Tag Archives: health

Cancer-Causing Mutations Can Occur By Chance as Millions of Cells Divide

“When the DNA double helix was first revealed by Watson and Crick in 1953, its structure seemed perfect and robust, well-designed to resist most of the disruptive influences that might be present inside living cells. For example, the bases in the double helix are turned inward and thus are not very susceptible to direct attack by chemical mutagens. Moreover, the linkages between adjacent bases were found to be resistant to cleavage by alkaline ions that arise continually in the cell.

“But while the double helix itself is relatively resistant to chemical attack, the process of maintaining a cell’s genetic integrity has a weak link. The vulnerability derives from the need to replicate the cell’s genome each time the cell goes through the process of growth and division. The resulting duplicate copies of the genome enable the mother cell to endow each of its daughters with a genome precisely equivalent to the one that it carries itself.

“This process of DNA replication has flaws. On occasion, a cell will miscopy a sequence of its DNA prior to cell division, and as a consequence, one of its daughters will receive a slightly miscopied genome, in effect a mutated one. Even the best-functioning cells will occasionally miscopy one in a million (or ten million) bases during each cycle of DNA replication. Hence, cell growth and division create vulnerability mutation.

“This imperfection suggested another way cancer formation might be accelerated. Agents that promote cell growth will indirectly create mutations simply because they force cells to replicate their DNA. More DNA copying means more inadvertent copying mistakes, hence more mistakes.”

Alternative Medicine and Statistical Validation

“The resistance to statistical evidence is even more pronounced with regard to ‘alternative medicine,’ a vast field that encompasses everything from herbal supplements to energy therapy to yoga…Many adherents and advocates of alternative medicine reject not only Western treatments but the Westernized notion of statistical testing. They sometimes claim that their practices are too ‘individual’ or ‘holistic’ to study scientifically and instead rely on anecdotes and case studies without adequate controls or control groups for comparison. I’m agnostic about whether alternative medicine is effective. But it verges on idiocy to claim that the effectiveness cannot be tested. If it really is important, as alternative medicine advocates claim, to take into account a larger set of information about the patient…then providers who do so should produce better results…When it comes to the back-end inquiry of finding out which treatments are effective, there is no East and West. I throw my lot with two past editors-in-chief of the New England Journal of Medicine, Marcia Angell and Jerome Kassirer: ‘It is time for the scientific community to stop giving alternative medicine a free ride. There cannot be two kinds of medicine–conventional and alternative. There is only one medicine that has been adequately tested and medicine that has not, medicine that works and medicine that may or may not work.” (p. 229)