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PFAS. A widely used class of chemicals in industrial and consumer goods has been linked to higher weight gain after a diet. Research from Harvard shows that women are particularly affected.
Obesogens
It concerns the class of PerFluor-Alkyl Substances (PFAS). These substances have previously been associated with cancer, disrupted hormone balance, immune system disorders, and obesity. PFAS are seen as obesogenic substances because they can have a disrupting effect on body weight regulation.
Research from Harvard has shown that higher levels of PFAS in the blood were associated with a lower resting metabolic rate (RMR). This means that during normal daily activities, you burn fewer calories. The same diet then leads to higher weight. The results were published last week in PLOS Medicine [1].
Obesogens have been linked with excess weight gain and obesity in animal models, but human data has been sparse. Now, for the first time, our findings have revealed a novel pathway through which PFASs might interfere with human body weight regulation and thus contribute to the obesity epidemic
Qi Sun, Department of Nutrition, Harvard Chan School.
PFAS and Weight Gain
The researchers, together with colleagues from Louisiana State University and Tulane University, analyzed data from 621 obese people and people with overweight. These were part of the clinical trial
Prevention of Obesity Using Novel Dietary Strategies (POUNDS LOST). This research was conducted about ten years ago and compared the effect of four (heart-healthy) diets. Participants followed the diet for 6 months and were then followed for another one and a half years. The researchers from Harvard and colleagues used this data to see if there was a relationship between the amount of PFAS in the blood and weight over those two years.
In the first six months of the clinical trial, participants lost an average of 6.4 kilos. In the following 18 months, they gained an average of 2.7 kilos. The people who regained the most weight also had the highest concentrations of PFAS in their blood. This association was strongest in women. Women in the group with the highest concentrations of PFAS gained the most weight. On average, 1.7 to 2.2 kilos more than the women in the group with the lowest concentrations. As mentioned, the RMR was also lower in the group of women with high concentrations of PFAS.
According to the researchers, we should not only associate PFAS with scary diseases. Obesity is a major health problem worldwide. Avoiding PFAS is therefore recommended by the researchers. However, one might wonder if it makes sense to worry about PFAS here and now.
Personally, I find it a bit of a storm in a teacup.
PFAS
PFAS have been used since the sixties in various products from clothing to food packaging. The American 3M (known by the older generation for floppy disks) was the largest user worldwide. Since the seventies, concerns have been raised about potential health effects.
Multiple studies have shown that PFAS have contaminated drinking water near industrial sites and military bases. They can accumulate in water and the food chain and thus end up in your body. Unfortunately, they can linger there for a long time. Depending on the type of PFAS, the way it is used, and the purpose for which it is used, it can reach your body in various ways. Tons of PFAS have ended up in seawater, freshwater, and drinking water [2].
PFAS in the Netherlands
The highest concentrations have been found in the Dutch rivers in the Rhine near Lobith. In 1993, a major study showed that there was a global contamination with PFAS. 3M decided to completely phase out the use by 2000.
Since then, regulations have been significantly tightened [2]. Also, more and more research is being done to map the extent of contamination as accurately as possible [3]. Depending on the type of PFAS and the region, however, we see differences in the current development of detected amounts in people. Especially in Europe, we see a sharp decline in some PFAS concentrations in the blood of people since stricter regulations were introduced in 2006. Only in a few industries is the use still allowed (such as coatings for films and hydraulic fluids for airplanes and firefighting foam).
In the Netherlands, one might wonder to what extent one still needs to take action. Here it is legally stipulated that the quality must be safe for unfiltered use. The research uses 10-year-old American data. Here we have a bit more confidence in our government’s protection. Guns are for the police and water filters for water companies. Let’s keep it simple.
References
- Gang Liu, Klodian Dhana, Jeremy D. Furtado, Jennifer Rood, Geng Zong, Liming Liang, Lu Qi, George A. Bray, Lilian DeJonge, Brent Coull, Philippe Grandjean, Qi Sun. Perfluoroalkyl substances and changes in body weight and resting metabolic rate in response to weight-loss diets: A prospective study. PLOS Medicine, 2018; 15 (2): e1002502 DOI: 10.1371/journal.pmed.1002502
- dare.uva.nl/search?metis.record.id=399874
- expertisecentrumpfas.nl/application/files/8515/0702/5617/Kennisdocument_PFAS_hoofdstuk_veldwerk_en_analyse_v1-2.pdf
