Links between nutrition and the effects of air pollution were highlighted at a recent food science event in Valencia, Spain.
At the Third International Conference on Nutrition & Food Science, which recently took place in Valencia, Spain, a key focus was the importance of nutrition in daily life. By communicating cutting-edge research, supported by DSM, the conference demonstrated that nutrition-associated solutions can play a major role in tackling a number of global health concerns and make advances towards a better and healthier future. A particular focus this year, sponsored by DSM, was the importance of micronutrients such as vitamin E and omega-3s — and the need for further research to explore the benefits of advanced nutrition — in reducing the impact of urban air pollution on human health.
Dr Fernando Holguin, Associate Professor of Medicine, Division of Pulmonary Allergy and Critical Care, University of Pittsburgh Medical Centre, set the scene with his presentation: Impact of Air Pollution on Human Health. He explained that air pollution is a global problem with far reaching consequences and that exposure to pollutants has been associated with increased rates of cardiovascular and respiratory morbidity and mortality throughout the world, particularly in urban settings where concentrations are usually higher. However, he noted, not every pollutant conveys the same risk and not everyone exposed is equally susceptible. In addition, he emphasised that there is no safe air pollution level at which adverse health effects are absent and noted that these complexities have made it very challenging to legislate and develop adequate protection strategies.
Dr Holguin's talk included a broad overview of air pollutant criteria and their related health effects; he discussed different types of pollutants and how these relate to different outcomes, reviewed what is known about susceptibility factors and showed examples of what happens to health outcomes when pollution levels drop. He concluded by arguing the case that new interventions are urgently needed to reduce the health effects among those that are more vulnerable and/or most highly exposed and stated: When it comes to air pollution and its impact on human health, not all polluters are the same, it matters who you are and both chronic and acute exposures lead to different outcomes (and may involve different mechanistic pathways). He reiterated: No absolute safe levels exist and reducing emissions improve outcomes. But, important questions remain, including how and whom we can protect.
Jane Ellen Clougherty, Assistant Professor/Director of Exposure Science, also from the University of Pittsburgh, added to the debate by discussing “Nutritional Solutions to Counteract the Impact of Air Pollution.” Dr Clougherty’s current studies examine variations in the diesel-related organic constituents of fine particles and employ geographic information system (GIS)-based methods to elucidate how social and environmental exposures may alter the asthmatic response to air pollution and the efficacy of pharmaceutical interventions for asthma in clinical trials. Her presentation examined issues related to air pollution exposure science and epidemiology, and the combined effects of environmental exposures and nutrition on health outcomes. Including recent data on the variation in fine particle concentrations within and between cities, she noted how the spatial distribution of air pollution sources (such as vehicular traffic, power plants and industry) leads to differences in the chemical composition of airborne fine particles across cities. She also described recent evidence for variations in population susceptibility across urban space and, in particular, air pollution susceptibility. Introducing the concept of nutritional/pharmaceutical intervention, Jane suggested that a better understanding of the pollutant mix and its chemical composition is required in target areas, and that target outcomes — such as asthma, respiratory disease and cardiovascular disease — need to be identified. She added that biochemical pathways and responses such as inflammation, which can be affected by multiple pollutants/stressors, should be a point of focus and that, when considering anti-pollutant measures, both timing and physiological impact need careful consideration.
DSM’s Principal Scientist, Daniel Raederstorff, followed by discussing how the chronic exposure to air pollution, particularly ambient fine particulate matter, has been reported to increase cardiovascular mortality and the risk of several chronic diseases (CVD, diabetes, COPD, cancer) via oxidative stress and inflammation. Thus, he stated, air pollution is a significant threat to human health. “With 80% of the global population now living in regions that exceed WHO air quality guidelines, air pollution needs to be the central focus of government regulation and environmental reform,” he explained. “Recent research has highlighted the potential of targeted nutrition to combat the decreased antioxidant capability, respiratory inflammation and neurological symptoms associated with certain pollutants.” The consumption of a healthy diet is critical to maintain human health, he added, and epidemiological studies have shown that a Mediterranean diet rich in micronutrients and secondary plant metabolites, and an adequate intake of essential micronutrients, can effectively reduce the risk of cardiovascular diseases and chronic diseases through anti-oxidative and anti-inflammatory activities.
The first human intervention studies, for example, have indicated that nutrients such as omega-3 PUFAs, antioxidants (vitamins C and E) and B vitamins may attenuate the damage induced by air pollution. In a recent study, vitamin E and C boosted superoxide dismutase (SOD) and glutathione reductase, and normalised glutathione and glutathione peroxide altered by pollution exposure. Other studies have shown that fish oil attenuated heart rate variability decline caused by air pollution, boosted endogenous antioxidant defence (SOD, GSH) and inhibited lipoperoxidation (LPO). “In the presence of air pollution, healthy nutrition with an adequate intake of essential micronutrients is even more critical to avoid the double “hit” that may further promote damage induced by air pollution,” concluded Daniel.
Professor Lisa Wood from the Centre for Asthma and Respiratory Diseases, University of Newcastle, Australia, concluded the presentations by discussing “Nutritional Modulation of Inflammation in Airway Diseases.” She explained: Westernised diets are characterised by a low intake of fruit, vegetables, whole grains and fish, and an increased intake of processed foods. This dietary pattern results in a nutrient profile that is low in beneficial nutrients such as antioxidants (carotenoids, tocopherols and flavonoids) and omega-3 polyunsaturated fatty acids. As these nutrients protect against inflammation, Western populations are more susceptible to inflammatory insults that can trigger diseases such as asthma. Asthma is a chronic inflammatory disease derived from an exaggerated immune response to triggers such as allergens, viruses and air pollution. The exposure of susceptible individuals to these triggers results in reduced lung function and symptoms including breathlessness, coughing and wheezing.
