The applied science of longevity is a quickly emerging topic among our patients and it’s gaining momentum in the medical profession too. And there’s plenty of exciting reasons for the focus.
The future is near
We’re living in exponential times; all around us we see disruptions in industries like online video streaming, ride-share and shopping. Many predict that health and medicine is now due for its own disruption. That’s because with the emergence of artificial intelligence and machine learning, coupled with advances in our understanding of genetics and gene expression, we’re coming closer than ever before to new under-standings of complex biological systems. All of this is paving the way for what many believe will come in our life time: the next-step-change in human longevity. Just think, it wasn’t long ago, evolutionarily speaking, that we only lived into our 30s and 40s. But now, in large part because of the advent of antibiotics and public health measures, current life expectancies chart us into our 80s. It’s even believed that the first person who will live to 150 years old may have already been born.
Lifespan vs healthspan
Can we live longer, be healthier and optimize our performance? This is a compelling question that many, including myself, are deeply keen on pursuing. Technically, longevity implies to simply live longer. But when asked, many people state that it isn’t for them. People fear feeling old and frail for ongoing decades beyond current life expectancies. It just doesn’t appeal. But this tells us how we also need to emphasize the desired goal of simultaneously pushing out healthspan. More succinctly, the longevity focus is the science of delaying onset of chronic disease (lifespan) while improving quality of life (healthspan).
The longevity field is complex and evolving quickly. And while it isn’t possible to do human studies on longevity (as they would be 100+ yearlong studies), what is clear is that current scientific ideas may prove false, while other studies may emerge victorious. For doctors like myself, it’s wise to hold strong beliefs and yet be nimble with the ability to shift as new data emerges. I’m personally grateful for the work of Dr. Peter Attia in this space, and credit much of my knowledge and approach to his efforts. (peterattiamd.com)
Our healthspan expanded
Humans, in general, enjoy good health for the first half of their lives then typically begin a slow decline in function. In the last decade or so, this decline is most rapid and where the majority of health care expenditure occurs. For longevity studies, the goal is to push out this curve and compress morbidity. In other words, live healthier for longer. An ideal outcome for patients may be to enjoy long healthy lives with a short and rapid decline at the end. And whether or not we agree that living longer is better, we can all likely agree that lengthening healthspan, staying healthy for a longer portion of our lives, is a very desired outcome.
The healthspan objective
We know that no one wants to live forever if they feel awful. So our goal is to increase longevity, which means to increase both healthspan and lifespan. Lifespan seems more obvious, it’s how long we live, but what does it really mean to improve healthspan? Broadly speaking, we want to feel well enough to want to stay alive for longer.
Key aspects that make up healthspan include
-Mind and cognition: the ability to maintain executive function, processing speed and memory.
-Body and structure: the ability to maintain muscle mass, functional movement, freedom from pain.
-Distress tolerance: the ability to deal with emotional or physical pain, discomfort or stress and maintain resilience.
-Sense of purpose and connectedness: the individual’s sense of community; an often overlooked aspect of health.
Strategy for longevity
If our goal is to improve longevity, how do we develop the specific plan? We know that about 80% of deaths are attributed to cardiovascular/cerebrovascular disease, cancer, neurodegenerative disease and accidental death So more broadly, we must turn to studies of centenarians, non-human literature and molecular insights in order to develop new strategies.
About 0.4% of the population appear to die of similar disease that afflict the rest of us, however the appearance of these conditions appear delayed by about 20 years. We have discovered that behaviour plays a role but importantly, there appear to be consistent genes that are protective against chronic disease in this population. Certain genes identified are protective against atherosclerosis, Alzheimer’s and cancer. Some of these have been targets for drugs (ie. new lipid lowering medications).
Given the fact that we simply can’t do human trials lasting 100+ years to study longevity in humans, we can turn to non-human literature and look for evidence on lifespan for different organisms that may translate into benefit in humans. The theory is that if something appears to work across billions of years of evolution, then it’s highly probably to be of benefit in us. Stated another way, if an intervention yields benefit to yeast, flies, worms and mammals, then it deserves a look.
Basic science has led to some key concepts as they pertain to aging that are worthy of incorporation into our overall strategy:
Nutrient sensing: never in human history have we been exposed to the nutrient abundance that we are today; meaning, we’ve never before had access to as much food as we could want at any given time of the day. The bottom line: the withdrawal of this constant abundance of nutrients appears to result in benefit from a longevity perspective.
-Autophagy: the process by which cells break down cellular components that are dysfunctional or un-necessary. Enabling autophagy appears crucial to healthy aging as this cellular clearance may rid the body of un-healthy cells that can lead to chronic disease and cancer.
-Senescence: referring to cells that are not performing properly and adversely affecting other cells. In animal models, when these cells are knocked out, the aging process appears to reverse.
-Inflammation: now postulated as a root common cause of many chronic conditions including heart disease, cancer and neurodegenerative diseases.
As a medical doctor, I’m keen on the study of longevity in large part because at its core, longevity studies seek to address the main causes of chronic disease thereby keeping us healthier for longer, while allowing us to remain productive members of society. And the science of longevity is evolving rapidly! We’re already aware of broad practical steps we can all take every day to help us tip the longevity scales in our favour.
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