Tuesday, April 19, 2011
Pregnant Woman's Diet Affects Child's Obesity Risk
In a Nursing class i once took, i remember my Professor saying that all the weight you really need to gain during your pregnancy is about 25 to 30 pounds, and to be completely honest that's completely fine,its just hard controlling the cravings, and as much as i want to try to stay within that weight group once I'm pregnant i know it will be easier said then done.
What a woman eats when she is pregnant can affect her child's risk of obesity, regardless of how fat or thin she is, and what her baby weighs at birth, according to a new study published in the journal Diabetes recently.
The British Heart Foundation said the study provides strong evidence of the need to help women of child-bearing age follow a healthy lifestyle and diet.
Led by Southampton University in the UK, and including members from New Zealand and Singapore, the international team of researchers found that a process called epigenetic change alters the function of an unborn baby's DNA in response to changes in the mother's diet.
These changes can be detected by sampling the umbilical cord at birth for "epigenetic markers" of obesity risk.
Using these epigenetic markers, the researchers were surprised to find they could predict 25% of the variation of fatness in the 300 children when they reached the age of 6 or 9 years.
The children were born to mothers who had participated in two longitudinal studies based in Southampton.
Previous studies on animals had already shown that the mother's diet in pregnancy affects offsprings' body composition, and results in epigenetic changes in genes that control metabolic processes, but until this study, it was not clear whether this also happened in humans.
Study leader Keith Godfrey, Professor of Epidemiology and Human Development at the University of Southampton, told the press this was the first time a study has shown that it is not just genes and lifestyle that affects our risk of obesity, but also what happens while we grow in our mother's womb, including what she ate.
"A mother's nutrition while pregnant can cause important epigenetic changes that contribute to her offspring's risk of obesity during childhood," said Godfrey.
Epigenetic changes, which affect how DNA is expressed without actually changing the coding sequences passed down to the child from its biological parents, also influence how our bodies respond to lifestyle factors like diet and exercise.
For example, epigenetic changes can affect how DNA instructions are interpreted in the creation of cells, proteins and other building blocks in the body.
One process that changes the expression of DNA is methylation, and the researchers in this study scanned the methylation status of 68 locations (called CpGs 5′) on 5 candidate genes in the umbilical cord tissue DNA of the children at birth.
They replicated the results with a second independent cohort.
For the study, the researchers used childhood adiposity or amount of fat mass as a measure of obesity rather than BMI.
They found that the epigenetic markers explained at least 25% of the variance in childhood adiposity or fatness, and in the first cohort, methylation of a gene called RXRA and another called eNOS were independently linked to childhood fat mass.