"Our daughters are entering womanhood earlier these days.
It seems too early!  Can it be related to the hormones in our meat and dairy?"

Uncountable times this has come up in conversation.  We care so much for our children growing into adults and wonder about them maturing earlier every generation, earlier than we'd like!  I believe we are artificially speeding the process with the foods that are laced with hormones.  Following is a study presented by John McDougal, MD. 
~Susan Oshel, CPM~

DIET-INDUCED
PRECOCIOUS PUBERTY

Fourth- and fifth-grade children should be thinking about school, homework, bike riding, summer vacations, children's games, and friends without the turbulence of strong sexual urges overshadowing their lives--but they're not. Remember how disruptive your sex drive has been to your own thoughts, feelings, and actions. Now imagine forcing those same overpowering emotions upon a child of 9 or 10 years old. As a direct result of eating the rich Western diet, children are now having to deal with all the problems of puberty, at an age far younger than we were originally designed to mature. The consequences are many of our children are emotionally disturbed and physically injured, and we have chaos in our classrooms.

A recent study from the University of North Carolina at Chapel Hill published in the medical journal Pediatrics reported "...girls seen in a sample of pediatric practices from across the United States are developing pubertal characteristics at younger ages than currently used norms." "At age 3 years, 3% of African-American and 1% of white girls showed breast and/or pubic hair development, with proportions increasing to 27.2% and 6.7%, respectively, at 7 years of age. At age 8, 48.3% of African-American girls and 14.7% of white girls had begun development." (99:505, 1997).

They found the mean age (years) of onset of:
African American White
Breast development 8.87 9.96
Pubic hair 8.78 10.51
Menses 12.16 12.88
Boys are also maturing much earlier too, however they have not been studied to the extent of girls, probably because their secondary sexual characteristic developments are not as evident or dramatic.

PUTTING ADULT HORMONES IN A CHILD'S BODY

As populations of people have gradually changed their diets from plant-based to animal-based, (rich in meats, dairy products, and refined foods) the onset of sexual maturity has decreased at a rate of about 2 to 6 months per decade. For example, the age of onset of the first menses, a time known as menarche, has decreased steadily from age 17.2 years in Norway in 1830 to age 13.2 years in 1950 (WHO Monograph 62:500, 1976). Similar changes have been seen in other western European countries over the past 160 years. In Britain, over the past 150 years the average age of menarche has fallen from 16.5 years to 12.8 years (Lancet 342:1375, 1993).

In the United States, in 1900, girls started their first periods at age 14 years, by 1960 they were menstruating by an average age 12.7. In Japan, in 1875, little girls became women capable of having babies at 16.5 years of age. Just after WW II (1950) they started their first periods at age 15.2. By 1960 the age of menarche was 13.9, by 1970 it fell to 12.5--just like little white girls in the United States. The slowest onset of maturity, with an mean age of menarche of 18-19 years, was observed in women of Papua New Guinea in the 1960s--a time when the people ate a nearly vegetarian, very low-fat diet.

CAUSE OF EARLY MATURATION

The gradual shift from a plant-based diet to a diet of animal-based, high-fat, highly-processed foods has resulted in every society in a decrease in the age of onset of maturity of the boys and girls. Many investigations have come to this "diet-menarche connection" by looking at different aspects of the eating. For example, protein-rich foods, especially beef and pork, and low-fiber diets, which, of course, mean diets high in meats, dairy products, and processed plant foods, have been found associated with earlier menarche (Am J Clin Nutr 54:805, 1991; Hum Biol 28:393, 1956; Int J Cancer 28:685, 1981). Vegetarians have also been observed to have a later onset of menarche, compared to nonvegetarians (Nutr Res 7:471, 1987). Vigorous exercise has also been shown to delay the onset of menarche (Br J Cancer 55:681, 1987; Am J Epidemiol 138:217, 1993). A common pathway for the effects of diet and lifestyle (mostly exercise) on menarche is female sex hormones, primarily estrogen. Earlier and greater rises in hormone activity bring on earlier puberty. Estrogen promotes the development of secondary sex characteristics: causing uterine growth, thickening of the vaginal tissues, and development of the breasts; and along with other hormones, the final signal that a little girl is now a woman capable of childbearing, she starts to bleed (menstruation).

ESTROGEN FROM OUR FOOD

There are several ways in which our diet brings earlier and stronger estrogen effects to a little girl's body:

Obesity is one cause of higher estrogen levels. Male hormones called androstenedione made in the adrenal gland and ovaries are converted in the fat (adipose) cells into estrogen (estrone). The fatter a person, the more hormone produced (Am J Obstet Gynecol 130:448, 1978). Obesity in children, especially in young girls, is on the rise; therefore this is becoming an even more important source of female hormone, as Americans eat more fat and calories.

Other sources of estrogen result from the kinds of bacterial populations growing in the intestine. When fed a high-fat, low-fiber diet, the large bowel will grow bacteria that have the ability to convert bile acids into sex hormones, which are then absorbed through the gut wall and into the blood stream (Lancet 2:472, 1971). Bile acids are produced by the liver for the purpose of digesting fats. The more fat consumed, the more bile acids flow into the intestine to be converted to sex hormones.

