Diet Linked to Twin Births
Scientific American
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Over the last 30 years, the number of twin births has nearly trebled. This rise seems to have followed the introduction of in vitro fertilization and a preference for having children later in life. But in the mid-1990s, doctors began limiting the number of transferred embryos and still the proportion of twin births rose. Now new research seems to show that growth hormone in the food supply may be responsible.
"The continuing increase in the twinning rate into the 1990s, however, may also be a consequence of the introduction of growth hormone treatment of cows to enhance their milk and beef production," argues physician Gary Steinman of the Long Island Jewish Medical Center.
Steinman and his international colleagues solicited answers on a questionnaire from mothers. He then compared the number of twin births from those who consumed meat and/or milk and those who consumed no animal products at all. The omnivores and vegetarians were five times more likely to have twins than the vegans.
Steinman argues that insulin-like growth factor, a protein released by the liver in response to growth hormone, may be the reason. Studies have shown that the protein increases ovulation and that it persists in the body after entering via digested food, particularly milk. Daily drinking of a glass of milk over a 12-week period raised levels of the protein in the body by 10 percent and vegan women have 13 percent lower concentrations of it in their blood.
May 22, 2006
Scientific American
_____________
Over the last 30 years, the number of twin births has nearly trebled. This rise seems to have followed the introduction of in vitro fertilization and a preference for having children later in life. But in the mid-1990s, doctors began limiting the number of transferred embryos and still the proportion of twin births rose. Now new research seems to show that growth hormone in the food supply may be responsible.
"The continuing increase in the twinning rate into the 1990s, however, may also be a consequence of the introduction of growth hormone treatment of cows to enhance their milk and beef production," argues physician Gary Steinman of the Long Island Jewish Medical Center.
Steinman and his international colleagues solicited answers on a questionnaire from mothers. He then compared the number of twin births from those who consumed meat and/or milk and those who consumed no animal products at all. The omnivores and vegetarians were five times more likely to have twins than the vegans.
Steinman argues that insulin-like growth factor, a protein released by the liver in response to growth hormone, may be the reason. Studies have shown that the protein increases ovulation and that it persists in the body after entering via digested food, particularly milk. Daily drinking of a glass of milk over a 12-week period raised levels of the protein in the body by 10 percent and vegan women have 13 percent lower concentrations of it in their blood.
May 22, 2006
