Update: 23 November 2024

Genetic Testing, Nutrigenomics, and Epigenetics

Author: Julie Casper, C. Ac.

The Jetsons

The Jetsons. ©Copyright, Hanna-Barbera.

Are we there yet?

Genetic testing is being characterized by its advocates as the ‘future of medicine.’ Today the science is still in its infancy, and most s are not Federally regulated or independently analyzed. Undeterred, companies are actively marketing their genetic testing products.

Contents

  1. New Era of "Personalized Nutrition"
  2. Epigenetics
  3. Que Será, Será
  4. The Future is Now: hTMA, Personalized Nutrition and Predictive Medicine
  5. Introduction to Genetic Testing
  6. Nutrigenetics and Nutrigenomics
  7. Epigenetic Expression
  8. Personalized Nutrition and hTMA
  9. What is Progress?
  10. Resources
  11. References

New Era of "Personalized Nutrition"

The concept of "personalized medicine" is now being extended to the field of nutrition. Personalized medicine is a new and evolving science in which physicians hope to be able to use diagnostic tests to better predict which medical treatments will work best for each patient. By combining a patient's test data with their medical history doctors hope they will be able to prescribe targeted treatment plans that will be more effective than the current approach.

The new concept of "personalized nutrition" is based on the fact that nutrients (macronutrients, micronutrients) alter molecular processes (e.g., DNA structure, gene expression, metabolism, etc.) which in turn may alter the onset and progression of disease. One of the more obvious problems with applying a genetic test result to a person's nutritional protocol is that it does not take into account information about the patient's health status and other factors that influence their health. Personalized nutrition protocols that include general dietary improvements may provide some positive results simply due to the improved dietary improvements. However, the application of specific nutrient supplementation based on an individual's genome is unproven, and as a consequence may cause harm.

Epigenetics

Epi-genetics (the prefix ‘epi’- from Greek: above, outside of, around) is the study of external or environmental factors that turn genes on and off, and affect how cells interpret and express genetic code. Dynamic alterations in the transcriptional potential of a cell may or may not be heritable. Transcription is the first step of gene expression, in which a particular segment of DNA is copied into RNA. Unlike genetics based on changes to the genotype, changes in gene expression of epigenetics have other causes (i.e., external or environmental).

Genome
The genome is the haploid set of chromosomes (complete set of genes or genetic material) in each cell of a multicellular organism. It consists of DNA (or RNA in RNA viruses). A gene is a unit of heredity that is transferred from parent to offspring which determines some characteristic of the child. The genome includes both genes, and non-coding sequences of DNA/RNA. The genome is largely static within an individual.
Epigenome

The epigenome is involved in regulating gene expression, development, tissue differentiation, and suppression of transposable elements. The epigenome can be dynamically altered by external environmental factors, whereas the underlying genome is not.

The genes contained in DNA are provided by both parents, and are copied and inherited across generations. Physical traits like eye color, height, weight, blood type, etc. are the result. DNA is passed on to new cells during development and when reproduced within the body. Epigenetics is the study of how inherited traits are changed by influences other than a change to the DNA sequence. Non-genetic or inherited factors can cause genes to express themselves differently by modifying or changing their expression. This is done by activation, or silencing, of specific genes through abnormal methylation processes.

Que Será, Será

We've got it all wrong. For a very long time now, popular media headlines have been promoting the notion that DNA and genes are predictive (will I be pretty? will I be rich?). The problem is, they are promoting theoretical concepts that we now know were incorrect. Previous ideas suggesting that DNA is an instructional blueprint, are based on dozens of highly unlikely assumptions.

The entire conceptual model of the gene is being challenged — and revised. Scientists now understand that the information in the DNA code can only serve as a template for a protein. It cannot possibly serve as instructions for the more complex task of putting the proteins together into a fully functioning being, no more than the keys on a typewriter can produce a story.

These new, and radical revisions of the gene concept need to reach the general public soon — before past social policy mistakes are repeated. Ken Richardson, It's the End of the Gene As We Know It

hTMA, Personalized Nutrition and Predictive Medicine

In contrast to genetic or nutrigenetic testing, the clinical science of hair tissue mineral analysis (hTMA) is firmly established. With hTMA, the benefit of having an accurate metabolic analysis that provides clinicians with the diagnostic ability to prescribe an individualized corrective nutritional protocol is possible now.

