Ultraviolet (UV) radiation is responsible for 90% of the visible signs of aging on the skin of whites, says Dr. Michael J. Martin, former Assistant Clinical Professor in the Dept. of Epidemiology and Biostatistics at University of California, San Francisco.
Blacks' skin, however, ages much slower.
Why are most dark-skinned blacks protected from harmful UV rays? Because compared to whites, blacks possess more melanin, the pigment that gives skin its color.
Melanin
Melanin offers protection against UV rays for blacks and other dark-skinned people. Conversely, fair-skinned people are much less protected and more susceptible to skin cancer. Furthermore, albinos' skin offers no protection.
Although blacks' skin produces more melanin than whites', all skin has the same number of melanocytes, the cells that manufacture the melanin.
Melanocytes manufacture melanin from an amino acid, tyrosin, with the help of an enzyme, tyrosinase. In the bottom layer of the epidermis above the dermis, UV light stimulates the production of melanin in the form of insoluble melanosomes. These surround the epidermal cells, which move up to the surface of the skin. The result is a tan.
Blacks' skin produce more melanin, even in the absence of sunlight, and their type of melanin, eumelanin, is more effective at blocking solar rays. However, white skin produces melanin only in the presence of sunlight and after the UV rays have penetrated the lower portion of the epidermis and have caused skin damage.
Melanin also functions as an excellent free radical scavenger. It affects the delicately designed lipids that hold moisture in the stratum corneum (the outermost layer of the epidermis). If the skin loses its moisture, it becomes rigid and cracks, says Sergio Nacht, PhD., Senior Vice-President of Enhanced Derm Technologies, Inc. in Redwood City.
UV Radiation and Skin
UV-A has the longest wavelength, is not filtered by the ozone and passes through glass. It reaches the earth all year long and the amount is comparatively stable. It can penetrate the skin down to the dermis, beneath the four layers of epidermis. It is responsible for most of the visible signs of aging, due to damage to collagen and elastic fibers of the connective tissue of the dermis.
UV-A radiation also plays a role in the development of sunburns and skin cancer. Tanning salon lamps emit a large amount of UV-A rays to generate tans, so the American Academy of Dermatology does not recommend their use.
UV-B radiation, which is partially filtered by the ozone, penetrates the skin to the bottom layer of the epidermis where the basal cells are produced. UV-B can break the molecular bonds, disturbing the dividing cells and altering their structure. Compared with UV-A, UV-B is responsible for most of DNAs damage. It also causes most sunburns. During a sunburn the reddening of the skin, erythema, is caused by dilation of capillaries.
More UV-B is present during summer months between 10 a.m. and 4 p.m. and at latitudes closer to the equator. Furthermore, at high altitudes the air is thinner and cleaner, so UV-B radiation is more abundant.
UV-C, which is generally filtered by the ozone, has the shortest wavelength and the most energy, or intensity. It can sterilize hospital equipment and kill bacteria.
In addition, UV light that reaches the earth is scattered in all directions, and up to 85% is reflected from surfaces.
The Theory of Melanin for Environmental Adaptation
Originally, people of a particular race resided in a particular area. As time went on, their skin adapted to the environment. For instance, people who lived geographically close to the equator had darker skin, and people who lived far from the equator had lighter skin.
In Scotland, which lies at a northern latitude, descendants of the Britons have white skin. When their skin is exposed to the meager sunlight, the scant amount of melanin their skin produces is unable to block the sunlight. Therefore, their bodies are able to make Vitamin D with the help of sunlight. Vitamin D, a vitamin found in fish oil, is necessary to prevent rickets, a bone disease caused by too little calcium.
In contrast, in Africa, which is near the equator, blacks require intense sunlight to penetrate their dark skin to make Vitamin D. This is all well and good. However, when blacks lived in England during the Industrial Revolution, they were the first to develop symptoms of rickets, such as retarded growth, bowed legs and fractures because not enough sunlight was available.
Fortunately, in 1930, Vitamin D was discovered and dispensed as a supplement to add to the diet.
On the other hand, the skin of whites in Australia are in complete opposition to their climate. Consequently, intense UV radiation has been the major cause of skin damage and skin cancer Down Under.
About The Author
Saturday, January 3, 2009
Friday, January 2, 2009
What You Eat Affects How You Breathe
Is there a connection between Asthma and Diet? Yes. What you consume very much so affects the functioning of your respiratory organs-it affects everything. Consequently, if one is seeking to control asthma symptoms and attacks, this is the one factor one has to strongly consider.
