Most people do not think of the industrial revolution when they think of the breast feeding-formula feeding debates but it is arguably the reason the discussion exists today (National Academy of Sciences, foodtimeline.org, wikipedia.com). In the early 19th century breast feeding was the norm around the world. Women who had difficulties with breast feeding found wet nurses for their infants or created homemade formulas. The 1845 advent of the rubber nipple was the first step toward the formula feeding boon of the 20th century. Enterprising budding industrialists introduced the first manufactured formulas in 1867, advertising them as equal or superior to breast milk (though later generations would repudiate these claims). Yet formula and the bottle would have remained the recourse for women who could not nurse or find a wet nurse had not two other major changes taken place. Perhaps the most critical change was in the minds of newly industrialized countries—namely the discovery and acceptance of germ theory. The desire to avoid potentially tainted milk combined with medicine’s endorsement of formula to change the tide against breast feeding. Yet more than half of the infants in the United States were still breast fed until the late 1920s/early 1930s when refridgeration became more common. By the 1950s breast feeding was summarily dethroned as the preferred method of infant feeding with the rise of commercialized formulas.
Breast feeding provides infants with more than energy (Fomon, Anderson et al.). Proteins, vitamins and minerals are used by the infant to grow and mature. Antibodies, growth factors and enzymes provided by the mother aid immunity, growth and development until the infant’s own systems mature. Lipids and neurotransmitters aid in brain development while other components of breast milk sharpen vision. Formulas have developed remarkably in the last 150 years but they do not provide all the beneficial components of breast milk nor do they necessarily provide them in a form usable by the infant. As the infant’s systems are developing some components of breast milk rely on other components for activation or digestion. Furthermore, while some doctors may prescribe, or at least be aware of a potential need for, vitamin K and iron to breast-fed infants (likely dependent on the mother’s own levels) most components are in the ratio needed by the infant at that stage of development, measurements that are often difficult to apply to formula ingredients.
The superiority of breast milk to formula is advocated by doctors today. Debates exist, however, on the duration and exclusivity of breast feeding. The World Health Organization (WHO) and American Academy of Pediatrics (AAP) both recommend exclusive breast feeding for the first 6 months (except in rare circumstances, discussed below). Exclusive not only means without formula supplementation but also without supplementation of other milks, liquids or solid foods. At 6 months of age solid foods can be introduced and fed along with breast milk until at least age 12 months (AAP) or 24 months (WHO). Neither organization makes overt recommendations on when to stop breast feeding, ie when breast milk is no longer providing what solid foods and the toddler’s body cannot, but simply recommend continuing as long as both mother and child desire it. Mothers in developing countries may find extra benefit in prolonged breast feeding due to the high risk of contaminated water and food that would more harshly effect toddlers over older children and adults with more mature organs.
Certainly today some women may find, as they have throughout history, extreme difficulty in nursing. For these women, adoptive parents, and others the formula options are quite good compared to earlier forms (Owen, Fomon, Kramer et al., Anderson et al.). Nutrients are made more bioavailable and mineral contaminants such as lead have been removed. Developed countries see little difference in formula-fed infants compared with breast-fed infants in the long run. Certainly breast-fed infants are ill less frequently and less seriously when they are ill (mostly applicable to respiratory and gastrointestinal disease) while being breast fed. They may also have a slight advantage with mental acuity (one study suggests an average of 3 points on an IQ test) and visual acuity in the long term. Although formula-fed infants are by no means absolutely doomed to a life poor health and average achievement, it is simply not a complete replacement for breast milk. Advantages to formula feeding over breast feeding exist for particular situation as well. For women who are on drugs, chemotherapy, radiation, are infected with HIV or TB, or have infants with a rare genetic disorder that prevents the digestion of breast milk formula is recommended by the AAP over breast milk. The WHO has similar recommendations but does point out that while HIV can be transmitted by breast feeding (from 5-20% transmission rate for some breast feeding to 30-45% transmission rate for 18-24 months of breast feeding) other immunological (including HIV) and nutritional benefits from breast milk will be lost. In the United States and other developed countries, as stated above, choosing formula may not present a long-term observable effect but in developing countries it could mean gambling with the child’s life as much as the risk of HIV infection.
Breast feeding is best for the mother and child (Ruowei et al., Fomon, Anderson et al., Hediger et al). It is the natural process both bodies desire and should be promoted over formula feeding in almost all cases in the US. Multiple studies have shown, however, that only approximately 71% of infants in the US are ever breast fed and only approximately 14% of these infants are breast fed exclusively for 6 months. The percentage of mothers who nurse has been increasing since the late 1960s. Most women who breast feed exclusively are white, at least 25 years of age, well-educated and reside on the west side of the country. Mothers who are black, young and without a high school diploma are most likely not to breast feed. While infants in low socioeconomic groups could benefit greatly from breast feeding over formula feeding the education and resources to breast feed, especially in single-parent homes, are lacking.