A high-fat diet also raises a woman's estrogen levels by recirculation her own estrogen. Estrogen, made in the ovaries, is secreted into the blood stream where it circulates throughout the body affecting the breasts, uterus, ovaries, skin, and other tissues. After one complete passage, all of it is then removed by the liver and excreted into the intestine. To prevent re-absorption by the intestine, this hormone is combined in the liver with a non-absorbable substance. A high-fat, low-fiber diet, especially one high in meats, encourages growth of the bacteria in the colon that produce enzymes that break apart these non-absorbable, estrogen-complexes. The "freed" hormone is then absorbed back into the blood stream for another circulation. The net effect is higher biologic activity of estrogen in a woman's body
(Rev Infect Dis 6(suppl1):S85, 1984; N Engl J Med 307:1542, 1982).

The intake of high-fat foods--especially fish, meat, eggs, fats and oils, and dairy products--is the primary source of environmental chemicals in the American population. These chemicals are attracted to, and concentrated in fat--the fat in our foods and the fat in our bodies. Many of these chemicals (mostly pesticides), such as atrazine, DDT (its metabolite DDE), dieldrin, endosulfan, and toxaphene have an estrogenic effect. When studied singly these chemicals may have only a weak estrogenic effect. However, when the chemicals were tested in combination estrogenic activity shot up 160- to 1600-fold (Science 272:1489, 1996 & 272:1418, 1996). Americans used a record amount of pesticides, insecticides, and herbicides in 1995 despite claims by the chemical industry and farmers that they are cutting pesticide use (BMJ 312:1498, 1996).

Another interesting source is from dairy products. In modern dairy farming most dairy cows are pregnant; however, unlike women, they continue to lactate. Pregnancy causes high levels of circulating estrogen in the animals body. As a result he milk produced by these pregnant cows contains high levels of estrogen (estrone) (Lancet 341:1392, 1993).

HARMING THE CHILDREN

Strong sexual drives keep people's thoughts focused on the members of the opposite sex (and sometimes the same sex), causing many to make irrational decisions and exhibit disturbing behaviors (you know this). Classroom antics, acts of bravado, and dangerous stunts are commonly performed by boys and girls in order to gain the attention from peers. This kind of behavior becomes more frequent and daring with the onset of sexual urges.

By no great surprise, early sexual maturation is associated with an earlier initiation of sexual activity and an earlier age of first pregnancy (Am J Epidemiol 119:765, 1984; J Early Adolesc Health Care 6:383, 1985). This means risking sexually transmitted diseases at a younger age, which can lead to serious health problems like painful herpes, infertility, and deadly AIDS. Three million teenagers suffer from sexually transmitted diseases annually. Earlier sexual activity can mean marriage at a younger age with a higher risk of divorce. More than 90% of teenage marriages end in divorce.

Teenage pregnancies are an expected consequence of early sexual activity. One million teenagers become pregnant each year and nearly half of them give birth. The birth rate for young teens (age 15 to 17) is steadily rising. Between 1986 and 1991 the rate increased by 27%. In 1991 nearly 4 in 100 teenagers had a baby between ages 15 and 17.

Children having children results in high rates of single motherhood, a disruption or discontinuation of the mother's education, and poverty. A teenage mother is at greater risk of pregnancy complications, such as premature and prolonged labor, and preeclampsia, than older mothers. The baby is also at greater risk, with 9% low-birth weight deliveries (under 5.5 pounds), compared to 7% nationally. Low-birth weight babies have a higher risk of complications, like respiratory distress syndrome and bleeding, and they are at a 40-times greater risk of death during their first month of life compared to a normal weight infant.

Children who reach sexual maturity later in life also eventually grow taller as adults (Southern Med J 82:443, 1989). The reason for this is that sex hormones close the growth (epiphysial) plates of bones, halting further longitudinal growth.

LATER CONSEQUENCES

Breast cancer is a hormone dependent disease, promoted by estrogen. Not surprisingly, early onset of menstruation is associated with a greater risk of breast cancer (JNCI:47:935, 1971). Women who start their menstrual periods before the age of 14 have an average age of onset of breast cancer of 55.1 years, whereas those who start their menses after age 14 have the average age of onset of 57.6 years. Furthermore, survivals from breast cancer were lowest for women who started their periods at or before the age of 11 years (Europ. J Cancer 12:701, 1976). The optimal age of onset of periods with respect to survival was age 15 years. Earlier Menarche is also associated with a greater risk of coronary artery disease (Am J Epidemiol 126:861, 1987).

SOLVING SOCIETY'S PROBLEMS

Developed countries, the United States being an excellent example, suffer overwhelming problems with their youth--gang violence, teenage pregnancies, illiteracy, classroom tyranny, and school dropouts. Problems untouched by billions of government dollars and countless social programs. One tangible step in setting our youth back on track is to feed them better. Feed them a starch-based diet that will allow our children to remain thinking, feeling, and acting like children for the correct number of years--until their late teens. Then when they have physically grown to adults allow them to develop those drives that are essential for our species to procreate. By no coincidence, the same diet this newsletter has advocated for the physical health of individuals is the same diet that could restore a whole lot of health to our society.

© John McDougall, MD, used by permission
http://www.drmcdougall.com

John & Mary McDougall