Want to keep learning?

This content is taken from the Monash University's online course, Food as Medicine: Food and our Genome. Join the course to learn more.

Skip to 0 minutes and 3 seconds DR.

Skip to 0 minutes and 3 seconds CHIARA MURGIA: The way we respond to food depends on our genetic background. And this is something that, as a professional, I’ve seen in practise for a long time. For example, some metabolic conditions depend on genetic mutations that affect the ability to utilise certain nutrients of food. One well-described example is the metabolic genetic condition phenylketonuria, a metabolic disease that is caused by a genetic mutation in the gene that codes for the enzyme phenylalanine hydroxylase. The carrier of this mutation are unable to metabolise the essential amino acid phenylalanine. So this is a case in which a perfectly good and essential component of our diet become a poisoning component for the carrier of this genetic mutation.

Skip to 1 minute and 3 seconds Another well-described example of this is lactose intolerance, the inability to digest the sugar contained in milk, the lactose. It is what is more frequent in the human population. Now we know that this is a situation that’s far more common than we used to think, and that the majority of the human population hasn’t got the ability to digest lactose past infancy. And this is caused by polymorphism in the regulatory region of the gene that codes for the enzyme lactase. What we have now with the completion of the Human Genome Project is the improvement of the technology that allow the sequencing of nucleic acids, DNA and RNA, and the computational technology to analyse the big data that come from the sequencing.

Skip to 2 minutes and 0 seconds And now we are in a position to identify gene variants that are linked to chronic conditions associated with diet and lifestyle. In particular, technologies that led to identifying a large number of gene variants associated with chronic conditions are called genome-wide association studies. These types of studies, genome-wide association studies, compare two groups of population, the one with a condition, chronic disease type 2 diabetes, obesity, cardiovascular condition, and a group of healthy population, and investigate what gene variants are associated with the disease group. And so we now have a very large number of loci that are associated with those chronic conditions.

Skip to 2 minutes and 51 seconds It’s also important to consider that genome-wide association study, that by definition association studies do not identify the causal link between the gene variant and the disease. The way the experiment is done doesn’t calculate the contribution that each polymorphism provides to the disease. Very often, the contribution of each of these polymorphism, what we call effect size, can be quite small. A good example of this is the identification of a few polymorphs in the gene FTO associated with obesity. FTo increases the risk of developing obesity of 1.7 times. So it’s still a very small contribution that needs to be put into the context of all the other polymorphs of that particular individual, together with lifestyle, including diet and exercise.

Skip to 3 minutes and 57 seconds So while doctors and dietitians have seen the effect of genetic background on the response of food and dietetic pattern, now we are in the position of understanding the mechanism behind this response. And we can foresee that in the near future we’ll be able to apply this knowledge and translate it into practice, allowing a more targeted and personalised approach to the advice by a health professional.

Nutritional genomics

Watch Chiara provide an overview of nutritional genomics, and present her vision for how this knowledge of identifying gene variants can be applied allowing a more targeted and personalised approach to advice by healthcare professionals.

Talking point

Within the Comments, share with other learners your thoughts on the points raised by Chiara as well your responses to the following questions:

  • Is this area currently relevant to healthcare practice?

  • Is it only something that should be considered for the future?

Don’t forget to contribute to the discussion by reviewing comments made by other learners, making sure you provide constructive feedback and commentary. You can also ‘Like’ comments or follow other learners throughout the course.

RACGP members, please engage deeply in the course

In order to meet the RACGP QI&CPD Program requirements to receive 40 Category 1 points, RACGP members must complete all parts of this course, being sure to make careful and considered responses to all of the talking points listed in this step, and throughout the course.

Because reflective and exploratory discussions are critical to learning, once you’ve shared your own thoughts, respond to at least one comment from another learner for each discussion point.

Doing so will allow you to build on your own ideas on how you can apply new approaches to your professional practice.

Share this video:

This video is from the free online course:

Food as Medicine: Food and our Genome

Monash University

Get a taste of this course

Find out what this course is like by previewing some of the course steps before you join: