the-psoriasis-treatment

Our body naturally produces as much as 10,000 IU of vitamin D based on a few minutes of sun exposure when the sun is high. Getting that much vitamin D from dietary sources is very difficult, even after “fortification”. The above refers to pre-sunburn exposure. Sunburn is not associated with increased vitamin D production; it is associated with skin damage and cancer. Solar ultraviolet (UV) radiation is generally divided into two main types: UVB (wavelength: 280–320 nm) and UVA (320–400 nm). Vitamin D is produced primarily based on UVB radiation. Nevertheless, UVA is much more abundant, amounting to about 90 percent of the sun’s UV radiation. UVA seems to cause the most skin damage, although there is some debate on this. If this is correct, one would expect skin pigmentation to be our body’s defense primarily against UVA radiation, not UVB radiation. If so, one’s ability to produce vitamin D based on UVB should not go down significantly as one’s skin becomes darker. Also, vitamin D ...

New evidence published in Archives of Internal Medicine has it that eating more dietary fiber, particularly from whole grains, could lead to a longer life. The large study found a high-fiber diet reduced risk of heart disease and cancer, as well as infectious and respiratory illnesses. This is great news for those eating diets high in fiber. What’s also interesting is that another reason why dietary fiber is protective to health is because of its influence on telomeres. Telomeres are the protective caps at the end of chromosomes, and their length is considered the closest way to measure lifespan in humans. As reported in a prospective cohort study published in the March 2010 issue of American Journal of Clinical Nutrition (AJCN), telomere length is positively associated with higher fiber intake in women. Dietary fiber from whole grains appears to provide the strongest benefit. In addition, in the AJCN study, the researchers found telomere length was negatively associated with inc...

Panel of scientists debate on "What is Life?" Sometime between 4 and 3.5 billion years ago, the emergence of life had intense beginnings on a young planet in the midst of a so-called primordial soup—consisting of water vapor, carbon monoxide, carbon dioxide, nitrogen, and ammonia and shaped by strong winds, electrical storms, volcanic eruptions, and ultraviolet radiation. In 1953, Stanley Miller and Harold Urey put Earth's primitive conditions to test for the first time in a famous laboratory experiment. It yielded variety of amino acids and organic compounds. The researchers realized something more: that no early form of life could have ever survived the world of today, because of the presence of oxygen that directly attacks at the bonds that holds together complex molecules. Scientists also now know that the original blueprint of life was not DNA, but short RNA strands that may have also served as their own biological catalysts, before enzymes ever evolved, providing fo...

In this post on the China Study II data we have seen that wheat apparently displaces dietary fat a lot, primarily fat from animal sources. We have also seen in that post that wheat is strongly and positively associated with mortality in both the 35-69 and 70-79 age ranges, whereas dietary fat is strongly and negatively associated with mortality in those ranges. This opens the door for the hypothesis that wheat increased mortality in the China Study II sample mainly by displacing dietary fat, and not necessarily by being a primary cause of health problems. In fact, given the strong displacement effect discussed in the previous post, I thought that this hypothesis was quite compelling. I was partly wrong, as you’ll see below. A counterintuitive hypothesis no doubt, given that wheat is unlikely to have been part of the diet of our Paleolithic ancestors, and thus the modern human digestive tract may be maladapted to it. Moreover, wheat’s main protein (gluten) is implicated in ce...

Sarah Tishkoff Most African populations have lactose intolerance, but as recently as 3 kya a few pastoral populations have gained the ability to digest milk, which provides evidence of yet another example of ongoing evolution in human population since the time of their origins. Sarah Tishkoff has been studying this phenomenon of recent lactose tolerance in African pastoralist populations. She shared her findings on Sunday morning at #AAASmtg in Washington DC. The ability to digest milk as infants is with the expression of lactase-phlorizine hydrolase (lactase), which is specifically expressed by brushborder cells in the small intestine. But shortly after weaning, the expression of lactase decreases sharply -- that is, except in populations that are lactase persistent. In 2002, an elegant genetic study found the gene for lactase in European populations. Tishkoff showed us in charts and on a map how she performed genetic studies on the African pastoralist populations with lactase to...

Nina Jablonsky On Sunday morning at #AAASmtg in Washington DC,  Nina Jablonski  talked to use about human skin pigmentation as an example of natural selection. "Human skin is colorful, it's mostly naked, it's sweaty, and it's tough yet sensitive," Jablonski said. The gradient of human skin pigmentation is very clear in the old world, as it's lighter in the northern countries and darker in Africa. But why did human skin pigmentation evolve as it did? When you look at other apes and humans, our relatives have lightly pigmented skin covered by dark hair -- this was the ancestral pigmentation of our lineage. "When you think of Lucy's species, you can think of lightly pigmented skin covered by dark hair," she said, noting that eventually as the hominins became more naked they developed more melanin. When  Homo ergaster 1.6 mya was foraging in the savannah, the species would have needed more naked and sweaty skin for keeping cool. In addition, Jablons...

