December 17, 2003
According to a new British study, defiency of the trace mineral selenium might quadruple the risk of pre-eclampsia in pregnant women.
According to British researchers, pregnant women with a low content of the vital trace mineral selenium have up to four times as high a risk of developing pre-eclampsia compared to women who are not deficient in this substance.
This is the result of a new study published in the November issue of the American Journal of Obstetrics and Gynecology. The researchers behind the study are not quite aware why some women develop pre-eclampsia which involves hypertension, kidney damage, and reduced blood supply to the placenta.
They suggest, however, that it might be connected with the decreasing intake of selenium in several countries. In Britain, the selenium content of wheat is 10 – 50 times lower than that of the USA and Canada, for example, making it difficult to maintain an adequate intake of this important substance.
The risk of premature delivery
In the recently published study made by a group of scientists led by Dr. Margaret P. Rayman at the University of Surry in Guildford, the toe nail clippings of 53 pregnant women with early signs of pre-eclampsia were studied and compared to toe nail clippings from 53 healthy women. Selenium accumulates in nails which makes nail clippings such a good gauge of people’s selenium status.
The researchers observed that the average selenium content of the toe nail clippings were considerably lower in the women with early signs of pre-eclampsia. The researchers also found that the pre-eclamptic women with the lowest selenium values were far more likely to deliver prematurely.
One of the reasons for pre-eclampsia is believed to be oxidants (a kind of toxins) that arise as a consequence of a poorly functioning placenta. As selenium is an effective antioxidant, it is very likely that a lack of this substance can contribute to the development of pre-eclampsia.
Worries of reduced selenium intakes
The leading researcher, Margaret Rayman, has expressed her concern about the declining intake of selenium in Britain where the dietary selenium intake is reduced by more than 50% compared to what it was 20 – 25 years ago. This is due to the selenium content of crops being significantly lower than it used to be.
“Selenium is an extremely important substance which is known to be able to prevent various forms of cancer, including prostate cancer and skin cancer. What really worries me is the observation that the authorities systematically reduce the recommended daily dose of selenium while new research shows just how important it is to get adequate amounts of this substance. 15 – 20 years ago, the recommended daily dose (RDA) was 125 mcg. a day – recently the RDA was reduced to 40 mcg. This completely opposes common sense,” says Claus Hancke, the chairman of the Danish Vitality Council.
The British group of researchers are already planning a new study intended to clarify if dietary supplements of selenium can protect against pre-eclampsia.
By: Vitality Council
American Journal of Obstetrics and Gynecology (vol. 189, no. 5).