EVOLUTION OF SKIN COLOR-A HISTORICAL INSIGHT

The old apartheid practices based on skin color have practically disappeared in most parts of the world while the American slavery system that used imported African people with dark colored skin remains only in memory. Probably if to day's knowledge about the role skin color plays in maintaining good health was known 300 years ago, people would have given more respect to a dark skinned person than what the latter received from their fair skinned cousins! For quiet some time knowledge about the critical role played by Vitamin D in bone formation and development was in the public domain and that this particular micro nutrient cannot be synthesized by the human body was also known. It is underneath the human skin that Vitamin D is formed from its precursors through the action of Ultra Violet Rays (UVR), so abundantly available to those living near the equator and the extent of synthesis is a function of time of exposure. The advantage of darker skin is that it not only allows synthesis of Vitamin D but also protects the skin from DNA damage eventually leading to skin cancer. It is not an accident that light skinned population generally live farther from the Equator where sun light is comparatively less and environmental temperature is low for people to be outside their homes for long time. Under such conditions protection from UV rays is not a major problem and that is how the pigmentation started declining progressively. This evolutionary development is purely a response to the environment and cannot be associated with any brain function. Thus color of the skin does not influence the IQ or any function associated with intelligence or skills. Here is a commentary on this interesting interpretation of the evolutionary development over the years.    

"The human lineage originated, and first flourished biologically and culturally, in Africa. Evolutionarily, each of us is African; the first people had darkly pigmented skin and were thus well-adapted to handle the high levels of UVR (ultraviolet radiation) in equatorial regions. As Jablonski explains in her talk, UVR has both benefits and costs for the human body. On the plus side, when it strikes the skin it catalyzes Vitamin D, which is essential for bone and immune health; on the minus side, it can cause DNA damage and skin cancers. In ancient Africa, melanin acted as a natural sun screen to protect people from the dangers while still allowing the benefits of Vitamin D synthesis from the sun. When people from some ancestral populations migrated north out of Africa, they encountered much less intense UVR. The previously adaptive sun screen of melanin was now a disadvantage, and thus lightly pigmented skin evolved. People with light skin in these northern regions spent enough time in the sun that, typically, their skin still synthesized adequate vitamin D, a process helped along in some areas by diets heavy in fish. What we have nowadays is also a balance of pluses and minuses: A lovely rainbow diversity of skin colors that reflects the map of our ancestors' relatively recent geography, and an unfortunate risk of vitamin D deficiency that comes with spending the bulk of our hours indoors in artificial light".

Vitamin D deficiency is manifested among people of all skin colors because of the new living style where exposure to sun light is progressively being reduced due to artificially lighted houses, heavy dependence on automobiles, less and less walking in the open and other undesirable practices. Of course there is a billion dollar industry riding on skin care products including sun screens which will help to some extent in lessening the dangers of incidence of cancer but choosing a right time for walking under the sun cannot  be of any risk as long as the exposure is not for long time. According to health experts even a daily 15 minutes exposure should be adequate for generating the required quantum of Vitamin D and maintain a blood level of 30 micro gram uniformly.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

  

"SPACE" JUICE-SPIN OFF FROM SPACE EXPLORATION PROGRAMS

Recent splashing of a news item in popular media regarding the effectiveness of a fruit juice blend evolved by NASA in the US for consumption by their astronauts during space travel in improving the health of human skin created lot of excitement among people concerned with the progressive deterioration of skin during the aging process. Of course the cosmetic industry is also interested in marketing products that can improve skin health without use of chemicals having any side effects. NASA's interest was, of course, not keeping their astronauts young but to protect them from the ill effects of radiation encountered in outer space. The juice blend named AS10, probably because it has about 10 fruit juices mixed in some proportion to make use of the high antioxidant properties exhibited by the fruits from which juice is extracted and these fruits containing high levels of anthocyanins are known to have excellent anti oxidant properties as measured by in vitro studies. These fruits include Cupuacu, acai, acerola, prickly pear, yumberry , grape and pomegranate besides some vegetables and green tea extract. Though this product was being used in space flights, its civilian use has not yet been established so far. Probably it is a question of time before an entirely new industry is spawned around this innovative product. Here is a take on this development about which lot will be heard in the coming days.

