Environmental pollutants - could they be causing weight gain?

There's been quite a lot of research in recent years on the impact of various pollutants on weight gain. About four years ago, a Spanish study linked exposure to hexachlorobenzene (HCB) in the umblicial cords of newborns, and found that those who'd been exposed in the womb were more likely to be overwieght at six. (This chemical is mainly used to treat seeds, so it had implications for those living in and around agricultural areas.)
Now there's new evidence that perfluorooctanoic acid (PFOA) may also be linked to weight gain. PFOA is ubiquitous - it's found even in the middle of the Pacific Ocean and all the inhabited continents, and is now found in animals, poor sods. It's been made since 1951, and was used in non-stick surfaces (they say it's not anymore), outdoor clothing, treatments for carpets and tiles and more.

Environmental pollutant linked with overweight

The levels of the environmental pollutant perfluorooctanoic acid (PFOA) that mothers had in their blood during pregnancy increased the risk of obesity in their daughters at 20 years of age. The findings come from a recent study of Danish women in which the Norwegian Institute of Public Health participated.

In recent decades, there has been a sharp increase in the number of overweight children and adults worldwide. It is suspected that diet and exercise alone cannot explain this large weight increase.

Researchers suggest that the increasing levels of endocrine disrupters in the environment may be a possible contributing factor. Therefore, this study was established and discovered the following:

Daughters of mothers with the highest concentrations of PFOA in the blood during pregnancy were three times as likely to be overweight at the age of about 20 years as daughters of mothers with the lowest PFOA levels.
The calculations took into account many variables, such as maternal weight and lifestyle factors.
An association was also found between PFOA exposure before birth and elevated levels of insulin and leptin, two hormones that are linked to obesity.
Levels of insulin and leptin were also elevated in the sons of mothers with high PFOA, but the relationship was weaker than for girls.
There was no increased risk of development of obesity among the sons.

What does this mean for us?

It is still too early to say what this might mean for us. The study indicates that factors such as environmental pollutants, in addition to diet and physical activity, play a role in the obesity epidemic seen today although this remains to be confirmed by similar studies.
EurekAlert, 22 February 2012