vitamin c and radiation exposure

Vitamin C: Protection Against Radiation Exposure

Vitamin C is a popular vitamin best known for its immune strengthening properties. In fact, this water soluble micronutrient plays a critical role in sustaining life. Our body will simply fall apart without it. Vitamin C helps to maintain the integrity of our skeletal system, is required for growth and repair of connective tissues and as a co-factor for biosynthesis of collagen and other important metabolic reactions. It also helps in the prevention and treatment of many infections and chronic conditions including arthritis, cardiovascular diseases, eye degenerative disorders, premature aging and cancer.

Vitamin C is a potent anti-oxidant and much of its health imparting properties are drawn from its powerful ability to fight and neutralize free radicals – highly reactive oxygen species that can cause excessive oxidative damage to DNA, cell membranes and other delicate cellular structures. And this property makes Vitamin C indispensable when it comes to minimizing the dangerous side effects of ionic radiations, the kind emitted during Fukushima and other nuclear disasters.

How ionizing radiation damages cells

As radioactive material decays, it releases high frequency radiations into the environment. These radiations are basically fast moving energy particles – alpha particles, gamma rays and beta particles – that crash into a living cell with a force high enough to knock off electrons free from the molecules of the cell. This results in the formation of highly reactive free radicals and their metabolites that further disrupt the chemical bonds between the surrounding molecules like proteins, DNA, lipids and carbohydrates – damaging their fragile structures and impacting their ability to function normally.

The most severe form of radiation damage occurs when DNA is damaged. The ionizing radiations incapacitate the cellular DNA in two major ways:

  1. The water in our body happens to absorb most of the radiation and gets ionized in the process, readily forming free radicals and their metabolites. Almost 80 % of the radiation induced DNA damage results through this mechanism.
  2. Radiations can also collide directly with DNA molecules, thus ionizing and injuring these directly.

DNA contains genes that carry unique genetic information or instructions to make new cells. A DNA molecule is made up of two long strands that are entwined around each other like a twisted ladder and held by chemical subunits. Ionizing radiations cause the formation of strand breaks in the DNA [1]. Our body can easily repair single-strand breaks (where only one of the two strands has been cleaved) by employing specialized DNA repair enzymes. On the other hand, correction of double-strand breaks (where both DNA strands are injured) is difficult and complicated, and may result in erroneous re-joining of broken ends.

This kind of error in the DNA repair can cause mutations. This change in the structure of DNA alters normal cellular processes, including mechanisms that dictate how and when cells divide. Such misdirection leads to uncontrollable cell division causing cancer and chromosomal abnormalities that can even be passed from one generation to another. With significant damage to DNA, it even loses the ability to replicate further and the cells die.

It is very well proven that ionizing radiation can damage DNA, resulting in many types of cancer and inherited mutations. To sum it up, health risks from the unfortunate Fukushima nuclear accident include increased risk of thyroid cancer, other types of solid cancer, hereditary diseases, fertility issues, impaired immunity, birth defects and cardiovascular diseases.

Also, low level exposure to ionizing radiations produces other biological damage besides causing latent cancer.  In fact, low level chronic radiations are thought to exert much more long-term impact on the exposed population than short-high doses. Ionizing radiation can cause inheritable genetic mutations that can be expressed in the offspring of exposed organisms, be it plants, animals or human beings. While these genetic mutations result in major abnormalities in the offspring and may be easily noticeable, it is also possible that some inherited mutations may either show up only as subtle effects or have bearings that do not appear until much later generations.

In addition, the cells present in the vicinity of an exposed cell can be impacted too. Scientists explain it as a bystander effect phenomenon. Cells that have been irradiated impact the surrounding healthy cells by transmitting signals and end up generating the same kind of responses in the non-irradiated cells that results in faulty gene expression, cell proliferation, apoptosis and cell death. “Most well-known important factors affecting radiation-induced bystander effect include free radicals, immune system factors, expression changes of some genes involved in inflammation pathway and epigenetic factors.” [2]

What also deserves the spotlight is the impact of radiations on immunity. Ionizing radiations cause deadly damage to bone marrow stem cells, lymphocytes and natural killer cells. These white blood cells are responsible, in a major way, for our innate and adaptive immunity – protecting our body against opportunistic infections and diseases including cancer. Yes, our immune cells actually have the capability to fight the cancer cells but clearly, damage to these fighter cells is only likely to make people more prone to cancer and opportunistic pathogens.

Government authorities and health experts all over the world may try hard to assure us that the radiation risks from Fukushima are overstated. But we have taken our lessons from the studies on survivors of Chernobyl, Hiroshima and Nagasaki nuclear disasters. And the data points out that on-going radiations indeed have far-reaching consequences for us as well as our entire biological ecosystem, putting the health of present as well as future generations in total jeopardy. The potential risks are much higher for small children and pregnant women as the radiations have the most impact on fast reproducing cells in their bodies making them more vulnerable to the toxic side effects.

What is troubling is that the Fukushima nuclear disaster site is still a source of toxic radionuclides entering the adjoining sea water, making the situation graver. Research from Woods Hole Oceanographic Institution shows that Fukushima radiation is making its way along the U.S. West Coast. “Scientists monitoring the spread of radiation in the ocean from the Fukushima nuclear accident report finding an increased number of sites off the US West Coast showing signs of contamination from Fukushima. This includes the highest detected level to date from a sample collected about 1,600 miles west of San Francisco.” [3]

Can we do something to negate the short as well as long-term damaging effects of these radiations? Fortunately, anti-oxidants, also called free radical scavengers, can destroy free radicals and minimize radiation induced toxicity. And Vitamin C clearly takes a lead.

