Posted on 11/21/2008 11:19:16 PM PST by neverdem
Mice eating high-fat foods confer changes on at least two subsequent generations.
You are what you eat, and so are your progeny and, perhaps, your progeny's progeny — at least, if you're a mouse.
According to research presented at the Society for Neuroscience's 38th annual meeting in Washington DC held from 15–19 November, mice fed on a high-fat diet throughout their pregnancies and suckling had offspring that were larger than normal — a trait that was also passed on to their offspring's offspring.
It is the first time that a gestating mother's diet has been shown to confer this trait on to two consecutive generations.
Long-term impact The work is part of a larger study being conducted by neuroscientist Tracy Bale and her colleagues at the University of Pennsylvania in Philadelphia. "We wanted to know if the current increase in rates of obesity we are seeing all over the United States could have a longer-term impact," says Bale.
The mice descended from mothers on the high-fat diet were about 20% heavier than those descended from mothers kept on normal food. They were not much fatter, but they were significantly longer. They also tended to overeat, whether or not they themselves were on a high-fat or normal diet. And they were insulin-insensitive, a feature of diabetes that frequently leads to obesity.
Their own offspring — the second generation after the mothers on a fatty diet — did not overeat, but were large and insulin-insensitive. These traits were not just inherited through the female line: male pups born to mothers on a high-fat diet also transmitted them to their own offspring.
Biochemical modifications The scientists wanted to know which genes were involved in passing on these traits. When they looked at the brains of these mice, they found epigenetic changes in the hypothalamus, a brain area involved in the control of feeding behaviour. Epigenetic changes — biochemical modifications (such as methylation) that affect the functioning of DNA without altering its nucleotide sequence — can be induced by environmental factors and can be inherited. The team is now searching for the specific genes whose methylation state is changed in these mice.
The mice in the experiment did not get fat, probably because mice do not usually have this tendency. But, in similar circumstances, humans would feel the effects, because overeating predisposes people to obesity, says Bale. If people inherit both a tendency to overeat and insulin insensitivity, then the cycle of pathological obesity will be hard to break, she says.
If the genes involved in transmitting the tendency towards obesity are identified, "then at least we can be encouraged to make decisions conducive to our health — and that of our children, and our children's children," says Bale.
Neuroscientist Li-Huei Tsai, of the the Picower Institute for Learning and Memory at the Massachusetts Institute of Technology in Cambridge, chaired the session in which Bale's work was presented. "Epigenetic modification of the brain, so that environmental factors can change behaviour and well-being in a heritable way, is one of the major recent advances in brain research over the last decade," says Tsai.
Another reason why fat people should not reproduce.
That’s really interesting. Thank you for posting this.
And they cause you harm exactly how?
The scientists wanted to know which genes were involved in passing on these traits. When they looked at the brains of these mice, they found epigenetic changes in the hypothalamus, a brain area involved in the control of feeding behaviour.
Too bad they didn't specify which generation, but this is fascinating stuff. IIRC, this is the second time I came across a prior generation's diet having an effect on their descendents outcome. The first was a famine in a Scandinavian country about a hundred years ago where they kept good records, and they checked on type II diabetes in the grandkids. It was on a PBS show about epigenetics.
Those pinheads probably are sitting on compelling statistical evidence that obesity is also related to one’s great great aunt’s choice of lip gloss and the number of registered Democrats in a given household.
I’m sure you wrote that comment on the spur-of-the-moment, not meaning to actually offend anyone. Am I correct?
I was just being facetious. Its an interesting article.
Very good.
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FReepmail me if you want on or off my health and science ping list.
Are you familiar with the concept of epigenetics?
damn, i thought obesity was mostly from your OWN diet. too much fork and spoon action....
the next time my carpi’s are too tight i know who to blame! never mind the half pan of double fudge caramel coated brownies i ate and the pesky fact that my grandparents, parents and kin are all wafer thin....and all three of my kids...
FREERIDE so you can eat whatever you want!
It occurs to me that epigenetics might allow for much faster adaptation to environmental changes than random mutations. Think of it as "sleeper genes" in DNA ready to turn on when changes in the environment occur.
This is good reason why one should not become a fat pot smoking DemonRAT. The grandchildren will have be in a permanant state of the munchies and constantly forgetting things like how to tie your shoes and the Constitution.
My experience may be anecdotal, but it is exactly opposite of the example given in the study.
My paternal grandparents ate lots of fat. Farm folk, nothing was cooked w/out a good helping of lard. My grandfather’s favorite part of a ham was the crackle, they ate fatback, and fried chicken (I don’t think I ever had chicken any other way than fried at my grandparents.) Biscuits with butter, eggs, bacon and gravy for breakfast, etc. Both lived into their 80’s and neither was overweight. Their 10 offspring were all on the normal to thin side.
My maternal grandparents ate far less fat. The typical meat, one starch, vegetable and salad meal. Breakfast was always cereal, oatmeal, cream of wheat, etc. And I don’t think I ever had fried anything there. All of their offspring (4) tended to have to battle weight their entire lives. My grandparents died at young ages, my grandmother in her early 60’s.
As to the grandkids, it’s a mixed bag. None obese, but once we hit our late 40’s, even with a very healthy diet, we all had to start limiting calories in order to win the “battle of the bulge.”
I assume this was an impulsive attempt at humor...
Interesting article. Thanks for the ping!
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