How To Defend Your Body From Viruses and Breathing Difficulties
Recent research suggests that a compound called ‘sulforaphane’ may have both a preventative and curative benefit against viruses and breathing problems.
Sulforaphane is found in cruciferous vegetables such as broccoli and kale. The highest concentration available is found in broccoli sprout juice.
It is generated by damage to the plant and is involved in protecting the plant from insect predators. In mammals it activates the Nrf2 pathway, which supercharges the immune system.
Sulforaphane has also been shown to have antiviral properties. Studies have shown that sulforaphane reduces viral load in the nose, increases Natural Killer cell production, displays antiviral activity against H1N1 Influenza virus, and can suppress replication of Hepatitis C Virus and inhibit HIV infection of macrophages through Nrf2. [2-5] Interestingly, heat shock proteins which are produced upon sulforaphane consumption are also known to have antiviral properties. 
Inducer of NRF2 antioxidant pathway
Sulforaphane may be particularly beneficial for the elderly. It is a powerful inducer of Nrf2, which regulates expression of more than 200 cytoprotective genes (provide protection to cells against harmful agents.), including an antiviral pathway that impairs virus reproduction. [7,8] Nrf2 signaling is thought to decrease with age. According to one study, exercise induced Nrf2-signaling has been shown to be impaired in aging.  Sulforaphane was also shown to restore the age-related decrease of Th1 immunity in old mice. 
Sulforaphane treats ARDS (Acute respiratory distress syndrome)
Animal and in vitro studies have shown that sulforaphane can mitigate the inflammatory damage to the lungs in ARDS. In one study, sulforaphane doubled the survivability of rabbits with ARDS. [11,12] Sulforaphane is also a potent inhibitor of NFkB, which is a master inducer of inflammation.  In one study, influenza virus-induced markers of inflammation were significantly lower in smokers after consumption of broccoli sprout homogenate. 
Protection for the lungs
Sulforaphane has a protective effect on the lungs. In a 12 week study in Qidong, China, consumption of sulforaphane was associated with immediate and sustained increase in urinary excretion of airborne pollutants, benzene 61% and acrolein 23%.  In another study, daily 100 æmol sulforaphane for 14 days was shown to improve the broncho-protective response in asthmatics. 
Broccoli sprouts contain the highest levels of precursors to sulforaphane: glucoraphanin and myrosinase.
- Hyun TK. (2020) A recent overview on sulforaphane as a dietary epigenetic modulator. EXCLI J. 19:131-134. https://www.ncbi.nlm.nih.gov/pubmed/32194360.
- Mller L, Meyer M, Bauer RN et al. (2016) Effect of Broccoli Sprouts and Live Attenuated Influenza Virus on Peripheral Blood Natural Killer Cells: A Randomized, Double-Blind Study. PLoS One. 11(1):e0147742. https://www.ncbi.nlm.nih.gov/pubmed/26820305.
- Li Z, Liu Y, Fang Z et al. (2019) Natural Sulforaphane From Broccoli Seeds Against Influenza A Virus Replication in MDCK Cells. Natural Product Communications, June 2019: 1-8. https://journals.sagepub.com/doi/pdf/10.1177/1934578X19858221.
- Yu JS Chen WC, Tseng CK et al. (2016) Sulforaphane Suppresses Hepatitis C Virus Replication by Up-Regulating Heme Oxygenase-1 Expression through PI3K/Nrf2 Pathway. PLoS One. 11(3):e0152236. https://www.ncbi.nlm.nih.gov/pubmed/27023634.
- Furuya AK, Sharifi HJ, Jellinger RM, et al. (2016) Sulforaphane Inhibits HIV Infection of Macrophages through Nrf2. PLoS Pathog. 12(4):e1005581. https://www.ncbi.nlm.nih.gov/pubmed/27093399.
- Tsan MF, Gao B. (2009) Heat shock proteins and immune system. J Leukoc Biol. 85:905-910. https://www.ncbi.nlm.nih.gov/pubmed/19276179.
- Houghton CA (2019) Sulforaphane: Its “Coming of Age” as a Clinically Relevant Nutraceutical in the Prevention and Treatment of Chronic Disease. Oxid Med Cell Longev. 2019:2716870. https://www.ncbi.nlm.nih.gov/pubmed/31737167.
- Wyler E, Franke V, Menegatti J et al. (2019) Single-cell RNA-sequencing of herpes simplex virus 1-infected cells connects NRF2 activation to an antiviral program. Nat Commun. 10:4878. https://www.ncbi.nlm.nih.gov/pubmed/31653857.
- Done AJ, Gage MJ, Nieto NC, Traustad¢ttir T. (2016) Exercise-induced Nrf2-signaling is impaired in aging. Free Radic Biol Med. 96:130-8. https://www.ncbi.nlm.nih.gov/pubmed/27109910.
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- Patel V, Dial K, Wu J, Gauthier AG. (2020) Dietary Antioxidants Significantly Attenuate Hyperoxia-Induced Acute Inflammatory Lung Injury by Enhancing Macrophage Function via Reducing the Accumulation of Airway HMGB1. Int J Mol Sci. ;21(3). pii:E977. https://www.ncbi.nlm.nih.gov/pubmed/32024151.
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- Kensler TW, Ng D, Carmella SG et al, (2012) Modulation of the metabolism of airborne pollutants by glucoraphanin-rich and sulforaphane-rich broccoli sprout beverages in Qidong, China. Carcinogenesis. 33:101-107. https://www.ncbi.nlm.nih.gov/pubmed/22045030.
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- Sun Y, Zhou S, Guo H, et al. (2020) Protective effects of sulforaphane on type 2 diabetes-induced cardiomyopathy via AMPK-mediated activation of lipid metabolic pathways and NRF2 function. Metabolism. 102:154002. https://www.ncbi.nlm.nih.gov/pubmed/31706979.
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