Hormones and Nitrites and Antibiotics, Oh My!!

When the National Academy of Sciences released its report, Possible Health Effects of Exposure to Residential Electric and Magnetic Fields, it demonstrated how true scientists ought to behave. Unfortunately, such behavior has been rare in the realm of human nutrition. This report was the results of an exhaustive three-year review of the possible health effects of exposure to residential electromagnetic fields (EMF). “Our committee evaluated over five hundred studies,” the committee chair Charles Stevens said, “and in the end all we can say is that the evidence doesn’t point to these fields as being a health risk.” What’s remarkable is that the review panel had been “generally viewed as packed with scientists who might have reason to prefer that the controversy not be quite resolved” (Park, 2000).

The vice chair of the panel was an epidemiologist who had staked his reputation on a link between EMF and cancer. Perhaps half of the sixteen panel members were involved in research related to the health effects of EMF. A report refuting the purported health effects of EMF would likely lead to the elimination of funding for their research. They might be inclined to decide it was better to err of the side of caution and simply call for more research, as some previous groups had done.

Despite this potential conflict of interest, the panel unanimously concluded that “the current body of evidence does not show that exposure to these fields presents a human health hazard.” And if this had just been a matter of science, that should have settled it. But there were others involved in the issue who had their own interests. For years reporters had been writing stories about EMF-hazards from power-lines and residential wiring. Newsletters were devoted entirely to the EMF-health issue. For them, the controversy was their livelihood. For these folks to now write that it had all been a false alarm would have been miraculous. And, as history shows, that did not happen.

Whatever the scientific failings of various researchers in the diet-nutrition-human health scandal of the last half century, there is an equally culpable group of individuals who’ve made their livelihood from perpetuating various myths about what a “healthy” diet ought to be. Largely this has been a call to reduce our consumption of animal products, and to reinforce their arguments they perpetuate myths about our food supply. Let’s consider the subjects of antibiotics, nitrites, and antibiotics in meat produced by “conventional” practices in the United States.

Image from zmescience.com

Hormone-Free?

Many have cited the presence of hormones in animal products as a reason for buying organic products or avoiding them altogether. First of all, there is no such thing as hormone-free food. All multi-cellular organisms contain hormones, whether they are cattle, cabbages, chickens — or people. Livestock and poultry can be grown without added hormones, but they cannot be hormone-free. Federal law prohibits the use of hormones in poultry and swine production, so the next time you see “No added hormones” on a package of chicken or pork, realized that you’re looking at another example of a “guaranteed not to turn pink in the can” claim. It’s factually true, but misleading. It implies that some pork or chicken is produced with added hormones.

Hormones like estrogen are used in modern beef production to increase the amount of lean beef that can be harvested from cattle. These hormones are the same as, or synthetic versions of, those naturally produced by cattle. But the amount of estrogen in beef, from either implanted or non-implanted steers, is a fraction of what is found in soybean oil, wheat germ, eggs, and what is produced by the human body (Rains, 2009).

Table 1. Estrogenic activity of common foods (ng/500g)

(Hoff man and Eversol, 1986, Hartman et al, 1998, Shore and Shemesh, 2003, USDA-ARS, 2002) Units are nanograms (ng) of estrone plus estradiol for animal products and isoflavones for plant products per 500 grams of food

Note: Beef from non-implanted heifers and cows, either open or pregnant, would have higher estrogen content.

Table 2. Estrogenic production in humans, and potential estrogen intake from implanted beef

(Hoffman and Eversol, 1986)

Okay, so both plant and animal products contain hormones, but plant hormones don’t affect mammals, right? Wrong! The fact that phytoestrogens (estrogenic substances from plants) can produce effects in mammals has long been known. Bennetts et al. (1946) described severe clinical abnormalities in sheep grazed on highly estrogenic subterranean clover (Trifolium subterraneum) pastures. This syndrome, called “clover disease,” included very low lambing rates, prolapsed of the uterus and dystocia in ewes and enlargement of the bulbo-urethral glands and death in the wethers. (It should be noted that this herbage was extraordinarily high in phytoestrogen, as much as 5 percent of dry matter.)

