Dietary Iodine May Possibly Prevent SARS-Cov 2 Infection

 Dietary Iodine May Possibly Prevent SARS-Cov 2 Infection

SARS-CoV 2 (COVID-19) is a

• highly contagious and often deadly virus 
• airborne agent entering humans via the nose and mouth 
• lodging in the bronchi and lungs

Vaccines are now available but 

• require years before billions of people can be immunized
• many countries cannot afford expensive vaccines
• may not be very effective against mutant forms of the virus

Preventative measures are few

• Enforced economic shutdowns and strict social distancing
• Are difficult to enforce and 
• cannot be sustained forever and 
• only delay the pandemic spread

Here we will show that dietary iodine

• may allow some people to avoid becoming infected
• may dampen the rate of COVID-19 transmission
• Dietary iodine (I- or iodide ion) is available to many and is cheap

The protective mammalian enzyme lactoperoxidase is 

• extruded into human lungs and saliva [1]
• catalyses the oxidation of iodide with H2O2 into the products 
• hypoiodite (IO-) and hypoiodous acid (HOI)

Both products are potent, non-specific antimicrobial agents and 

• are lethal to the influenza virus [2]
• The mechanism by which lactoperoxidase and iodide ion destroys many types of viral invaders is understood in fine detail
• is similar to the mechanism of viral destruction exhibited by the protective enzyme myeloperoxidase found in natural killer cells (NK cells)

The lactoperoxidase system is recognised as 

• the first line of defence against airborne viral infections 

The 3-dimensional structures of lactoperoxidase with I- has shown that

• iodide ion binds at many sites to lactoperoxidase including 
• the active substrate binding site [3]
• evidence of the importance of this enzyme for production of HOI and IO-

The COVID-19 infection rate is low in Japan despite being 

• densely populated islands and 
• has not enforced a strict lock down 

The typical Japanese diet is 

• rich in seafood including kelp and seaweed - both high in iodine
• The average Japanese adult consumes 
• more than twice the iodine than the US RDA (150 μg) but 
• still under the recommended upper daily limit of 1,100 μg per day

There is an inverse correlation between iodine intake and COVID-19 infections

• this is more than a correlation but a causal relationship
• has been shown true for past influenza pandemics [4]

Increasing I- (iodide ion or iodine) in mammalian airways has been shown to 

• enhance the lactoperoxidase system performance and kill viral agents [5] 
• Both IO- and HOI are non-specific, anti-viral agents 
• the destructive activity is independent of the SARS-CoV 2 type (mutant)
• in fact nearly independent of any virus type

Estimated that 2 billion people worldwide suffer iodine insufficiency

• COVID-19 has decimated the elderly and institutionalized
• These people typically have a diet deficient in iodine [6] 

Nothing is known about the age-dependence of lactoperoxidase activity

• Smokers are also hit hard by the corona virus
• carbon monoxide (CO), a major gaseous constituent of cigarette smoke, binds to and inactivates lactoperoxidase [7]

I propose a cheap method for containing COVID-19

• encourage nutritional and health professionals to consider
• recommending increasing iodine intake by
• liberal use of iodized salts and 
• consumption of more seafood, including kelp and seaweed

Hope that nutritionists and epidemiologists will study this correlation

• especially about areas close to the seashore
• and areas of iodine insufficiency

Such preventative measures can be quickly instituted by all and

• especially low income nations
• and land-locked countries

Positive effects should be quickly observed 

• The long-term health effects of increased iodide intake should not be serious since
• median longevity of the Japanese is the highest of any industrial nation 

Do not think this measure will eliminate the COVID-19 pandemic but 

• even a small decrease in the transmission rate can have 
• immediate and positive results for everyone

References

• Sharma S, Singh AK, Kaushik S, Sinha M, Singh RP, Sharma P, Sirohi H, Kaur P, Singh TP. Review Article Lactoperoxidase: structural insights into the function, ligand binding and inhibition. Int J Biochem Mol Biol. 4(3),108-128 (2013). URL https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3776144/pdf/ijbmb0004-0108.pdf
• [2] Patel U, Gingerich A, Widman L, Sarr D, Tripp RA, Rada B. Susceptibility of influenza viruses to hypothiocyanite and hypoiodite produced by lactoperoxidase in a cell-free system. PLOS ONE. 13(7),e0199167 (2018).  DOI:10.1371/journal.pone.0199167
• [3] Viswanathan V, Rani C, Ahmad N, Singh PK, Sharma P, Kaur P, Sharma S, Singh TP. Structure of Yak Lactoperoxidase at 1.55 Å Resolution. Protein J. Online ahead of print (2021). DOI:10.1007/s10930-020-09957-2
• [4] Menon IGK. The 1957 Pandemic of Influenza in India. Bulletin World Health Organisation 20(2-3),199-224 (1959). PMID:13651910 
• [5] Fischer AJ, Lennemann NJ, Krishnamurthy S, Pocza P, Durairaj L, Launspach JL, Rhein BA,Wohlford-Lenane C, Lorentzen D, Ban B, McCray PB. Enhancement of Respiratory Mucosal Antiviral Defenses by the Oxidation of Iodide. Am J Resp Cell Mol Biol. 45(4),874-881 (2011). DOI:10.1165/rcmb.2010-0329oc
• [6] Vural Z, Avery A, Kalogiros DI, Coneyworth LJ, Welham SJM. Trace Mineral Intake and Deficiencies in Older Adults Living in the Community and Institutions: A Systematic Review. Nutrients. 12(4),1072 (2020). DOI:10.3390/nu12041072
• [7] Singh AK, Smith ML, Yamini S, Ohlsson P-I, Sinha M, Kaur P, Sharma S, Paul JAK, Singh TP, Paul K-G. Bovine Carbonyl Lactoperoxidase Structure at 2.0Å Resolution & Infrared Spectra as a Function of pH. Protein J. 31,598-608 (2012).  DOI:10.1007/s10930-012-9436-3