A moderately high protein diet could reduce a woman’s chances of becoming pregnant, according to new research presented at the 20th annual conference of the European Society of Human Reproduction and Embryology today on Monday 28 June.
Researchers from the USA have found that a diet containing 25% protein disrupted the normal genetic imprinting pattern in mice embryos at a very early stage in their development. The diet also adversely affected subsequent embryo implantation in the womb and foetal development.
The research was carried out by a team led by Dr David Gardner, Scientific Director of the Colorado Center for Reproductive Medicine, Englewood, USA,
Dr Gardner said: “Although our investigations were conducted in mice, our data may have implications for diet and reproduction in humans.”
Previous research has shown that the amount of protein in the diet affects the levels of ammonium within the female reproductive tract in cows and mice. It is known that ammonium adversely affects mouse embryos developed in culture in the laboratory, inducing altered imprinting of the H19 gene and retarding foetal development. The H19 gene, found on chromosome 7, is an important gene involved in growth.
Normally, genes act in the same way, whether they are transmitted by the mother or the father. But, a few genes break this genetic rule. Whether they are switched on (expressed) or off depends on whether they are inherited from the mother or the father. The process of inheriting specifically from the mother or the father is called imprinting.
Dr Gardner set out to discover the effect of a moderately high protein diet on imprinting and the viability of mouse blastocysts (early embryos) during reproduction in the living animal.
He fed mice on a diet containing either 25% protein (moderately high) or 14% protein (as the control group) for four weeks. The mice were mated and 42 of the resulting blastocysts were examined to discover the imprinting status of the H19 gene; 174 blastocysts from mice on both diets were transferred to mice eating a normal diet in order to discover the effects of the maternal diet during the preimplantation stages on subsequent foetal development.