The emotional, biosocial, nutritional and developmental benefits to breast feeding over formula feeding are proven (Ruowei et al., Fomon). What remains is to provide viable options for women and infants for whom breast feeding is not an option and resources for working mothers to breast feed their infants for at least the first 6 months to a year. Widespread education and cultural shifts may be required as they were to make the shift to formula in the 19th and 20th centuries (Montagu).
National Academy of Sciences. Evaluating the Safety of New Ingredients, 2004.
WHO: http://www.who.int/topics/breastfeeding/en/
http://www.who.int/nutrition/publications/HIV_IF_guide_for_healthcare.pdf
AAP: http://aappolicy.aappublications.org/cgi/content/full/pediatrics%3b100/6/1035
http://pediatrics.aappublications.org/cgi/content/abstract/112/5/1196
Foodtimeline.org
Wikipedia.com
Ruowei, L. et al. Changes in Public Attitudes toward Breastfeeding in the United States, 199-2003. Journal of the American Dietetic Association. Vol. 107. No. 1, 2007.
Montagu, M. Nature, Nurture and Nutrition. The American Journal for Clinical Nutrition. Vol. 5 No. 3, 1957.
Forman, M. et al. Exclusive breastfeeding of newborns among married women in the United States: the National Natality Surveys of 1969 and 1980. The American Journal for Clinical Nutrition. Vol. 42. 864-869, 1985.
Owen, G. Interaction of the infant formula industry with the academic community. The American Society for Clinical Nutrition. Vol. 46. 221-225, 1987.
Fomon, S. Reflections on infant feeding in the 1970s and 1980s. The American Journal for Clinical Nutrition. Vol. 46 171-182., 1987.
Anderson, J. et al. Breast-feeding and cognitive development: a meta-analysis. The American Journal for Clinical Nutrition. Vol. 70. 525-535, 1999.
Hediger, M. et al. Early infant feedign and growth status of US-born infants and children aged 4-71 mo: analyses from the third National Health and Nutrition Examination Survey, 1988-1994. The American Journal for Clinical Nutrition. Vol. 72. 159-167, 2000.
Kramer, M. et al. Infant growth and health outcomes associated with 3 compared with 6 mo of exclusive breastfeeding. The American Journal for Clinical Nutrition. Vol. 78. 291-295, 2003.
Obsessive-compulsive disorder is in my DNA
May 15, 2007
If I think back about it, I seem to remember that the sequencing of the human genome slightly predates the obsession with DNA in pop culture. I’m not thinking about actual scientific work related to DNA that pops up in newspapers every day but more the trend to use DNA as a scapegoat. Statements like: I can’t help that I’m a shopaholic, it’s in my DNA. As someone who actually knows a thing or two about DNA this tends to make my eye twitch. The human genome may be sequenced but not all of our genes have been identified. Even so I can say with fair certainty that there has not been sufficient evolutionary time for a shoe gene to develop.
I can ignore these statements and take them as they’re meant to be: a statement of a trait that the person perceives to be innate and unchangeable. The real problem I find is in movies and TV. Misrepresentation in film is by no means limited to biology but it does pull me out the moment. A second after the shudder runs through my body I wonder who actually learns these mistakes. I mean, I learned the definition of a score from the recitation of the Gettysburg Address in Bill and Ted’s Excellent Adventure so someone could believe that genes can skip generations or disappear completely as claimed in 28 Weeks Later, right? I know what they’re getting at, that gene *expression* might be recessive and not shown in the offspring. Or that the gene may have been mutated or lost in an individual’s somatic cells and not their gametes (sex cells) (much like that which causes a melanoma from too many summers at the beach) and hence hereditable.
I don’t meant to pick on one film, it is, certainly, not the only, or even most blatant, offender. Red Planet, with Val Kilmer and Benjamin Bratt, had several references to nematodes. Unfortunately for them nematodes are a type of worm. The critters in question were not. Clearly a checkable fact. CSI Miami pushes the boundaries of believable at times, all the more dangerous for their otherwise fairly accurate portrayal of the biology of forensics. As an example, in one episode epithelial skin cells were removed from rough upholstery on a car seat and used to identify an assailant. While it is technically possible to get enough DNA from a few cells to identify a person it is difficult. Moreover, the outermost skin cells are dead and do not contain a nucleus. The chances that the cells that remained on the upholstery after the car crashed were from a deeper, nucleated skin layer are, well, the kind of odds Hollywood makes good on.
The fact is that errors are everywhere in movies and the only people who usually care are those who know they’re mistakes. Errors may happen even after fact checking (I think I’d forgive the incorrect phase of the moon during the moon landing in Apollo 13) but films that are not specifically relying on a fantasy element should make sure that their basic facts are sound. Have all the bubbling beakers you want if that’s your aesthetic but gravity doesn’t let up on Tuesday afternoons, Amelia Earhart wasn’t born in 1987 and *individuals* don’t evolve. Just ask Wikipedia.
I suppose I should take the stance of some historians on the movie Troy. While factually inaccurate in many ways the movie was viscerally correct and, more importantly, had inspired many college students to register for history courses. I just don’t think 28 Weeks Later is going to cause a surge in students registered for virology.
