There are 8760 hours in a typical year. A typical 30-year old will spend about 2900 of those hours sleeping, around 160 of them impaired or incapacitated by illness and will experience perhaps 2000 hours of peak mental function.
As one ages, the fraction of hours spent sleeping decreases slightly, but eventually the annual hours of peak mental function declines as well, and the annual hours spent ill increases nonlinearlly until one eventually makes that final hospital visit.
There is a hope that medical technology, accelerated via a Singularity, will advance to the point where we have full mastery over biology and can economically repair organ and cellular damage faster than aging accumulates it. There is sufficient evidence to put a reasonable bet on that happening by mid-century.
But for most of us that still leaves an unnaceptably high risk of death in the cumulative years between now and then. Cyronics enrollment offers a further hope, but in practice probably only results in a modest improvement in long term survival odds after full discounting for the technical risks and uncertainties.
In the end it all comes down to a die roll. Wouldn't you like to get an extra +1 or two?
With a simple evolutionary health optimization, one can:
- achieve perhaps a 10% increase in peak mental hours per year
- slow aging and prolong expected lifespan by at least ten years (before considering future medical advances)
- significantly reduce chance of death before mid-century
- shift body weight to a healthier equilibrium, increase attractiveness, general mood and happiness
Evolution and Health
Our bodies are the collective result of countless layers of mindless complex adaptations, evolutionary godshatter from a bygone history. The current sub-species or races of humans today are just a small sampling of a much larger space of genetically related human ancestors who roamed the earth for hundreds of thousands of years before the modern era. Our modern genomes are a wide and highly irregular sampling of this diverse set of historical adaptations.
For most of that time the earth was considerably colder and very different than it is today - we currently live in a warm peak between large glaciations. These wide climate swings created complex dynamic patterns of shifting ecological niches. At glacial peaks, sea levels were over 100 meters lower than today and most of the terrestrial world was connected, allowing large waves of nomadic migration in giant mammals.
Again and again tribes of homo sapiens with increasingly advanced technological hunting cultures expanded out of Africa, where humans originated and the ecosystems had more time to co-evolve. The farther humans migrated out of Africa, the more they encountered megafauna unadapted to human hunting, and the more they became specialized technological apex predators.
By roughly 10,000 BC nearly all the terrestrial megafauna outside of Africa was extinct. Shortly thereafter early agricultural centers began to spring up in several megafauna-depleted regions; nascent civilizations in the making - only to fail and rise again. In the ten thousand years or so since these first large-scale farming experiments, the homo sapien genome has had limited time for any new novel adaptations.
This historical observation leads to a simple but suprisingly powerful top-level belief. Our genome is optimized for genetic fitness functions that no longer exist; an evolutionary environment from the paleolithic era. Thus all else being equal we should expect significant deviations from that environment to have negative effects more often than positive.
Evolution is near-sighted. In thou art godshatter, Eliezer Yudkowsky asks:
Why wasn't a concept of "inclusive genetic fitness" programmed into us, along with a library of explicit strategies? Then you could dispense with all the reinforcers. The organism would be born knowing that, with high probability, fatty foods would lead to fitness. If the organism later learned that this was no longer the case, it would stop eating fatty foods.
One answer is that explicit linguistic conceptual knowledge is much more complex and developed long after simple reinforcement strategies. The other perhaps more obvious answer is that explicit conceptual strategies are inherently serial and are thus extremely computationally limited in the slow but massively parallel human brain. Every day our brains are unconsciously evaluating vast quantities of probabilistic inferences tied to simple reinforcers in an attempt to maximize our inclusive genetic fitness and spread our genes.
Regardless of whether or not we are interested in maximizing genetic fitness, we can now use our advanced conceptual knowledge of evolution, genetics, and health to identify and map out the hidden assumptions of the numerous ancient programs in the genome, how they can go wrong in the novel modern environment, and how we can best trick these adaptive systems back into their optimal operating modes.
Evolution had no incentive to optimize for environments significantly different than those it encountered, and the web of complex interdependent genetic programs that maintain our bodies have numerous subtle minor failure modes, most of which are not fully understood.
A key insight is that the web of hormones, metabolism and gene expression are highly complex and inter-related, and one gets full benefit only by correcting the majority of the deviations. If this is done then one can significantly reduce the chance of succumbing to the diseases of civilization.
What are some of the modern environmental deviations?
Hunter-gatherers were certainly not sedentary, but probably had an average daily activity level still below that of today's professional athletes. It's pretty clear though that they spent a good chunk of time walking and running. The effects of exercise on health have been fairly well studied. Of interest to pragmatic instrumental rationalists is that only mild exercise is required. Studies have shown that the main longevity boost is somewhere around 2 to 5 years and requires just 100 to 300 calories of exercise per day.  Suspected mechanisms involve cortisol regulation, endorphins, and triggers that activate cellular repair. Sex may be the most efficient form of exercise for the calorie budget.
Our ancestors ate a variety of foods with significant geographic and temporal variation. But if you sum the typical average over a swath of ancestors, it is believed to have consisted largely of lean game meat, offal, fish, nuts, higher-fiber vegetables, low-sugar fruits, shellfish and insects. At the macro-level the diet would be more balanced between protein, fat and carbohydrate, significantly different than the high carbohydrate and low protein modern diet.
Modern humans today eat a diet that is superficially super-good - it consists of the foods blind evolutionary adaptations thought we needed more of . . . ten thousand years ago. Our taste buds are primed to favor foods that are rich in calories overall and high in ancient rarities such as sodium and certain fats.
