Scientists for the longest time believed that your genetics were determined at birth, and nothing you could do could change them. In the 1990's scientists began to find that there are factors above and beyond genes that determined how genes are expressed and even passed on to children. This goes back to the whole Nature vs. Nurture argument and trying to determine which is more important. The genes you are born with are your nature, but how they are read, interpreted and expressed would be considered your nurture.
Is it possible to change the ways your genes are expressed so that you can be more healthy? Can you actually ward off such life-threatening diseases as cancer? Is this some wild, crazy fringe scientific theory or does it hold some truth? And if it is true, why aren't people hearing more about it?
What is epigenetics?
Epigenetics can be defined as the study of heritable changes in gene function that cannot be explained by changes in DNA sequence. The Greek prefix epi- in epigenetics implies features that are "on top of" or "in addition to" genetics; thus epigenetic traits exist on top of or in addition to the traditional molecular basis for inheritance. (source: Wikipedia)
How can epigenetics be used to improve my health?
That's the real question behind all of this. It's great that scientist have found that gene expression can be modified, and in some cases passed along to future generations. But how can this be done in a way to benefit my health now?
One promise that epigenetics holds is that through lifestyle changes such as better nutrition and exercise, that genetically influenced diseases such as diabetes and cancer can be improved or even reversed. The current reality is that scientists have found evidence of being able to alter gene expression chemically, and that some of those modifications can be passed along to offspring.
In 2008, the National Institutes of Health announced that $190 million had been earmarked for epigenetics research over the next five years. In announcing the funding, government officials noted that epigenetics has the potential to explain mechanisms of aging, human development, and the origins of cancer, heart disease, mental illness, as well as several other conditions. Some investigators, like Randy Jirtle, PhD, of Duke University Medical Center, think epigenetics may ultimately turn out to have a greater role in disease than genetics. (source: Wikipedia)
The example of colon cancer
Colorectal cancer (CRC) is a disease associated with increasing age and there is strong evidence that the risk of CRC can be modified by lifestyle and environmental factors. It has been demonstrated that diet may account for or prevent as much as 80% of CRC incidence. Diet may affect gut mucosa either directly from the luminal side or indirectly through whole-body metabolism. Food-derived compounds that are constantly present in the intestine, or the blood content of nutrients, hormones and growth factors, may shift cellular balance toward harmful outcomes, such as increased susceptibility for genetic and epigenetic changes in a genome.
There is a strong assumption that diet, especially Western-type diet, contributes to the development of CRC. In 2007, the World Cancer Research Fund and the American Institute for Cancer Research published their 2nd comprehensive review entitled ‘Food, Nutrition, Physical Activity and the Prevention of Cancer; a Global Perspective’ (http://www.dietandcancerreport.org) supporting this belief. Based on mainly prospective cohort studies it was concluded that there is convincing evidence that red and processed meat, substantial consumption of alcoholic drinks, body fat and abdominal fatness, and the factors that lead to greater adult attained height or its consequences are causes of CRC. In addition, foods containing dietary fiber, garlic, milk and calcium probably protect against this cancer. Moreover, non-starchy vegetables, fruits, fish, foods containing folate, vitamin D, or selenium may protect against CRC, and foods containing animal fats or sugar may cause CRC. In a recent study, CRC re-occurrence was also shown to be significantly higher in subjects consuming the most Westernized diet compared to diets with more fiber and less fat and sugar . (Source: Diet and epigenetics in colon cancer abstract)
The bottom line
This blog post just gives you a taste of what is going on in the field of epigenetics. It is just taking off, and it offers some amazing possibilities to improve our lives and those of our future generations.
But the bottom line is, we already knew that eating right and exercising leads to better health. The solution for a morbidly obese person who has diabetes isn't insulin shots for the rest of his life. It is to get him active, moving and eating better and voila the condition gets better. It may not always happen that way, but we all know that being healthy is its own reward.