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Journal of Ecosystem & Ecography | ISSN: 2157-7625 | Volume: 8
June 28-29, 2018 | Alexandria, Egypt
International Pre Conference Workshop on
Microbial Ecology & Eco Systems
Genes and the Environment: The Science of Epigenetics
Tito N Habib
Head of Molecular Genetics' Lab., Zoology Department, Faculty of Science, Sohag University, Egypt
A
t one time scientists believed our DNA held the key to preventing and reversing disease. But we now know that our environment—
not our genes—is the primary driver of health and longevity. The science of epigenetics is turning what we’ve long held true about
biological destiny upside down. Although it remains true that our DNA—our genetic code—provides the blueprint for our physiological
makeup, researchers have discovered that there’s something extra controlling our genes—and food and herbs may in fact be the most
important factors in our genetic well-being. That extra “something” controlling our genes is the epigenome, the cellular material that sits on
top of the genome (the complete set of genetic material present in a cell or organism). While epigenomes do not alter the genetic code, they
direct genes to switch on (becoming active) or off (becoming dormant) through a variety of biological mechanisms. This intriguing finding
means that your genetic heritage is not the primary determinant of your health, disease risk, or longevity.
In other words, whether or not you develop a disease is determined by how your genome is being directed to express itself. The abnormal
gene (genotype) isn’t necessarily a player in forming the phenotype (the characteristics of an individual resulting from the interaction
of the genotype with the environment). These changes in gene activity do not involve alterations to the genetic code, but are in great
part determined by the choices we make. For example, increased chronic activation of the sympathetic nervous system can cause the
β-adrenergic receptors to promote the metastatic phenotype in breast cancer and other cancers. So here we have a strong link between high
stress behavior, and specifically lack of vagus nerve activity (the most important nerve of the parasympathetic nervous system that extends
throughout the body and calms us down), determining gene expression.1
Most of these factors influencing the genome are pretty straightforward—diet, lifestyle, exercise, sleep habits, environmental factors, stress,
and social relationships have all been shown to influence the expression of your genetic inheritance. Other factors, including aging, cause
chemical modifications that switch genes on and off. And certain diseases, such as cancer, initiate changes that cause genes to deviate from
their normal, healthy state. We now know that genes account for about 10 percent of human disease. So if our genes aren’t driving disease,
what is?
The Exposome as the Primary Driver of Health and Disease:
The “exposome” is a concept that was originally proposed by Christopher
Wild in 2005. It refers to the sum of all non-genetic exposures in an individual lifetime, starting from the moment of conception. It
encompasses everything from the food we eat, to the water we drink, to the air we breathe, to the social interactions we have, to the lifestyle
choices we make, to the health of our parents at the time of our conception. In short, it’s the word scientists are using to describe the full
range of environmental exposures that influence our health. The exposome has been broken down into the following three categories:
1. Specific External Environment:
This includes diet, physical activity, water, consumer and personal care products, lifestyle choices like
smoking, infectious agents, chemical pollutants, etc. It also includes our environment at the earliest stages of our life, including our
mother and father’s health at the time of our conception and gestation, the method of our birth, whether we were breastfed or not, and
our early life bond with our mother and other social and psychological influences.
2. General External Environment:
This includes climate; urban vs. rural setting; traffic; our wider economic, social, and psychological
influences including social status, education, financial status, and stress.
3. Internal Environment:
This includes internal biological factors such as metabolism, the microbiome, inflammation, hormones, and
oxidative stress.
The reason the exposome is important as a concept is that we now know it is the primary driver of human health and disease. If genes
cause less than 10 percent of disease, it follows that the exposome—our diet, lifestyle, and environment—drive the remaining 90 percent.
The emerging field of epigenetics holds great promise for complex diseases including cancer, Alzheimer’s, cardiovascular disease, and
autoimmune, reproductive, and neurobehavioral illnesses. Through the process of epigenetic reprograming, using whole foods and
botanicals rich in a diversity of molecular health-promoting compounds, it is possible to rewrite the instructions to your cells, activating
desirable genes while deactivating undesirable genes. As an herbalist, I’m particularly intrigued by traditional herbs and spices that exhibit
Tito N Habib, J Ecosys Ecograph 2018, Volume: 8
DOI: 10.4172/2157-7625-C2-035