Nutrition Can Modulate the Toxicity of Environmental Pollutants: Implications in Risk Assessment and Human Health

Article excerpt

BACKGROUND: The paradigm of human risk assessment includes many variables that must be viewed collectively in order to improve human health and prevent chronic disease. The pathology of chronic diseases is complex, however, and may be influenced by exposure to environmental pollutants, a sedentary lifestyle, and poor dietary habits. Much of the emerging evidence suggests that nutrition can modulate the toxicity of environmental pollutants, which may alter human risks associated with toxicant exposures.

OBJECTIVES: In this commentary, we discuss the basis for recommending that nutrition be considered a critical variable in disease outcomes associated with exposure to environmental pollutants, thus establishing the importance of incorporating nutrition within the context of cumulative risk assessment.

DISCUSSION: A convincing body of research indicates that nutrition is a modulator of vulnerability to environmental insults; thus, it is timely to consider nutrition as a vital component of human risk assessment. Nutrition may serve as either an agonise or an antagonist (e.g., high-fat foods or foods rich in antioxidants, respectively) of the health impacts associated with exposure to environmental pollutants. Dietary practices and food choices may help explain the large variability observed in human risk assessment.

CONCLUSION: We recommend that nutrition and dietary practices be incorporated into future environmental research and the development of risk assessment paradigms. Healthful nutrition interventions might be a powerful approach to reduce disease risks associated with many environmental toxic insults and should be considered a variable within the context of cumulative risk assessment and, where appropriate, a potential tool for subsequent risk reduction.

KEY WORDS: anti-inflammatory nutrients, environmental pollutants, nutrition, risk assessment, risk reduction. Environ Health Perspect 120:771-774 (2012). [Online 22 February 2012]

The U.S. Environmental Protection Agency (EPA) defines risk as "the chance of harmful effects to human health or to ecological systems resulting from exposure to an environmental stressor" (U.S. EPA 2011). As the use of chemicals and pollutant emissions increase (i.e., as more chemicals or toxic substances are used in manufacturing and other venues, such as agriculture), it has become clear that humans are environmentally exposed not only to an ever increasing number of potential toxicants but also to harmful mixtures of these toxic substances. As a result, the U.S. EPA began addressing the issue of cumulative risk assessment with its Framework for Cumulative Risk Assessment, a report that defines cumulative risk as the combined risks to health by multiple agents or stressors (U.S. EPA 2003). In addition, a report by the National Research Council (2009), strongly recommended nonchemical stressors (psychosocial, physical, and dietary variables) in risk assessment, even in the absence of population-specific data. These cumulative risk debates and recent publications (Lewis et al. 2011; National Research Council 2009; Sexton and Linder 2011) substantially support our hypothesis that unhealthy dietary practices by themselves can compromise health, thus further increasing a person's vulnerability to additional chemical stressors. In contrast, intervention with healthy dietary practices can contribute to health and metabolic stability, thus potentially reducing vulnerability to disease-causing environmental pollutants.

Diet-related chronic diseases represent the single largest cause of morbidity and mortality worldwide, and the health burden of obesity-related disease complications and of other chronic health problems continues to grow (Astrup et al. 2008; Satia 2009). In fact, the United Nations High-Level Meeting on Non-communicable Diseases, held in September 2011, highlighted the urgent need to address the 57 million deaths per year attributed to noncommunicable diseases (of which cardiovascular disease plays a primary role) through an increased focus on research and development, a better understanding of the factors leading to these diseases, and more effective research translation (United Nations General Assembly 2011). …