According to medical research, Asthma is an allergic inflammation of the lungs. Moreover, an asthma attack can be triggered by chemicals, air pollutants, pollens, molds, dust, animal dander, foods, exercise, and even temperature changes.
However, friends, speaking from my experiences with asthma from the age of 7 till I was about 20, the one factor I think is the most influential negatively on one?s respiratory and overall health, will be what one consumes.
This is a fact that has been in effect in several programs aimed at correcting respiratory health such as the Breath Retaining Program for Asthmatics developed by the Russian, Dr. Buteyko. Within weeks of adhering to his advice, many a chronic asthmatic has been able to give up the use of ventolin inhalers.
Now, I never had to use his program; however, in my quest to get rid of acne, I stumbled on the dietetic change that miraculously cured my asthma, halitosis and overall lethargy. Being amazed at how this change in eating habits worked for not one, but all of my health challenges, was what made me research and discover that such a program as his even exists.
?Well, what is the dietetic suggestion?? one might ask. Quite simply, it is to give up all processed foods and animal products such as meat, milk, eggs and the like from your diet-plain and simple.
Two quotes come to mind in advocating this: ?You are what you consume? and ?Let your foods be you medicine and your medicine your foods?
Now, I ask you a question: ?What is the main physical emission that occurs during an asthma attack with all the wheezing and coughs?? It is mucus.
All the foods listed above are highly mucus forming and upon digestion (if they ever do get digested that is), they leave one with an excessive lining of mucus and slime. Keep in mind that the lungs are the most important excretory organs, when you add its functioning to this fact, it becomes apparent that the consumption of these substances are really only wreaking havoc on the body.
In addition, from my own experience, DO NOT CONSUME LIQUIDS WITH YOUR MEALS AT ANY TIME. This inhibits digestion by diluting the necessary juices in your stomach designated for that purpose. As a result, it hinders the much needed expansion of the diaphragm and consequently a constriction of the lungs- the bellows of life giving air- which results in the wheezing sounds any asthma patient is familiar with.
So what should one eat as an asthma patient?
Well, the foods that are the exact opposite, mucus binding or non-mucus forming foods. These are quite simply fruits and vegetables. Make sure they are organic if possible or at least not in the list of the ?dirty dozen? i.e. the ones most contaminated with pesticides such as Apples, Mexican Melons, Grapes etc?
Trust me on this; I?m speaking from experience, you will do very well to avoid the fruits in that list when it comes to asthma. Nonetheless you?d still be much better off steering clear of those food substances labeled as mucus-forming earlier on.
Other minor factors will still come into play in regards to a natural asthma treatment, however, diet is arguably THE factor to monitor the most.
Remember what you eat affects how you breathe?and how you breathe affects how you live.
Here?s to breathing freer.
According to medical research, Asthma is an allergic inflammation of the lungs. Moreover, an asthma attack can be triggered by chemicals, air pollutants, pollens, molds, dust, animal dander, foods, exercise, and even temperature changes.
However, friends, speaking from my experiences with asthma from the age of 7 till I was about 20, the one factor I think is the most influential negatively on one?s respiratory and overall health, will be what one consumes.
This is a fact that has been in effect in several programs aimed at correcting respiratory health such as the Breath Retaining Program for Asthmatics developed by the Russian, Dr. Buteyko. Within weeks of adhering to his advice, many a chronic asthmatic has been able to give up the use of ventolin inhalers.
Now, I never had to use his program; however, in my quest to get rid of acne, I stumbled on the dietetic change that miraculously cured my asthma, halitosis and overall lethargy. Being amazed at how this change in eating habits worked for not one, but all of my health challenges, was what made me research and discover that such a program as his even exists.
?Well, what is the dietetic suggestion?? one might ask. Quite simply, it is to give up all processed foods and animal products such as meat, milk, eggs and the like from your diet-plain and simple.
Two quotes come to mind in advocating this: ?You are what you consume? and ?Let your foods be you medicine and your medicine your foods?
Now, I ask you a question: ?What is the main physical emission that occurs during an asthma attack with all the wheezing and coughs?? It is mucus.
All the foods listed above are highly mucus forming and upon digestion (if they ever do get digested that is), they leave one with an excessive lining of mucus and slime. Keep in mind that the lungs are the most important excretory organs, when you add its functioning to this fact, it becomes apparent that the consumption of these substances are really only wreaking havoc on the body.
