NOTES for Week 9

I. PHEROMONES

Pheromones are called 'the sixth sense.' It is argued that humans like many animals can receive chemical messages. A wide range of animals, from insects to hogs, respond to them. Musk, a pheromone for deer is found on store shelves as an after-shave lotion. Realm© is said to contain human pheromone.

The alleged sensor in humans is the vomeronasal organ (VNO) found in the nose. People who insist that human pheromones are significant say that when humans began wearing clothes, pheromones lost their importance.

According to Martha McClintock at the University of Chicago, the 'sixth sense' human pheromones do exist. These substances have been well documented in insects and many mammals. In those animals, pheromones do such things as block pregnancies, influence mating, identify territory, and influence the timing of puberty and dominance.

McClintock has pursued pheromones for thirty years. She gained fame in 1971 when-as an undergraduate-documented that 135 women in her dormitory coordinated their menstrual cycles. The phenomenon is called menstrual synchrony.

The possible medical implications are possible tools for regulating ovulation in couples having conception difficulty, alleviation of depression, and management of prostate problems in men.

..... CJ '99

Resources

Bishop, J. "Sixth-Sense Therapy Path to Be Reported" Wall Street Journal April 11, 1996.

Gorner, P. "U. Of C. researchers find evidence pheromones may influence humans" Chicago Tribune March 12, 1998.

Kluger, J. "Following Our Noses" Time March 23, 1998.

Ritter, M. "Making sense of armpit air" Hammond Post-Tribune March 12, 1998.

Winslow, R. "Birds Do It, Bees Do It...Now Akzo Bets We Do It: Steer by Pheromones" Wall Street Journal July 21, 1997.

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II. HORMONE DISRUPTORS-ARE THEY REAL?

In recent years, many have suggested that artificial chemicals in the environment, called "hormone disruptors" or "endocrine disruptors" can disrupt our natural hormones by sending erroneous signals or blocking legitimate signals. In the 80's and 90's, fish and beluga whales with severe malformations have appeared. There have been cancers, ulcers, and other deformations.

Some have suggested that environmental chemicals acting as hormone disruptors are responsible for an increase in ovarian and breast cancer.

Hormone-like chemicals are present in some consumer products such as pesticides, detergents, cosmetics, paints, and packaging materials including plastic containers and food wraps.

There is an abundance of literature on this subject. To get into to subject, see Colborn, Dumanoski, and Myers Our Stolen Future. The impacts reported for humans are decreased sperm counts in men (not due to a popular soft drink) and breast cancer.

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A survey of 225 practicing pediatricians have reported that premature secondary sexual characteristics (pubic hair/breast development) are now found in 144.7% of white girls and 48.3% of African-American girls between their eighth and ninth birthday. The study also found that 1% of whites and 3% of African Americans had such characteristics at age three. A link to environmental hormone disruptors is suspected.

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The hormone disruptor hypothesis has its critics. Professor Andre Lecloux of the European Chemical Industry Council dismisses the hypothesis as very controversial and in most cases not substantiated.

Critics also say that the nature and extent of the effects of exposure on humans are not well established because evidence is limited.

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Resources: This summary was prepared from two excellent term papers prepared by XuanLan Thi Phan and Martha Mejia for OSCI 590 Dental Anthropology, Hominid Evolution, and Human Variation, Oral Sciences at the UIC College of Dentistry, Summer, 1998.

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TEXT Nutrition and Health Through the Life Cycle pp 204-234

-These notes are intended as a study guide, not a substitute for the reading in the TEXT Ch 9.

-At each age, nutritional needs are different. In an impoverished setting, the infant is especially vulnerable during the weaning period. This is when the death rate is the highest.

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I. PRENATAL NUTRITION pp 2024-206

-Infants with a birth weight below 5.5 lbs. are 30 to 40 times more likely to die than an infant having a normal birth weight.

-Poor placenta development occurs if the mom is malnourished. This contributes to a lower birth weight.

-Low birth weights are seen in moms who smoke heavily during the pregnancy. Smoking is the most common drug problem in pregnancy.

-There are few documented reports on bad effects of marijuana on infants.

-If full term infants, acute malnutrition is more of a risk than chronic malnourishment.

-Two or more drinks a day can produce FAS (fetal alcohol syndrome). The symptoms of FAS are small head circumference, small infant size, retardation and a host of other problems. Alcohol is a known teratogen.

