In recent years, the field of systems biology has emerged as a powerful approach to understanding the body. Systems biology focuses on understanding biological systems as a whole, rather than studying individual components in isolation. It aims to uncover the complex interactions and relationships between genes, proteins, cells, and their environment, with the goal of elucidating how these interactions give rise to the behavior and function of living organisms. In medicine, this perspective provides a holistic perspective on disease mechanisms and offers a framework for providing a personalized approach to health. It recognizes that the development of lifestyle diseases, such as type 2 diabetes, cannot be attributed solely to genetic predispositions. Instead, a comprehensive understanding of how genetic predispositions interact with environmental and lifestyle factors, such as diet, chemical exposure, stress, exercise, and the microbiome, is crucial in determining not only how the disease manifests, but also how to prevent it.
The influence of gene-environment interactions is seen in numerous chronic diseases. Common diseases, such as obesity, type 2 diabetes, metabolic syndrome, heart disease, osteoporosis, and dementia are all linked to genetic predispositions; however, the genes themselves do not determine the onset, rather it is how they interact with the environment that defines expression and disease manifestation. One important factor that showcases the interconnectedness of genes, environment, and lifestyle is vitamin D and osteoporosis.
Examples Of How Genes Interact with Our Environment and Lead to Disease
Osteoporosis, a condition characterized by reduced bone density and increased fracture risk, is influenced by a variety of factors, including genetic predispositions and lifestyle choices. Vitamin D, primarily obtained through sunlight exposure and dietary sources, plays a critical role in calcium absorption and bone health. Genetic variations in the vitamin D receptor gene (VDR) can affect the likelihood for vitamin D deficiency and predispose one to osteoporosis. However, the impact of genetic variations can be modulated by environmental and lifestyle factors. For instance, inadequate sun exposure can exacerbate the effects of these genetic variations, leading to compromised bone health. Conversely, sufficient sun exposure and an adequate weight resistant training with proper nutrition can help mitigate the risk associated with genetic predispositions, emphasizing the importance of considering both genes and environmental factors in disease prevention.
Cardiovascular disease, particularly coronary artery disease (CAD), is a multifactorial condition influenced by complex gene-environment interactions. Risk factors include, high blood pressure, obesity, high LDL cholesterol, insulin resistance and diabetes, poor diet, inactivity, and chemical exposure, such as cigarette smoke are all linked to an increase in risk. In addition, several genetic factors have been implicated in CAD susceptibility. The frequencies of the GSTM1 and GSTM1/T1 null genotypes are higher in CAD patients and result in an increase in oxidative damage and lipid peroxidation, especially in the presence of certain environmental chemicals found in cigarettes and automobile pollution. Genetic variations in the MTHFR gene are associated with elevations in homocysteine, which has been associated with coronary artery diseases and considered an independent risk factor for cardiovascular-related diseases.
Similar to the VDR genotypes and osteoporosis, the presence of GST null genotypes and at-risk variants within the MTHFR gene do not determine CAD; it is likely the exposure to environmental chemicals, low antioxidant intake, vitamin B deficiencies and metabolic dysregulation that interact with these predispositions to lead to the development. If a person is aware of these predispositions, often this can provide the insight and motivation to make necessary adjustments in diet and lifestyle to reduce risk.
Understanding one’s genetic predispositions are therefore essential in identifying who is prone to certain lifestyle diseases and what testing and preventative strategies are essential to prevent subsequent downstream effects. By acknowledging the complex interplay between genetic predispositions, environmental exposures, and lifestyle choices, we can make informed decisions and adopt personalized strategies to mitigate disease risk.
To hear more about the topic listen to Dr. Robyn Murphy on an episode of The Shift
By Dr. Robyn Murphy, ND
Scientific Advisory Board Member