Hormesis Mechanisms

Every second the average person in the United States is "hit" by 15,000 particles of ionizing radiation, mostly from background sources. (The 1,500 "hits" mentioned earlier were only from cosmic sources.) Why does a relatively small increase in this exposure have a positive effect on the health of individuals? That physiological changes occur is unquestionable: it has been known for almost a century that low doses of radiation increase the production of lymphocytes (white blood cells). Other changes observed to occur are:

• Increased number of immune system helper T cells
• Decreased number of immune system suppressor T cells
• Increased activity of the p53 protein [a protein that reputedly decreases the incidence of many cancers]
• Increased free-radical scavenger activity (while radiation causes the creation of free radicals, it simultaneously produces much more of the remedy than of the problem).

The above, among others, are considered to be part of the cell's defensive system against chemical and radiation insults. Interestingly, high doses of radiation have a "reverse effect" on these very same cellular activities.

In the previous quotation from Dr. Rockwell, it was noted that a poor job in the cellular repair and removal business is what causes us potentially fatal problems. The body just doesn't do well with a bunch of sick, dying or dead cells hanging around. An interesting discovery resulting from the hormesis research led by Dr. Sohei Kondo was that low-dose radiation increased apoptosis - often referred to as altruistic cell suicide. [Dr. Kondo is professor emeritus of biology at Osaka University, and senior researcher at the Atomic Energy Research Institute, Kinki University, Osaka, Japan.]

By the process of apoptosis, damaged cells were absorbed without necrosis (a fancy scientific way of saying the cellular bodies were carted off before becoming offensive) and, at the same time, healthy cell replacement was stimulated.

In considering what hormesis is, we should also be aware of what it isn't. It is not the action of radiation on a single isolated cell. In experiments involving single cells in vitro [literally, "in glass," although almost all "glass" dishes these days are actually plastic], they behave as the LNT theorists would predict: the more radiation, the less vitality. [Critics of hormesis often point out isolated cell experiments as proof against the phenomenon.]

But when a society of cells, such as those making up an organ or an organism, is subjected to a relatively low dose of ionizing radiation, protective action (homeostasis) occurs, and the effect can be quite dramatic, as will be shown in the chapters on evidence.

One final analogy: we are aware that introducing the cowpox virus into our body causes the immune system to gear up and produce antibodies that also happen to be effective against smallpox. What isn't commonly known, however, is that inoculation against one disease increases the body's resistance to others. A 1986 English study showed a decrease in death from malignant disease for all who were inoculated, as children, for any one of eight diseases. Children inoculated against measles, for example, had a better chance to survive diphtheria or whooping cough, even while lacking those specific inoculations.

Similarly, low doses of radiation "inoculate" the body to the negative effects of future high doses - while at the same time appear to have positive effects in increasing general immune competency. Those who would like to learn more about radiobiological and hormetic effects should find the references in chapter 15 to be interesting. They allude to the Japanese research on the subject, which is well ahead of that being done in the United States.