While there is a wide-spread belief that residues of growth-promoting hormones in milk or meat might cause early puberty or increased height in children, the data strongly suggests that this cannot be the case. Tom Naughton says that math is one way we can tell if we’re being lied to. So let’s do some math!

We can calculate how much beef from hormone-implanted cattle a pre-puberal boy or girl would need to consume to have sex hormone levels equal to those of adult men or women.

(1) Given that pre-puberal and adult males produce 65,000 and 6,400,000 ng of testosterone per day, respectively, and that steak from a steer given testosterone contains 0.9 ng of testosterone per 3 ounces of meat, a boy would need to consume 1.3 million pounds of implanted beef per day to consume sufficient testosterone to achieve an adult’s level (Smith, 2011).

(2) Given that pre-puberal and adult females produce 41,000 and 513,000 ng of estrogen per day, respectively, and that steak from a steer given estrogen contains 1.9 ng estrogen per 3 ounces of meat, a girl would need to consume more than 46,000 pounds of implanted beef per day to consume sufficient estrogen to achieve an adult’s level (Smith, 2011).

And it should be noted that oral estrogens generally have poor bio-availability (0.1-12%) due to extensive metabolism after absorption from the gut (Oral testosterone and progesterone are also reported to have low bioavailability) (Doyle, 2000). Since both of the proceeding calculations assume 100% absorption of the hormone from the digestive system, the amount either child would need to eat would be almost 10 times greater!

While Europe has banned the importation of hormone-treated beef from the U.S. and other countries, this is a political/economic issue NOT a scientific one. The World Organization for Animal Health and the Codex Alimentarius Commission (the FAO/WHO Food Standards Commission) have affirmed that hormone use in cattle production is safe for consumers (McEwen and McNab, 1997, FAO/WHO 1999, 2009). Unfortunately, European political bodies have rejected the science and refused to lift the ban, in large part to protect their producers from U.S. competition. That’s fair as a political issue, but not if it’s clothed in unfounded health concerns.

"Uncured"?

Another theme in the “animal products are bad for you” narrative is that nitrite in cured meat is linked to diseases like cancer. Rather than spend time explaining the true meaning of the word “linked” in this connection, I highly recommend that you view Tom Naughton’s video Science for Smart People. In response to this reputed health-risk, many consumers avoid cured meat products. Numerous products are now available which are labeled “uncured.” What does this product claim mean? Are nitrites actually harmful?

Image from unbreaded.com

Nitrite plays a very important role in cured meats by preventing the growth of Clostridium botulinum, which can cause the deadly disease botulism, and preventing spoilage. In addition, it gives cured meats their characteristic color and flavor. The U.S. Department of Agriculture (USDA) allows no more than 156 parts per million (ppm) nitrite in curing meat products, with 120 ppm the commonly used amount. But that’s the amount used in the process. The amount in the final products is typically 10 ppm (AMI, 2008, Sebranek and Bacus, 2007).

Less than five percent of our daily nitrite intake comes from cured meats like ham, bacon and hot dogs. Ninety-three percent comes from leafy vegetables and tubers. Vegetables contain nitrate which is reduced to nitrite when it comes into contact with saliva in our mouths. Table 3 lists the amount of nitrate found in some vegetables (AMI, 2008):

Table 3. Nitrate content of selected vegetables

Some uncured products are available today that use ingredients like beet or celery juice or natural sea salt instead of sodium nitrate. These “natural” products all contain nitrate. When this nitrate is exposed to certain types of bacteria in the product, it is converted to nitrite, producing a product with similar color and taste to traditionally cured meat products. The amount of nitrite consumed from uncured meat products versus traditionally cured meat products is virtually the same( AMI, 2008, Sebranek and Bacus, 2007).

