Cutting-edge science can be used to fashion mirages. We are led to believe there is value in the product, a drink to quench our thirst for knowledge. But when we have spent our money, we are stuck sifting sand through our fingers.
Genomics, the field that investigates the entirety of our genetic material and how its instructions and regulatory mechanisms turn a simple molecule into a complex organism, is rife for exploitation. We are still riding a wave of direct-to-consumer saliva kits that promise to unlock the secrets of our genes: what is our cardiovascular risk? will we like the taste of cilantro? do we have a unibrow? As if these promises have already lost their luster, a new tide is rising. Some companies are now offering testing kits to evaluate how old our bodies really are by measuring specific marks on our genes that are altered by our environment and behaviour. By warning us of our true biological age--the wear and tear on our flesh-and-blood automobiles--these expensive assessments feed us tailored health advice. But is this sudden apparition in the marketplace sustaining or insubstantial?
These new products, which require a saliva sample (or occasionally blood or urine), are based on epigenetics, a very real and exciting branch of genomics. In a very simplistic way, epigenetics studies how our DNA is regulated. Imagine you are visually impaired and are reading a text in Braille. You move your fingers over patterns of dots representing letters. But if a sentence worth of dots is obscured by adhesive putty, you can’t read it. In a nutshell, this is epigenetics. Our genes are read to make proteins but our body can temporarily stop this activity in a variety of ways, chief among them by a process known as methylation. You can think of methyl groups as molecular putty made up of a carbon atom bound to three hydrogen atoms. In the right place, a cluster of methyl groups can render a gene inactive, and these methylation patterns over our genes are continually evolving. Drink alcohol long enough and the pattern will change. Work a stressful job and the pattern will change. One wonders if a simple sneeze can change the pattern as well.
Tick tock goes the epigenetic clock
In the past decade, a growing number of “epigenetic clocks” have been described in the scientific literature. The name is not literal. There are no precise metal cogs inside our bodies keeping track of time. The “clock” is metaphorical, a specific set of spots in our DNA that contain these adhesive putty marks I described above, and the changes in these marks over time correlate with age. So a group of people all aged 50 would essentially share the same putty pattern at these spots. Another group of people aged 70 would have a different pattern at these same spots. Know the code and you can deduce the age, plus or minus a few years. The existence of these means of assessing age by looking at specific methylation patterns has important ramifications in many fields. Researchers are gaining an understanding of aging at the molecular level. Forensic specialists may eventually have a new tool to determine the age of a dead body. Even immigration personnel may soon be able to test age claims in this way. But since most of us know how old we are, why is this new technology being sold to consumers?
Dr. Alison Bernstein, an assistant professor at Michigan State University who studies epigenetics in the context of Parkinson’s disease, tells me that there is a hypothesis in the field that, when the body is dealing with certain diseases, these mobile putty marks deviate from what you would expect for its age. The idea is that this true “biological age”--distinct from your chronological age which advances one year each time the Earth completes its orbit around the Sun--is tied to diseases in some way. “This is an emerging topic,” she clarifies, “and in many cases, the data remains sparse.” Direct-to-consumer epigenetic kits claim to tell you if your body is essentially aging faster than it should (because of stress, excess alcohol consumption, chronic smoke exposure) and what you can do to reverse that course. But the big question researchers are asking themselves is which way the causal arrow points: do the changes to epigenetic clocks contribute to aging or are they a consequence of aging... or are they helpful ways in which our bodies compensate as a response to aging and disease, in which case reversing their pattern would not be advantageous? A review article published last year found a lot of contradictory studies on what specific epigenetic clocks are linked to with regards to age-related conditions, and a review from 2017 reported that one of the most reliable clocks was actually not associated with things like alcohol use, smoking, diabetes and hypertension.