Also, hTMA is a valuable clinical tool when testing for exposure to toxic metals. It is recommended by the EPA and used by biomonitoring agencies worldwide. Long-term deviations of mineral retention or losses can be detected in hair, and concentrations of most elements in hair are significantly higher than in blood serum. The genome cannot provide this information. hTMA provides a record of past as well as present trace element levels, the genome does not. Hair analysis identifies substances entering from the blood serum and external sources. hTMA is less expensive than genetic tests and more cost-effective than other methods of nutrient mineral and toxicological testing.

Today, hTMA is an accurate medical test for obtaining diagnostic, screening, and biomonitoring information. hTMA provides comprehensive information about nutritional and health status. hTMA is useful for predictive medicine because test data provides early indications of an individual's trending toward disease.

Introduction to Genetic Testing

Genetic testing covers an array of techniques including the analysis of human DNA, RNA, or protein. Some genetic tests are used in healthcare to detect gene variants associated with a specific disease or condition, as well as for non clinical uses such as paternity testing and forensics. In the clinical setting, genetic tests may be performed to identify a genetic cause of a disease or confirm a diagnosis, predict potential disease, or detect when an individual might pass a specific genetic mutation to their children. Other genetic tests are used to screen newborns, fetuses, or embryos for possible genetic defects.

GAO Direct Genetic Tests - report

The findings of an investigative report by the U.S. Government Accountability Office (GAO), cite that the clinical relevance of consumer DNA testing is unproven, and that "genetic test results are confusing to consumers, misleading, and further complicated by deceptive marketing."

How to evaluate a genetic test

Nutrigenetics and Nutrigenomics

Author: Rene Sterling, PhD, MHA (excerpt from Genetics in Medicine magazine).

Nutrigenomics examines relationships among genes, diet, and health. Specifically, nutrigenomic research is "the study of how foods affect the expression of genetic information in an individual and how an individual's genetic makeup affects the metabolism and response to nutrients and other bioactive components in food."1 Included among the aims of nutrigenomic research are to:

  1. Identify genes and gene variants that may be significant in understanding genetic responses to diet.
  2. Identify genotypes associated with diet-related disease.
  3. Modify diet for the treatment or prevention of disease.
  4. Improve dietary guidelines at group and individual levels.2345

Although there is growing expectation that nutrigenomic research will improve individual and group health through personalized nutrition67 the field faces several methodological challenges, including:

These and other challenges contribute to inconsistent findings across genetic association studies and complicate the development of nutrigenomic interventions to improve individual health.12

Despite these challenges, biotechnology companies and laboratories are offering genetic services based on findings from nutrigenomic research. These services include nutrigenomic tests for variants in several genes associated with diet-related disease or other health conditions that have multiple causes, such as heart disease, diabetes, and osteoporosis. Companies also offer supplement, diet, and lifestyle recommendations based on nutrigenomic test results and other health-related information (e.g., smoking status, exercise habits, family history of disease).

Like the majority of commercially available genetic services, nutrigenomic services are sold as laboratory services, whereby the laboratory uses an in-house protocol to analyze patient or consumer specimens and prepare a report of test results. Unlike in vitro diagnostic "test kits" that are manufactured and labeled with instructions for a specific clinical use by multiple laboratories, laboratory services are not currently regulated by the U.S. Food and Drug Administration (FDA), including their validity, utility, branding, and marketing.13

Epigenetic Expression

Excerpt from a TEI bulletin. Author: Dr. David Watts, Director of Research

Epigenetics affect genetic expression in the embryo by activating and deactivating genes to guide the differentiation of stem cells. Stem cells are used to form specialized cells, such as heart cells, muscle, nerve, skin cells etc. Following birth, there are many influences that act upon the genome. These include environmental factors, hormones, stress and nutrition. The nutritional influence begins in utero and is affected by the nutritional status and environment of the mother. Even the mother's emotional status can influence the developing fetus.

Inheritable epigenetic changes in gene expression are responsive to environmental influences. Genetic mutations of DNA sequences on the other hand, are not affected by external or environmental influences.

