Basic concepts of genetics
DNA is a term that most people have heard of, it is an abbreviation for deoxyribonucleic acid, which refers to the hereditary material contained within almost all cells in living organisms including the human body. The building blocks of DNA are chemical molecules called ‘bases’, of which there are four possible options. While all DNA contains these four bases, the sequence in which the bases are arranged varies from person to person and is not only responsible for our unique inherited traits, but is necessary to instruct all cellular processes for life. A critical function of DNA is to act as a template for duplication when new cells are created in the body, a process which continually occurs as part of normal growth and repair, so that new cells contain an exact copy of the DNA.
Genes containing DNA are inherited from the parents by their offspring. While our genes and 99.9% of DNA in humans is identical, slight variations in the sequence of the DNA bases occurs and this is what contributes to a person’s unique inherited traits (such as hair and eye colour, weight and susceptibility for disease). All genes collectively (estimated to be approximately 22,000 genes) form the human genome, which contains all necessary instructions for cells to build and sustain life.
Often genes are providing the instructions to create a particular enzyme or protein. Enzymes (which can be proteins themselves) participate in the synthesis of a protein or may catalyse chemical reactions to facilitate crucial functions taking place inside of cells. A protein is a chain of amino acids which is determined by the sequence that the bases were organised in. The significance of a protein being created is that proteins are tasked with carrying out precise functions within a cell. This genetic process which starts with DNA and resulting into a protein being built is known as gene expression.
Altered gene expression can occur for a number of reasons, including a genetic variation. Genetic variation is usually the result of a change to a single base which is known as a single nucleotide polymorphism. This commonly sees an interaction between the gene and the environment (which includes nutritional and lifestyle factors) which may affect the gene’s abilities and changes the resulting protein and its biological activities. This type of genetic variation alone is not sufficient to cause disease, but can convey susceptibility to disease. By altering the exposure to the environmental factor, it is possible to regulate the gene and it’s variation to influence disease susceptibility. This is leads us to the fascinating topic of nutritional genomics (nutrigenomics).
What is Nutrigenomics
Nutrigenomics is a fast growing field of science that studies the relationship between our unique combination of genes and their interaction with nutrients. The growing understanding of how biologically active compounds from food can positively or negatively influence our state of health has attracted a great deal of interest from researchers, nutritionists and medical professionals who strive to utilise genetic information to deliver a truly personalised approach to healthcare by treating at an epigenetic level.
Whilst it was once thought that very little could be done about the genes that we were born with, we now know this is not necessarily true. Nutritional and lifestyle factors act as epigenetic signals to alter gene expression, in other words, acting as a switch to turn on or off the activity of a gene.
Reasons for testing
The accessibility to affordable testing coupled with enhanced understanding gene expression enables clinicians insight into their patient’s unique genetic makeup which serves to build on the evidence base that guides clinical decision-making and enables uniquely customised treatments to be developed. It can improve the accuracy of clinical management decisions by targeting nutritional and dietary advice and nutrient therapy to the individual’s unique genome. Testing can help to:
- Reveal your sensitivities and susceptibilities (including to foods, specific nutrients and environmental factors)
- Predict your responsiveness to particular dietary and exercise protocols
- Improve the management of chronic conditions
- Individualise preventative healthcare to reduce the risk of disease development
- Optimise athletic performance and recovery
- Direct prescription of medications by estimating the rate of metabolism and likely response (pharmacogenomics)
How you could benefit
Unfortunately there is no easy ‘one size fits all’ approach to health and you may find you are doing all of the ‘right things’, yet you are still facing persisting health problems. Knowing your genetic makeup may provide the answers you have been seeking and the missing keys to finally make progress in a particular area of your health.
Consider weight loss for instance. Many popular diets may work for some, but not for others. Signing up for a gym weight-loss challenge may see some people lose lots of weight but for others, they lose no weight at all. Sadly, it’s not uncommon for people to end up eating very little and exercising excessively to achieve a ‘calorie-deficit’ in a last ditch attempt to shift weight and still weight loss does not prevail.
Nutrigenomic testing could help inform:
- The most appropriate weight-loss diet plan based on your genetics and scientific evidence
- How your body responds to fats and carbohydrates – would you benefit from eating more or less?
- How your body responds to exercise – how much and at what intensity is needed for weight loss?
- Behaviours to be aware of - whether you are prone to having a sweet tooth or snacking, expected satiety levels after eating, addictive tendencies etc
- Whether your circadian rhythm (sleep cycle) plays a key role in retaining weight
- Whether your genes are playing a role in your weight management struggles – have this confirmed and learn the tools to work with your genes rather than against them
Detection of gene variants
Testing is primarily seeking to detect variants in your genes because these variants influence how genes function, affecting biological and metabolic processes that impact on our health. It could be that a variation leads to an amplified or supressed metabolic process for example. This in turn, may have an important bearing on a person’s state of health or risk of developing disease.
A gene variation may result in the amplification of the enzymatic activity dominant in liver detoxification of caffeine and the person may be classified as a ‘rapid metaboliser’ which is associated with protective health benefits. An alternative variant of the same gene could result in supressed enzymatic activity and the person be classified as a ‘slow metaboliser’ which is associated with poor tolerance and the potential for adverse health outcomes.
