New research from New York State University has confirmed a link exists between Bisphenol A (BPA) and obesity. But there are a few caveats that reveal an even bigger link exposed in other research: The combination of sugary sodas in canned and plastic containers.
The NYSU medical researchers studied 2,838 kids between six and 19 years old, using the National Health and Nutritional Examination Survey between 2003-2008 (NHANES 2003-2008) The scientists compared the intake of the kids' urinary BPA levels with their BMI to determine the relative degree of obesity and general weight status. Out of the population, 1,047 qualified as obese and 590 of the kids were overweight. The researchers also cross-referenced the results with the kids' ages and ethnicity.
Their findings determined that while over 22% of kids with the most urinary BPA levels (highest quartile) were obese, only 10% of kids with the lowest BPA levels (lowest quartile) were obese.
More than twice the obesity rate is more than a strong association. The study's lead researcher Dr. Leonardo Trasande told HealthDay that, "BPA has been associated with adult obesity and heart disease," and the findings "raise further questions about the need to limit BPA exposure in children."
But the NYSU study also presented a wrinkle in the data. The association between BPA and obesity was primarily among teenagers of all races, and white children.
This has produced some skepticism regarding whether the relationship with BPA is solid enough, even though the obesity rates were more than twice for those with the most BPA in their urine overall, and other research has also found a definite link between hormone disruption and BPA, along with the potential for weight gain with higher BPA exposure.
For example, another recent study, this one from Shanghai's Jiao-Tong University School of Medicine, found that BPA exposure was related to higher levels of fat mass among women. The study tested 246 premenopausal women over 20 years old who were otherwise healthy.
Most convincing is another study, published this past July from the West Virginia University School of Medicine. This study also found a link between BPA and obesity, but this link was consistent across all genders and races. Interestingly, this study also used the National Health and Nutritional Examination Survey 2003-2008 data to collect the findings.
And the findings were just as stark. Those with the highest levels of BPA in their urine were nearly 70% more likely to be obese.
The difference between the West Virginia University study and the NYSU study? The West Virginia study tracked adult men and women, while the NYSU tracked kids aged six through 19 years old.
As we correlate the data from these two studies, we find that the connection between BPA and obesity is evident amongst all teenagers and all adults. The data is robust and the evidence clear.
This leaves the only yet-to-understand group being younger non-white children.
One of the confounders not discussed or eliminated in the research was breastfeeding. A 2012 study from Australia's Flinders University School of Medicine found that children who were breastfed were significantly less likely to be obese during their childhood than those who did not breastfeed.
Other childhood confounders also exist. Physical activity, diet of the mother and childhood diet are also factors that prove difficult to eliminate.
One of the most important factors to be considered between children and teenagers is the consumption of sugary sodas. Sodas provide the most popular vehicle for BPA consumption – from soda cans to plastic bottles of cola and other drinks.
In a 2011 study by the U.S. Centers of Disease Control, kids between the ages of 12 and 19 – teenagers – were the largest consumers of sugary sodas among all ages. Teenage boys consume an average of 273 kcal of soda per day, and teenage girls consume an average of 171 kcal of sugary drinks a day. This contrasts greatly from kids between six and eleven years old, who only consume an average of 112 kcal (girls) to 141 kcal (boys).
Adults aged 20 to 39 years old also drink less sugary drinks than teenagers, but not by much. They drink between 252 kcal (men) and 138 kcal (women). This is still dramatically higher than children, and almost at par with the teenagers.
This correlation indicates a clear relationship between BPA, sugary drinks and obesity, because after all, most sugary sodas are consumed in BPA containers. And numerous studies have found a link between obesity and the consumption of sugary sodas.
This connection is especially definite for sodas sweetened with high fructose corn syrup (HFCS). For example, in a study from Taipei's National Yang Ming University, kids who drank more HFCS sodas were between three and five times more likely to be obese than those who drank the least amount of HFCS-sweetened sodas.
What we find amongst this combination of research is what we might call a double-whammy: A sugary HFCS soda in a container made with BPA that disrupts hormones and stimulates fat cell growth. This double-whammy is what we are feeding our kids. It is also what our young adults are hooked on - a sugary sweet HFCS caffeine buzz in contaminated containers compounded by overeating and less activity. This combination is quickly turning America into, well, the land of blimps.
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