Wednesday, 27 April 2011

Theme of the week: "Can your diet in pregnancy make your baby fat?"

To me, it seems rather obvious that one's diet during pregnancy will affect the unborn child. Anything you eat will be processed by the gut and substances, whether they are nutritious or not so nutritious, will be passed on to the foetus via the placenta. After all, the only way it has access to food is through its mother!

Plus, as a scientist in physiology and neuroscience, I know for example that certain nutrients (sugar!!) actually change the wiring in your brain, and, in the case of sugar increase your liking of sugar (yes this sounds a lot like how addiction works...). I don't know whether this happens in foetuses as it does in adults, as their brains haven't fully developed yet, but I imagine that what you eat during pregnancy might have an effect on your child's (brain) development, and on how your child deals with hunger and satiety later on in life.

Thus, I wasn't surprised to read about a recent study in which a link has been found between a mother's diet during pregnancy and her child's body fat level at the age of 6 or 9.
It made me think, though, that mother's (or I should say "parents", really!) are the main influence on their kid's health not only before, but also after birth, because they are (or should be!) cooking their daily dinners. So whether it happens before or after birth, a child's level of body fat will depend on what its parents are feeding it (ah, let's discuss 'nutritious' school lunches some other time!).

So, is it important to know whether a mother's diet also affects a childs fat levels before birth? Everyone knows that healthy food is important in general, and when pregnant in particular. I think mothers have a responsability to make sure that their unborn babies are not negatively affected by their mother's behavior, be it by drinking, smoking or the things they eat. I thought this was common sense, so I was shocked to read in the research paper that a mere 24-31% of all mothers included in the study were actually smoking during pregnancy...

Furthermore, I think to only study a child's fat levels is giving a rather limiting picture. I do realise that researchers need to start somewhere if they want to build a clear picture of how things work, but I also think that there's too much focus on fat, in the news, in commercials, fashion, health information etc.

What do you think?
Do we need more studies to tell us how important healthy food is? How important healthy behaviour is?
Should we focus on fat this much?
Why is it so difficult to behave healthily when there is so much information about how damaging certain behaviors (smoking, drinking, bad diet etc) are?
Are people deliberately ignoring this kind of information or is the addiction that strong?

Please share your opinions on this topic with us!!

For more background, you can read the article on the NHS website
The original article is publised in Diabetes 2011, published online April 6.

1 comment:

  1. As a follow up to this post, below is an extensive list of comments by Peter Voshol (integrative physiologist @ Cambridge University), who has access to the original research paper published in Diabetes.
    The study appears to have some flaws which make it difficult to draw solid conclusions, let alone be a basis for diet advice to pregnant women. And in any case, at The Therapy Room, we prefer to see people as individuals, needing individual dietary advice based on their individual bodies and life styles rather than generalized statements like 'eat more/less carbohydrates' (ehh, which kind of carbohydrates??) or 'eat more/less fat' (ehh, which kind of fats??).

    So here are Peter's comments, please be encouraged to share your opinion with us!

    Dear all,
    Here you have the original paper. Excuse the very technical manuscript. Basically they looked at ‘methylation’ of 5 candidate genes in the umbilical cord. Methylation is measuring with very expensive equipment how much methyl-groups (CH3) are attached to a piece of DNA (Genes). The ‘candidate genes’ are ‘selected’ from 78 genes that are in some way ASSOCIATED with obesity in humans and animals. They ‘selected’ 5 which had the best correlation with fat mass measurements of the children at the age of 9 years. Furthermore, food questionnaires where takes from the pregnant mothers at gestation week 15 to ‘assess’ dietary intake. And then they do a lot of statistical analysis to show associations between amount of methylation and fat mass at 9 years. And separate association between carbohydrate intake in the mothers at week 15 of gestation and amount of methylation of the ‘selected’ genes.
    1) Low carbohydrate intake is associated with higher methylation
    2) Higher methylation is associated with higher fat mass (weight and percentage) at age 6 and 9.

    1) 15 umbilical cord where tested.
    2) It is unclear whether the food intake questionnaires are in any way related to the mother of the specific 15 children that were analyzed at age 9?
    3) There does not seem to be any food intake questionnaires with the second study age 6 year old children. That only shows an association between methylation state and fat mass.
    4) What is the functional effect of the methylation on the ‘selected’ genes? And is that relevant in other ‘organs’ then the umbilical cord? Animal work suggest that but still not functional!
    5) Which carbohydrate intake, a calorie is not a calorie and equal a carbohydrate is not a carbohydrate of course? And when?
    6) Food intake and environment of the children growing after birth till 6 or 9 years, so life-style growing up? How does this influence the body fat mass?
    7) Where the mothers overweight during pregnancy and thus this influence methylation in the umbilical cord/foetus?
    8) Are these children overweight/adipose? The 6 year old seem to have more fat then the 9 year olds. Is this a generation effect? Or is this a growing effect (babies have more fat and slowly lose this during growth)? Is 20% fat in 9 year olds fat?
    9) They say the effect of the methylation is greater than that of birth weight (which has a predicting effect on body weight and fat mass) as they have shown in a previous paper. Looking at that paper you see actually that indeed mother BMI/fat mass is associated with the children’s fat mass at age 9 but they do not mention that in this study (or correct for that?).
    10) IT IS ALL ASSOCIATION AND NOT ANYTHING CAUSAL!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    Overall of course of interest for basic science to understand epigenetics, the genetic imprinting done by ‘environmental circumstances’ on mother and father before and during conception! But it is far off from anything specifically useful as guideline for nutrition, function, meaning age 6 or 9 and then adulthood of course or even understanding why?

    So perhaps this can be used as a comment.

    Thanks and warm regards,