Because aging is so complex and multifaceted, there are dozens of measures that could be used. These range from things as simple as taking a selfie, to multisystem assessments that require specialized technology and algorithms. These are some of the ways you can estimate your biological age, many of which can even be done from the comfort of your home without the need for a doctor visit.
Functional Measures of Aging
Probably one of the simplest ways to estimate aging is at the functional level, using a measure of what we call “deficit accumulation.” The deficit accumulation measure is a count of the diseases and/or high-risk conditions that a person has. It is very easy to calculate, completely noninvasive, and does not require you to invest in data beyond what you may already have from your last doctor visit.
There are, however, a few minor disadvantages of this measure:
- It may not be able to differentiate aging rates in younger or otherwise healthy adults for whom deficits have not started to pile up.
- It will give you an overall biological age measure and cannot detect tissue- or organ-specific aging rates.
- In estimating the number of deficits, all conditions are counted equally. For instance, having a diagnosis of diabetes is more dangerous than hypertension or arthritis. Yet the deficit accumulation measures don’t distinguish between the severe and the mild.
- They aren’t very good when it comes to helping people prevent disease or extend healthspan.
Multisystems Aging Measures
In 2018, I published an aging measure that combined multidimensional information from lab tests meant to capture functioning in various physiological systems. The exciting thing about this measure was that it uses standard clinical data—things most people get measured annually during a regular checkup with their doctor. Even if you haven’t been to see your primary care physician recent memory, for readers in the United States, the lab tests used estimate aging are so common that they can be acquired relatively inexpensively (for about fifty dollars) by visiting either a Quest Diagnostics or Labcorp. Nearly all the lab tests used to estimate biological age are included in a standard chemistry panel and complete count (CBC) panels. The only measure not included is called “C-reactive protein,” which can be measured using a separate test from the same blood draw.
Overall, nine measures go into the equation that together combines information on physiological states for a number of different systems, including cardiovascular, immune, liver, kidney, and metabolic, and then combines these to generate an overall biological age measure for the person. When merged with information on your chronological age, we are able to estimate what we call “phenotypic age.” The term “phenotypic” can be defined as a characteristic of an individual resulting from the interaction of their genotype and the environment — and thus, we used “phenotypic age” to refer to a characteristic aging profile of an individual that is influenced by both genetic and nongenetic factors.
For readers interested in determining their biological age from this measure, it is actually remarkably easy to do. As a first step, you would simply visit your doctor or a lab facility and request the nine tests shown in the table below. Once you have these results in hand, there are various freely available websites offering the equation as an online calculator. For instance, a web interface can be found at Longevity Advantage. Similarly, you can review the Aging.AI tools offered by long-time lab tester Dr. Michael Lustgarten.
Epigenetic Age
Epigenetics refers to the chemical alterations that change the conformation of your genome and regulate which parts are used or not (the recipe deciding what ingredients each cell uses to generate its phenotype). Specifically, DNA methylation refers to a chemical tag (methyl group) that is added to one of the nucleotides, or letters in the DNA sequence (A, C, G, T). Usually when we talk about DNA methylation in mammals, we are referring to methyl tags added to a specific cytosines (the Cs) that lie alongside a guanine (G). These so- called “CpGs” are scattered throughout the genome, and when methyls are added to them, this will typically cause that part of the genome to fold in on itself and “turn off.”
Age has an enormous effect on a person’s DNA methylation levels and scientists have used advanced computational algorithms to predict out an age based on the patterns of methylation across hundreds of thousands of CpGs scattered throughout the genome. Today, there are direct to consumer tests available that will estimate epigenetic age by measuring DNA methylation patterns in cells captured in a saliva or blood sample. While not all of these are reliable or valid, a number have been shown to contain useful information for assessing a person’s risk of death or disease, beyond knowing chronological age alone.
Now What?
Let’s imagine you enter everything in and the biological age value that pops up on your computer screen is not what you were hoping for. The good news is, you can likely change it. While your genes and (to some extent) the adversities you experience throughout your life are beyond your control, our study suggests the biggest influence on your aging comes down to the choices you make regarding exercise, smoking, drinking, nutrition, and sleep. This was the best news we could hope for, because this also happens to be the one thing you have the most control over in your life.
Adapted from TRUE AGE by arrangement with Avery Books, a member of Penguin Group (USA) LLC,
a Penguin Random House Company. Copyright © 2022, Morgan Levine, PhD
Author: Morgan Levine, PhD
Morgan Levine is an assistant professor of pathology at Yale University School of Medicine and the author of True Age: Cutting-Edge Research to Help Turn Back the Clock. Her research focuses on the science of biological aging, specifically using bioinformatics to quantify the aging process and test how lifestyle and pharmaceutical interventions alter the rate of aging. As a leading voice in the field of aging and longevity science, she has been featured in media outlets such as CNN, The Guardian, Time, Newsweek, The Huffington Post, the BBC, and many more. She also appeared in the DocuSeries by Netflix and Goop, alongside Gwyneth Paltrow, which was released in early 2020.