In addition, from my own experience, DO NOT CONSUME LIQUIDS WITH YOUR MEALS AT ANY TIME. This inhibits digestion by diluting the necessary juices in your stomach designated for that purpose. As a result, it hinders the much needed expansion of the diaphragm and consequently a constriction of the lungs- the bellows of life giving air- which results in the wheezing sounds any asthma patient is familiar with.
So what should one eat as an asthma patient?
Well, the foods that are the exact opposite, mucus binding or non-mucus forming foods. These are quite simply fruits and vegetables. Make sure they are organic if possible or at least not in the list of the ?dirty dozen? i.e. the ones most contaminated with pesticides such as Apples, Mexican Melons, Grapes etc?
Trust me on this; I?m speaking from experience, you will do very well to avoid the fruits in that list when it comes to asthma. Nonetheless you?d still be much better off steering clear of those food substances labeled as mucus-forming earlier on.
Other minor factors will still come into play in regards to a natural asthma treatment, however, diet is arguably THE factor to monitor the most.
Remember what you eat affects how you breathe?and how you breathe affects how you live.
Here?s to breathing freer.
Thursday, January 1, 2009
What’s that Dark Spot – Facial Skin Care Hints for Dealing with Hyperpigmentation
Do you have dark patches of skin on your face? You may be suffering from a condition called Hyperpigmentation. Hyperpigmentation happens when your body over produces melanin in your skin. Melanin is the naturally occurring chemical that is causes your skin to brown – usually as a result of tanning. Unfortunately, Hyperpigmentation may be one of the many menopause symptoms you experience.
We usually have an indication that Hyperpigmentation may be approaching and are able to implement some facial skin care to prevent it. Freckles are a sign of hyperpigmentation. While these little freckles might not be a big deal, as we get older the freckles often darken or become bigger. Another common symptom is age spots. These age spots are usually found on the face or the hands. Both freckles and age spots are signs of sun damage.
Hyperpigmentation can happen to anyone, regardless of age or race and can be found on any part of the body. Sun damage is certainly a factor in hyperpigmentation, but there are a number of other factors that can contribute to dark, uneven spots on the skin.
Of course, genetics is a factor in hyperpigmentation. If you have fair skin, light hair and eyes, you will always have to pay special attention to keeping your skin from being damaged by the sun. But hyperpigmentation can also be caused by hormonal changes in the body, which is why it becomes more common as menopause symptoms.
During pregnancy, women may experience a form of hyperpigmentation that is called the “mask of pregnancy”. This may occur on the face or on the abdomen. Taking birth control pills will sometimes mimic pregnancy, and can cause hyperpigmentation. Often, after the pregnancy or after you stop taking birth control pills, the hyperpigmentation goes away.
As you age and go through perimenopause or begin to experience menopause symptoms, the changes in hormone levels may cause hyperpigmentation patches to occur. Unfortunately, these patches don’t disappear or even lighten on their own. There are a number of expensive facial skin care options, including dermabrasion or laser treatments that help these dark patches.
There’s another facial skin care option that could work wonders on hyperpigmentation problems. Look for products that contain hydroquinone. Hydroquinone lightens dark skin patches – it’s actually a bleaching agent. You can find products with Hydroquinone in most cosmetic lines, or you can visit a dermatologist for a medication that contains a stronger bleaching agent.
In addition to using bleaching agents, you have to be extra careful to prevent sun damage or exposure. Because your skin is already susceptible to sun damage and hyperpigmentation, you must be vigilant to always use sun block, wear hats, and generally minimize your exposure to the sun.
Hyperpigmentation can be avoided or minimized with an active approach of sun awareness, good facial skin care, and lightening agents. You’ll probably never be free of hyperpigmentation, but you can certainly lighten it to the point that it’s practically invisible.
We usually have an indication that Hyperpigmentation may be approaching and are able to implement some facial skin care to prevent it. Freckles are a sign of hyperpigmentation. While these little freckles might not be a big deal, as we get older the freckles often darken or become bigger. Another common symptom is age spots. These age spots are usually found on the face or the hands. Both freckles and age spots are signs of sun damage.
Hyperpigmentation can happen to anyone, regardless of age or race and can be found on any part of the body. Sun damage is certainly a factor in hyperpigmentation, but there are a number of other factors that can contribute to dark, uneven spots on the skin.
Of course, genetics is a factor in hyperpigmentation. If you have fair skin, light hair and eyes, you will always have to pay special attention to keeping your skin from being damaged by the sun. But hyperpigmentation can also be caused by hormonal changes in the body, which is why it becomes more common as menopause symptoms.
