November is National Diabetes Awareness Month

The approach to diabetes management starts with the foundations of lifestyle modification such as diet, exercise, and sleep, but, this month, we want to explore a lesser known risk factor for metabolic dysfunction and diabetes that many may not be aware of: obesogens.

Obesogens are environmental chemicals that promote metabolic dysfunction and weight gain.

These chemicals are found in many different products such as plastic packaging, personal care and household products, as well as food and water.

Below, we outline some of the most common obesogens that we know of today, their potential effects, the available research, and a brief overview of mitigation strategies.

The most common obesogens are bisphenol A (BPA), phthalates, perfluoroalkyl substances (PFAS), organochlorine pesticides, and parabens. The evidence linking exposure to these chemicals with metabolic dysfunction, obesity, and type 2 diabetes is still limited, but below is a short synopsis of effects that have been studied:

Bisphenol A (BPA)

  • Multiple meta-analyses link BPA exposure with increased risk of obesity, insulin resistance, and type 2 diabetes 

  • These types of effects were found in both children and adults 

  • Some studies show that BPA may promote adipogenesis (creation of new fat cells) and elevated inflammation 

Phthalates 

  • Prenatal exposure to phthalates is associated with increased obesity, insulin resistance, and diabetes risk 

PFAS

  • Multiple epidemiologic studies and meta-analyses show that PFAS is associated with higher BMI, obesity, and type 2 diabetes

  • Higher levels of PFAS exposure may have a dose-dependent effect on obesity and insulin resistance partly through mechanisms involving increased inflammation and oxidative stress

Organochlorine pesticides

  • Common types include Dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE)

  • Evidence is strongest for DDE exposure and risk for higher BMI, elevated markers of inflammation, obesity and insulin resistance

Parabens 

  • The evidence linking parabens to adverse metabolic outcomes including diabetes and obesity is less clear 

  • Some evidence demonstrates possible associations between methylparaben and ethylparaben exposure and type 2 diabetes risk and obesity; however, more research is needed

What benefit, if any, do current studies investigating reduction of these compounds demonstrate? 

  • Reducing BPA exposure early in life is associated with lower risk of insulin resistance and obesity over time

  • Some studies show that lowering BPA intake can improve insulin sensitivity

  • Evidence demonstrates that reducing phthalate exposure could improve glucose metabolism

  • PFAS reduction interventions still have mixed results. More research is needed as the current evidence is not robust 

  • Direct interventional evidence for improved outcomes with reduction of exposure to organochlorine pesticides and parabens is limited 

  • Overall, the strongest evidence linking reduction of exposure with improved health outcomes exists for BPA and phthalates

Strategies to mitigate obesogen exposure: 

  • Avoid plastic containers, heated plastic and plastic packaging when possible

  • Minimize consumption of processed and packaged foods

  • Avoid personal care products with paraben or phthalate-containing ingredients 

  • Check sources of water and food for levels of PFAS and pesticides

Our understanding of the effects of obesogens is still evolving. The evidence is still far from conclusive; however, it may be worth looking into some of the mitigation strategies above if you can find some obvious sources of these chemical exposures in your own life.

The discussion of obesogens also raises an important final point: while what we eat and how we move are typically the most important factors that determine our risk of type 2 diabetes, there are many other factors to consider. This is especially true if you feel like you have already optimized your diet and exercise and still find that you are not meeting your metabolic health goals.  Obesogens represent an often overlooked exposure that could potentially increase the risk of metabolic dysfunction, including type 2 diabetes and obesity. While complete avoidance of these chemicals in modern life is most likely not practical or achievable, we can take simple steps to reduce our exposure over time.