Air pollutants are harmful and affect everyone, but may be additionally detrimental for people who exercise at higher levels (with higher inhalation rates) both outdoors and indoors. Since runners, bikers, aerobics class participants and other fitness buffs, require more oxygen and deeper inhalation. they typically inhale higher level of pollutants. For example, a fitness center study comparing the inhalation of pollutants of indoor aerobics class vs. less intense activity, showed 2x's the amount of pollutants inhaled by the higher intensity aerobics class. (1) Moreover, the air pollutants tend to become trapped deeper into the lung tissue. Furthermore, air pollutants are most often not apparent and the fitness ethusiast is unlikely to be aware of the inhalation hazard.
Air pollutants have been associated with respiratory mortality (3), development of atherosclerosis (2), diabetes (5) and neuropatholgies (via increased neuro inflammation) (4). While doctors support the need for exercise, many will caution about exercising outdoors, especially where air pollution levels may be higher.
SOURCES OF AIR POLLUTION:
Sulforaphane is a powerful phase 2 detoxifier, which enables the detoxfication and excretion of harmful pollutants and toxins. In a clinical trial in china, glucoraphain in broccoli sprout (beverage), which contains the powerful precursor of sulforaphane, was shown to effectively detoxify several major air pollutants.(6) Compared to placebo, the broccoli sprout beverage showed "rapid and sustained increases in the levels of excretion of the glutathione-derived conjugates of benzene (61%), acrolein (23%)". Another study, also showed increased excretion of the air pollutant crotonaldehyde.(7)
Effective results showed detoxification of airborne pollutants from study participants.(6,7) Sulforaphane may also have an inhibitory effect against cancer, including lung cancer, via activation of Nrf2 antioxidant pathway. (10)
Diesel Exhaust Fine Particles - The fine particles form diesel exhaust are considered a significant health hazard which impacts especially outdoor exercise. At high cardiac output, diesel increased pulmonary vasoconstriction (8) and increased oxidative stress and allergic inflammatory response.(9) Sulforaphane induces phase II enzymes which can block the oxidant and allergic inflammation harmful effect of the diesel exhaust particles. (9)
(1) Ramos CA, et al. Estimating the inhaled dose of pollutants during indoor physical activity. Sci Total Environ. 2015 Sep 15
(2) Bai Y, et al. Fine particulate matter air pollution and atherosclerosis: Mechanistic insights. Biochim Biophys Acta. 2016 May 6.
(3) Brunekreef B, et al. Effects of long-term exposure to traffic-related air pollution on respiratory and cardiovascular mortality in the Netherlands: the NLCS-AIR study. Res Rep Health Eff Inst. 2009 Mar
(4) Jørgensen JT, et al. Long-term exposure to ambient air pollution and incidence of brain tumours: The Danish Nurse Cohort. Neurotoxicology. 2016 Jun 2
(5) Hansen AB, et al. Long-term exposure to fine particulate matter and incidence of diabetes in the Danish Nurse Cohort. Environ Intl 2016 May;
(6) Egner PA, et al. Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage: results of a randomized clinical trial in China. Cancer Prev Res (Phila). 2014 Aug
(7) Kensler TW, et al. Modulation of the metabolism of airborne pollutants by glucoraphanin-rich and sulforaphane-rich broccoli sprout beverages in Qidong, China. Carcinogenesis. 2012 Jan
(8) Wauters A, et al. At high cardiac output, diesel exhaust exposure increases pulmonary vascular resistance and decreases distensibility of pulmonary resistive vessels.
(9) Wan J, et al. Antioxidant enzyme induction: a new protective approach against the adverse effects of diesel exhaust particles. Inhal Toxicol. 2007
(10) Yang L, et al. Frugal chemoprevention: targeting Nrf2 with foods rich in sulforaphane. Semin Oncol. 2016 Feb