While some people question whether nitrite from vegetable sources or saliva is different from the nitrite that is added to cured meats, experts like Jeff Sindelar, Ph.D., University of Wisconsin, say emphatically: “Where you receive it (nitrite) actually makes no difference because nitrite is nitrite. In other words, the nitrite derived from celery or other vegetables is exactly same as the nitrite found in cured meats.” (AMI, 2011)

Okay, so there’s nitrate in lots of our food-stuffs and our bodies convert it to nitrite, but is nitrite harmful? The U.S. National Toxicology Program (NTP) is considered the “gold standard” in determining whether substances cause cancer. Its multi-year study in which rats and mice were fed high levels of sodium nitrite found that nitrite was not associated with cancer. NTP maintains a list of chemicals found to be carcinogenic. Sodium nitrite is not on that list (USHHS, 2005).

Not only does nitrite not cause cancer, scientists at the National Institutes of Health and the University of Texas Health Science Center at Houston have discovered that nitrite actually has health benefits (Gladwin, MT, et al., 2005). When nitrite’s safety was questioned in the 1970s, scientists had not yet discovered that the human body makes nitrite as part of its normal, healthy nitrogen cycle. Study after study has shown that nitrite can: Regulate blood pressure (Webb, 2008, Larsen, et al., 2006); Prevent injury from heart attack (Bryan, et al., 2007); Prevent brain damage following a stroke (Jung, et al., 2006); Prevent preeclampsia in pregnant women (Rosselli, 1997); Promote wound healing (Garcia-Saura, et al., 2010); Promote successful organ transplantation (Duranski, et al., 2005); Treat sickle cell anemia (Mack, et al., 2008); Prevent gastric ulcers (Lundberg, et al., 2008).

“The idea it’s bad for you has not played out,” according to Marc Gladwin (AMI, 2011). This is code for “the hypothesis was wrong.” Indeed, Gladwin’s group found that infusing nitrite into patients with a variety of health conditions was an inexpensive and extremely effective treatment.

Anti-antibiotics

Another issue purportedly supporting the “animal products are bad for you and the environment” narrative is the belief that antibiotic use in livestock production is increasing and that this is a threat to human health. One purported threat comes from the consumption of foodstuffs that contain antibiotic residues. Another is that the use of antibiotics in animal agriculture leads to the development of antibiotic resistant bacteria.

First some background. Two terms frequently used to describe antibiotic use in livestock and poultry production are “therapeutic” and “sub-therapeutic.” When an animal exhibits clinical signs of an illness, a veterinarian may prescribe an antibiotic drug to treat that condition - just as a doctor would with a human. This approach is called a “therapeutic” use of prescriptions, and this represents the majority of antibiotics used by animal agriculture (AMI, 2010).

“Subtherapeutic” refers to the use of antibiotics in a preventative, or prophylactic, manner. Antibiotics are administered at vulnerable times, such as weaning, when animals are very susceptible to disease that can kill quickly, sometimes in less than 24 hours. It is often easier to control the total herd health through the early prevention of a contagious illness. Remember the saying “an ounce of prevention is worth a pound of cure”? Some antibiotics offer an added benefit of enhancing livestock and poultry growth when administered, but, according to a 2007 survey, only an estimated 13 percent of antibiotics are used in growth promotion and heightened attention to the issue is discouraging such use even more (Graham, 2007, AMI, 2010).

Antibiotic use in livestock and poultry production is strictly regulated by officials at the U.S. Food and Drug Administration. Meat and poultry are inspected in plants by the U.S. Department of Agriculture to ensure that they comply with all federal safety rules. Issues surrounding antibiotic use and resistance are extremely complex and involve both human and veterinary use. While recent news has focused on veterinary antibiotic use, many experts have cautioned against overuse of antibiotics in humans for decades.

