PhotoperiodEffect.com

1. Aren't you trying to explain too much with way too little, here? Isn't it going beyond mere science to think that one simple cause would have all these many terrible effects?

First, there is indeed something to be explained, and perhaps a single entity – the diseases of modernity. These are in some sense one entity, because they are clearly the products of industrialization – all but unknown in undeveloped regions of the world until just recently; and that also happens to be when electric light has come to those same regions along with other industrial wonders. For example, after only a decade or two of very rapid development, countries such as China and Mexico now, very suddenly, have a profound problem in dealing with emerging modern diseases such as metabolic disorder (diabetes, obesity and high blood pressure), multiple sclerosis and eczema. These were all but unknown before. By and large what we think of as chronic diseases are a very modern phenomenon, almost entirely of the last two hundred years. It is this explosion of chronic illness that needs to be explained; and while more that one factor is involved, it would not be surprising if a single over-riding cause is doing most of the damage. Suggesting this, is the profound degree of co-morbidity amongst these chronic illnesses. As just one illustration of this, it has recently been suggested that Alzheimer's disease might be simply a third kind of diabetes, and thus, part of what is now called “metabolic disorder”. Also supportive of this is the remarkable amount of “comorbidity” amongst these modern illnesses. To stick with Alzheimer's, merely being obese doubles your risk, and add in high cholesterol and high blood pressure and your risk of Alzheimer's may be as high as six times normal. [Prevention magazine website] The list of comorbidities, many quite strong, between modern chronic illnesses is remarkably long. These comorbidities are discussed in more detail in the section titled “Modern Illness”. Moreover, the similarities in the specific dietary factors found to help protect against each of these illnesses, such as low saturated fats, fish oil, and antioxidants (which do part of the job the principle night hormone and antioxidant melatonin does) is even more striking. In many cases, research is now detailing the mechanisms that might explain just why, say, disrupted nights interfere with the metabolization of most fats, and the exact consequences of that - but even without such precise details, the similarities in risk factors, protective habits, and the number of patients with one of these illnesses who also have at least one other modern chronic illness is eerie – or as most medical researchers would say “very striking”. Many of these illnesses are now not just being considered together by medical researchers, but increasingly being lumped together as single diseases: diabetes, overweight and hypertension as “metabolic syndrome”, Alzheimer's as “a third kind of diabetes”, etc.

Second, melatonin is the hormone that's most immediately affected by dark and light, and to quote wikipedia.org: “It is referred to by some biochemists and human physiologists as the master hormone, because it regulates the production of most human hormones, both paracrine and endocrine.” In turn, these other hormones affect nearly every other process in the body. Moreover, melatonin is not just an antioxidant, but the most powerful antioxidant known. Antioxidants mop up free radicals, which damage us in completely random ways by combining with any other molecule in our bodies. Even gene expression can be affected, and that controls... well, that controls everything. So we should expect the consequences of disrupting day and night, and therefore the normal melatonin cycle, to be extremely diverse – as indeed they do seem to be. Your genetic makeup may have a large say in just what goes wrong, and how, but a very great deal can go wrong – pretty much everything, in one way or another, to one degree or another - once melatonin levels become abnormally low, or erratic: and that is just what the sun or artificial lights do – they shut melatonin off.

Third, the explanation of a great deal with just a little is the overall aim of science, and as I detail in another essay included as an appendix, this is in fact the fullest expression of Occam's Razor, or if you like, Occam's Principle. As the history of science shows, this principle isn't always accurate, the simplest explanation that covers the most ground isn't always the best or final explanation. But as the history of science also shows, it's the way to bet. In any case, such broad explanations (that fit the evidence) are what scientists are supposed to look for, not shy away from. And if you think that other explanations or collections of explanations fit the evidence and the increasing epidemic [technically, that's a redundancy] of chronic diseases better than the “light hypothesis”; good luck finding much in the literature that will be of help to you in that quest. The “hygiene hypothesis”, which asks whether the relative lack of germs in modern settings might be causing “atopic” disorders (hyper-reactive immune responses to benign substances) such as asthma and hayfever is the only serious attempt I can think of to propose some single root cause for even some of these illnesses, and that theory is now widely regarded, even by it's proposer, as an interesting failure, at best.