“We have undertaken a series of experiments that demonstrate the role of antioxidants and omega-3 fatty acids in asthma,” said Lisa, “and demonstrated that antioxidant defences are impaired (carotenoids, vitamin E and glutathione) and oxidative stress is increased (8-isoprostane) in asthma. In cell culture and animal models, we have demonstrated that both lycopene (a carotenoid) and omega-3 fatty acids reduce the inflammatory response to common asthma triggers, including rhinovirus infection and allergens. In clinical studies, we have shown that manipulating the intake of antioxidant-rich foods modulates inflammation, lung function and asthma symptoms.” She continued: “We conclude that the increased intake of antioxidants and omega-3 fatty acids may attenuate inflammation in asthma, thereby providing a useful addition to current asthma management strategies. As asthma affects approximately 300 million people worldwide, the potential health and economic benefits of establishing non-pharmacological approaches to disease management are enormous.”
Further Discussion
A large number of inflammatory biomarkers and reactive oxygen species are unfavourably changed — acutely as well as chronically — by the fine particulate matter present in polluted air. These changes are known to mediate both physiological reactions, such as ageing, and pathological reactions, such as vascular calcification. These reactions increase the risk of illness and mortality from non-communicable diseases, especially cardiovascular and respiratory diseases. “The rising exposure to pollutants is associated with increased rates of cardiovascular and respiratory afflictions worldwide. The variation in associated risk between different pollutants provides huge challenges to the legislation and development of adequate industrial production regulation. Therefore, protection strategies for people who are more vulnerable and most highly exposed must be highlighted as a necessary target,” said Dr Fernando Holguin.
“Current diets are characterised by an increasing intake of prepackaged foods. This dietary pattern results in a nutrient profile that is low in beneficial nutrients, such as antioxidants and omega-3 polyunsaturated fatty acids (PUFAs),” agreed Professor Lisa Wood. “As these nutrients protect against inflammation, populations are thus more susceptible to the damaging effects of pollutants, which can trigger chronic diseases such as asthma. Increasing the intake of antioxidants and PUFAs may reduce inflammation, providing opportunities for asthma management.”
“In recent months, there have been a number of assessments by different research groups to indicate that insufficient intake of micronutrients has the potential to have severe long-term effects on the health of urban populations,” summarised Professor Manfred Eggersdorfer, Senior Vice President, Nutrition Science & Advocacy at DSM and Professor for Healthy Ageing at the University of Groningen. “The associated healthcare costs are significant and this meeting has provided an important bridge between academic research and industry to drive progress in the field of nutrition and food science.”
Interestingly, scientific research conducted in the past decade has shown that micronutrients, especially vitamin C and vitamin E, can help to reduce the oxidative stress induced by particulate matter in polluted air. “In a Brazilian investigation, for instance, subjects were exposed — either directly or indirectly — to aerial pollution from an electric power plant. In response to direct exposure to airborne contamination, levels of growth hormones in blood cells and the structure of plasma and red blood cells changed significantly. These reactions indicate that oxidative damage occurred and that an endogenous detoxification process was initiated. Interestingly, though, scientific research conducted in the past decade has shown that daily supplementation with vitamins C and E effectively normalised these harmful changes and significantly augment the anti-oxidative capacity,” said Manfred.
The problem of fine airborne particulate matter is not insoluble in theoretical terms. That said, the process involves numerous steps. Nutritional solutions such as the provision of appropriate quantities of vitamins C and E hold the promise of helping to combat fine particulate matter and its unfavourable impact on the quality and duration of life.
Bibliography
- C.A. Pope, M. Ezzati and D.W. Dockery, “Fine-Particulate Air Pollution and Life Expectancy in the United States,” New Engl. J. Med. 360, 376–386 (2009).
- R.D. Brook, et al., “Particulate Matter Air Pollution and Cardiovascular Disease: An Update to the Scientific Statement from The American Heart Association,” Circulation 121, 2331–2378 (2010).
- F. Holguin, et al., Air Pollution and Heart Rate Variability Among the Elderly in Mexico City, Epidemiology 14, 521Ð527 (2003).
- I. Romieu, et al., Omega-3 Fatty Acid Prevents Heart Rate Variability Reductions Associated with Particulate Matter, Am. J. Respir. Crit. Care Med. 172, 1534Ð1540 (2005).
- H. Tong, et al., “Omega-3 Fatty Acid Supplementation Appears to Attenuate Particulate Air Pollution-Induced Cardiac Effects and Lipid Changes in Healthy Middle-Aged Adults,” Environ. Health Perspect. 120, 952–957 (2012).
- I. Romieu, et al., “The Effect of Supplementation with Omega-3 Polyunsaturated Fatty Acids on Markers of Oxidative Stress in Elderly Exposed to PM(2.5),” Environ. Health Perspect. 116, 1237–1242 (2008).
- F.P. Possamai, et al., “Antioxidant Intervention Compensates Oxidative Stress in Blood of Subjects Exposed to Emissions from a Coal Electric-Power Plant in South Brazil,” Environ. Toxicol. Pharmacol. 30, 175–180 (2010).
