Historically, NIEHS has dedicated the bulk of its resources to studying things in the environment that are potentially bad and finding ways to prevent exposures that may increase susceptibility to disease and ill health. However, I believe that exposure avoidance is only part of the equation.
I am increasingly interested in the role healthy food and healthy lifestyles can play in reducing the harmful effects of various toxicants. Such a proactive stance can empower individuals and communities to take control of their health. It also is a practical approach, as we live in a world of numerous environmental risks, and it is challenging to avoid them all.
Recently, I spoke with institute grant recipient Bernhard "Bernie" Hennig, Ph.D., an international leader in research into how nutrients can mediate negative effects of chemicals such as polychlorinated biphenyls (PCBs), which persist in the environment and affect many people.
Hennig conducts studies at the NIEHS-funded University of Kentucky Superfund Research Center, where for 17 years he served as center director. We talked about his work and the importance of sharing related research information with vulnerable communities.
Also, he discussed how a multidisciplinary scientific approach can expand knowledge of the complex interactions between nutrition and our environmental exposures, and he shared his career path and personal interest in diet and issues related to obesity.
Rick Woychik: Can you provide Environmental Factor readers with background on your research and what spurred your interest in nutrition and toxicology?
Bernie Hennig: I have always been interested in healthy living, and when I started my academic journey years ago, I was in the field of biochemistry but very interested in nutrition and obesity. I began to study what we now call cardiometabolic diseases, specifically atherosclerosis. That is a condition in which fat and cholesterol accumulate in the arteries.
Over time, we learned that these and other noncommunicable diseases, including cancer, may be linked to inflammation, which is caused by oxidative stress and other factors. During my postdoctoral training at the University of Iowa in the 1980s, we tried to understand the mechanisms of cardiovascular disease, including how an inflammatory response triggered in the vascular system could lead to biological dysfunction and poor health.
During that period, I became interested in Omega-6 and Omega-3 fatty acids. We found that the former, which are common in many processed foods, are quite pro-inflammatory, in contrast with the latter, which are found in fish and certain dietary supplements. Eventually, I was recruited to the University of Kentucky as a young faculty member to conduct related research.
At the Superfund Research Center here, there is strong interest in PCBs, and we found that the substances contribute to inflammation. We further discovered that Omega-6 fatty acids worsened inflammation caused by PCBs, and that Omega-3 fatty acids protected against it. And that is how my interest in the intersection of nutrition and toxicology began.
Later, we focused on polyphenols, which are bioactive nutrients in fruits and vegetables. We learned that they may act as antioxidants and reduce inflammation resulting from exposure to PCBs. Now, in a similar context, we are starting to examine chemicals such as PFAS [per- and polyfluoroalkyl substances], and that is quite exciting.
RW: It is encouraging to know you are interested in PFAS, which are both ubiquitous and persistent in the environment. This is not a matter of just a few chemical entities because there are thousands of different PFAS compounds. And, of course, those in turn interact with all the other exposures we experience in our lives, including the food that we consume.
In my view, a major task in environmental health sciences research is to better understand that totality of our exposures, which is called the exposome. Can you talk a little bit about how your work intersects with that concept?
BH: I believe that embracing good nutrition is a very sensible way of confronting the fact that we live in a complex environment and experience a variety of exposures and chemical mixtures. Many people want the “magic pill,” but that just does not exist.
The message I promote is that the food we eat and whether we are active has tremendous influence in the long term on our vulnerability to other stressors. At my center, we focus on chemicals, but of course stressors can range from noise pollution to socioeconomic problems.
As you know, genetics also is an important factor, and it can affect not only how our bodies respond to toxicants but also how they respond to the good things, such as nutrition and exercise.
This whole balance — our genetics, our exposures, and our lifestyle choices — explains much about disease outcomes. And we are learning more and more that the whole body — multiple biological systems — are interacting and influencing our health for better or worse.
We have done quite a bit of work recently showing that persistent organic pollutants contribute to dysbiosis — dysfunction in our microbiome — and accelerate nonalcoholic fatty liver disease and a variety of other health problems. Our data suggest a link between the gut, the liver, and many other organs in the inflammatory process that paves the way for disease.
RW: So, we can’t control our genes, and in many cases, we are all challenged with the environmental exposures we experience. However, we can control what we consume and how much exercise we get, and based on your research, that may positively influence how our body responds to various stressors. Given the critical role of nutrition, what foods or dietary practices do you recommend?
BH: I should point out that our work has confirmed what many have known for years, which is that plant-derived foods are better for long-term health. But for many people, a hot dog is much more palatable than a bowl of salad, and in places like eastern Kentucky, there are issues such as socioeconomic disparities that can further pull people away from good nutrition.
For those of us working in this field, a key challenge is to translate our research into clear, easily understandable public health messaging that helps individuals and communities learn about better nutrition options and their many health benefits. This is something that Dawn Brewer, who leads our center’s Community Engagement Core, is especially interested in [see sidebar].
The idea is to focus on whole foods because in our culture, we don't eat enough of them. Our meals should include some fruits and vegetables, and some fiber. The bottom line is that consuming nutrients that reduce oxidative stress and inflammation is beneficial to our health, and we should try to eat more fresh foods with each meal.
I think there is a great opportunity to continue to advance the kind of research we have talked about today, which combines insights from nutrition, toxicology, and other disciplines, such as metabolomics. I am proud of our work at the Superfund Research Center, and I am excited to continue to contribute to this important scientific effort.
(Rick Woychik, Ph.D., directs NIEHS and the National Toxicology Program.)
Check out these papers for more detail on Hennig’s research and ideas. — Ed.
Hoffman JB, Petriello MC, Morris AJ, Mottaleb MA, Sui Y, Zhou C, Deng P, Wang C, Hennig B. 2020. Prebiotic inulin consumption reduces dioxin-like PCB 126-mediated hepatotoxicity and gut dysbiosis in hyperlipidemic Ldlr deficient mice. Environ Pollut 261:114183.
Deng P, Barney J, Petriello MC, Morris AJ, Wahlang B, Hennig B. 2019. Hepatic metabolomics reveals that liver injury increases PCB 126-induced oxidative stress and metabolic dysfunction. Chemosphere 217:140–149.
Petriello MC, Newsome BJ, Dziubla TD, Hilt JZ, Bhattacharyya D, Hennig B. 2014. Modulation of persistent organic pollutant toxicity through nutritional intervention: emerging opportunities in biomedicine and environmental remediation. Sci Total Environ 491–492:11–6.
Hennig B, Ormsbee L, McClain CJ, Watkins BA, Blumberg B, Bachas LG, Sanderson W, Thompson C, Suk WA. 2012. Nutrition can modulate the toxicity of environmental pollutants: implications in risk assessment and human health. Environ Health Perspect 120(6):771–774.
Hennig B, Ettinger AS, Jandacek RJ, Koo S, McClain C, Seifried H, Silverstone A, Watkins B, Suk WA. 2007. Using nutrition for intervention and prevention against environmental chemical toxicity and associated diseases. Environ Health Perspect 115(4):493–495.