Should we all be eating according to our genes?
Many conditions and diseases are caused, prevented or managed by our diets in some way. So it makes sense that many public health messages aiming to tackle these health issues focus on improving our nutrition. And when speaking to the population as a whole, it makes sense to share one unified message to encourage people to make changes.
But we are all unique when it comes to our genetic make-up and our lifestyles, and the way our bodies respond to (and are affected by) different types and amounts of nutrients differs too. Fascinatingly, what we eat affects our genes, and our genes affect what happens when we eat certain foods. As a result, broad nutritional advice will never work for every individual person. Therefore, we can never expect broad nutritional advice to be fully effective in improving our health. A more effective approach would be to share personalised nutrition recommendations based on what we know about that person’s unique genome!
However, this is currently easier said than done. The fact we’re talking about cumulative effects of thousands of different genes and the fact that no one’s lifestyle is identical makes this a really complex area of science and there’s lots we don’t know. Despite this, many Direct to Consumer (DTC) genetic testing companies are promising to reveal all sorts of ‘facts’ about your nutrition needs and corresponding dietary advice. Caution should always be exercised when using one of these companies today, as there are lots of things to be aware of:
Firstly, not all practitioners actually know how to correctly interpret results of the genetic tests currently on the market. There are few credible courses out there on this topic (the module I’ve completed at uni is one of them!) so never assume that every company employs qualified professionals in this area, particularly when we know how little robust research we currently have. Secondly, sharing nutrition advice based on genes is all well and good, but testing companies don’t take a person’s lifestyle into account and we know, this can have a significant impact on health outcomes and what the corresponding advice should be! Also, revealing information about someone’s health based on their genes could cause a lot of worry if not handled sensitively.
There is limited regulation around the validity and accuracy of testing. This is a huge concern. And even any regulation that does exist varies across countries (e.g. Germany is very strict, USA less so!). Without regulation, there are questions around whether genetic tests should even be allowed to be sold directly to consumers yet. If they’re deemed to be acceptable, should they be limited to non-clinical information like sports performance? Should counselling be a legal requirement when sharing distressing clinical findings with people…? Maybe. On the other hand, it can be argued that people are entitled to information about themselves regardless. We need to strike a balance between safely controlling information and access to it.
Exploitation is occurring. I can easily see a world where supplements and health app developers use such test results to capitalise on vulnerable consumers (its starting already!). It also begs the question of what then happens with this data and how it might be used.
There are of course companies out there offering personalised nutrition advice in an ethical and professional way; its just knowing what to look out for in a DTC company. A simplified list of things to look out for include the likes of:
Ensuring relevant and qualified health professionals are involved in the day to day running of the business and the dissemination of advice
The company upholds scientific rigour, such as lab certification, a well-evidenced selection of genes it can test for and a thorough understanding of that evidence, and that it considers a person’s holistic health and lifestyle beyond just their genes
Ethical and secure data storage
Transparent and accurate communication, ideally using a consultation to share results with the individual as opposed to just a report
So in summary, today’s opportunities for personalised nutrition are currently limited, and DTC companies offering genetic testing to reveal personalised nutrition recommendations should be approached with caution. But given the growing interest in this field and the emerging knowledge we’re gaining in this area, I’m sure we’ll see alot more research, regulation and access in relation to personalised nutrition in future.