In the 1940s, antibiotics became available in general human medicine. Within a decade, medical journals contained cautions about the overuse of antibiotics to treat illnesses for which they were not warranted. Scientists warned that the overuse of antibiotics in humans could potentially create resistant strains of bacteria. Concerns about the overuse of antibiotics in humans continued throughout the following decades. A 1999 study of pediatricians in the journal Pediatrics found that more than half of doctors reported writing 10 or more antibiotic prescriptions in the past month that they believed to be unwarranted and did so in response to parental pressure (Bauchner, et al., 1999). Interviews with patients revealed that patients often exaggerated symptoms and pressured doctors to secure a prescription for antibiotics even when it is not needed. By and large, those interviewees believed that antibiotics were needed to treat everything but the common cold (Pechère, 2001). For more than 40 years, antibiotics regulated and approved by the Food and Drug Administration (FDA) have been used to treat sick animals, prevent illness and maintain the health of animals. The use of antibiotics in livestock production has been relatively steady over time, but in responding to concerns about the development of antibiotic resistant bacteria, public attention seems to have shifted away from human use toward agriculture (AMI, 2010).

Some argue that the use of antibiotics in food animals could create strains of bacteria that are resistant to antibiotics and ultimately infect humans, but years of research have failed to prove that this evolution is occurring or that it is risking human life (AMI, 2010). One often-cited statistic comes from the Union of Concerned Scientists (UCS), which claims that 70 percent of antibiotics produced in the U.S. are fed to livestock. It’s hard to understand how the UCS came up with this statistic since antibiotic use in humans is not tracked. Still, one would reasonably expect that 302 million head of American livestock and 6.27 billion American chickens and turkeys would require more antibiotics than 309 million people who weigh a fraction of a full grown steer and far less than a typical market hog.

Denmark banned non-therapeutic antibiotic use in 2000. “There seems to be little evidence after 10 years that public health has improved since the Danish ban on growth promoting and preventive antibiotics.” (Hurd, 2010) “Salmonella and Campylobacter illness rates have not decreased and methicillin resistant Staphylococcus aureus (MRSA) has been steadily increasing for the last 10 years. Additionally, the resistance levels in some key human infections has not declined, but increased.” (Hurd, 2010) While many had predicted that a ban on growth promotion and preventative antibiotic uses would reduce total antibiotic consumption in livestock, the Danish government reported that “for production animals consumption [of therapeutic antibiotics] has increased gradually by 110 percent from 1998 through 2008.” (Hurd, 2010) And the therapeutic antibiotics that are now being used are considered more important in human medicine. Overall the data suggest that the antibiotics previously used for growth promotion were preventing a great deal of illness, especially in pigs (Hurd, 2010).

The road from foolishness to fraud

This post opened with the example of the scientific debunking of EMF as a cause of childhood leukemia from Robert Park’s book Voodoo Science: The Road from Foolishness to Fraud. Tom Naugton mentioned this book in his videotaped presentation Science for Smart People.

In closing this post, I’d like to offer an extended quote from the book and issue a plea and a challenge to all my brothers and sisters in the low carb / paleo / primal community:

“Ideology, fraud, and foolishness were all present in the examples of voodoo science discussed in these pages. For those who intentionally set out to commit fraud, such as the makers of “Vitamin O,” we can have little sympathy. But most of the scientists and inventors we met started out like Joe Newman, believing that they had made a great discovery overlooked by everyone else. While it never pays to underestimate the human capacity for self deception, they must at some point begin to realize that things are not behaving as they had supposed.

“Like all those who have gone down this road before them, they will have reached a fork. In one direction lies the admission that they may have been mistaken. The more publicly and forcefully they have pressed their claim, the more difficult it will be to take that road. In the other direction is denial. Experiments may be repeated over and over in an attempt to make it come out “right,” or elaborate explanations will be concocted as to why contrary evidence cannot be trusted. Endless reasons may be found to postpone critical experiments that might settle the issue. The further scientists travel down that road, the less likely it becomes that they will ever turn back. Every appearance on nationwide television, every new investor, every bit of celebrity and wealth that comes their way makes turning back less likely. This is the road to fraud.”

We rightly challenge the lack of scientific rigor in the nutrition /diet / human health realm. We must rigorously examine, however, all of the bits of the narrative we’ve inherited from the deluded and, perhaps, fraudulent “conventional wisdom.”

