DNA tests with behavioral predictions are not as accurate as they might seem
DNA tests are becoming increasingly more accessible and popular, even here in Brazil. After the success of companies such as 23andMe and MyHeritage in the US, now Brazil has similar companies such as Genera and Multigene, which offer DNA tests from R$199. I decided to do mine and so I bought the full package offered by Genera in spite of my skepticism about some results, which include global ancestry, relative search, health and wellbeing (nutrition, sports performance, ageing), heritages and reaction to certain medicine.
The most simple packs are those focused on ancestry. As I already expected after checking this article from TAB, I got very few information of my Brazilian native or even African ancestry in my results — the proportion is 69% European, 14% American, 10% Middle Eastern and 7% African. It was nevertheless interesting to find in the tab for Americas the details on my ancestry from Amazon regions, the Andes, Central America and even a reference to the Tupi.
This kind of information may be useful to understand not only how a nation is formed (thus combining genetics, history, sociology, and anthropology), but it can also help us understand our history and then fight against racism (at least ideally). On the other hand, depending on the kind of test that purchase and the database offered by the company, this percentage may also vary. In other words: these numbers are not so accurate as they seem.
What caught my attention was, however, some results that addressed my behavioral patterns. The funniest one was the marker that said that I have a more daytime-based profile, whereas one of the hardest things for me is to sleep and wake up early, to the point that I even need meds to regulate my sleep or a lot of coffee to keep me awake — though I cannot drink more than two cups because, according to the test, I could feel anxious. Other results included that I had a diminished perception of satiety, something that made me realize why I often eat more than average (and also the fact that I have eating disorders), but then I saw that I had better performance when practicing intense exercise focused on strength. That info made me want to cry, because I hate stuff like Crossfit and HIIT.
Is it worth trusting and organizing our life after these results?
According to the geneticist Adam Rutherford, “genetics is a probabilistic science, and there are no genes ‘for’ anything in particular.” On an article published at Scientific American, the researcher exposed his doubts on the utility of these commercial DNA tests: “if you don’t have a PhD in genetics, these results can be misleading or even troubling.” One of the reasons is that even though somebody may have a gene that increases the chances of developing Alzheimer, for instance, most people won’t and too much of our lifestyle and, well, even destiny plays an important role here. In spite of these, there’s many people doing the same as Angelina Jolie, who decided to remove her breasts after finding out that she had high chances of developing breast cancer due to an already diagnosed genetic failure.
Additionally, psychiatrists may ask their patients to do DNA tests in order to understand what drugs would lead to better results in the treatment, but this wasn’t included in my pack and it is often more expensive than these regular ancestry tests. Some nutritionists and personal trainers may prescribe diets and exercises based on the results of these tests, but a research published in 2019 has shown that this kind of information is still too inaccurate.
Two researchers from Stanford wanted to prove if these tests were able to provide data that was accurate enough so people could change their behavior and make changes in their routine based on that. They used a sample of 200 volunteers, who received from the scientists some purposefully false information about the presence of certain genes that could restrict physical performance or satiety. But… in the end, it didn’t matter much what the DNA would say about these people: it was more important what the researchers told them than their actual genetic results.
Volunteers who were informed to have better physical performance due to their genetic configuration performed worse than people who were told the opposite. In the case of dieting, the volunteers ate the same meals and then received information on their perception of satiety. Curiously, those who were informed to have been genetically programmed to feel less full really felt less full and vice-versa, no matter what their actual results were. In other words, the research concluded that, more than their genetic predisposition, volunteers tend to demonstrate physiological response based on what they hear and not on what their DNA really is made of.
Right, so is it useless to do these DNA tests nowadays? Not necessarily. According to these same researchers from Stanford, our genetic data is only one part of the whole puzzle, and so is our mind. After these results, the scientists felt more challenged to give more attention to this aspect. But does this mean it’s all about changing our mindset and that we simply need to go under a neuro-linguistic programming to change your DNA quantically? No. Absolutely not.
The field of Behavioral Genetics, however, is still being developed and it is getting better as more people have their DNA mapped and their data shared for analysis. Websites such as Sano Genetics offer the opportunity for people to share their raw genetic data to be used in academic research, for instance. On the other hand, I have seen in social media several people that are growing interested in using these same data for biohacking, ethological studies and even some kind of revival of phrenology and eugenics as some try to find “the gene of evil” or how to improve someone’s academic, physical, and intellectual performance.
Like I addressed here in another article, biohacking has been used to improve people’s performance yet. It could sound like a good idea being able to quantify how much food you need to take or how much exercise you need to make so you can achieve “the best version of yourself”, but this is a good strategy only for high performance athletes. It’s not very useful for average people, also because this could trigger psychological consequences such as eating disorders, body image distortion, anxiety or even OCD. Between December 2000 and January 2021, for instance, we have seen some Brazilian influencers openly talking about their problem with compulsive eating after adopting restrictive diets, which by retrospect were the very tools that helped them raise their influence empire alongside dieting products ads, fitness training videos and photos with motivational subtitles.
It’s funny to see that this kind of reflection already appeared in Byung-Chul Han’s work when he talks about the multiplication of gyms, wellness culture and the overwhelming number of “fitness influencers”: we live in an achievement society where individuals exploit themselves to achieve their best version and, in this case, success can be found in the perfectioning of health (normally only in its physical and aesthetic senses). Learning more about our DNA, something so profound and “immutable”, could be risky if we don’t consider the lack of accurate data and the deliberate pseudoscientific exploits scattered out there.
Maybe, in the future, when we have more accuracy in this kind of analysis, we will be able to use it more strategically. I suspect that, due to the complexity of our mind (and here I’m not talking only about consciousness, but emotions, impulses and personality), it’s going to be very hard to quantify this kind of thing without taking the risk of making huge mistakes. Knowing that some habit is harmful doesn’t stop someone from maintaining this same habit — like biting nails or plucking hair off. So, in other words, knowing that certain kinds of exercise or diet are favorable to me doesn’t really mean I will be able to follow it religiously. It’s much more complex and risky than it may seem at first sight.