As human beings, like all other living beings, we all follow the same cycle: birth, growth, aging, and death—the four seasons of life (or the natural order of life). However, as you surely have noticed, the rate of aging is different between species. For example, cats and dogs age much faster than Humans. While Jonathan (tortoise) is beating the record at 191 years of age—we are slowly getting there. Science and medicine are always improving, and finding new ways to increase our time on earth. In other words, we can leverage our knowledge to increase our life expectancy.
With the increase in lifespan (aka: the number of years that we are alive) in the last centuries, also came with it an increase in the number of age-associated disorders (for example, diabetes and dementia). Therefore, this brings the question: Could we live longer and healthier? After all, the ultimate goal is to die young as late as possible.
The answer seems to be “yes”.If you imagine, in 500 years life expectancy has almost doubled. And we are still improving. This new idea led to the emergence of a new term in our vocabulary: healthspan. We are no longer focusing on living more years. Instead, we are now aiming to be healthier for longer.
How Do We Deal with Aging?
The search for youth has led to an increase in companies that sell products aiming to disguise aging. Perhaps the most common example comes from the cosmetic industry. Just turn on the TV and you will see an ad for a cream to reduce wrinkles.
Nothing against a good anti-aging cream, but this approach is somewhat limited (and only touches the surface of the aging problem). We can even say that it’s only addressing the symptom, not the cause.
Nonetheless, this initial anti-aging approach has forced science and medicine to consider new ideas. And, slowly but surely, we are seeing how this industry is evolving. It’s becoming more sophisticated, and the focus has been shifting towards the root of the problem—our cells. For example, you probably have heard about stem cells; and how they can potentially be used to help our bodies recover from cancers, such as leukemia (to give one example). This is an example of a recent field in medicine, which is called regenerative medicine.
The good news is that it is predicted that the regenerative medicine business will grow up to 95.5 billion dollars in 2030. Still, the bad news is that it will not be immediately available to people through the “traditional” healthcare system. As you probably already know, passing regulations and adopting new concepts and therapies take a long time.
With these two examples, you can see that there are two major approaches: one that works from the outside (i.e anti-aging creams); and another that works from the inside (i.e.regenerative medicine).
While using creams helps us to look younger; the truth is that our internal clock is not changing. Therefore, if we really want to be younger for longer, we need to make changes that work from the inside out. What does this mean? It means that we need to help our bodies and our cells to age slower.
But wait! Can we measure the age of our cells?
Yes! And ‘what happens to cells’ is the key to finding out our biological age.
Chronological Age vs Biological Age
Have you ever noticed that some people look younger than their age (even without any sort of plastic surgery or special skincare)? Or that some people look older than their peers in the same age bracket? This can be explained by differences in biological age (not in chronological age).
Chronological age corresponds to the unavoidable age that results from the time that has passed since we were born. It is the same for everyone. On the other hand, biological age is a measure based on different biomarkers in our cells or tissues. It is the calculation of our biology’s actual age.
In other words, we can have two 40-year-olds (same chronological age), but they may not share the same biological age. Thus, one can look and feel younger/older than the other.
But why is that? And, what are these “real age” biomarkers?
To answer the first question, it’s crucial to notice that our biological age can vary because we have different lifestyles. Thus, different exposure to the various factors that contribute to our bodies’ wear and tear.
Second, biomarkers (in general) are indicators used to easily identify a disease (or a given condition). In the context of biomedicine, they can be biomolecules that scientists have identified as unique characteristics found in a given disease. Imagine players of a team all wearing the same jersey. But on their backs, they all have a different number and that’s their biomarker. For example, in previous articles, we discussed inflammation. The molecules that the immune system uses to transmit information (aka: cytokines) can be considered biomarkers for inflammation. In the same way, we have biomarkers for inflammation, there are biomarkers for cellular age. Knowing this, scientists are always searching for the most accurate aging biomarkers. Many have been found, but today we will only focus on two of the most well-known biomarkers: telomeres and epigenetic clocks.