"These startling images may prove that a fruit drink developed by Nasa to protect astronauts from radiation can rejuvenate the skin. A groundbreaking study has shown that the concoction, known as AS10, dramatically reduces wrinkles, blemishes and sun damage after four months. Visia photographs – which reveal the condition of the skin below the surface by using different types of light exposure – were taken of 180 participants at the start of the trial, and again after four months of drinking two shots of AS10 a day. By the end UV spots were reduced by 30 per cent and wrinkles by 17 per cent. AS10 was developed as a nutritional supplement for astronauts to protect them from the damaging effects of high levels of radiation outside the Earth's atmosphere. The drink contains a blend of fruits including cupuacu (a Brazilian fruit from the cacao plant family), acai, acerola, prickly pear and yumberry, which all provide vitamins and phytochemicals – compounds known to block the harmful effects of radiation. Other ingredients are grape, green tea, pomegranate and vegetables. Radiation particles alter oxygen molecules in the body to create reactive oxygen species (ROS) – so-called 'free radicals' which damage cells in a process known as oxidative stress. This process has been linked to diseases such as cancer and Alzheimer's. The toxic molecules are also thought to play a role in the skin ageing process. ROS are created naturally within the body as cells generate energy, but also through environmental factors such as chemicals and ultraviolet light from the sun – the strongest stress to skin. Mobile phone radiation, cigarette smoke and alcohol also generate ROS. Space-age: AS10 was developed in conjunction with Nasa for the Astronaut Programme to ensure they received enough fruit and vegetables 'Think of them as little Pac-men taking bites out of molecules that are essential for cells to function,' says Dr Aaron Barson, the nutritional scientist from Utah who carried out the AS10 study after patients reported dramatic improvement from the drink.AS10 is thought to improve skin condition because the drink's large quantities of antioxidants ward off oxidative stress, allowing the skin to heal naturally. Antioxidants attach themselves to ROS and neutralise them before they cause damage.  Dr Barson says: 'The skin is the first body tissue to be exposed to UV rays and we know it is sensitive to oxidative stress. Our study shows it greatly benefits from a reduction in this stress. The effects of oxidative stress on the skin can be quickly modified and the skin can heal itself by drinking AS10.' Dr Barson suggests that the results may have been even better had the trial been conducted during the winter, when exposure to ultraviolet light would have been less.  A second, larger study is planned this summer to investigate for how long the effects last and whether skin condition reaches a plateau or deteriorates once the drink is no longer consumed.  The main drawback is the high price of the drink. The women in the trial drank a sherry glass – 60ml – of AS10 a day. At £30 per 750ml bottle, the cost was just under £300 over the four months. Cosmetic dermatologist Dr Sam Bunting says: 'The Visia scans show a marked improvement in the level of UV spots, which represent sun damage beneath the surface of the skin. The kind of interventions that might deliver this level of improvement are glycolic skin peels, which use acids to strip away layers of skin, retinoids, high-potency Vitamin C and hydroquinone with the use of sun block on a daily basis. 'If these changes were due to AS10, this would be of great interest as UV is responsible for 80 per cent of the skin changes we associate with ageing.' She adds that although AS10 might well do what it claims, a critical appraisal of the methods in the study would be required to back this up. Cosmetic dermatologist Dr Mervyn Patterson, of Woodford Medical, agrees. He says: 'These images show a reduction in the degree of pigmentation on the skin caused by UV exposure. This could be due to the drink.' But he says daily use of sunscreen with UVB/UVA sun protection factor of 50+ could deliver results on a par with AS10. 'It is more likely to protect the skin, resulting in reductions in redness and pigmentation and a subtle reduction in wrinkles.'"

Scientifically the principle based on which this product was designed is sound as most of the fruits used contain large amounts of the colored pigments anthocyanins which are known to have high antioxidant properties. There are a number of variants among anthocyanins and each fruit has a compliment of these phytochemicals in different proportions with varying properties and their absorption across the intestine and further metabolism remain unclear. Probably this may the reason why multiple sources of anthocyanins are used to formulate this juice product. As the report suggests the existing data may not be sufficient to make any definite  health claims and much more studies need to be carried out with large scale clinical trials to conclusively establish the beneficial effect of AS10. Also not clear is whether this product is curative in nature or can be a preventive material that can ensure continued health benefits if taken regularly. The cosmetic products industry which has a plethora of products under the Sun-screen category may not be immediately interested unless AS10 is dried without adversely affecting its beneficial properties, for easy incorporation into cream type of consumer friendly product for external application. One of the imponderable factors that may come in the way of successful marketing of AS10 is its manufacturing cost which at present is considered exorbitant for most consumers. Probably increased volume of production by the organized sector may bring down the cost significantly if the product establishes itself as a reliable health oriented product with long term benefits.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com