(Natural News) No one would argue that getting cancer is a stroke of bad luck — but is that really the only cause? Researchers from Johns Hopkins Kimmel Cancer Center have recently claimed that errors in DNA copying occur “at random.” The team alleges that despite the long-standing belief that cancer is often due to lifestyle or dietary habits, up to two-thirds of all cancer cases are caused by nothing more than random mistakes in DNA copying. But are these mistakes really all that random?
Only a very small number of cancers — about 5 percent — are due to faulty inherited genes. Past research has indicated that up to 90 percent of all cancer cases can be attributed to diet, lifestyle and other environmental factors, but this new study stands to contradict previous findings. While the team found that most lung cancers were caused by things like smoking, the Johns Hopkins team found that up to 95 percent of prostate, bone and brain cancers were caused purely by “DNA copying errors.”
Overall, the team claims that 66 percent of all cancers are caused by so-called copying errors and just 29 percent of cancers are caused by lifestyle — a stark contrast to past research.
Does diet play a hidden role?
Past studies have found that cancer risk is not solely dependent on what you yourself eat. Indeed, what you eat over the course of your life does not just affect your own health, but also that of your children, and your children’s children. This would suggest that in order to truly calculate the “randomness” of these DNA copying errors, researchers would not just need to look at the DNA and lifestyle habits of a single subject, but also the DNA and lifestyle habits of that subject’s parents and grandparents.
In other words, what appears to be a “random error” in copying could be anything but. As Leslie A. Pray, Ph.D., explains, errors in replication occur on a fairly frequent basis. These errors are normally repaired after the replication phase, during a process called “mismatch repair.” Copying mistakes that are not identified and corrected during this process go on to become mutations. Pray explains that these so-called random mistakes are caused by chemical reactions within the cells.
Epigenetics, nutrition and cancer
Studies of epigenetics — which refers to changes in gene expression due to external forces — have used animal models to show that identical embryos implanted in different mothers can have wildly different gene expression, based on what the mother was fed. Enzymes and other chemicals present in the DNA’s environment affect how the DNA unwinds its various parts to make proteins or new cells.
This falls in line with Pray’s explanation of DNA errors and mutations, but with the added emphasis on how what you eat can impact the enzymes and chemicals present in the DNA’s environment — and subsequently, cause differences in gene expression.
In the mouse studies, otherwise identical mice exhibited differences in fur color, weight and risk of chronic disease, all because of what their mother was fed during pregnancy.
As Live Science explains, the findings demonstrate how nutrition affects genetic expression: Mice with identical DNA had drastically different gene expression due to nutrient availability, or the lack thereof, because what their mothers ate affected what enzymes and chemicals were surrounding the DNA. This holds true for humans as well. Research shows that diet affects all human cells, including sperm and egg cells.
This begs the question: If what we eat can so subtly influence genetic expression via the DNA cell’s environment, could it not also influence DNA copying errors as well? If, as Dr. Pray suggests, copying errors are caused by chemical reactions in the DNA’s environment, then it certainly seems that what you eat does play a role.
It would also seem reasonable to hypothesize that what one’s parent eats may cause an egg or sperm cell’s DNA to change, and possibly become more apt to undergo another change later in life that would initiate cancer.
In 2010, research revealed that the effects of diet could also increase your grandchildren’s cancer risks, even if they themselves followed a healthy diet. The study, which was conducted using rats, found that following a high-fat diet high in omega-6 fatty acids resulted in offspring with a 30 percent increase in breast cancer risk.
Omega-6 fats are known for their disastrous epigenetic effects, like turning off genes that control cell death — which plays a substantial role in cancer cell proliferation –and these effects may extend to multiple future generations. This underscores how nutrition can influence genetics in a way that may appear random. Furthermore, the researchers of this study themselves note that epigenetics seem to have a strong relationship with diet, and that epigenetic markers may extend for several generations, suggesting that “random” cancers may not always be so random after all.