When you do schooling, science or health you need a yardstick to measure progress with. School is grades, science is the success of experiments and health is recovery from disease. Until very recently there has been no way to measure aging progress without waiting for the subject to die. The problems this caused in the field of aging science has been immense, for aging in worms, flies and mice often have little bearing on human longevity. We can now extend lifespan in the worm called C. eligans by hundreds of percent, but cannot even try that in humans–yet. Ever since I have gotten really interested in aging in the early 1980’s the search has been on for biomarkers of aging. With such a biomarker using death as the endpoint is no longer needed; we can use the biomarker to determining success or failure of an aging treatment.
So far human aging intervention studies are exceedingly difficult to do for a number or reasons, including compliance by the study’s participants and aging of the scientists doing the study. Often a really long-term study will be supplanted by new technology making it difficult to proceed when new and better technology exists to fix the problem you are working on.
Biomarkers are beginning to be used extensively in humans. PSA (prostate specific antigen) is a good example. When a man gets prostate cancer the cancer cells produces a lot more PSA which can be detected in the blood allowing us to use it as a biomarker of prostate cancer. While many people can look at a person and guess within a few years of how old a person is, until recently we could not look at a cell and do the same thing.
Finding the biomarkers of aging has been a key goal of aging science ever since I really started following the field in the 1980’s. Without a way of telling whether your experiment was a true aging intervention (other than the animal living longer) your experiments were restricted to short-lived animals. This was good for determining the underlying biology of aging, but extending lifespan in a worm that only lives a few weeks, like C. elegans, is a lot different than finding a solution to human aging.
Your genome (DNA) uses something called methylation to help control genes being turned on or off. The pattern of methylation changes as we age. This change appears to occur in a very predictable fashion. At last we have a biomarker that can be used for aging.
The accuracy of this is proving remarkably accurate, allowing us to come within a few years to how much longer you can be expected to live. While this science is so new it is not yet well researched it is holding out a great deal of promise. With it we will be able to do an aging intervention and within a few years determine if the intervention has changed the methylation pattern for better or worse. This will show if the intervention is worth doing, or not.
So far aging testing using methylation has not yet been approved for use in people. In the meantime, there are other techniques we can do that tracks how well you might be doing to extend your lifespan. I like keeping logs and following a lot of data, so the concept of using microlives to track my progress on slowing my aging is feasible.
The concept of microlives was developed by David Spiegelhalter and Alejandro Leiva. The general idea is to take a person in their early 20’s who has about half a million hours left to live. In other words, they would be expected to die in their late 70’s or early 80’s. Half a million hours is a bit clumsy to think about, so he made it a million-half hour bits of time (science doesn’t really care what bit of time you use, only that it is consistent). Thus, the term was born: microlives. His purpose in looking at microlives was to examine what activities is that person likely to, indulge in that would result in increasing or decreasing the number of microlives they were likely to live. Smoking, for example: 15-24 cigarettes will result in losing 10 microlives (5 hours of your expected lifespan). Exercising 20 minutes will result in gaining 2 microlives–at least the first 20 minutes you do every day. The second 20 minutes will only gain you 1 microlife and if you exercise more than an hour a day you may actually start losing microlives!.
All of this data is the result of large studies looking at people’s habits against how long they live. So if 100 people who exercise 20 minutes a day are compared with 100 people who do not, the average of how much longer they live is 2 microlives or an hour for the first 20 minutes they exercise each day. So to gain 5 years of life you would need to exercise 20 minutes every day starting when you are 20. This sounds a little depressing–especially if you are already 50, but if you start looking at all the possible things that can gain you microlives, you will see there are a lot of possibilities. Enough to add a significant amount of time to your lifespan, even if you are already older.
Some microlives are negative, meaning you won’t live as long if you do these things. Smoking, eating red meat, obesity, etc. Many microlives are positive. 20-40 minutes of exercise daily, taking statins, intermittent fasting, eating nuts, having a good social life, eating vegetables, , etc.
I use microlives to help me change my habits toward a healthier lifestyle. Some have well developed microlives (by that I mean they are well researched so you know what you will gain, like exercise) and some don’t like the habit I am trying to form of not sitting for longer than 10-15 minutes at a time. I have been working on my microlife habits for a while and in the 2+ years since I began tracking them, I have added more than 200 days to my expected lifespan. The biggest gains I have made have been from intermittent fasting, where I gain 24 microlives for fasting half a day and 48 microlives for fasting a full day (note: because there is no data on life extension for humans through intermittent fasting, 48 microlives for fasting a day is really just an estimate, derived from the life extension you get in mice when they do intermittent fasting). Whether this will really prove to be valid is difficult, at this point, to day.
I also lose microlives. My greatest loss is my high blood pressure, which I have been struggling with for years. Because I have seen a lot of negative data about drugs, I am pretty negative about taking drugs so I have been trying to control my blood pressure without them, but my success has been limited. I am going to make a serious effort at controlling my blood pressure during this 15-week cruise around the world that I am on; if I fail, I will end up on drugs since I think my high blood pressure will be more damaging that the drugs I would take to lower it. So, over this northern summer (2019 summer in Alaska–since I am currently off the coast of Australia southern winter might be more appropriate to say!) I will try to improve my health sufficiently so drugs will not be necessary. For a few of the things I will be trying see my previous blog about biohacking.
Some microlives I consider as a loss just because I had the opportunity to gain them, but did not. Like eating vegetables. My family is not good at eating enough vegetables, and if I eat 5 servings of vegetables, I gain 4 microlives…but I seldom manage to eat that many in any given day. Once the opportunity has gone by, you can’t get it back–the next day is a new opportunity for me to try again, but in the mean time I have lost out!
There are other biomarkers of aging but they are less well proven (at least in my mind). I have not yet done a methylation test to see how my physiological age compares to my chronological age. I hope to do that this fall, time and money permitting.
5/25/19. Because I am on a ship where it is really expensive to have internet ($30 a day), I am only getting online twice a week. But I didn’t manage to get this edited properly, so there is some left to do. Pardon the gaps and omissions; I will get this finished and will upload it the next time I am online.