References:

American Meat Institute (AMI). 2011. Meat MythCrushers: Setting the Record Straight. Champaign, IL. Accessed June 3, 2011.

American Meat Institute. 2010. Antibiotic Use in Livestock Production: Ensuring Meat Safety. Champaign, IL. Accessed June 3, 2011.

American Meat Institute. 2008. Sodium Nitrite: The Facts. AMI Fact Sheet. American Meat Institute. Washington, D.C. Accessed June 2, 2011.

Bauchner, H, S.I. Pelton, J.O. Klein. 1999. Parents, physicians and antibiotic use, Pediatrics; 103 (2) 395-401. Abstract accessed May 18, 2011.

Bennetts, H.W., E.J. Underood, and F.L. Shier. 1946. A specific breeding problem of sheep on subterranean clover pastures in Western Australia. Australian Veterinary Journal. 22.2-12. Abstract accessed June 2, 2011.

Bryan, N.S., J.W. Calvert, J.W. Elrod, S. Gundewar, S.Y. Ji, and D.J. Lefer. 2007. Dietary nitrite supplementation protects against myocardial ischemia-reperfusion injury. Proc Natl Acad Sci USA 104: 19144–19149. Accessed May 24, 2011.

Doyle, E., 2000. Human Safety of Hormone Implants Used to Promote Growth in Cattle. Food Research Institute. University of Wisconsin. Madison, WI. Accessed June 2, 2011.

Duranski, M.R., J. J.M. Greer, A. Dejam, S. Jaganmohan, N. Hogg, W. Langston, R.P. Patel, S. Yet, X. Wang, C.G. Kevil, M.T. Gladwin, and D.J. Lefer. 2005. Cytoprotective effects of nitrite during in vivo ischemia-reperfusion of the heart and liver, Journal of Clinical Investigation 115; 1232-1240. Accessed May 24, 2011.

Food and Agriculture Organization/World Health Organization (FAO/WHO). 1999. Joint FAO/WHO Expert Committee on Food Additives. Fifty-second meeting, Rome. Accessed June 2, 2011.

Food and Agriculture Organization/World Health Organization. 2009. Joint FAO/WHO Foods Standards Programme. Codex Alimentarius Commission. Thirty-Second Session. FAO Headquarters, Rome, Italy, 29 June - 4 July 2009. Accessed June 2, 2011.

Food and Drug Administration (FDA). 2011. Steroid Hormone Implants Used for Growth in Food-Producing Animals. Center for Veterinary Medicine. Product Safety Information. Accessed May 26, 2011.

Garcia-Saura, M.F., B.O. Fernandez, B.P. McAllister, D.R. Whitlock, W.W. Cruikshank and M. Feelisch. 2010. Dermal Nitrite Application Enhances Global Nitric Oxide Availability: New Therapeutic Potential for Immunomodulation? Journal of Investigative Dermatology, 130, 608-611. Accessed May 24, 2011.

Gladwin, MT, A.N. Schechter, D.B. Kim-Shapiro, R.P. Patel, N. Hogg, S. Shiva, R.O. Cannon, III, M. Kelm, D.A. Wink, M.G. Espey, E.H. Oldfield, R.M. Pluta, B.A. Freeman, J.R. Lancaster, Jr, M..Feelisch and J.O. Lundberg. 2005 The emerging biology of the nitrite anion. Nature Chemical Biology 1, 308 – 314. Abstract accessed May 24, 2011.

Graham, J.P., J.J. Boland, E. Silbergeld. 2007. Growth Promoting Antibiotics in Food Animal Production: An Economic Analysis. Public Health Reports. 122: 79-122. Accessed June 3, 2011.

Hartmann, S., M. Lacorn and H. Steinhart. 1998. Natural occurrence of steroid hormones in food. Food Chemistry 62:7-20.

Hoffman, B. and Eversol. 1986. In Drug Residues in Animals, A. G. Rico (Ed.), pp. 111-146. Academic Press, New York.