We now have specific evidence for a whole range of health problems associated with the modern diet: excess calories and caloric density, high glycemic index causing excessive insulin production and spiking (mainly via over-abundance of concentrated starch and sugar), imbalanced omega 3 / omega 6 fatty acid profile and imbalanced sodium/potassium profile.
The exact mechanisms are complex and not fully understood, but in general this diet will cause one to put on weight and is linked longer term to an entire cluster of diseases - largely the metabolic syndrome and cardiovascular disease.
A simplified paleo-diet solution:
- eliminate high fructose corn syrup and sugarey drinks in general. They are empty extra calories that will not contribute to satiation. The sugar/insulin spikes accelerate some metabolic aging processes.
- reduce or eliminate the starchy foods: bread, pasta, potatoes, and rice. Replace with real vegetables - the kind that actually have high micronutrient content and high fiber content.
- shift meat preferences towards the healthier fat spectrum: prefer fish, then grass fed beef, chicken, beef, pork
- limit fried foods and vegetable oil
- generally avoid processed foods, favor nuts and berries for snacks
- switch to lower sodium salts
- supplement vitamin D (more on that later), omega 3's, and vitamin B and potassium to suit diet
Nights would overall be much darker than they are today (unless one lives in some remote wilderness), and that darkness would start much earlier. Campfire light is considerably different than modern artificial illumination.
Even small amounts of light can block melatonin production. Thus modern human's sleep cycle is completely unoptimized. We don't get enough bright sunlight in the day, and we get far too much light at night. The evidence suggests that melatonin/sleep imbalance can effect everything from mood to the immune system to aging itself.
Interestingly enough, human melatonin production may be optimized to ignore campfire light (from wikipedia):
Production of melatonin by the pineal gland is inhibited by light and permitted by darkness. For this reason melatonin has been called "the hormone of darkness". Its onset each evening is called the Dim-Light Melatonin Onset (DLMO). Secretion of melatonin as well as its level in the blood, peaks in the middle of the night, and gradually falls during the second half of the night, with normal variations in timing according to an individual's chronotype.
It is principally blue light, around 480nm, that suppresses melatonin, increasingly with increased light intensity and length of exposure. Until recent history, humans in temperate climates were exposed to few hours of (blue) daylight in the winter; their fires gave predominantly yellow light. Wearing glasses that block blue light in the hours before bedtime may avoid melatonin loss. Kayumov et al. showed that light containing only wavelengths greater than 530 nm does not suppress melatonin in bright-light conditions. Use of blue-blocking goggles the last hours before bedtime has also been advised for people who need to adjust to an earlier bedtime, as melatonin promotes sleepiness.
Melatonin can be supplemented at night, but I also intend to outfit my apartment with blue-filtered lights, or perhaps try blue-filtered glasses. I have noticed that sleep is also more effective when one wakes up slowly to bright daylight.
In some sense most terrestrial vertebrates are partially solar powered - plants are not the only creatures to use solar energy directly. Unless you are currently taking 5000 IU of vitamin D3 per day the odds are you probably are vitamin D deficient.
"Vitamin" D is perhaps a misnomer. I can do no better than quote from the Vitamin D council :
Technically not a "vitamin," vitamin D is in a class by itself. Its metabolic product, calcitriol, is actually a secosteroid hormone that is the key that unlocks binding sites on the human genome. The human genome contains more than 2,700 binding sites for calcitriol; those binding sites are near genes involved in virtually every known major disease of humans.
Current research has implicated vitamin D deficiency as a major factor in the pathology of at least 17 varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, periodontal disease, and more.
What does Vitamin D do at all these gene expression sites? We don't really know yet.
However it is clear that D is somehow involved heavily in immune regulation and brain development. Interestingly enough, almost all of the modern diseases of civilization are either inflammatory diseases or are immune regulated, including cancer, cardiovascular disease and Alzheimer's, just to name a few.
An interesting quote from that article:
One of the researchers who made the discovery, professor of medicine Robert Heaney of Creighton University in Nebraska, says vitamin D deficiency is showing up in so many illnesses besides cancer that nearly all disease figures in Canada and the U.S. will need to be re-evaluated. "We don't really know what the status of chronic disease is in the North American population," he said, "until we normalize vitamin D status." (emphasis added)
I'm not aware of any other supplement, drug, or food that has this level of cancer protection. Indeed drug companies have been working on patentable vitamin D analogues for years. This is the sad state of our medical industry. The reality is most of us today are deficient - and our cancer rates are thus abnormally elevated. But we don't need an expensive new vitamin D derived drug to reduce cancer incidence.
Low vitamin D levels are also linked to metabolic syndrome and thus weight gain and diabetes. Abdominal fat in particular is linked to a cluster of diseases, including cancer, and higher vitamin D levels in the blood are linked to lower weight, and strangely - higher educational status.
It also may boost intelligence; deficiency has been linked to cognitive decline with age.
And finally, vitamin D defeciency fits the epidemic profile of autism, and has been proposed as a cause of this disorder.
Another role of D may be as a form of summer/seasonal signalling hormone, and could explain the apparent link between VDDS, metabolic syndrome, and weight.
If you are low on vitamin D, your body is perhaps stuck in some eternal state of fall or winter, suppressing high-energy or risky endeavors and attempting to put on fat. You are thus not getting the full mileage of your genome.
Light in general has benefits beyond vitamin D. Did you know that total light exposure has a measurable effect on mood? In fact bright light therapy is a treatment for numerous psychiatric disorders.
1. Statement on Exercise: Benefits and Recommendations for Physical Activity Programs for All Americans, from the American Heart Association
2. My father founded the Vitamin D council in 2003 and is a tireless promoter and advocate for D. So I may have some bias, but at this point perhaps it's just an inside view, because D's health effects are now widely known and little of this is as controversial as it was just 5 years ago.