CTG Education FAQs


A: Nutritional genetics (nutrigenetics) is the study of how variants in your genes may increase or decrease your needs for specific nutrients and other bioactive food components (parts of foods and plants not already classified as nutrients). Making changes in your diet and lifestyle to meet these needs will help reduce your risk of certain diseases later on in life. Gene variants have also been shown to be useful in clinical practice, in managing weight loss and clinical conditions.

A: Nutritional genomics (nutrigenomics) is the study of the effects of nutrients and other bioactive dietary compounds on the expression of your genes (whether or not your genes are turned on or off, up-regulated or down-regulated) and your risk for certain diseases. People often use nutrigenomics as an umbrella term for both nutrigenetics and nutrigenomics; however, we propose that the efficacy and power of dietary intervention will entail health professionals being able to use nutrition to impact gene expression.

A: A gene is a segment of DNA (short for deoxyribonucleic acid) that contains information on hereditary characteristics such as hair color, eye color, and height, as well as susceptibility to certain diseases. Genes contain the instruction manual for how, when and where we make each of the many thousands of proteins required for life. There are approximately 20,000 – 25,000 genes found in our chromosomes.

Each gene is comprised of thousands of combinations of four genetic ‘letters’ that make up our genetic code: A, T, C and G, for adenine, thymine, cytosine and guanine, respectively. It is thought that every individual’s DNA contains approximately 3 billion of these genetic letters, known as nucleotides or bases. Each gene’s code combines the ‘letters’ A, T, C and G in various ways, spelling out the ‘words’ that specify which amino acid is needed at every step in the process of making the proteins required for our bodies to develop and function. Our genes may also tell us whether we are predisposed to specific health risks.

A: We all have small differences in the information our DNA contains (except identical twins), and it’s these differences that make each of us unique. Of the 3 billion nucleotides mentioned above, it is estimated that we are all different from each other in about 3 million of our genetic ‘letters’. For example, one genetic ‘letter’ (A,T,C or G) may be replaced by another. These variants can change metabolic processes in the body, just as altering one letter in a word can completely change its meaning; for instance, from ‘g’oat to ‘c’oat. When a variant affects only one genetic letter, as in the goat-to-coat example, it is called a SNP, pronounced ‘snip,’ (single nucleotide polymorphism). In other words, there has been a single nucleotide or base change. Nutrigenomics is concerned with how these small genetic changes in our DNA sequence can change the way our body responds to different foods and bioactive compounds.

A: In most cases, a SNP will have no effect on metabolic processes or on disease risk. In certain cases, these gene variants may be beneficial and protective, decreasing risk for certain diseases. However, sometimes a variant can affect a metabolic pathway that results in an enzyme not working as it should. The enzyme may, for example, work faster or slower than is best for the body. This alteration in enzyme activity, when combined with particular diet or lifestyle choices, may contribute to an increased risk susceptibility to developing common health conditions, such as cardiovascular disease, diabetes, osteoporosis, etc.

A: The gene MTHFR, which codes for the enzyme methylenetetrahydrofolate reductase, has a SNP identified as 677 C>T, which means that at nucleotide position number 677 on the MTHFR gene, a ‘C’ genetic letter has been substituted by a ‘T’ genetic letter. This substitution causes a decrease in MTHFR enzymatic activity. Among the consequences of this change are increased homocysteine levels and the potential for an increased risk for cardiovascular disease, certain cancers and many other conditions. What makes this SNP such an interesting one is the interaction with the B vitamin folate. Research has shown that in the presence of the ‘T’ genetic letter, homocysteine levels may be elevated when folate intake is low.

A: Initially genetic research was focused on what are known as inborn errors of metabolism. In these conditions a single gene variant may be responsible for the development of the disease. These diseases are passed down in families and usually display a strong family history. In the beginning, genetic research focused on discovering high penetrance gene variants that were causing these disorders. High penetrance gene variants are rare in the general population. What makes them distinct is that a high penetrance gene variant by itself can cause disease. In most cases the presence of the high penetrance variant means that an individual who has such a variant has an 80 – 90% chance of manifesting the disease. In these cases diet and lifestyle play a small role in the prevention and management of the disease. Examples of a high penetrance gene variant would be the variants of the BRCA1 and BRCA2 genes. The presence of specific variants of these genes confers a very high risk for the development of breast cancer. It is important to note, though, that only about 5% of all breast cancers are caused by these variants; the other 95% of breast cancers are the consequence of many genes (with low penetrance variants) interacting with diet and lifestyle choices.

Another example concerns the variants involved in the development of familial hypercholesterolemia (FH). The presence of a specific variant in the LDLR gene usually results in very high cholesterol levels and requires pharmacologic intervention. Dietary treatment certainly plays a role, but by itself it will not be able to prevent cardiovascular disease nor treat it.

