On a busy weeknight, takeout and fast food are easy dinner solutions. But your family’s favorite to-go meal may come with a side of toxic fluorinated chemicals. These are called polyfluoroalkyl substances (PFAS) and they are a family of greaseproof, waterproof and non-stick industrial compounds. They are used in hundreds of consumer products, including ones that touch your food. PFAS is among a group of Persistent Organic Pollutants (POP) that can lead to kidney damage. In this blog, we will discuss these environmental toxins and kidney health.
By Majd Isreb, MD, FACP, FASN, IFMCP
Sources of Exposure
The impact of environmental exposure to these chemicals is increasingly recognized. In the past, the focus was on heavy metals such as lead and cadmium. The major risk to kidney health was job-related exposure. More recently, emerging research is proving that the general public is also at risk for exposure to a wide range of chemicals as a consequence of normal daily activities.
The activities that increase exposure to chemicals that negatively impact kidney health include:
- Dietary intake of food or drink, such as contamination of drinking water with these chemicals
- Domestic and commercial food preparation due to food additives
- Textile and household maintenance procedures as in preparing furniture with flame retardants
- Routine medical and dental care can be associated with exposure to toxic chemicals, for example, implants or dental fillings
The increase in environmental pollution, a result of accelerated urbanization worldwide, has become a global public health challenge.
Persistent Organic Pollutants (POP) and Kidney Health
Recently, POPs have been detected on military bases, as well as in public water supplies from industrial contamination and in agricultural and crop products. Exposure to POP has been linked to cancer including cancer of the kidney. There is also mounting evidence that POPs contribute to kidney disease. The kidneys are very sensitive organs. Studies demonstrated that the kidneys are the major site of elimination of these substances which makes them vulnerable to their negative effects.
In fact, studies point to PFAS as contributing directly to the worsening of kidney function. They can also indirectly lead to changes in human metabolism, which can lead to kidney disease.
Toxicology studies show that the tubules of the kidneys are the most affected (see our blog about the nephron). When part of the kidneys is affected, their function is reduced. This leads to a further buildup of these chemicals increasing their toxicity on the body and the kidneys. This creates a vicious cycle that amplifies the effect of toxic exposure. What is most concerning is that children and adolescents are and will be more exposed to these substances throughout their life span.
The Role of Genetics
Our bodies detoxify foreign chemicals in the liver via specific processes and they are eliminated in the kidney by other routes. The failure of these processes of detoxification and elimination may lead to greater toxicity of POPs. Genetics, epigenetics, or minor changes in the detoxification processes can have a significant impact on kidney health. Therefore, a normal exposure level for one person may be toxic for another, especially in the long term. Therefore, checking for genetic abnormalities is a crucial element in identifying the risk of exposure.
Heavy Metals
For years, kidney doctors (nephrologists) have known that heavy metals can impact kidney health. The most well-known of these include Arsenic, Lead, and Cadmium.
Arsenic is used in the pressure treatment of wood. It can lead to structural changes in the kidneys which can lead to kidney disease. Contamination of drinking water, soil, and rice with arsenic has been linked to hypertension and kidney injury leading to kidney disease.
Cadmium is used in batteries, pigments, coatings, and plastics. It has also been used in phosphate fertilizers and can lead to soil and water contamination with subsequent accumulation in plants, particularly root vegetables (carrots, etc.) It can also be found in tobacco cigarettes and inhaled in second-hand smoke. In fact, it is estimated that individuals who smoke one pack of cigarettes each day will absorb 1-2 mcg of cadmium daily. Cadmium exposure leads to the development of diabetes, decreased renal function, increased urine output, and loss of some minerals from the kidneys. It appears that vitamin D and Zinc can protect the kidneys from cadmium.
Lead is used in welding, batteries, and in the production of pottery, glazing of ceramic pots, and water pipes (which can lead to contamination of community water as happened in Flint, MI). Many children are exposed to lead by ingestion of contaminated soil or food and herbs grown in those soils. Sadly, as recently as 2017, a large population of adults and children in the United States have blood lead levels that are higher than what is considered safe. In addition to cognitive delays in children, relatively modest levels of Lead in the body can cause progressive kidney damage, elevated blood pressure, and gout.
Testing for Exposure
Unfortunately, after chronic exposure to these pollutants, our body adapts and stores them in tissues such as fat or bone. So, a simple blood test may not detect these substances. The best analysis to detect them is a provoked urine collection. This requires a physician familiar with carefully provoked urine testing to order a medication that encourages the release of these toxins from storage so that they can be collected in your urine. If you suspect you are exposed ask your Integrative or Functional Medicine nephrologist to test you.
References
- John W. Stanifer, et al. Perfluorinated Chemicals as Emerging Environmental Threats to Kidney Health. Clin. J. Am. Soc. Nephrol. 2018. 13:1479-1492
- Sarah E. Orr, Christy C. Bridges. Chronic Kidney Disease and Exposure to Nephrotoxic Metals. Int. J. Mol. Sci. 2017. 18, 1039