Fourth, it may seem very strange to lay-people that a single problem could lead to very different results in different patients. Even if it might be understandable to the reader that one cause could result in many adverse consequences to everybody, how could the variation be so great as it is – one person obese and diabetic, another thin with multiple sclerosis? Well, the variation isn't as great as it might seem. We're finding more and more comorbidities (cases of multiple diseases, such as stroke, diabetes, migraine and obesity in one patient, for example.) But also, we know that stress affects different people differently – humans are immensely complex, our genetic inheritance varies, and we all have different environmental conditions affecting us as well – not just extremely different light exposure, at different times in our lives, but very different nutritional backgrounds (starting with being breastfed or not, a large variable), different workloads, and exposure to toxins and organic solvents, just for starters.

Genetic variation can be expected to be least visible, and least important in it's consequences, when environmental conditions are held steady, and are near to the conditions we evolved within. Conversely, there is what I have referred to as the principle of “genetic unmasking” in which previously innocuous, mildly beneficial or unimportant variations in genetic inheritance suddenly become very strongly harmful, or even very strongly beneficial as we alter our environment in a way nature never did before. This can even give the (phenotypical) illusion that human genetic variation is much greater than it may seem in wild species, or seemed to researchers only a few generations before (not long ago genetic involvement in disease was in fact considered to be very rare, now the pendulum has swung very much the other way.)

For example, if too much light causes widespread atopy (autoimmune diseases), as I believe; then genes that result in very active immune systems may suddenly go from being a help, to being sharply disadvantageous. Iceland's deCode Genetics may have based their business on just such a strategy, having discovered a specific variation of the chromosome-13 inflammation gene that also doubles the risk of heart attack, opening up avenues of treatment for those individuals (it's now known that this variation does in fact result in more inflammation, and it is thought that inflammation may cause fatty plaque coating blood vessels to break up, causing heart attack blockages.) [p.58 September 2004 Technology Review Magazine, www.technologyreview.com] If light or something like it is at the root of modern chronic illnesses, it would not be surprising if this genetic variation found by DeCode also turned out to be significant for some other chronic illnesses. So it's really not that surprising that altering the length of our days under light far beyond what our ancestors encountered for millions of years before, would “unmask” a rather spectacular variation in genetic differences and consequent symptoms and illnesses that were previously not very important – and such variation would also be multiplied considerably by the extraordinary variations in living conditions and environments possible today, now that our choices are so much broader.

If we took one hundred people out on 18hr a day forced hikes every day, this profound stress would affect different people differently. The most fit might actually emerge in pretty good shape. Some would suffer crippling knee problems or back problems, some migraines, some low blood pressure, some perhaps high blood pressure, a few might have strokes, the chances of an additional cancer case or severe infection would go up (since our bodies protective mechanisms couldn't be as active) and so on, and so on. Such an endless forced hike, lasting decades, is a pretty good allegory for excess light stretching out our days decade after decade, forcing us to be far more active in many ways than we would be under natural conditions. If we use artificial lights after sunset, then our mitochondria are on such a forced march, whether they like it or not.

By analogy, there are many individual diseases which nonetheless show such extreme variation that their diagnoses are often very difficult, or often long delayed, due to the extreme variation in their symptoms. Syphilis and multiple sclerosis are both often referred to as “the great imitator” for this reason. Interestingly, there is reason to suppose that mitochondrial diseases (which I've said are a likely result of too much light) are especially unpredictable and variable in their consequences, given the wide range of problems found as a result of mitochondrial respiratory chain diseases. [16224730]

It might also be noted that some of these diseases, at least in the short run, make another consequence a great deal less likely – at first, diabetes actually lowers blood pressure, making stroke and possibly multiple sclerosis (amongst other conditions) far less likely. Later, as diabetes progresses, damage to the kidneys sharply raises blood pressure however. Such interactions between conditions further increase variability amongst patient symptomology, even if the cause might be singular or similar.