To better understand telomeres, we need to discuss our DNA. DNA is almost like a line of code that contains all the information that regulates your biology. As you can imagine, this information is precious and needs to be protected. Cells organize the DNA in well-compacted structures that are called chromosomes (imagine an elongated wool yarn). And at the tip of the yarn, there is a region called a telomere (imagine a cap on that wool yarn). The function of the telomere is to protect the DNA. However, over time, these telomeres become smaller and smaller.13 As we age, these protective caps wear off. Consequently,our DNA becomes more exposed and less protected against degeneration. And, as a result, our cells and tissues may also start getting compromised instructions from our DNA. Therefore, the length of the telomeres is commonly used as a biomarker for aging13.
If telomeres protect the DNA, the epigenetic clocks are marks on the DNA that protect the wrong information from being accessed by the cells. Why are these epigenetic clocks important? Cells have a complete copy of the DNA. But each cell is specialized. Therefore, it only needs portions (different regions) of the DNA to perform its functions. For example, heart cells only use “heart genes”. So, the “brain genes” are blocked in the heart, and vice-versa. This control is performed by epigenetics (meaning above the genome). One of the ways that these cells do this is by leaving flags in regions that need to be blocked (aka: CpG methylation). While the scientific community is yet to find a consensus, the theory is: that by looking at the different patterns of CpG methylation in the complete genome, we can use these as a biomarker to accurately determine our biological age.
Each day, scientists are innovating with simpler, and more accessible ways to measure our biological age. Or, in the case of the third-generation epigenetic clocks, by looking at fewer CpG, but incorporating other biomarkers (such as cholesterol levels and body-mass-index) through long periods of time.
The Importance Of Quantification
It is important to understand how we age. Because once we have the methods to quantify our biological age, we can accurately start finding out the causes of our accelerated aging rate. Only what is measured gets improved. Remember? This way, knowing the root of our problem, we can intervene in a customized way. Therefore, this intervention can not only take into account the information from aging tests; but also your health records. And even in a more personalized fashion: your own DNA (which is unique to you, unless you have an identical twin).
Please keep in mind that sequencing the DNA is not always black and white. The interactions between genes are so extensive that it is hard to pinpoint a disease to a single gene (with few exceptions). In other words, when it is not shown as clear evidence of a genetic disease, we interpret it as a “predisposition”. For example, if we have a mutation in a gene associated with obesity, it does not necessarily mean that we will be obese. It means that we have the predisposition to be obese. But, as discussed in our previous lectures, we can control what we eat and ultimately our weight.
In the same way these choices will affect how our “obesity gene” is expressed, it will also influence our aging. Research shows that there is a potential benefit in adopting a healthier lifestyle and diet to cause epigenetic changes that decrease the aging rate.
Aging and Hormones
One last aspect of aging is the change in hormone levels. Some even say that hormones decline as we age. Although we prefer to raise questions by saying that we age as our hormones decline. But that is not the point here.
During adolescence, humans experience an abundance of hormones. This hormonal phenomenon marks the transition into biological adulthood; and a time of growth and vitality. Then, as we age, this hormonal curve inverts. Men, for example, experience a gradual drop in testosterone over time. This is concerning because testosterone has been studied for its cardiac and vascular protective effects; body composition enhancing qualities; regulating our immune system; and even in aging rate and all-cause mortality. Yes, testosterone may help protect humans from chronic-age-related conditions.
This now raises the question. Is it possible that hormones are not declining due to aging, but instead, aging is occurring due to the decline in hormonal levels?
Some researchers consider this “hormonal fountain of youth” only a mythological idea. However, many regenerative medicine practitioners beg to differ.
The good thing is that you don’t have to “believe” in anyone. With access to biological age testing and aging rates, we can introduce a hormonal therapeutic approach (or any other approach); and evaluate the efficacy of these methods. This data allows us to reach our own objective conclusions.
The bottom line is that the environment around us plays an important role in our health and longevity. Thus, we can directly influence the quantity and quality of time we spend on this earth. The key is data-driven personalized medicine. By assessing your genetic predispositions; your current biochemistry; and even your aging rate; you have the data you need to objectively start making changes. These changes will allow you to slow down your aging and ensure that you will enjoy a good healthspan. In other words, die young as late as possible”.
Not sure where to start?
Marcos de Andrade MD, MBA
Chief Executive Officer