However, these diseases occur in only a small fraction of the population. The major killer diseases are the chronic diseases such as heart disease, many cancers, and Type 2 diabetes. These conditions are caused by a combination of low penetrance genetic risk factors as well as adverse dietary and lifestyle choices. Nutrigenomics is therefore concerned with these chronic diseases of lifestyle. A low penetrance variant refers to the kind of variants that we are concerned with in nutrigenomics. These are variants that are fairly common in the population. They do not cause disease by themselves; their ability to increase susceptibility to disease results from their interaction with dietary and lifestyle choices and with other low penetrance gene variants.

Whereas familial hypercholesterolemia is caused by a single high penetrance gene variant, the majority of unfavourable lipid levels in the population is caused by a combination of low penetrance gene variants in genes such as CETP, LPL, and LIPC, interacting with an individuals diet and lifestyle. Similarly, it has been shown that low penetrance (and therefore fairly common) gene variants in metabolic pathways such as oxidative stress, detoxification and methylation, interact with an individuals diet and lifestyle to increase the risk of different cancers.

A: Low penetrance gene variants that are the focus of nutrigenomics cannot be used to diagnose disease for the reasons discussed above. They must be considered together with the diet and lifestyle choices that an individual makes. Rather, these variants provide useful information on disease risk susceptibility and can guide nutritional choices.

A: The April 2005 issue of the Journal of the American Dietetic Association was titled: Nutritional genomics in practice: Where do we begin? DeBusk suggested in 2005 that the future of dietetics was unquestionably intertwined with nutritional genomics. We believe that this is true for all health professionals, who will encounter nutrigenomics in their professional associations, journals, conferences, and most importantly from their patients.

There is a knowledge gap for most health professionals that limits their ability to choose the best commercial nutrigenetic test, meaningfully interpret the results, select an appropriate intervention and communicate the results and recommendations to their patients. Some would argue that all health professionals require at least a working knowledge of nutrigenomics, not being provided in their professional training.


A: The Foundations in Nutrigenomics is exactly that – foundational. It is a comprehensive, introductory course covering all the basics (and a bit more) to enable practitioners to confidently use nutrigenetic testing in their clinical practice. The focus is more on nutrigenetics than nutrigenomics, but the number of SNPs and the detail explored is more than enough to get you testing ASAP.


TIMELINE:                      START ANYTIME – 2-3 months part time or 2-3 weeks full time

LOCATION:                    Online – you just need a decent internet connection

DEADLINE:                     At your own pace – but we encourage you try get it done within 6 months from date of enrollment

A:  The Foundations course is the minimum we consider a health professional requires in order to meaningfully practice. It is a comprehensive, introductory course covering all the basics (and a bit more) to enable practitioners to confidently use nutrigenetic testing in their clinical practice.

A. Foundations Students will receive the 150-page ebook SNP JOURNAL, free of charge. The SNP JOURNAL has been developed to provide students with a clear and concise review of 40 of the most commonly encountered SNPs in commercial nutrigenetic tests.

A. The course is designed for health practitioners, educators and scientists whose services integrate cutting edge nutritional science into client or food solutions. Practitioners include: dietitians, medical doctors, specialist doctors, naturopaths, psychiatrists, nurses, nutritionists, dentists, chiropractors, and other allied health professionals. If you are unsure please email admin@ctgeducation.com.

A: If you are a registered full-time student you will qualify for a 30% discount, please email admin@ctgeducation.com with a copy of your student registration and you will receive a coupon code to register. If you are unsure if you qualify for the discount please email admin@ctgeducation.com.

A:  The course is self-paced. You can start at any time, in any time zone, and go as slowly or as quickly as you like. At any time during and after the course you will be able to access the modules for revision. Students require access to a computer and adequate Internet capability. Students come from all countries around the world and have different work and family commitments. For this reason, we acknowledge that the course requires the greatest amount of flexibility.

A. On completion of the Foundations course students will receive a certificate from CTG Education, signed by both Dr Yael Joffe and Dr Christine Houghton. Accreditation for the Foundations in Nutrigenomics course is provided by CTG, the training organization specifically tailored to the needs of the practicing clinician.

The Foundations course is currently accredited as follows:

In the USA:

  • CDR – 25 CEUs
  • BCNS – 25 CEUs

In South Africa

  • 30 CPD points – 5 of which are Ethics points

A: Students will be able to communicate with the student coordinator, and if required with their instructors as well. In addition, a Facebook forum is provided for students to share their course experiences, and post questions for the instructors and each other.

A: The cost of the Foundations course is USD $595; this will include the SNP journal eBook which is valued at USD $79.50.

Payment is done via PayPal



    You must first “enrol/register” to purchase a CTG course.


    Once registered, go to the "MY ACCOUNT" page. This page serves as your personal account page on the CTG website.


    Go to the "CTG SHOP" page and choose your course, and click "ADD TO BASKET". Click "VIEW BASKET" and commence the purchasing process by clicking "PROCEED TO CHECKOUT".


    Follow the billing process and choose your payment method: PayPal or a credit card payment via Paygate.


    Go to the "LOGIN TO MY COURSE" page which will include a link to your purchased course on our LMS system. When you log out of the LMS, you will be directed back to the CTG site. Access your purchased course by simply visiting the "LOGIN TO MY COURSE" page.