There is a chronic anxiety among populations who focus on the diseases acquired by their genetic line. Many define the potential of their own health based on what happened to their father and mother. Although a great deal of who we are appears to have been written in our genes, our actual health potential is more determined by our lifestyle, what we consume, our environment but more than anything else, what we think.
Studies at the world-leading Minnesota Center for Twin and Family suggest that many of our traits are more than 50% inherited, including obedience to authority, vulnerability to stress, and risk-seeking. Researchers have even suggested that when it comes to issues such as religion and politics, our choices are much more determined by our genes than we think.
Many find this disturbing. The idea that unconscious biological forces drive our beliefs and actions would seem to pose a real threat to our free will. We like to think that we make choices on the basis of our own conscious deliberations. But isn’t all that thinking things over irrelevant if our final decision was already written in our genetic code? And doesn’t the whole edifice of personal responsibility collapse if we accept that “my genes made me do it”?
Genes are only part of our health story, explains Jeffrey S. Bland, PhD, FACN, FACB, author of the book, Genetic Nutritioneering: How You Can Modify Inherited Traits and Live a Longer, Healthier Life. The propensity for certain health conditions that you inherit from your family is not, by a long shot, the sole determinant of whether or not most folks will get sick. Your lifestyle choices have a significant impact, especially when it comes to chronic illnesses such as heart disease.
In the fields of infant nutrition, diabetes, obesity, and the metabolic syndrome, the term “metabolic programming” has been coined to give a name to the observation that environmental experiences early in life may be “genomically” remembered and give rise to health outcomes manifesting later in life. Epigenetics emerges as an important mechanism underlying this phenomenon.
Epigenetics is the phenomena whereby genetically identical cells express their genes differently, resulting in different physical traits. Researchers from the Boston University Cancer Center published two articles about this in Anticancer Research and Epigenomics.
Cancer progression is extremely complex, however. It also is well known that new mutations and the activation of more cancer causing genes occur throughout the development and progression of cancer.
“If we believe that everything in nature occurs in an organized fashion, then it is logical to assume that cancer development cannot be as disorganized as it may seem,” said Sibaji Sarkar, PhD, instructor of medicine at BUSM and the articles corresponding author. “There should be a general mechanism that initiates cancer progression from predisposed progenitor cells, which likely involves epigenetic changes.”
Increasingly, biologists are finding that non-genetic variation acquired during the life of an organism can sometimes be passed on to offspring–a phenomenon known as epigenetic inheritance.
The majority of epigenetic changes occur at specific times in an individual’s life, from their time in the womb, to the development as newborns, then in puberty, and again in old age.
Environmental factors that influence epigenetic patterns — e.g., diet, epigenetic disruptors in the environment such as chemicals, etc. – may also have long term, multigenerational effects.
In recent years, faith in the explanatory power of genes has waned. Today, few scientists believe that there is a simple “gene for” anything. Almost all inherited features or traits are the products of complex interactions of numerous genes combined with processes we have no concept of. However, the fact that there is no one genetic trigger has not by itself undermined the claim that many of our deepest character traits, dispositions and even opinions are genetically determined. This worry is only slightly tempered by what we are learning about epigenetics, which shows how many inherited traits only get “switched on” in certain environments.
The common mistake people make is to assume that if, for example, a disease is 90% heritable, then 90% of people with that disease inherited the condition from their parents. But heritability is not about “chance or risk of passing it on”, said Tim Spector, Professor of Genetics and Author. “It simply means how much of the variation within a given population is down to genes. Crucially, this will be different according to the environment of that population.
Biologists have suspected for years that some kind of epigenetic inheritance occurs at the cellular level. The different kinds of cells in our bodies provide an example. Skin cells and brain cells have different forms and functions, despite having exactly the same DNA. There must be mechanisms–other than DNA–that make sure skin cells stay skin cells when they divide.
The existence of this epigenetic switch is indirectly supported by the fact that tumors develop through different stages. When cells rapidly grow during cancer progression, they become stuck in their current stage of development and their cell characteristics do not change. This is the reason that there are so many types of leukemia — the characteristics that a leukemia cell possesses when it begins to rapidly grow and expand are the characteristics that it will keep until the rapid growth stops.
Dr. Bruce Lipton refers to the work of Dr. Dean Ornish to extrapolate. “Dr. Ornish has taken conventional cardiovascular patients, provided them with important lifestyle insights (better diet, stress-reduction techniques, and so on), and without drugs, the cardiovascular disease was resolved. Ornish relayed that if he’d gotten the same results with a drug, every doctor would be prescribing it.”
Even the strictest lifestyle changes don’t cure cancer in everyone. What about genetic predispositions to getting the disease? “It used to be that we thought a mutant gene caused cancer,” Lipton admitted, “but with epigenetics, all of that has changed.”
“If we believe that all of the irreversible changes, mutations and effects of carcinogens make cells rapidly grow, then the mechanism that allows cells to stop growing and assume new changes in character must be of great importance,” added Sarkar. “The study of cancer progression is key to understanding how cancer cells continue to differentiate.”During cancer progression, there are different stages of rapid growth and differentiation. The control that allows for this switch between growth and differentiation can only be achieved through reversible mechanisms, such as epigenetic changes.
If we believe that all of the irreversible changes, mutations and effects of carcinogens make cells rapidly grow, then the mechanism that allows cells to stop growing and assume new changes in character must be of great importance,” added Sarkar. “The study of cancer progression is key to understanding how cancer cells continue to differentiate.”During cancer progression, there are different stages of rapid growth and differentiation. The control that allows for this switch between growth and differentiation can only be achieved through reversible mechanisms, such as epigenetic changes.
Sarkar and colleagues have previously proposed that epigenetic changes are involved in cancer progenitor cell formation and cancer progression. They also believe that epigenetic changes have the ability to control rapid growth and change of characteristics (different grades/types of tumors) which may involve physiological processes that the cancer cells are subjected to within the body’s terrain.
Identical twins show us that in the nature-versus-nurture debate, there is no winner. Both have their role to play in shaping who we are. But although we have reason to doubt that our genes determine our lives in some absolute way, this does not solve a bigger worry about whether or not we have free will.
Who we are appears to be a product of both nature, nurture and consciousness itself in whatever proportion they contribute. You are often shaped by forces beyond yourself, and can choose what you become. And so when you go on to make the choices in life that really matter, you do so on the basis of beliefs, values and dispositions that you have chosen whether you are conscious of those choices or not.
It is very possible that our entire reality is define but what we feel and this shapes what we are. We always have free choice and will to make ourselves into something that we believe we are. The question is, do you believe it?