Showing posts with label depression. Show all posts
Showing posts with label depression. Show all posts

Daniel Suelo, the man who quit money, seems remarkably healthy

Daniel James Shellabarger (better known as Daniel Suelo) is portrayed in the bestselling 2012 nonfiction book by Mark Sundeen titled “The Man Who Quit Money” ().

Apparently Suelo stopped using money in 2000, and lives in a cave near the city of Moab in Utah. His diet comprises primarily wild vegetables and fruits, insects, and road kill; as well as discarded or donated food he gets from others when he visits the city. The photo below is from a recent BBC documentary. An interesting 2006 YouTube clip on Suelo is titled “Moneyless in Moab” ().



Suelo is listed as having been born in 1961 (), and the photo above appears to have been taken in 2012. If these dates are correct, he is 51 in the photo above. I cannot help but think that he looks remarkably healthy. The 40-50 age period is one that often sets the stage for many diseases of civilization in urban societies.

Suelo’s decision seems like a radical one, at least to me. There are always complex motivations behind radical decisions. In the case of Suelo, some of these motivations are captured in the comment below, which is part of a review of the book “The Man Who Quit Money” posted on Amazon.com by a reader.

[…] a picture of Suelo not as an untarnished hero, but a man who has wrestled with heartbreak, depression, disillusionment with his family's faith, and his repugnance to working for the pure sake of making money and buying things. Whether or not you are inspired to follow Suelo's example, this book will make you think.

Many people have been inspired by Suelo’s story, to some extent because they see that adopting a radical form of “simple living” () may not only be possible but also liberating. Obviously Suelo’s lifestyle, as it is now, would not be possible without the help of others who adopt a more “traditional” lifestyle. Below is a critical review by a reader of the book, posted on Amazon.com, which harshly reflects this perspective.

Any infantile mentality charmed by this inane story should simply generalize the message - visualize a world in which all of us live like the parasitic protagonist. How fortunate for Suelo that there are still people who engage in productive work and indirectly and unknowingly keep the human sponge alive […] Suelo never quit money he simply quit contributing anything and continues to survive simply as a parasite.

Still, Suelo’s story is interesting, including from a human health perspective. An article on Details.com by Christopher Ketcham provides a glimpse at what a day in Suelo’s life looks like (). It seems that on most days he has one main meal per day.

It is hard to get a sense of the nutrient composition of his diet. It looks like his diet is limited in but not devoid of industrial foods, and one in which food consumption is sporadic, opportunistic, and driven primarily by hunger and availability – not by stress or set meal times, for example.

He probably walks a lot; his cave is one hour away from Moab by foot, and it looks like he goes to Moab often. Apparently he almost never gets sick.

Suelo also writes a blog (), which has many followers, and also maintains other websites, from the Public Library in Moab. His first blog post has over 1,000 comments under it ().

Vitamin D levels: Sunlight, age, and toxicity

Calcidiol is a pre-hormone that is produced based on vitamin D3 in the liver. Blood concentration of calcidiol is considered to be a reliable indicator of vitamin D status. In the research literature, calcidiol is usually referred to as 25-Hydroxyvitamin or 25(OH)D. Calcidiol is converted in the kidneys into calcitriol, which is the active form of vitamin D.

The table below (from: Vieth, 1999; full reference at the end of this post; click on it to enlarge), shows the average blood vitamin D levels of people living or working in sun-rich environments. To convert from nmol/L to ng/mL, divide by 2.496. For example, 100 nmol/L = 100 / 2.496 ng/mL = 40.1 ng/mL. At the time of this writing, Vieth (1999) had 692 citations on Google Scholar, and probably more than that on Web of Science. This article has had, and continues having, a high impact among researchers.


The maximum average level of blood (or serum) vitamin D shown in the table is 163 nmol/L (65 ng/mL). Given that the human body produces vitamin D naturally from sunlight, it is reasonable to assume that those blood vitamin D levels are not yet at the toxic range. In fact, one of the individuals, a farmer in Puerto Rico, had a level of 225 nmol/L (90 ng/mL). That individual had no signs of toxicity.

Several studies show that pre-sunburn full-body exposure to sunlight is equivalent to an oral vitamin D intake of approximately 250 µg (10,000 IU).

In spite of claims to the contrary, vitamin D production based on sunlight does not cease after 40 years of age or so. Studies reviewed by Vieth suggest that among the elderly (i.e., those aged 65 or above) pre-sunburn full-body exposure to sunlight is equivalent to an oral vitamin D intake of 218 µg (8,700 IU).

Sunlight-induced vitamin D production does seem to decrease with age, but not dramatically.

Post-sunburn sunlight exposure does not increase vitamin D production. Since each person is different, a good rule of thumb to estimate the number of minutes of sunlight exposure needed to maximize vitamin D production is the number of minutes preceding sunburn. For a light-skinned person, this can be as little as 7 minutes.

Vitamin D accumulation in the body follows a battery-like pattern, increasing and decreasing gradually. The figure below, from Vieth’s article, shows the gradual increase in blood vitamin D concentrations following the start of daily supplementation. This suggests that levels start to plateau at around 1 month, with higher levels reaching a plateau after 2 months.


While sunlight exposure does not lead to toxic levels of vitamin D, oral intake may. Below is a figure, also from Vieth’s article, that plots blood levels of vitamin D against oral intake amounts. The X’s indicate points at which intoxication symptoms were observed. While typically intoxication starts at the 50,000 IU intake level, one individual displayed signs of intoxication at 10,000 IU. That individual received a megadose that was supposed to provide vitamin D for an extended period of time.