Photo credit: Sara Fulcher on Flickr Where can we find a cure for cancer, new semiconductor technology, or the solution for turning waste plant materials into biofuels? The answer is enzymes that are produced through "directed evolution," according to Frances H. Arnold , professor of chemical engineering and biochemistry at the California Institute of Technology. Arnold's lab doesn't synthesize enzymes as other labs do. She and her team "evolve them" toward a certain desired goal in the same way that nature has done it for 3.5 billion years. Aronold presented an overview of her budding field of work to an audience at American Association for the Advancement of Science annual meeting (#AAASmtg) in Washington DC. The field of directed evolution is relatively new and includes few people at the present time, but Arnold sees high hopes for the future. "When I started engineering proteins a long time ago, there appeared to me an algorithm that dos a really go...

Anna Di Rienzo Humans originated in Africa and then dispersed all over the world to environments that differ in terms of climate, biodiversity, etc, which has brought selective pressures on different populations. At #AAASmtg in Washington DC on Saturday, Anna Di Rienzo presented her research on the how this dispersal has left signatures of adaptation to the pressures. Here are my notes from the talk. The "Out of Africa" theory has it that humans left Africa 50 Kya and then Neolithic revolution happened 14 Kya. They shifted away from foraging subsistence to horticulture. We also know that levels of human skin pigmentation changed with latitude of populations. In addition, body size and proportions changed. For example, Inuit have quite different proportions for the cold North. Metabolic traits differ across human populations also, causing disease related traits to occur such as high blood pressure, high triglycerides, or high cholesterol. A prominent example is the rising pr...

Note: Vitamin C is fascinating topic and there's no better way to understand it than through the eyes of my boss, Dr. Rockway. I'm glad I had the pleasure of editing her article and posting it here. David By Susie Rockway, Ph.D. Vitamin C, or ascorbic acid (ascorbate), is the most frequently taken dietary supplement in North America. Yet, despite its widespread use, national surveys report that 15 percent of the population still doesn't get enough vitamin C to meet recommended amounts for health. Initially, the Recommended Daily Intake (RDI) for vitamin C was set at 60 milligrams, the amount required to prevent scurvy. The deficiency disease—commonly characterized by bleeding gums and loosened teeth helped identify the vitamin as having an essential role in collagen formation. However, more recent research has now made it clear that more dietary vitamin C is needed to saturate body tissues such as the brain, heart, liver, and adrenal glands. Consequently, in 2000, the RDI...

The idea that protein leaches calcium from the bones has been around for a while. It is related to the notion that protein, especially from animal foods, increases blood acidity. The body then uses its main reservoir of calcium, the bones, to reduce blood acidity. Chris Masterjohn does not agree with this idea . This post generally supports Chris’s view, and adds a twist to it, related to plant protein consumption. The “eat-meat-lose-bone” idea has apparently become popular due to the position taken by Loren Cordain on the topic. Dr. Cordain has also made several important and invaluable contributions to our understanding of the diets of our Paleolithic ancestors. He has argued in his book, The Paleo Diet , and elsewhere (see, e.g., here ) that to counter the acid load of protein one should eat fruits and vegetables. The latter are believed to have an alkaline load. If the idea that protein leaches calcium from the bones is correct, one would expect to see a negative association betwee...

Listen up, men! On this Valentine's Day, why not surprise your special lady with chocolates that are healthier for her heart? Dark chocolate eaten in moderate amounts weekly is associated with improved cardiovascular fitness in women, research suggests. Scientists are only beginning to understand why dark chocolate is heart healthy, but a new study offers this explanation—its rich content of cocoa antioxidant compounds, called polyphenols, could enhance activity of special proteins called sterol regulatory element binding proteins (SREBPs), which are involved in cholesterol metabolism. These activated SREBPs then bind to genes on DNA (sterol regulatory element sequences) that boost liver production of another protein called apolipoprotein A1 (ApoA1), which is the major protein component of HDL "good" cholesterol. Correspondingly, cocoa polyphenols also decreased production of another protein in the liver called apolipoprotein B (ApoB), which is the major protein componen...

Spending too much time sitting down is clearly unnatural, particularly if you sit down on very comfortable chairs . Sitting down per se is probably natural, given the human anatomy, but not sitting down for hours in the same position. Also, comfortable furniture is an apparently benign Neolithic invention, but over several years it may stealthily contributed to the metabolic syndrome and the diseases of civilization. Getting an elevated workstation may be a bit expensive. At work, you may have to go through a bit of a battle with your employer to get it (unless you are " teh boz "), only to find out that having to work standing up all the time is not what you really wanted. That may not be very natural either. So what is one to do? One possible solution is to buy a small foldable plastic table (or chair) like the one on the figure below, which may cost you less than $10, and put it on your work desk. I have been doing this for quite a while now, and it works fine for me. The...