This is a (temporary only) link to a New York Times article cited in this post.
http://www.nytimes.com/2003/10/07/science/07GENE.html
......
Two things are true I thin k, almost beyond dispute. First, persons who become significantly overweight or downright obese do so because they are consuming more energy (calories) than they are expending through activity. Second, the number of persons in the overweight/obese category has skyrocketed during the past two decades.
Let’s make a hypothetical model here. Consider the town of Francouersville, with a population that has remained constant at 100 over the past two decades. In 1983 there were 10 people who were overweight, and 5 of these were obese. In 1993, 20 people were overweight. and 10 of these were obese. In 2003, 50 people were overweight, and 30 of them were obese.
Something else remains constant: the overweight and the obese are in that condition because they consumed more than they expended, whether they were 10 out of 100, 20 out of 100, or 50 out of 100. This fact is true of every one of these persons, whatever the year.
But this explanation, which is valid of every individual, does not seem to me to explain in any adequate way, the increase over time in the incidence of overweight/obesity. We might say that in the last 30 years dietary will power—the ability of individuals to make good choices about what they eat and how much they eat—has decreased precipitously. But although that explains why there has been an increase in corpulence, there remains the question: why has dietary will power decreased?
Various explanations have been offered for the increased incidence of significant weight problems_ urban sprawl, television, fast food restaurants, and so on and on. And indeed, these may be contributing causes.
But I’ve got another hunch, a glimmer of an entirely hypothetical and speculative explanation. It came yesterday (October 7) in a New York Times science section piece, “A Pregnant Mother’s Diet May Turn the Genes Around.” The story dealt with fat yellow mice, which were both fat and yellow because of a single gene. The mice were so nearly pure-bred strains that their offspring would be genetically identical, yet in some instances the genetically identical offspring proved to be thin and brown, and also significantly longer lived.
The story introduced me to an area of scientific inquiry I’d never even heard of, epigenetics. (Look it up on Google if like me you’re uninformed about it.) There’s a lot of technical vocabulary, like “methylation,:but the upshot is that various things during pregnancy, diet being chief among them, can influence the expression of genes in the offspring that result from their parents’ mating. Everything, it would seem, is not determined at the moment of conception, by the genetic material in a single sperm cell and a single ovum. The resulting DNA is subject to interuterine influences.
Below are some excerpts from the NYT article:
“Scientists have long known that what pregnant mothers eat -
“whether they are mice, fruit flies or humans - can
profoundly affect the susceptibility of their offspring to
disease. But until now they have not understood why, said
Dr. Randy Jirtle, a professor of radiation oncology at Duke
and senior investigator of the study, which was reported in
the Aug. 1 issue of Molecular and Cellular Biology.
“The research is a milestone in the relatively new science
of epigenetics, the study of how environmental factors like
diet, stress and maternal nutrition can change gene
function without altering the DNA sequence in any way.
“Such factors have been shown to play a role in cancer,
stroke, diabetes, schizophrenia, manic depression and other
diseases as well as in shaping behavioral traits in
offspring.
“Most geneticists are focusing on sequences of genes in
trying to understand which gene goes with which illness or
behavior, said Dr. Thomas Insel, director of the National
Institute of Mental Health. "But these epigenetic effects
could turn out to be much more important. The field is
revolutionary," he said, "and humbling."
...
“Fleeting exposure to anything that influences methylation
patterns during development can change the animal or person
. More than a decade ago, for example, epidemiological
studies showed that some women who ate diets low in folic
acid ran a higher risk of having babies with abnormalities
in the spinal cord and brain, called neural tube defects.
“To reduce this risk, folic acid was added to grains eaten
by all Americans, and the incidence of neural tube defects
fell substantially. But while there is no evidence that
extra folic acid is harmful to the millions of people who
eat fortified grains regularly, Dr. Waterland said, there
is also no evidence that it is innocuous.
“The worry is that excess folic acid may play a role in
disorders like obesity or autism, which are on the rise, he
said. Researchers are just beginning to study the question.
...
“Epidemiological evidence shows that undernutrition and
overnutrition in critical stages of development can lead to
health problems in second and third generations, Dr.
Waterland said.
“A Dutch famine near the end of World War II led to an
increased incidence of schizophrenia in adults who had been
food-deprived during the first trimester of their mothers'
pregnancy. Malnourishment among pregnant women in the South
during the Civil War and the Depression has been proposed
as an explanation for the high incidence of stroke among
subsequent generations.
“And the modern American diet, so full of fats and sugars,
could be exerting epigenetic effects on future generations,
positive or negative. Abnormal methylation patterns are a
hallmark of most cancers, including colon, lung, prostate
and breast cancer, said Dr. Peter Laird, an associate
professor of biochemistry and molecular biology at the
University of Southern California School of Medicine. “
-----------
What I’m thinking is that few of us, surely the majority, have the slightest idea what we
are putting in our mouths after a visit to the grocery store, if we buy processed foods, foods loaded with high fructose corn syrup, and so on. We know even less about the side effects of “pixiliated apochryphal pseudo-sodium hydrogenated testis extract with cantharides flavor.” Could it be that mothers who consume this stuff pass on to their children whatever it is that leads to obesity/lack of willpower?
My wife is downstairs making cookies, trying a new recipe. The ingredients are things like flour, sugar, lime juice, lime peel, butter. Not all of them are conducive to health in large quantity. But we know what they are, and the recipes are age old.
Linear Mode