Non-toxic levels of 10,000 IU are achieved naturally through sunlight exposure. This applies to modern humans and probably our Paleolithic ancestors. Yet, modern humans normally limit their sun exposure and intake of vitamin D to levels (400 IU) that are only effective to avoid osteomalacia, the softening of the bones due to poor mineralization.

Very likely the natural production of 10,000 IU based on sunlight was adaptive in our evolutionary past, and also necessary for good health today. This is consistent with the many reports of diseases associated with chronic vitamin D deficiency, even at levels that avoid osteomalacia. Among those diseases are: hypertension, tuberculosis, various types of cancer, gingivitis, multiple sclerosis, chronic inflammation, seasonal affective disorder, and premature senescence.

Reference:

Reinhold Vieth (May 1999). Vitamin D supplementation, 25-hydroxyvitamin D concentrations, and safety. American Journal of Clinical Nutrition, Vol. 69, No. 5, 842-856.

Vitamin D deficiency, seasonal depression, and diseases of civilization

George Hamilton admits that he has been addicted to sunbathing for much of his life. The photo below (from: phoenix.fanster.com), shows him at the age of about 70. In spite of possibly too much sun exposure, he looks young for his age, in remarkably good health, and free from skin cancer. How come? Maybe his secret is vitamin D.


Vitamin D is a fat-soluble pro-hormone; not actually a vitamin, technically speaking. That is, it is a substance that is a precursor to hormones, which are known as calcipherol hormones (calcidiol and calcitriols). The hormones synthesized by the human body from vitamin D have a number of functions. One of these functions is the regulation of calcium in the bloodstream via the parathyroid glands.

The biological design of humans suggests that we are meant to obtain most of our vitamin D from sunlight exposure. Vitamin D is produced from cholesterol as the skin is exposed to sunlight. This is one of the many reasons (see here for more) why cholesterol is very important for human health.

Seasonal depression is a sign of vitamin D deficiency. This often occurs during the winter, when sun exposure is significantly decreased, a phenomenon known as seasonal affective disorder (SAD). This alone is a cause of many other health problems, as depression (even if it is seasonal) may lead to obesity, injury due to accidents, and even suicide.

For most individuals, as little as 10 minutes of sunlight exposure generates many times the recommended daily value of vitamin D (400 IU), whereas a typical westernized diet yields about 100 IU. The recommended 400 IU (1 IU = 25 ng) is believed by many researchers to be too low, and levels of 1,000 IU or more to be advisable. The upper limit for optimal health seems to be around 10,000 IU. It is unlikely that this upper limit can be exceeded due to sunlight exposure, as noted below.

Cod liver oil is a good source of vitamin D, with one tablespoon providing approximately 1,360 IU. Certain oily fish species are also good sources; examples are herring, salmon and sardines. For optimal vitamin and mineral intake and absorption, it is a good idea to eat these fish whole. (See here for a post on eating sardines whole.)

Periodic sun exposure (e.g., every few days) has a similar effect to daily exposure, because vitamin D has a half-life of about 25 days. That is, without any use by the body, it would take approximately 25 days for vitamin D levels to fall to half of their maximum levels.

The body responds to vitamin D intake in a "battery-like" manner, fully replenishing the battery over a certain amount of time. This could be achieved by moderate (pre-sunburn) and regular sunlight exposure over a period of 1 to 2 months for most people. Like most fat-soluble vitamins, vitamin D is stored in fat tissue, and slowly used by the body.

Whenever sun exposure is limited or sunlight scarce for long periods of time, supplementation may be needed. Excessive supplementation of vitamin D (i.e., significantly more than 10,000 IU per day) can cause serious problems, as the relationship between vitamin D levels and health complications follows a U curve pattern. These problems can be acute or chronic. In other words, too little vitamin D is bad for our health, and too much is also bad.

The figure below (click on it to enlarge), from Tuohimaa et al. (2009), shows two mice. The one on the left has a genetic mutation that leads to high levels of vitamin D-derived hormones in the blood. Both mice have about the same age, 8 months, but the mutant mouse shows marked signs of premature aging.


It is important to note that the skin wrinkles of the mice on the left have nothing to do with sun exposure; they are associated with excessive vitamin D-derived hormone levels in the body (hypervitaminosis D) and related effects. They are a sign of accelerated aging.

Production of vitamin D and related hormones based on sunlight exposure is tightly regulated by various physiological and biochemical mechanisms. Because of that, it seems to be impossible for someone to develop hypervitaminosis D due to sunlight exposure. This does NOT seem to be the case with vitamin D supplementation, which can cause hypervitaminosis D.

In addition to winter depression, chronic vitamin D deficiency is associated with an increased risk of the following chronic diseases: osteoporosis, cancer, diabetes, autoimmune disorders, hypertension, and atherosclerosis.

The fact that these diseases are also known as the diseases of civilization should not be surprising to anyone. Industrialization has led to a significant decrease in sunlight exposure. In cold weather, our Paleolithic ancestors would probably seek sunlight. That would be one of their main sources of warmth. In fact, one does not have to go back that far in time (100 years should be enough) to find much higher average levels of sunlight exposure than today.

Modern humans, particularly in urban environments, have artificial heating, artificial lighting, and warm clothes. There is little or no incentive for them to try to increase their skin's sunlight exposure in cold weather.

References:

W. Hoogendijk, A. Beekman, D. Deeg, P. Lips, B. Penninx. Depression is associated with decreased 25-hydroxyvitamin-D and increased parathyroid hormone levels in old age. European Psychiatry, Volume 24, Supplement 1, 2009, Page S317.

P. Tuohimaa, T. Keisala, A. Minasyan, J. Cachat, A. Kalueff. Vitamin D, nervous system and aging. Psychoneuroendocrinology, Volume 34, Supplement 1, December 2009, Pages S278-S286.
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