During pregnancy, women may experience a form of hyperpigmentation that is called the “mask of pregnancy”. This may occur on the face or on the abdomen. Taking birth control pills will sometimes mimic pregnancy, and can cause hyperpigmentation. Often, after the pregnancy or after you stop taking birth control pills, the hyperpigmentation goes away.
As you age and go through perimenopause or begin to experience menopause symptoms, the changes in hormone levels may cause hyperpigmentation patches to occur. Unfortunately, these patches don’t disappear or even lighten on their own. There are a number of expensive facial skin care options, including dermabrasion or laser treatments that help these dark patches.
There’s another facial skin care option that could work wonders on hyperpigmentation problems. Look for products that contain hydroquinone. Hydroquinone lightens dark skin patches – it’s actually a bleaching agent. You can find products with Hydroquinone in most cosmetic lines, or you can visit a dermatologist for a medication that contains a stronger bleaching agent.
In addition to using bleaching agents, you have to be extra careful to prevent sun damage or exposure. Because your skin is already susceptible to sun damage and hyperpigmentation, you must be vigilant to always use sun block, wear hats, and generally minimize your exposure to the sun.
Hyperpigmentation can be avoided or minimized with an active approach of sun awareness, good facial skin care, and lightening agents. You’ll probably never be free of hyperpigmentation, but you can certainly lighten it to the point that it’s practically invisible.
Wednesday, December 31, 2008
The Secret of Beautiful Skin
The secret of beautiful skin involves protecting it from the outside and nourishing it from the inside.
Women spend hundreds of millions of dollars on expensive miracle skincare products, but great looking skin does not have to be expensive!
The secret of beautiful skin is simply concentrating on both the inside and outside and this does not have to be expensive.
Protection from the outside
Harmful UV rays are far and away the biggest cause of skin damage and the advice when choosing a day cream is to make sure that is SPF 15.
In the evening use any cream you feel suits your skin type were all different, but don?t spend a lot of money, all you need to do is keep the skin hydrated.
There is no point in moisturizing your skin and then let the suns rays destroy it.
Everyday prevention is definitely better than cure. On the subject of cure, all the creams that claim to repair damage are simply pedalling to vanity ? They don?t.
The myth of beautiful skin
A moisturizer can keep the skin hydrated and with SPF protect it and that?s all.
Its common sense, however many women fall for the hundreds of millions of year advertising campaigns that claim to give them a quick miracle and end up disappointed.
The real secret of beautiful skin is protection from the outside and nourishment from within - Combine the two and you will have beautiful skin.
Here are some great foods to include in your diet for radiant skin.
Drink lots of water
Two liters of water a day should be drunk this helps keep the skin hydrated and flush away toxins from the body
Eat vegetables & Fruit
Eat 2 - 3 portions of vegetables for lots of nutrients for the skin,
The best ones are below, but really any vegetable or fruit is good and in terms of vegetables try and eat them raw if you can.
Sweet potatoes tomatoes and spinach
For three important antioxidants
Beta-carotene is present in sweet potatoes, lycopene in tomatoes and lutein in spinach.
They enter the skin and help reflect harmful UV rays and act as a permanent sunscreen.
Cherries, blueberries, blackberries, grapes
Contain anthocyanins an antioxidant that keeps the skin supplied with nutrients through the blood vessels that lead into the face.
Oily fish
As we all know oily fish are a great source of protein to regenerate collagen and elastin, as well as omega 3 oils, these are essential to keep the skin both subtle and hydrated.
Good sources include: Salmon, mackerel, herrings and sardines.
Crab, sardines, lean beef and wheat germ
A good source of copper, a trace element that is essential for the making of melanin, the pigment in the skin that helps to absorb harmful UV rays from the sun.
It also helps fight age spots which are the most obvious sign of skin aging.
Soya milk, lentils, bean sprouts, yogurt & wholegrain cereals
These contain plant oestrogens, which help make lubricating oils and collagen in the skin for a healthier complexion. They also repair collagen and elastin, which slow down the thinning of the skin and the formation of fine lines which most women fear!
Oats
Contain the trace element silic acid, which is used to make the spongy cells that lie between collagen and elastin fibers. This makes the skin full and plump and by consequence slows down the formation of fine lines.
Whole meal pitta, gogi berries & muesli
Pitta contains ferulic acid, berries contain vitamin c, muesli contains vitamin E. These are great antiaging vitamins
Vitamin C and e are great for fighting harmful UV rays and gogi berries have 15 times more vitamin C than an orange gram for gram.
The secret of beautiful skin is actually simple!