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-Mini-unit on Teratogens-

-Teratogens are chemical agents capable of producing a birth defect. A famous example is thalidomide which produced phocomelia (failure of limb formation). The most vulnerable time for teratogen action in pregnancy is in the early months of pregnancy.

-Some diseases produce birth defects: syphilis, measles, mumps, and chicken pox are examples.

-Some chemotherapy drugs for cancer treatment are known teratogens. So is sarin and other nerve gasses used in germ warfare. This was documented when these agents were used against the Kurds in Iran, back in 1988.

-Cortisone in large doses can cause birth anomalies.

-At Minimata Bay in Japan, consumption of fish contaminated with mercury compounds led to birth defects in children. One of the most wrenching magazine photographs of that era was of an elderly Japanese mom holding her adult disabled child.

-DES used to prevent miscarriages unfortunately caused cancer in subsequent children. This is an agent that crossed generations.

-Radioactive Iodine 131 can completely destroy the thyroid gland in a fetus.

-Cocaine addiction has been implicated so much with fetal developmental problems that 'cocaine baby' has become part of our vocabulary. A pediatrician at Northwestern Childrens Memorial, Dr. Ira Chasinov is often in the news as an expert on the problem.

-Tetracycline antibiotics bind permanently in bone and teeth forming at the time of drug ingestion. Teeth stained with tetracycline are an unsightly dark color. Ancient Nubian skeletons from the Sudan contain tetracycline that occurred naturally in stored grain used to make beer.

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-Many cultures acknowledge that the eating habits of pregnant women affect the child's development. Some of the taboos reflect belief systems much different from your own. For example, some say 'don't eat the meat of animals with horns, or else the umbilical cord will become twisted.' Do you recall the 'law of similars?'

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II. PROFILE: WARMING THE MALAY MOTHER pp 206-211

-Pay attention to the term couvade. The term means 'male pregnancy symptoms.' We will explain more about it in the next unit.

-Read how the hot-bed warming of the post-partum mom is based on the hot-cold theory. Is a woman considered 'hot' or cold?' Notice too the diet restrictions and their implication for population control.

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III. INFANT FEEDING pp 211-216

-According to the Merck Manual, over 50% of mothers are breast feeding today. That figure is higher in the higher socioeconomic groups.

-Prior to its recent gain in popularity, the decline in breast feeding began three centuries ago.

-Obesity in infants has been linked to overfeeding with bottle fed formulas. A German study of weight and breast feeding is cited in unit 9.4.

-There was a decline in breast feeding in developing nations in the 1960s. Social reformers in the Western World blamed the Nestle company for using advertising to get Third World mothers to give up breast milk and us Nestle formula mixed with contaminated water. NOTE: There is another side to this story. From their perspective, they wanted to be modern AND formula gave them a chance to leave the household and earn cash wages. Read unit 9.4.

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-Marasmus is a sort of starvation, a result of severe protein and calorie deprivation. It results in emaciation and retardation. There is no body fat and muscles atrophy.

-In contrast, Kwashiorkor is the nutritional disease most often seen in children weened on a protein-scarce diet.

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-When bottle feeding came on the scene, infection, contaminated water, rice water, and tea where gave as substitutes.

-The practice of bottle feeding also shortens the birth space and produces bigger families. Active breast feeding suppresses resumption of the ovulatory cycle and is considered a form of natural birth spacing.

-Commercial formulas today have replaced the older 'do it yourself' home made formulas based on cows' milk. Modern baby formulas are a nutritional triumph.

-Can women who aren't postpartum and guys are induced to successfully breast feed? See Diamond, J. Why Is Sex Fun?

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IV. WEANING AND EARLY CHILDHOOD pp 216-220

-The introduction to solid foods to the infant (when they can tolerate them) is accepted in this country.

-Breast feeding continues until 2 or 3 or 4 years of age in tropical and subtropical areas with protein-poor diets. Often these cultures have extended postpartum taboos and polygyny.

-Even in this country with the highways flooded with luxury vehicles, extremely disadvantaged people keep their infants-and event the elderly alive with pre chewed food.

-Cultures with prolonged breast feeding tend to view boys so fed as "feminized" and they 'make men out of them' with painful circumcision rites.

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-Kwashiorkor, the term for a nutritional disease due to a lack of protein in the diet, refers to a child 'displaced from the breast by the mother's second pregnancy.' Kwashiorkor results when there are plenty of carbohydrates but a lack of protein. The term has been taken to mean 'sugar baby.'

