As a scientist, I understand the concept of genetic variation. Infact, I spent the majority of my research career uncovering the ways the environment (ie. food) modifies our physiology, by interacting with our DNA (including our genes) and the way these genes are expressed (via epigenetic processes for example, and that’s a whole other story!).
But in my work as a nutritionist, I am somehow still intrigued every time I work with a new client, by how very different they are to my previous client. Or the person before them. It is the complex intricacies of these individuals, their level of activity, current diet and medical history for example, that makes them so very, very individual.
How one person reacts and changes with a certain nutrition program is different to the next person as a result of this delicate interplay between their DNA and their environment. And we have to consider how our diet affects the second genome living inside us too, the gut microbiome, which we have covered in previous blogs.
The completion of the human genome project in 2003 opened the way for much progress for our understanding of how our DNA and the environment interact but it also revealed that the majority of our DNA is infact “junk”. This ‘junk DNA’ is likely misnamed and its functions remain quite unclear, so we still have some way to go.
An article published last month in Cell highlights how individual we really are, in this instance with regards to our metabolism. Blood glucose levels were monitored around the clock for the 800 people in the study and showed that even when people ate identical meals, their glycaemic or blood glucose responses (how high the glucose ‘spiked’) were significantly varied. An individuals glycaemic response was also strongly associated with certain types of gut bacteria and how these function.
We are what we eat….but that might be very different to the next person, even if they eat the same!
I think it is important to reflect on these sorts of studies at a personal level too- to use this information when you’re frustrated about why a certain way of eating hasn’t shown the same results for you as it did for your sister or your best friend, for example. Or to help ease your mind about why you aren’t feeling the same high levels of energy as perhaps the person next to you feels, when they remove gluten or dairy from their diet. We are all individuals; our DNA tells us that and how our genes are expressed in different environments (eg. diets) shows us this.
It does entice me to stop to ponder the reach or relevance of broad, sweeping nutritional advice and specific dietary fads. Likewise it is intriguing to think about the opportunity we have to start to maximise the efficiency of a persons physiology with nutrition, absolutely targeted to their own unique genetic make up and biology. And perhaps even more exciting, is to think about this personalised nutrition approach in combination with other courses of treatment (pharmacological, lifestyle modifications etc), to synergistically improve an individual’s health or current disease state.
It is kind of mind blowing and seemingly out of reach to think about such possibilities but the reality is that it could start to happen in our lifetime. The practicality of this is being explored in projects such as the Food4Me program, which uses EU funds and combines expertise across 12 European countries to uncover the power of designing indivdualised diets.
Personalised nutrition is ofcourse what we do everyday as nutritionists but currently, this is on a relatively small scale. Using an individuals blood results, trialing different dietary exclusion protocols and measuring the response, and integrating a complete medical history into our approach- now this is personalising or tailoring nutrition! But imagine if we could expand this (eg. using data from whole DNA sequencing) and streamline this (eg. developing algorithms to ‘calculate’ this information into a usable form)…..then what?
It is such an interesting and exciting time to be working in health, and this sort of potential is what drives me to get out of bed everyday. The intersection of science and health, and really making a difference to the quality of an individuals life. That, is being a nutritionist.
Photo credit : http://www.eufic.org/