Role of nutrition in the prevention of diseases?

Answer 1

In a recent review, Using Nutrition for Intervention and Prevention against Environmental Chemical Toxicity and Associated Diseases, Hennigetal (2007) set out to find evidence to make the recommendation that nutrition should be considered a necessary variable in the study of human disease associated with exposure to environmental pollutants.

The authors remind us that diet related chronic diseases represent the single largest cause of mortality in developed nations, but are still rare or nonexistent among people who are hunter/gatherers. This "diseases of civilization" is influenced by elements that include diet, exposure to environmental agents, and genetic susceptibility.

The need to further understand the complex interplay between environmental exposure, nutrition, and disease risk was noted along with need to developing better tools to evaluate exposures, nutritional intake, and activity levels to determine how they interact with specific genotypes in correlation to disease.

There is no easy way protect against diseases associated with exposure to environmental pollutants, as many pollutants are persistent in the environment and bio-accumulate in the body. Removing these pollutants from the environment and industry is extremely costly and difficult to achieve. Environmental pollutants trigger signaling pathways that respond to the oxidative stress from pollutants. These same pathways are associated with many chronic diseases, therefore the researchers believe it is important to understand how these pollutants may modulate disease.

Studies have shown that diet and lifestyle changes can modify pathologies of some chronic diseases. For example, industrial workers exposed to petrochemicals developed nonalcoholic fatty liver disease, which resolved with removal from workplace exposure. Yet nutritional interventions, including antioxidant therapy, has also resulted in significant improvement. This researchers believe this may be important for those exposed to environmental toxicants.

Another aspect of chronic disease is inflammation. Nutrients and flavonoids have been associated with a reduced risk of chronic inflammatory diseases and therefore supplementation may be beneficial. Environmental toxicants such as heavy metals contribute to diminished levels of antioxidants that may aggravate inflammatory states. Dietary intake of omega-3 polyunsaturated fatty acids and poly phenols such as flavonoids may be beneficial.

Nutritional intervention has been shown to result in health improvements and lowering the toxicant body burden. Hennig and his colleagues cite a case of a patient who had an extremely high body burden of polychlorinated biphenyls (PCBs) and also suffered from Diabetes requiring daily injections of insulin. With supplemental foods containing the fat substitute olestra, the PCB body burden dramatically decreased and the patient's diabetes disappeared.

Another case cited by Hennig et al discovered that calcium supplementation was associated with a marked decrease of lead levels in both blood and breast-milk.

Hennig and his colleagues summarize by saying "there is a great need to further explore this nutritional paradigm in environmental toxicology and to improve our understanding of the relationship between nutrition, exposure to environmental toxicants, and disease" and "nutrition may be the most sensible means to develop intervention and prevention strategies for diseases associated with many environmental toxic insults."

The authors add that the National Institute of Health Sciences (NIEHS) "has taken a leadership role in addressing these uncertainties with an inclusive research approach that includes basic science, as well as translating research findings into public health prevention strategies. These strategies will hopefully make their way into the classroom and general education for physicians and ultimately to educational materials directed at the general public.

Nutrition can and should be an integral part of health and treatment. Surely it can't hurt to get better nutrition. Indeed it might be beneficial for both treatment and prevention. Time, and more studies aimed at nutritional intervention, will tell.