-When growth retardation is below 70% of the expected mean, there is a severe impairment of immune function with increased vulnerability to infection and disease.

-In some societies, little boys are more likely to be fed better than little girls. The result is that more girls get kwashiorkor.

-The signs include edema, fluid retention, the child is apathetic and miserable. It occurs mainly in the tropics/subtropics with starchy diets.

-Where cereals such as rice and wheat are used, the disease is less prevalent and is less severe. Other deficiencies occur also. There can b e concurrent vitamin deficiencies. Often there are parasitic infections and malaria.

-Kwashiorkor and marasmus both exhibit a failure to grow.

-Some cultures interpret the disease as evil spirits while western science sees it as nutritional disease.

-The authors stress that marasmus and kwashiorkor are part of a continuum described in older books as 'under nutrition.' Where there is general malnourishment, children with it show symptoms of nutritional disease, slow growth, and a lack of vitality.

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V. NUTRITION IN LATER CHILDHOOD AND ADOLESCENCE pp 220-224

-After age five, children are growing more slowly than at infancy. There is a burst of growth at adolescence known as the 'pubertal growth spurt.'

-In developing countries, children learn to forage. In the city it might by in the cupboard or garbage cans. In a rural setting, it might be wild fruits, berries, nuts, larvae, insects, mayfly, and so on.

-In many societies, child labor is important. Since they are smaller, they can do tasks at a lower energy cost-Poor nutrition leads to slower growth rates. Skeletal maturity is delayed-even to age 26. Does this remind you of high-altitude delayed growth?

-We forget that this country was once a 'developing country' and in those days, infants and young adults were shorter than now.

-An Important Growth Concept--

-The increase in height that began around 1870 is called the secular (generational) growth trend. The trend has been observed in every developing country and has three cardinal characteristics:

In the United States and Western Europe, menarche has dropped from 16 to 13. Some argue that it is simply because girls are fatter (above 17% body fat). Others blame hormone disruptors. Many experts think that the optimal nutrition available today is allowing us to express our maximum potential growth permitted by our genome. Be sure to read the controversial article in READER about 'healthy but small.'

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VI NUTRITION THROUGHOUT ADULT LIFE pp 224-226

-Sexual differences in nutrition begin early and continue throughout life.

-Malnutrition occurs more in girls than in boys. This is probably cultural. (Keep tucked away in your mind this seemingly contradictory, but well verified statement: girls are less likely than boys to be "bumped off" their normal growth curve by malnutrition or disease.)

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-Especially severe food taboos are imposed on women in many cultures, especially during widowhood, adolescence or pregnancy and lactation. Taboos imposed on nursing mothers seem to have little or no observable impact on children's health. Women's taboos may affect reproduction. When food is scarce, women are less likely to ovulate, conceive, or carry infants to term. Among Islamic folks, fasting is imposted during Ramadan. (My note: when I was in Egypt, it was during Ramadan. Folks fasted all day but at sunset it was-bring on the food! The guide said that food consumption is higher during Ramadan than any other time of the year.)

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VII. WORK AND SEASONAL STRESS IN ADULT LIFE pp 226-229

-This is a new unit in this edition. The seasonal stress in highland life in the Himalayas, Andes, and in Africa. In these traditional cultures, pregnant and nursing women must do as much work as others during part of the year. During periods of heavy work, women lose weight and fertility is reduced. Thus, birthing patterns show a seasonal pattern.

VIII. PROFILE: COCA CHEWING AND HEALTH IN THE HIGH ANDES pp 229-232

-Coca leaves have been chewed for thousands of years. I saw them chewed by heavily laden Peruvian porters on the Inca trail near Machu Picchu. They were moving briskly at that high altitude. I was out of breath.

-Coca leaf has a long history in Peru. Traces of them show up in the hair of mummies in Peru from a thousand years ago. Cocaine is only one of the many substances in coca. Cocaine has a long history in medicine and dentistry.

-Coca leaves are NOT addictive. There are no withdrawal symptoms. Lime is used to help release the alkaloids. The leaves are not swallowed.

-For the Inca, it was a sacred plant. (My note: this is a common theme in traditional societies. We encounter this theme consistently in our Native American Indians course.)

-Coca aids in conserving heat by vasoconstriction. There are some vitamins and minerals released during the chewing of the leaves. Moderate use is part of the cultural adaptation to the climate.

