Is the key to eating for good health written in our genes? Should it be our genes that dictate what we eat, rather than dietary guidelines? Welcome to the brave new world of nutrigenomics which attempts to answer these questions. Guest dietitian blogger and nutritional genomics expert Melissa Adamski outlines where science currently is at in this fascinating field and what future implications it may have for you.
Since scientists mapped the human genome about a decade ago, we know a lot more about how genes affect our health; including how they affect our nutritional needs. It was originally thought that we all had fairly similar nutrition requirements, however new research in genetics suggests this may not be the case.
What is nutritional genomics?
Nutritional genomics is the area of science that looks at the relationship between our genes, nutrition and health. It is the over-arching term for a number of exciting new areas of science including:
- Nutrigenetics is the area of science that looks at how the variations in our genes (small changes in genes between people) can affect our nutrition and health.
- Nutrigenomics differs from nutrigenetics. Nutrigenomics looks at how the foods we eat (and our nutrition) affect expression of our genes (or how our genes produce proteins from the instructions in our DNA).
- Epigenetics differs again and looks at how the environment we live in such as our nutrition and exercise can affect which genes are turned on or off in our body. Researchers believe this area is extremely important for females while they are pregnant as a mother’s nutrition may affect which genes in her baby are turned on or off which may affect a baby’s future health.
Why is nutritigenomics important to consider for our health?
Since the human genome was mapped in 2003, scientists have been learning more about how our genes make us individuals; and this includes how genetics affects our nutritional needs and health.
Traditionally, our nutrition requirements have been specified by public health nutritionists in a general ‘one size fits all’ approach e.g. we should all be eating five serves of vegetables a day. But what if we could go one step further?
By looking at a person’s genes we could tailor advice more specifically to not only say ‘eat five serves of vegetables a day’, but take it a step further to say ‘for you, it is best to include two serves of cruciferous vegetables and two serves of high beta carotene vegetables because your genetics require you to have more of these nutrients that other people.’
As our understanding about genetics increases, it opens up the idea of more ‘personalised’ nutrition advice. We already know that certain medical conditions may require people to have special dietary needs for good health. Geneticists, dietitians and other health professionals are now looking to genetics to understand how and if the information from our genes can be used to provide that next level of personalisation in nutrition advice.
Should we be eating according to our genes?
Sounds like an exciting and futuristic concept doesn’t it? Have a genetic test and be told all the foods that are best for you, which levels of nutrients you specifically need and which diseases you are more susceptible to.
While this sounds like a concept out of a science fiction movie, the future may be closer than you think. Nutrition and genetic researchers are constantly learning more about how small differences in our genes can affect our nutrition needs and what this means for our susceptibility to many chronic diseases.
Dietitians and geneticists are working together to not only understand how our genes affect our nutrition needs, but also what we then can do about this once we have this information.
Even though we have come a long way in our knowledge of nutritional genomics, we still have a long way to go yet before this is common place in every day nutrition practice.
Should I have a nutrigenomics test?
While there are currently healthcare professionals advertising that they offer genetic tests to tell you what you should be eating and if you will develop certain diseases, unfortunately not all of these are scientifically sound.
We must remember that just like any other area of our health, ‘medical’ tests can be developed by companies that may not give you the correct information.
If you want to have a nutritional genomics test done, or your healthcare professional offers you one, you need to have a good understanding of what the genetic test will actually tell you and whether or not the results will be able to be changed through a change in your diet.
What should I consider?
For anyone looking at having a genetic test, below are some basic questions to ask yourself first before making the decision.
- Who does the test? Are they a healthcare professional and what is their level of knowledge of genetics and nutrition?
- What do you want to know? Can a genetic test even answer your questions regarding nutrition and genetics? Will the answers influence any nutrition recommendations that may be made to you? If so, what could the potential recommendations be?
- Which company? Which company actually analyses your results? What expertise do their staff have and will your DNA sample be kept private?
- Interpretation of results? Who actually interprets your genetic test results and what qualifications do they have?
- Legal and discrimination issues? Depending on what sort of genetic test you have, it is important you understand whether the results may affect any insurance you may have.
Phew… wow that seems like a lot of questions to consider (and this isn’t even all of them) doesn’t it? It is just because this is such a young area of science and we as healthcare professionals and scientists still have a lot to learn.
Where to from here?
Even though the area of nutrigenomics sounds complicated at the moment , it doesn’t mean you should shy away from it. It is an exciting area, one that holds a lot of potential to improving health, reducing chronic disease and allowing you to learn more about your own nutrition requirements.
Everyone is encouraged to keep learning and reading about this exciting new area. Keep up to date with the latest research and knowledge so you can start using this information in understanding more about your own dietary needs.
But don’t be scared to ask questions and always talk to professionals in nutrition and genetics such as Accredited Practising Dietitians, genetic counselors and clinical geneticists to ensure you are receiving the most accurate information.
Because, who wants to eat ten Brussels sprouts a day because they are told they have to because of their genes, when in fact it may actually be no better for you than eating just one! (Poor old Brussels sprouts, I do actually love them).
Melissa Adamski BSc MND APD AN, is an Accredited Practising Dietitian and Accredited Nutritionist who has extensive experience working in the field of nutritional genomics. She currently lectures and consults to universities on the practical aspects of this emerging field and enjoys educating and inspiring the public and healthcare professionals on this exciting new area of science. Melissa is also a corporate dietitian, consulting to businesses on all things nutrition and runs her own successful private practice, Nutted Out Nutrition, in Melbourne, Australia.