated that hormones are used in 80% of the beef raised in the US. If the package doesn’t say “no artificial hormones,” you must check with the company to find out if they were used. For now, if you like your position at the top of the food chain but don’t want a side serving of sex hormones, you must look for packages marked “No artificial hormones” or “USDA-certified organic” on beef, lamb, and dairy products. To read more, go to: http://www.sustainabletable.org/issues/hormones/.
Thursday, March 8, 2007
On March 7, 2007 - Just as my book was rolling off the press, a new study comparing four different diets was published in the Journal of the American Medical Association (JAMA 2007; 297: 969-977). All the major news sources featured headlines reflecting their own particular bias: “This Proves Atkins is Best Diet” said the London Times; the Seattle Times reported “Study: Women lost a bit more with Atkins.”
The scientists who designed the study expressed surprise that the Atkins diet came out on top with an average loss of 10 pounds in a year and no adverse effects. I too was surprised at the results—not that low carb was the best of the diets tested, anyone who has tried it already knows that. What surprised me was that the difference was so small. I would have expected a loss of 50 to 100 pounds if the subjects were actually following a low-carb lifestyle.
I can suggest several possible explanations for the modest, but significant, difference the study discovered in the comparison:
- The women assigned to the Atkins regimen did not actually follow the Atkins plan. According to Dr. Michael Eades, who analyzed the charts in the report, they ate 61 grams of carbohydrate per day for the first two months and then went up to 140 by the end of the study. A far cry from the 20 and 50 specified as the target amount for the two phases. On a true Atkins plan, they would have increased their carb intake in small increments in order to discover how many they could tolerate. Some may have needed to stay at a lower number while others could handle more.
- Once the participants were on their own, they all gained weight, but the low carb group had an additional disadvantage. If you check out the offerings at any typical grocery store or restaurant, you find many low fat and low calorie choices, but it is almost impossible to find low carb products, especially since there is so much sugar hidden in unexpected places. I recently bought a package of fresh pork chops from the meat counter. It never occurred to me to check the nutrition label. As I was putting it away, I noticed the carb count. Every trace of fat had been trimmed away, but the meat had been injected with sugar. When pork is bred to be as lean as possible (the other white meat), it will be tough and dry—they shoot it full of sugar to make it taste better.
- The report stated that compliance was not good in any of the groups, and although it was better for the Atkins faction, low-carb diets are fundamentally different from others. Carbohydrates cause the pancreas to secrete insulin. Insulin is required to store fat—so eat fewer carbs—store less fat. But each person has a specific upper limit beyond which this metabolic advantage is lost. A few calories more or less won’t have much effect on a low-calorie regimen, but on a low-carb plan, if you exceed your critical number, you will produce enough insulin to cause weight gain. I once asked my scientist husband to define the word “quantum” for me. In trying to put it in words I could understand, he said, “nothing happens, nothing happens, nothing happens, everything happens!” That describes the result of just a few extra carbs on a diet that allows unlimited calories.
- There is another factor that is usually not mentioned when summarizing the different diet studies. Low carb dieters never have to experience hunger since they can eat as much as they like. It is the quality of the food and not the quantity that counts. And while exercise is a good thing, it is not essential for weight loss. This has been proved many times by people who were too heavy or too sick to be able to do it. Most of the other systems limit portion size and total calories and require a lot of sweat as well. Then if you fail to lose weight, they can say it is your own fault for not working hard enough!
- Every time a study that validates low-carb as an effective way to lose weight and reduce health risks is reported in the media, you will find several quotes warning that this diet has not been tested for long periods of time and that it may prove to be unsafe after 20 or 30 years. But, hey, we’ve been testing the low-fat diet (which was never based on scientific evidence) on Americans for 30 years now, and you only have to look around to see how effective that has been!
If this study really compared a low carb diet to all the others out there, it would have beaten the pants off the competition.