This month's Scientific American features an interesting article by Dina Fine Maron. "The Science of Health," addresses some of the factors involved in the increasingly earlier onset of puberty seen over time and across certain ethnic groups (whites, blacks and Mexicans are mentioned in the article).
Breast development, typical of 11-year-olds a generation ago, is now occurring in seven-year-olds and in some cases even in children as young as three. Boys too are starting puberty earlier than before, perhaps by as much as two years. This is a problem, since early puberty can set a child up for cancer and other diseases later in life.
Maron points the finger at obesity, "which appears to be the major factor sending girls into these uncharted waters." After all, in the past three decades the rate of childhood obesity has more than doubled. Yet while it is clear that obesity is part of the picture - fat cells secrete estrogen, which is the major hormone involved in puberty - I found it rather curious that the article's author neglected to mention what is most certainly the elephant in the room. Obesity's relationship to early puberty is not causal; it is concomitant. Both are effects.
What then is the cause of both obesity and early-onset puberty? A diet rich in high-fat animal products, including dairy foods, which are themselves rich in estrogen.
In countries where animal protein consumption is much less than what the standard American diet includes - for example in many parts of Asia - puberty onset occurs much later in a child's development. Throughout much of China the average age at menarche (first menstrual period) has been shown by survey to be seventeen years, a full six years later than in the United States!
And when we compare the increasing consumption of animal products over time (meat, egg and dairy consumption has skyrocketed since the appearance of fast food in the middle of the 20th century - McDonald's filed for a US trademark on the name in 1961) we see that it mimics the drop in average onset of puberty, which has fallen by 5 years since then, as obesity rates have risen.
Data linking animal protein consumption with early onset of puberty has been highlighted for decades and made popular in the works of T. Colin Campbell and John Robbins, among many other highly esteemed health experts.
Campbell writes: "The strong association of a high-animal protein, high-fat diet with reproductive hormones and early age of menarche . . . makes clear that we should not have our children consume diets high in animal-based foods."
Robbins showed nearly three decades ago, in his book A Diet for a New America, that the more animal fat eaten, the earlier the onset of puberty, and the more cancer. He includes a chart indicating that Japanese girls are reaching puberty several years younger than their ancestors did, which is due to dietary changes, specifically the replacement of traditional rice and vegetable fare with a diet much higher in animal fat. And the chart was from 1978! How much worse things have become since then!
I'd expect a periodical such as Scientific American, which prides itself on being at the forefront of medical breakthroughs, to catch up with the times, especially as concerns a topic with such far-reaching ramifications.
Blaming obesity allows scientists, who may or may not be influenced by special interest groups (like meat and dairy) to avoid the conversation of what particular foods are the biggest contributor to weight, and as many make a case for refined carbohydrates (bread, pasta, chips, candy, sodas), meat can duck under this doughy, frosty umbrella.
But as Neal Barnard, head of the Physician’s Committee for Responsible Medicine, writes: “It is easy to blame sodas when we have not come to terms with our collective addiction to the meat and cheese that are making us and our kids fat - or when we lack the courage to confront the industries that sell them.”
Until we do, make your life your message and eat the foods you wish your children would eat so they will too.