(My note: coca leaves are sold legally in Cuzco, so I bought a bag-about the size of a large M&M package. Chewing them was a disgusting experience. It was like chewing sawdust or autumn leaves. Did they have a kick? They did nothing for me! Did I bring any home? Not a chance! The stories about those Peruvian jails are grim; that was no place for me. Sorry.)

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IX. NUTRITION AND AGING pp 232-233

-A restricted diet is compatible with long life. Degenerative diseases such as cardiovascular disease have been linked to over consumption.

-Bone mass in men and women declines after the age of 50. The author says that in older persons, mild obesity is an advantage.

-Leaner women have menopause earlier.

-Amongst the elderly, low income old men have the worst diets. The single most important factor in elderly nutrition is economics.

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-The following remarks on extending life may interest you. These remarks are from Warshofsky, F. Stealing Time The New Science of Aging.

-In laboratory studies, calorie restricted diets have proven effective in extending the lives of laboratory rats. Their lives could be extended by 50% by simply cutting their calories to near-starvation levels. -In another study extending more than 25 years, thousands of mice were put on a calorie-restricted diet. When compared to their well-fed counterparts, they lived one-third longer.

-In fact, calorically restricted one-celled organisms, worms, mice, rodents, rats, fish, all live a great deal longer-equivalent to 150-160 human years.

-Researchers have found human volunteers, but not many. I can understand that. ..... CJ '99

READER: Body Size, Adaptation, and Function pp 39-45

-This article relates directly to the TEXT selection on nutrition this week.

-The "small but healthy" hypothesis assumes that a child can be raised in a food-deprived environment and yet grow up to be small but healthy. Read the article because, if nothing else, the central idea makes for a nice exam question. The article interests me because I do a growth and development section in my course at UIC.

-This article relates indirectly to the "secular (generational) growth trend" that is discussed above.

-We've said that many people grow up over nourished and suffer many health consequences: type II diabetes, cardiovascular disease, and so on.

-The "secular growth trend" is well documented. Why are people larger? Many speculate that good nutrition and health care allows people to grow to their maximum potential. First generation American born children of immigrants from, say, rural China grow significantly taller than their parents.

-The 'small but healthy' hypothesis assumes that people can grow up like bonsai trees!

-Does our genome provide for people to be stunted and yet healthy-to adapt, so to speak, to limited food availability by growing up small and thus with less food needs.

-Follow the rebuttal by the article. He has four criticisms listed pp 40-44. Understand them as you read.

-My own remarks: We've mentioned before that studies of human growth and development began as part of the social reform movement. Those studies documented the evils of child labor-in mines, factories, and fields.

-One axiom emerged early: good nutrition and social justice can be measured in the heights of the children in that society. Big differences in the heights of children who are well off and those who are deprived are evidence of 'differential access to resources.' In the industrialized world, only the Scandanavian countries have achieved social (nourishment) justice. Stunted children are disadvantaged children!

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READER: An Anthropological Perspective on Obesity pp 401-411

-One of the authors, Peter Brown is the editor of the READER. Melvin Konner is one of the authors of the stone age diet hypothesis. Read the article.

-The authors argue that throughout most of human history, obesity was never a common problem. (My comment: they slip this one on us so easily. Is it true? What is the evidence? I suspect they are correct, based on contemporary H/G studies, but folks, we are like the people from Missouri: Show me!)

-The authors propose three epidemiological facts:

-Fatness is probably an adaptation to successful completion of pregnancy (p 408).

-If breast milk is the sole food, the ongoing energy cost of lactation is higher than that of pregnancy. No wonder nursing moms feel tired!

-In many societies, fatness is linked to self-worth and sexuality. In our culture, however, it is stigmatized.

-In some cultures, being fat is a culturally defined standard of beauty. High status Efik pubescent girls in traditional Nigeria spend two years in seclusion-getting fat. Similar 'fattening huts' were found in other parts of Africa.

-Among the Havasupai (they live in the Grand Canyon), fat legs and fat arms are considered essential to beauty. The Tarahumara of Northern Mexico consider fat thighs as the first requisite of beauty.

-Cross culturally, plumpness in peripheral body fat is preferred. Standards of sexual beauty are based on images of nubile, postpubertal young adults in nearly all societies. In stratified societies, the appearance of the well-to-do is preferred. The ideal of the female body among middle/upper class America is thin. (Eight million Americans have eating disorders; anorexia nervosa is now showing up in middle age women!.)

..... CJ '99