Hurd, S. 2010. Danish Experience Offers Lessons for U.S. Antibiotic Use. Beef Issues Quarterly. Accessed June 2, 2011.

Jung, K., K. Chu, S. Ko, S. Lee, D. Sinn, D. Park, J. Kim, E. Song, M. Kim and J. Roh. 2006. Early intravenous infusion of sodium nitrite protects brain against in vivo ischemia-reperfusion injury. Stroke 37: 2744–2750. Accessed May 24, 2011.

Larsen F.J., B. Ekblom, K. Sahlin, J.O. Lundberg, E. Weitzberg. 2006. Effects of dietary nitrate on blood pressure in healthy volunteers. New England Journal of Medicine. 355: 2792–2793. Accessed May 24, 2011.

Lundberg, J.O, E. Weitzberg and M.T. Gladwin. 2008. The nitrate–nitrite–nitric oxide pathway in physiology and therapeutics. Nature Reviews Drug Discovery 7, 156-167. Abstract accessed May 26, 2011.

Mack, A. K., V.R. McGowan II, C.K. Tremonti, D. Ackah, C. Barnett, R.F. Machado, M. T. Gladwin, and G. J. Kato. 2008. Sodium nitrite promotes regional blood flow in patients with sickle cell disease: a phase I/II study. British Journal of Haematology. 142(6):971–978. Accessed May 26, 2011. 

McEwen, S.A. and W.B . McNab. 1997. Contaminants of non-biological origin in foods from animals. Rev. sci. tech. Off. int. Epiz. 16 (2), 684-693. Accessed June 2, 2011.

Park, Robert. 2000. Voodoo Science: The Road from Foolishness to Fraud. Oxford University Press, inc. New York, NY.

Pechère, J.C., 2001. Patients’ Interviews and Misuse of Antibiotics, Clinical Infectious Diseases. Clinical Infectious Diseases; 33(Suppl 3):S170–3. Accessed May 20, 2011.

Raines, Christopher. 2009. Hormones in my organic food? Yep. meatblogger.org. Accessed July 20, 2010.

Rosselli, M. 1997. Nitric Oxide and Reproduction. Molecular Human Reproduction, 3 (8) 639–641. Accessed May 25, 2011.

Sebranek, J.G, and J.N. Bacus. 2007. Natural and organic cured meat products: regulatory, manufacturing, marketing, quality and safety issues. AMSA White Paper Series, No. 1. American Meat Science Association, Savoy, IL . Accessed June 2, 2011.

Shore, L. S., and M. Shemesh. 2003. Naturally produced steroid hormones and their release into the environment. Pure Appl. Chem. 75:1859-71.

Smith, G. 2011. Hormones – Beef, Milk and Puberty. Where Food comes From Blog. Accessed May 26, 2011.

U.S. Department of Agriculture, Agricultural Research Service (USDA ARS). 2002. USDA-Iowa State University Database on the Isoflavone Content of Foods, Release 1.3. Nutrient Data Laboratory Web site: http://www.nal.usda.gov/fnic/foodcomp/Data/isoflav/isoflav.html. Accesed May 26, 2011.

U.S. Department of Agriculture, Food Safety and Inspection Service (USDA FSIS). 2009. 2008 FSIS National Residue Program Data. United States Department of Agriculture, Food Safety and Inspection Service. Office of Public Health Science. Washington, DC. Accessed June 2, 2011.

U.S. Department of Health and Human Services, Nation Toxicology Program (USHHS NTP). 2005. 11th Report on Carcinogens, Accessed May 23, 2011.

Webb A.J., N. Patel, S. Loukogeorgakis, M. Okorie, Z. Aboud, S. Misra, R. Rashid, P. Miall, J. Deanfield, N. Benjamin, R. MacAllister, A.J. Hobbs, A. Ahluwalia. 2008. Acute Blood Pressure Lowering, Vasoprotective, and Antiplatelet Properties of Dietary Nitrate via Bioconversion to Nitrite. Hypertension 51 (3)784-790. Accessed May 23, 2011.