Role of Vitamin C: Free radical scavenger

Vitamin C is a popular anti-oxidant that is known for its powerful ability to mop up damaging free radicals, even those created by radiation exposure. Many scientific studies demonstrate the protective role of high doses of Vitamin C in preventing radiation induced cellular damage. And so much so that a large body of research points out that Vitamin C can actually reverse the DNA damage caused by ionizing radiations.

  • A 2011 study by Dr. Atsuo Yanagisawa and team showed that Fukushima workers who took high-dose Vitamin C before going on to clean up the radioactive wreckage were protected against damage to DNA and overall cancer risk. “Workers with severe radiation exposure at the Fukushima nuclear plant had major reduction in cancer risk when supplemented with vitamin C and other anti-oxidative nutrients……. Four workers who took intravenous vitamin C (25,000 mg) therapy before they went in, and continuously took anti-oxidative supplements during the working period, had no significant change in both free DNA and overall cancer risk. Three workers that did not have preventive intravenous vitamin C had an increase in calculated cancer risk. After 2 months of intervention with intravenous vitamin C and oral anti-oxidative nutritional supplements, free DNA returned to normal level and cancer risk score was significantly decreased.” [4]This significant clinical evidence confirms the result of a 1993 study that showed “Vitamin C may have an important role as a radio-protector against accidental or medical radiation exposures, especially when radionuclides are incorporated in the body and deliver the dose in a chronic fashion.” [5]
  • The results from a 2004 study [6] showed that administration of ascorbic acid did protect mice against radiation-induced sickness, mortality and improved healing of wounds after exposure to whole-body gamma-radiation – adding to the evidence for the radio-protective nature of Vitamin C.
  • Bone marrow failure is believed to be one the most common complications after acute radiation exposure, causing severe pancytopenia – considerable loss of white blood cells, red blood cells as well as platelets. The reduction in all these blood cells leads to fatal immune dysfunction.  While bone marrow transplantation (BMT) or stem cell transplantation is significantly helpful in saving patients from radiation-caused bone marrow failure, the condition is followed by another serious complication – radiation-induced gastrointestinal (GI) syndrome.A 2010 [7] study showed that ascorbic acid treatment may effectively thwart GI syndrome caused by acute radiation exposure. The study paper explains that “ascorbic acid acts as a hydrogen donator to scavenge radiation-induced free radicals in both GI tract and bone marrow. Hydrogen donation is an important step toward chemical repair of damaged DNA, and ascorbic acid is believed to strongly contribute to this process.
  • Recently, a team of researchers investigated the effects of administration of ascorbic acid on mouse survival after the mice received whole body irradiation. The results of this 2015 study [8] published in PLoS One concluded that the “administration of high-dose ascorbic acid might reduce radiation lethality in mice even after exposure.”The research further discusses that after the radiation exposure, secondary reactive oxygen species and inflammatory cytokines are released. This explains why post-radiation therapy with ascorbic acid may be advantageous as it reduces “radiation-induced elevation of inflammatory cytokines and also elevation of free radical metabolites.”

What experts recommend? In the statement of “Environmental Radioactivity and Health” issued in 2011, The Japanese College of Intravenous Therapy (JCIT) strongly recommended that “People living in the affected areas should regularly take antioxidant supplements such as vitamin C to counteract the negative consequences of long-term low dose radiation exposure as well as to protect the health of coming generations.”

Vitamin C and Cancer

What makes Vitamin C therapy even more useful is that it also supports immune system functions, thus working along with the body’s inherent ability to fight cancerous cells. A study published in the Journal of Angiogenesis Research showed that high doses of Vitamin C restricts the formation of new blood vessels, that serve to carry increased flow of blood and nutrients to the tumor site required for growth and proliferation [9]. In addition, intravenous Vitamin C improves the quality of life in cancer patients by reducing the severity of devastating side effects that typically accompany conventional cancer treatment like chemotherapy and radiation therapy [10].

References:

  1. Scholes, G. (1983) Radiation effects on DNA. The Silvanus Thompson Memorial Lecture, April 1982. Br. J. Radiol. 56: 221–231.
  2. Najafi eat al. The Mechanisms of Radiation-Induced Bystander Effect. J Biomed Phys Eng. 2014
  3. Woods Hole Oceanographic Institution. Higher Levels of Fukushima Cesium Detected Offshore. 2015
  4. Yanagisawa A. Orthomolecular approaches against radiation exposure. Presentation Orthomolecular Medicine Today Conference. Toronto 2011 http://www.doctoryourself.com/Radiation_VitC.pptx.pdf
  5. Narra VR, Howell RW, Sastry KS, Rao DV. Vitamin C as a radioprotector against iodine-131 in vivo. J Nucl Med 1993; 34(4):637-40
  6. Jagetia GC, Rajanikant GK, Baliga MS, Rao KV, Kumar P. Augmentation of wound healing by ascorbic acid treatment in mice exposed to gamma-radiation. Int J Radiat Biol. 2004
  7. Pretreatment with Ascorbic Acid Prevents Lethal Gastrointestinal Syndrome in Mice Receiving a Massive Amount of Radiation J. Radiat. Res., 51, 145–156 (2010)
  8. Tomohito Sato et al. Treatment of Irradiated Mice with High-Dose Ascorbic Acid Reduced Lethality. PLoS One. 2015; 10(2): e0117020.
  9. Nina A Mikirova,Joseph J Casciari,and Neil H Riordan. Ascorbate inhibition of angiogenesis in aortic rings ex vivo and subcutaneous Matrigel plugs in vivo. Journal of Angiogenesis Research. 2010; 2: 2.
  10. Anitra C. Carr, Margreet C. M. Vissers, and John S. Cook. The Effect of Intravenous Vitamin C on Cancer- and Chemotherapy-Related Fatigue and Quality of Life. Frontiers in Oncology. 2014; 4: 283.