Pap smear need reduced by HPV vaccine
May 8, 2007
The greatest accomplishment in the history of public health initiatives, or so your dentist will tell you, was the addition of fluoride to public water supplies—a small amount of fluoride in drinking water dramatically reduces the incidence of cavities. The reasons for this success are simple: Fluoride-treated water is inexpensive and requires no effort on the part of the public, save to drink tap water.
Likewise, Papanicolau (Pap) screening has greatly reduced the mortality rate attributed to cervical cancer in the US and industrialized world (Hanna et al., Calloway et al., Hymel). Although Pap screening is fairly expensive, it is less expensive than treating cervical cancer. Patients with cervical cancer caught at an early stage through the Pap screening have a 100% survival rate over 5 years. In the US approximately 12,000 women a year are diagnosed with cervical cancer with about 4,000 women succumbing to the disease. The benefits of Pap screening are put into stark clarity, however, when worldwide figures are considered. As the second-leading cause of cancer death among women worldwide, cervical cancer affects about 500,000 women a year, half of whom may die of the disease. The lack of regular, or any, access to Pap screening and other medical treatment in the developing world accounts for this disparity.
Nearly all cases of cervical cancer result from a chronic human papilloma virus (HPV) infection. HPV strains 16 and 18 cause 50-60% and 10-20%, respectively, of cervical cancers, with 5 other strains making up most of the remaining 30% of cases (Hanna et al., Hymel). Additionally, strains 6 and 11 have been known to cause genital warts. Altogether approximately 40 HPV strains, or genotypes, affect genital tissue with cervical cancer being the most common resulting cancer. Statistics vary on prevalence of HPV in the US, but some estimate 6.2 million newly-infected persons each year. Studies suggest up to 70% of adults have had an HPV infection; most infections are cleared by the body and do not result in a chronic condition that may progress to cancer. Although a young age at first sexual experience, larger number of sexual partners and lack of condom use correlate with increased risk of HPV infection, infection often occurs soon after becoming sexually active.
Currently two HPV vaccines, Gardasil from Merck and Cervarix from GlaxoSmithKline, are on the market or are soon to be released (Calloway et al.). Gardasil covers both major genotypes involved in cervical cancer and both major genotypes causing genital warts. Cervarix will be used to prevent HPV-16 and -18 infections only, not vaccinating for the strains causing genital warts. Both vaccines were determined by the federal Food and Drug Administration to be completely safe and effective. Currently, recommendations are a series of 3 shots given to women aged 9-26, preferably before first sexual contact (ACS, Calloway et al., Roden et al.). Studies in women older than 26 or women who have had sex and may have had an HPV infection are ongoing and thus it is unknown whether the vaccine will be as effective in these women. Until a treatment for HPV infection is found it remains important for the preventative vaccination to be done before women have any sexual contact. Studies on men have not been prioritized as the incidences of penile or anal cancers are much lower than that of cervical cancer (Dunne et al., Hymel). While women may benefit from men being vaccinated as well it is not clear whether this benefit is beyond that from routine vaccinations of women.
Although Pap screening has been proven to be a tremendous benefit to women’s health, the high prevalence of HPV infections suggest that a relatively inexpensive vaccine series would be extremely valuable (Hanna et al., Calloway et al., Roden et al.). Vaccinations can be given with other childhood vaccinations before sexual contact giving, hopefully, lifelong protection. It is not yet known when or if booster shots will be needed. It is known, however, that Pap screening should be continued as long as the vaccinations do not cover all cancer-causing strains or questions on the length of time of protection given by the vaccine exist, although screening can be done tri-annually instead of every year. It is much easier and less expensive to complete a series of shots once than it is to have annual exams. The peace of mind that comes with protection from cancer can not be quantified.
It is hoped, especially for developing countries, that the vaccinations can be eventually given in one dose or through oral administration. Lack of access to medical care is a problem in many areas of the world; the observation that 80% of women with cervical cancer are in developing countries clearly illustrates this fact (Hanna et al., Roden et al.). Even in the US many people are forced to go without medical insurance at some point in their lives. HPV vaccination, especially in childhood when other vaccinations are needed, could eventually lead to the elimination of cervical cancer. While this is not as inexpensive or easy as a glass of water a day, a half a million women a year could avoid the pain of cervical cancer.
American Cancer Society, Vol. 57, No. 1, 1/2007
Hanna, E. and G. Bachman. HPV vaccination with Gardasil a breakthrough in women’s health. Informa Healthcare, 2006.
Calloway, C. et al. A Content Analysis of News Coverage of the HPV Vaccine by US Newspapers, January 2002-June 2005. Journal of Women’s Health. Vol. 15 No. 7, 2006.
Dunne, E. et al. Prevalence of HPV Infection among Men: A Systematic Review of the Literature. The Journal of Infectious Diseases. Vol. 194, p1044-1057, 2006.
Hymel, P. A. Decreasing Risk: Impact of HPV Vaccination on Outcomes. The American Journal of Managed Care. Vol. 12, No. 17.
Roden, R. and T.C. Wu. How will HPV vaccines affect cervical cancer? Nature Reviews. Vol. 6, 2006.
