Whoever thought the concept of genetic testing and “personalized medicine” would be introduced to so many by Angelina Jolie? Jolie’s courageous decision to undergo what may be the most heroic of personalized, preventive medical procedures—a double mastectomy—was based upon a genetic test that determined she carries the mutant form of the gene BRCA 1, which predicts a personal risk to breast cancer of more than 85% during a woman’s lifetime. From her experience, many women are now asking: Should I be tested? What would I decide to do if I found out that I too am a BRCA 1 carrier?
There is much more to these questions and their implications than meets the eye. In fact, this issue may signal a bellwether turning point in the understanding of genes and the risk to disease. The BRCA 1 gene was discovered by an amazing woman researcher, Dr. Mary Claire King, at the University of California at Berkeley in the early 1990s. In 2003, Dr. King reported that carriers of the mutant form of BRCA have a lifetime risk of developing breast cancer of more than 85%, but before 1940, for women who had the same BRCA mutation, the incidence of breast cancer was only 24%. What resulted in the same genetic set of characteristics for breast cancer incidence going from 24% in 1940 to 85% in 2013? Dr. King commented in an article in the prestigious scientific journal, Science (Volume 302; pages 643-50 ), that other changes in lifestyle and environment including, but not limited to, the lack of physical exercise and obesity in adolescence may be important modulating factors for the translation of a genetic risk to breast cancer into the initiation of cancer.
The startling takeaway from this story is that we cannot change our genes, but we can change the environment, diet and lifestyle that may encourage the genetic risk to be translated into cancer. Our genes are fixed, but the expressions of our genetic characteristics are not. The translation of a genetic marker of risk such as BRCA to become a cancer is dependent upon the lifestyle of the individual.
So what do genetic markers tell us? They may not tell us as much about how we are going to get sick and ultimately die as how we should live through proper lifestyle, diet and environment selection.
This is the power of having your genetic code deciphered at one of the major medical laboratories now offering tests. These tests are not designed to pick up specific genetic characteristics such as Huntington’s disease or sickle cell anemia, but rather genetic characteristics that relate to how modifiable we are to factors in our lifestyle, diet and environment that “turn off’ genes that may increase the risk to specific age-related diseases such as heart disease, diabetes and dementia. Furthermore, these tests might educate us about the lifestyle factors necessary to “turn on” the genes associated with a longer, healthier life.
Three reputable companies that provide quality direct-to-consumer genetic testing whose genetic information is coupled with lifestyle, diet and environmental information are 23andMe, Pathway Genomics, and Interleukin Genetics. Each of these laboratories has its own panel of genes that it evaluates within the whole of the human genome to “tease out” specific genetic characteristics whose expression as a health or disease factor is modifiable through personalized alteration in the individual’s lifestyle, diet and environment.
These genetic characteristics have to do with what type of diet a person might best respond to in order to maintain a healthy weight, or how prone an individual is to an adverse reaction to the protein gluten found in grains. The genetics speak to how a person may have an adverse response to exposure to specific drugs, chemicals and alcohol, or how much of a specific nutrient such as the B-vitamin folic acid a person might need for optimal function.
This information provides a guide for the individual to know something about their genetic strengths and weaknesses. It provides guidance about how to design a lifestyle program for the individual that focuses around genetic areas of susceptibility to reinforce genetic determinants of good health by supporting proper immune function, cellular repair processes and bioenergetics.
So how does this view of genetic expression and the influence of the lifestyle and environment relate to Jolie’s decision to have a bilateral mastectomy for the prevention of breast cancer? This is a very personal question and relates to the evaluation of risk from both a genetic and family history perspective. If the individual with the genetic risk has a genetic marker that has a high prevalence of disease, as is the case with the mutant BRCA genes, and they have a family history of breast and other female cancers, as was the case with Jolie, then the decision of the individual may be that the risk is too high to rely upon lifestyle, diet and environmental changes. The decision may turn to mastectomy.
For most genetic markers of risk to diseases like heart disease, stroke, type 2 diabetes, arthritis and dementia, the association between a specific gene and the disease is not nearly as strong as the association of the mutant BRCA genes and breast cancer. In fact, it has been found that for most of the diseases that people get in older age they are less than 50% related to specific genetic susceptibility and more than 50% related to how lifestyle, diet and environment influence the expression of the disease.
From gene to biomarker
The question is how do we know that a specific genetic factor is being “translated” in the individual into an eventual disease early enough to do something about it? This is the basis of personalized lifestyle healthcare. The combination of genetic information with other information that informs the person as to how their genes are being expressed provides the information necessary to develop a personalized program that enhances functional wellness and reduces the loss of biological function that is related to biological aging and the increased risk to preventable diseases. This additional information is termed “biomarkers” and includes such things as the level of cholesterol in your blood, the way that cholesterol is packaged in LDL or HDL forms, the level of inflammation in your body as measured by two proteins in your blood called C-reactive protein and fibrinogen, and your blood pressure and percentage body fat.
There are literally hundreds of different biomarkers that are used to assess specific functions within your body that relate to how your genes are being expressed in response to your lifestyle, diet and environment. The development of personalized lifestyle medicine is linked closely to the validation of various biomarkers that can be used by the healthcare practitioner to better understand how the genes of their patient are being translated into physiological, physical and mental functional status. Through this type of analysis, the trajectory of health or disease in the individual can be determined, and a personalized program developed for their individual need.
The takeaway from the emerging science of genetics is that we are not just our genes, but rather a combination of our genetic inheritance whose expression into how we look, act, perform and feel is influenced significantly by our lifestyle, diet and environment. The influence of our lifestyle and environment on how our genes are expressed is a major determinant of our health and vitality as we age. This is a very different interpretation of the impact of genetics on our health, which not long ago led to the belief that our genetics had the majority control on our health, and therefore our disease patterns were hardwired and predetermined by our genes. We now understand that defining our genetic strengths and susceptibilities through genetic testing coupled with biomarker analysis of important health and disease indicators will provide the important information we need in designing our own personalized lifestyle healthcare program that can both reduce the risk of preventable disease and improve function at any age.
Jeffrey Bland is Founder and President of the Personalized Lifestyle Medicine Institute (PLMI), the global leader in the discussion around personalized approaches to healthcare. Deanna Minich is Vice President of Education at PLMI. To learn more about PLMI, please visit plminstitute.org.