The Infantile Time Window

Toxic and Heavy Metal Exposure Early In Life May Promote Disease Later in Life Via Epigenetics

It is well known that nutrient mineral deficiency can impair neurological development. Iron deficiency is a good example. However, it is also known that iron excess can impair neurological development. Some transitional nutrients can cause later-life health disturbances when deficient in the diet, but in excess can be just as harmful. These include iron, copper, manganese and zinc as well as others. Heavy metals such as lead, cadmium, mercury, and arsenic are also neurotoxins, and when present early in life can contribute to impaired neurodevelopment and detrimental health effects later in life and have been called the "fetal origins of disease, or infantile time window," suggesting that early environmental metal exposure can program later life gene expression, or fetal programming.

Although DNA methylation is the most studied of the epigenetic processes that regulate gene silencing, studies have shown the relationship of mineral imbalance and neurological function as seen in hair tissue mineral analysis tests. Hair concentrations of cadmium compared to reference groups were found to be higher in children with mental retardation, learning disabilities, dyslexia and lower IQ. (Wright, 2007) Sanders, et al explored the effect of cadmium exposure in mothers and their newborns. Cadmium is known to cross the placental barrier from the mother to the fetus and impacts development. The study showed the adverse effect of cadmium on DNA methylation in both the maternal and fetal DNA. (Sanders 2013)

The Effects of Long-Term Nutritional Deficiencies and Disease

Official government recommendations on nutrition are primarily concerned with preventing short latency or short-term deficiency disease. Examples of short-term nutritional disease include vitamin C deficiency and scurvy, niacin deficiency and beriberi, iodine deficiency and goiter, and vitamin D deficiency and rickets. It is now recognized that the long-term, inadequate intake of many nutrients lead to several major chronic diseases in industrialized nations and may take years to manifest. Nutritional needs necessary to prevent chronic disease conditions are higher than the requirements necessary to prevent the effects of short-term deficiency conditions. Therefore, Heaney concluded, "[nutritional] recommendations based solely on preventing index diseases are no longer biologically defensible." (Heaney, R.P. 2003)

It is important to provide adequate essential nutrients to children for them to reach their full physical and intellectual potential. Cutberto Garza, director of the Food and Nutrition program of the U.N. University stated, "When a child needs iron or vitamin A or iodine, she needs it now. And if she doesn't get it, then you're going to pay for the rest of her life. But, if you meet that need, the positive outcomes are absolutely glorious."

Nutritional deficiencies begin to develop long before the symptoms of a health problem occur. This also is true of nutritional imbalances. The positive (or negative) impact nutrition has on a child's health status begins with the mother — well before conception.

hTMA Patterns, Reproduction and Environmental Endocrine Disruptors

Toxic chemicals in the environment, heavy metals (e.g., mercury) and the mother's nutritional status can impact fertility and reproduction. Research by Dickerson, et al, studied hair mineral concentrations in women with fertility problems who underwent in vitro fertilization treatment and investigated treatment outcomes. Mercury, zinc and selenium were analyzed. Hair mercury revealed a negative correlation with oocyte yield and follicle number following ovarian stimulation. The hair zinc and selenium correlated positively with oocyte yield after ovarian stimulation. Their data shows that mercury had a deleterious impact, while zinc and selenium had a positive impact in the ovarian response to gonadotropin therapy for in vitro fertilization. The researchers found that minerals such as zinc and selenium may be important for reproductive outcomes and are reflective of long term environmental exposure and dietary status. Their study concluded that hTMA offers a method of investigating the impact of long term exposure to endocrine disruptors and nutritional status on reproductive outcomes. (Dickerson, et.al. 2011).

Metabolomics and Nutritional Assessment

A paper was presented at a symposium of Experimental Biology on improving human nutrition through genomics, proteomics and biotechnologies, and was related to nutritional research related to the future of diet and health. This paper addressed concerns that all humans are not the same in respect to their response to diet. Some individuals may gain weight on a particular diet and others may lose weight on the same diet. This emphasizes the need to approach nutritional needs of individuals based upon their genetic and metabolic needs rather than try to place everyone under one simplistic umbrella. In quoting the authors, "it is clear that diversity of the human population is a nutritional reality. Once this diversity is realized, it becomes imperative that the problems of metabolic regulation, and their causes and interventions, will need to be personalized in order to be addressed and finally solved," it is obvious that individual metabolic assessment and a targeted nutritional approach is much more important than generalized nutritional recommendations. (German, et al. 2003)