Often we hear that patients are apprehensive about receiving their genetic testing result. We assure them that there is no need to be alarmed when a gene variation is detected it doesn’t necessary mean that it is detrimental for health. Many variations are actually beneficial to have.
A gene variant could mean that your body more efficiently removes lipids (fats) from circulation in your bloodstream. This has been shown to correlate with lower triglyceride levels in blood testing, higher levels of ‘good’ HDL cholesterol and lower blood pressure compared to people who do not have the gene variant.
It’s important to remember that gene variants that have been found to correlate with undesirable health outcomes like risk of developing a disease, can usually still be regulated or influenced epigenetically (eg; using nutrients or other compounds from food) to potentially mitigate the effects of the gene and achieve the desirable health outcome.
A gene variant that means that your body has increased potential to produce higher levels of C-reactive protein, which is a marker of inflammation that circulates in the bloodstream. This has been shown to correlate with an increased predisposition to chronic inflammatory disorders. This may mean that anti-inflammatory interventions may hold specific benefits for you, compared to a person who does not carry that gene variant. It could be as simple as including certain anti-inflammatory foods or nutritional supplements such as Omega-3 fats to reduce the inflammatory process and therefore modify the impact the gene could have on many disease processes.
Genomic testing offered by NEMQ
In the past, genetic tests accessible to the public have tended to be more geared towards quantity over quality. On occasion, NEMQ clinicians would be presented with a result that tested genes with seemingly little scientific evidence to inform of the gene’s biological activity or little was known about their implication for health. These tests held little practical value for patients. Other tests were found to provide excessive amounts of genetic information associated with health, but because so many genes were tested, it was overwhelming for the patient and we saw them struggle to make meaningful diet and lifestyle changes as a result. For those reasons, we took it upon ourselves to investigate the testing options to determine the Nutrigenomic testing that was best suited to NEMQ patients.
NEMQ now offers various genomic testing ‘panels’ which clusters genes tested under the specific area of health they function in. This is ideal for patients who undertake testing to answer a particular health-related question or curiosity as the genes tested will be strictly relevant and avoids ‘information overload’. Furthermore, only highly-evidenced genes with well-understood health implications are included in these panels. We have found that this allows patients to understand the important information contained within their result which translates into practical and highly achievable diet and lifestyle changes.
Panels currently available include:
DNA HEALTH PANEL
This panel provides the broadest overview of various critical biological functions that are key contributors to assessing your chronic disease risk. This panel is ideal for new patients to the clinic as it provides a great foundation of valuable information for your Doctor.
DNA Health tests 36 genes involved with:
DNA SPORT PANEL
This panel helps you to optimise your athletic training by understanding your key athletic strengths and weaknesses to maximise your genetic potential and reduce injury. Providing valuable information for athletes to provide to their personal trainers for development of a personalised training strategy.
DNA Sport tests genes involved with:
DNA OESTROGEN PANEL
This panel provides insight that enables you to improve oestrogen metabolism and reduce the risk for oestrogen driven conditions such as breast cancer.
DNA Oestrogen tests genes involved with:
This test does NOT test for BRCA genes, instead it looks at highly modifiable genetic variants to reduce your breast cancer risk - with or without a family history of breast cancer.
DNA SKIN PANEL
This panel help you to improve your skin’s health and resilience and reduce the signs of ageing.
DNA Skin looks at 19 genes involved with:
This panel provides understanding of the genetics behind your mental health.
DNA Mind tests 30 genes associated with:
- Mood disorders (depression, anxiety, bipolar disorder, post-traumatic stress disorder, risk-taking behaviour and stress sensitivity)
- Neurodegenerative disorders (Alzheimer's disease, dementia, cognitive decline and mild cognitive impairment)
- Addictive behaviour risk (alcohol, nicotine, cannabis addiction and psychosis response, opioids and eating disorder)
How to get tested
It is important that genetic testing is only undertaken in the context of a comprehensive health assessment and under the guidance of a trained clinician who:
- Understands the science behind the genes
- Is trained in how to accurately interpret the results
- Knows your health and medical history
- Is well-placed to make insightful diet, lifestyle recommendations, adjust treatment or arrange screening tests
Testing is quick and non-invasive. A saliva specimen is collected by the patient at home and only takes a few minutes to complete. The saliva specimen is then sent in the mail to the laboratory with results taking approximately 4 weeks to be received.
To order your genetic test, please speak to our friendly reception staff, or if you have questions speak to your NEMQ clinician during your next appointment.
DNALife 2019, <www.dnalife.healthcare/>.
Genetics Home Reference 2020, Help me understand genetics, <www.ghr.nlm.nih.gov/primer/basics/dna>.
Sales, NMR, Pelegrini, PB & Goersch, MC 2014, ‘Nutrigenomics: definitions and advances of this new science’, Journal of Nutrition and Metabolism, vol. 2014, <www.ncbi.nlm.nih.gov/pmc/articles/PMC3984860/>.
Morad, R 2017, ‘How diet can change your DNA’, Scientific American, <www.scientificamerican.com/custom-media/science-for-life/how-diet-can-change-your-dna/>.
Updated June 2020.
© 2020 Lifestyle Planning QLD Trust