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Good
Nutrition Can Reverse
Genetic Pre-Disposition To Obesity
In a study by the Liggins Institute, Southampton University and
AgResearch to be published this week in a United States journal,
the researchers describe molecular changes that can occur after
dietary intervention in early childhood.
Liggins director Professor Peter Gluckman, one of the researchers,
said it also showed that genetic switches set in the womb could
be reversed by nutritional changes in early childhood.
"It changes the way we should think about tackling the obesity
epidemic," he said from Britain last night.
"It's probably the most important intellectual breakthrough we've
made in understanding development."
In the experiments, the newborn offspring of well-fed and undernourished
female rats were dosed with leptin, a hormone that signals to
the body when it has eaten enough. When the young rats became
adults, the long-term effects were measured by checking genes
that regulate metabolism in the liver.
Hormones, especially leptin, regulate the body's ability to
burn fat. Leptin is released when sugar is metabolized in fat
cells, and if you eat a diet that causes excessive surges in leptin,
you will create disease. The standard American diet (SAD) is a
perfect example of the type of diet that will cause you to become
leptin-resistant, meaning your brain can no longer hear the signals
telling it to stop eating and storing fat.
Rats from well-fed mothers reacted to leptin in the opposite
way to those from undernourished mothers.
Professor Gluckman likened the process to female honey bees developing
as either queens or workers, depending on whether they were fed
royal jelly as larvae.
"This is the first suggestion that this fundamental biological
process operates in mammals, and has major implications for addressing
issues such as obesity," hesaid.
"Not everyone is the same - gene switches have been moved in
early development to make some more or less sensitive to fat in
the diet."
Co-researcher Dr Alan Beedle said the study, to be published
in the Proceedings of the National Academy of Sciences,
dispelled the common idea that a person's life course was set
by their genetic make-up at birth.
"It's really development, and modifiable factors during development,
that can change how we grow and what diseases you are susceptible
to as an adult," he said.
The study's message for developed nations was that mothers should
eat a balanced diet during pregnancy, with the right amounts of
protein and vitamins.
And if a fetus was under-nourished in the womb, it might be possible
to detect that by a blood test at birth and correct the condition
with good nutrition.
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