This mess in the data, which is slowly sorting itself out with better studies, may not be apparent when we visit the websites of companies eager to endow us with the power of this technology. We can read claims these tests will teach us how to reverse our biological age, that they represent a molecular version of the infamous body mass index (BMI), and that they yield science-based recommendations we can use to adopt better health habits. Many companies recommend taking the test again every six to twelve months to see if changes in behaviour can be seen in our epigenetic clock. And of course, there is that infamous disclaimer, like a “get out of jail free” card, that these kits have not been reviewed or approved by the Food and Drug Administration and are not intended to diagnose or treat any condition. Ranging in price from USD 300 to 700, I suppose they are meant to be expensive party favours.
Not pseudoscience but scienceploitation
The response I received when I asked actual researchers in the field of epigenetics was unanimous. Yes, these epigenetic clocks are real but they are not ready for prime time. “This field is too new at this point,” Dr. Bernstein tells me, “for there to be any evidence-based recommendations based on these results. If people are interested in this, I would rather they find a study to enrol in so the entire scientific community can gather the data needed to figure out that science.” For Dr. Meaghan J. Jones, an assistant professor in the department of biochemistry and medical genetics at the University of Manitoba, the idea that you can reverse your true biological age, as one company puts it, is problematic. “We really, really don’t know what ‘epigenetic age’ really means,” she tells me over email. “As far as I know, there is only one study which has done any work on actually reversing epigenetic age, so that claim is definitely too far.”
So much of the information provided by these epigenetic kits is available for free. Your doctor can tell you this. I can tell you this. But some people are lured into paying for the theatre of scientific wizardry to show them dots and lines and risk scores that will lead them to the same conclusion: that they need to quit smoking, reduce their alcohol consumption, mind what they eat and exercise more. But knowing this--either through routine recommendations from public health agencies or from a costly report from a direct-to-consumer company speaking to their epigenetic reality--is only the tip of a very large behavioural iceberg. The data we have on health behaviour change, as potentially biased as it has been reported to be, is bleak. Showing smokers they possess a real genetic predisposition to lung disease, which would make smoking cessation especially beneficial to them, can lead to a short-term uptick in cessation but the effect fades within a year. A major review of the evidence published in 2016 reported no significant effect of the communication of a DNA-based risk on smoking cessation, diet or physical activity, and no effect on alcohol use, medication use, or sun protection habits. Surely we need more robust studies of the long-term impact of genetic and epigenetic information on changes in health behaviour, but the grim evidence we have so far does not align with one company’s claim to “get ready to take control of your future” by learning about your epigenetics. Part of the issue is a limited health literacy: it has been estimated that about 12% of American adults can understand the majority of health information, and only 66% of smokers shown a test result for their genetic susceptibility to lung cancer can accurately interpret the result. Part of the problem is that our behaviour is very resistant to change. Tobacco products are addictive, our food environment invites overconsumption, and sedentariness feels good. As for learning about the health status of your eyes, ears and memory, as one epigenetic kit maker claims, Dr. Nadine Provençal, an assistant professor at Simon Fraser University who studies epigenetics, tells me that “your family physician can do that with better accuracy and validated diagnostic tests.”
The artificial maturation of cutting-edge science, like a child sat at the head of a board of directors with a fake mustache and oversized clothes, has been called “scienceploitation” by Timothy Caulfield, Canada Research Chair in Health Law and Policy at the University of Alberta. “It’s using science-y words and concepts,” he wrote to me, “to make a product seem more credible and certain. Even with professional athletes and others who are obsessed with marginal gains, the evidence often doesn’t support the marketing promise, as we have seen with direct-to-consumer genetic tests.” One day, the knowledge gained through rigorous research into the epigenetics of aging and disease may have concrete applications in treatment and prevention (especially if we can figure out effective ways of helping people improve their health behaviours), but right now the shimmering temptation of costly biological clock divination kits strikes me as very little more than a mirage.
Take-home message:
- An epigenetic clock is a way of assessing someone’s age by measuring marks that change over time on specific stretches of your DNA
- There is a theory that the progression through time of these patterns could change because of chronic disease and harmful health behaviour, meaning that your biological age could be different from your chronological age
- Some companies are selling direct-to-consumer kits to measure your biological age and give you tailored health advice, but the field is so new that these companies are showing a confidence that is not backed up by solid scientific evidence at this point