Personalized Nutrition and hTMA

To date, DNA methylation is probably the most understood mechanism in epigenetic research. Acetylation, ubiquitination and phosphorylation are also known to modify the genome. The methylation process requires over a dozen essential nutrients, including minerals such as zinc, magnesium, copper, selenium and vitamins such as B12, folate, choline, vitamin C, B2, niacin and others. Not only is the status of each nutrient important, but the interrelationship between these nutrients are important for normal methylation reactions.

hTMA is a safe, cost-effective test for providing results on a range of nutritional elements and their interrelationships. hTMA also provides data about an individual's nutritional status relative to the presence of heavy metals from the environment. A hTMA is an excellent clinical tool for developing personalized nutritional recommendations that are known to impact the epigenome. The use of hTMA for predictive medicine can aid the clinician in recognizing long-term nutritional imbalances and deficiencies that lead to chronic diseases.

What is Progress?

YO da

Always in motion, the future is.

Master Yoda

Nothing remains static.

The marvelous ideas and things that promote the well-being of life, represent the kind of "progress" that is good. Strictly speaking, progress means moving forward and it can lead to both good and bad things. It can be argued, of course, that "good, or bad" are subjective terms. But on a basic level, we all understand this distinction. For example, industrial-level agriculture is riddled with a multitude of unacceptable problems, from environmental toxicity to animal and human rights abuse. Factory farming is a clear example of bad progress. To many of us, synthetic chicken and synthetic milk doesn't seem like good progress either.

The science of genetic-test directed nutritional therapeutics is still in it's infancy. Someday it may prove to be good. Today however, we do not know. Many scientists agree that there are serious concerns and risks which need to be addressed first, not after the cows are out of the barn.

On the flip side, hTMA is an excellent example of good scientific progress. The science of hTMA has been developed slowly and carefully over decades — and is still evolving. Mineral analysis is based on the solid research on soil health and animal health that is more than 100 years old. The therapeutic results of hTMA for ‘personalized nutrition’ are clinically proven. hTMA represents leading-edge science that is both safe and effective, which is a good thing by definition.

Resources
References
  1. Kaput J, Dawson K. Complexity of type 2 diabetes mellitus data sets emerging from nutrigenomic research: a case for dimensionality reduction? Mutat Res 2007;622(1–2):19 –32.
  2. Ordovas JM, Mooser V. Nutrigenomics and nutrigenetics. Curr Opin Lipidol 2004; 15:101–108.
  3. Muller M, Kersten S. Nutrigenomics: goals and strategies. Nat Rev Genet 2003;4:315–322.
  4. Kauwell GPA. Emerging concepts in nutrigenomics: a preview of what is to come. Nutr Clin Pract 2005;20:75– 87.
  5. Stover PJ. Influence of human genetic variation on nutritional requirements. Am J Clin Nutr 2006;83:436S– 442S.
  6. Lampe JW. For debate: investment in nutrigenomics will advance the role of nutrition in public health. Cancer Epidemiol Biomarkers Prev 2006;15:2329 –2330.
  7. Kaput J. Developing the promise of nutrigenomics through complete science and international collaborations. Forum Nutr 2007;60:209 –223.
  8. Elliot R, Pico C, Dommels Y, Wybranska I, Hesketh J, Keijer J. Nutrigenomic approaches for benefit-risk analysis of foods and food components: defining markers of health. Br J Nutr 2007;98:1095–1100.
  9. Mutch DM, Wahli W, Williamson G. Nutrigenomics and nutrigenetics: the emerging faces of nutrition. FASEB J 2005;19:1602–1616.
  10. Martínez-González NA, Sudlow CL. Effects of apolipoprotein E genotype on outcome after ischemic stroke, intracerebral hemorrhage and subarachnoid hemorrhage. J Neurol Neurosurg Psychiatr 2006;77:1329 –1335.
  11. Kaput J, Ordovas JM, Ferguson L, et al. The case for strategic international alliances to harness nutritional genomics for public and personal health. Br J Nutr 2005;94:623–632.
  12. Hirschhorn JN, Lohmueller K, Byrne E, Hirschhorn K. A comprehensive review of genetic association studies. Genet Med 2002;4:45– 61.
  13. Javitt GH. In search of a coherent framework: options for FDA oversight of genetic tests. Food Drug Law J 2007;62:617– 652.
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