Protect from the outside and nourish from the inside. Forget the miracle cures follow the advice above and you will have beautiful radiant skin for life.
Women spend hundreds of millions of dollars on expensive miracle skincare products, but great looking skin does not have to be expensive!
The secret of beautiful skin is simply concentrating on both the inside and outside and this does not have to be expensive.
Protection from the outside
Harmful UV rays are far and away the biggest cause of skin damage and the advice when choosing a day cream is to make sure that is SPF 15.
In the evening use any cream you feel suits your skin type were all different, but don?t spend a lot of money, all you need to do is keep the skin hydrated.
There is no point in moisturizing your skin and then let the suns rays destroy it.
Everyday prevention is definitely better than cure. On the subject of cure, all the creams that claim to repair damage are simply pedalling to vanity ? They don?t.
The myth of beautiful skin
A moisturizer can keep the skin hydrated and with SPF protect it and that?s all.
Its common sense, however many women fall for the hundreds of millions of year advertising campaigns that claim to give them a quick miracle and end up disappointed.
The real secret of beautiful skin is protection from the outside and nourishment from within - Combine the two and you will have beautiful skin.
Here are some great foods to include in your diet for radiant skin.
Drink lots of water
Two liters of water a day should be drunk this helps keep the skin hydrated and flush away toxins from the body
Eat vegetables & Fruit
Eat 2 - 3 portions of vegetables for lots of nutrients for the skin,
The best ones are below, but really any vegetable or fruit is good and in terms of vegetables try and eat them raw if you can.
Sweet potatoes tomatoes and spinach
For three important antioxidants
Beta-carotene is present in sweet potatoes, lycopene in tomatoes and lutein in spinach.
They enter the skin and help reflect harmful UV rays and act as a permanent sunscreen.
Cherries, blueberries, blackberries, grapes
Contain anthocyanins an antioxidant that keeps the skin supplied with nutrients through the blood vessels that lead into the face.
Oily fish
As we all know oily fish are a great source of protein to regenerate collagen and elastin, as well as omega 3 oils, these are essential to keep the skin both subtle and hydrated.
Good sources include: Salmon, mackerel, herrings and sardines.
Crab, sardines, lean beef and wheat germ
A good source of copper, a trace element that is essential for the making of melanin, the pigment in the skin that helps to absorb harmful UV rays from the sun.
It also helps fight age spots which are the most obvious sign of skin aging.
Soya milk, lentils, bean sprouts, yogurt & wholegrain cereals
These contain plant oestrogens, which help make lubricating oils and collagen in the skin for a healthier complexion. They also repair collagen and elastin, which slow down the thinning of the skin and the formation of fine lines which most women fear!
Oats
Contain the trace element silic acid, which is used to make the spongy cells that lie between collagen and elastin fibers. This makes the skin full and plump and by consequence slows down the formation of fine lines.
Whole meal pitta, gogi berries & muesli
Pitta contains ferulic acid, berries contain vitamin c, muesli contains vitamin E. These are great antiaging vitamins
Vitamin C and e are great for fighting harmful UV rays and gogi berries have 15 times more vitamin C than an orange gram for gram.
The secret of beautiful skin is actually simple!
Protect from the outside and nourish from the inside. Forget the miracle cures follow the advice above and you will have beautiful radiant skin for life.
Tuesday, December 30, 2008
Pigmentation Disorders
Skin color is determined by a combination of pigments produced in the skin and natural colors of the external layers of the same. Without pigmentation, skin color would have a pale white with various ranges of pink, due to blood flowing through it. The main pigment of the skin is melanin, a dark brown pigment formed by cells (melanocytes) distributed among the other cells in the upper layer of skin, the epidermis.
The hypopigmentation, an abnormally low amount of pigment, it is generally restricted to small areas of skin. Usually stems from an inflammatory process prior to the skin or in exceptional cases may represent an inherited disease.
When skin is exposed to solar radiation increases the production of melanin and this produces the tan. An increase in the amount of melanin (hyperpigmentation) may be a response to hormonal abnormalities, such as those that may take place in Addison's disease during pregnancy or with use of oral contraceptives. The skin may also darken in diseases such as hemochromatosis or haemosiderosis, or as a response to many medications that are applied to the skin, are ingested or injected.
Albinism
The albinism is a rare hereditary disease in which no melanin is formed.
People with albinism (albino) may have white hair, pale skin and pink eyes. Often, they can also present abnormal vision and involuntary eye movements (nystagmus).
Because the melanin protects the skin from the sun, albinos are very prone to sunburn and, consequently, to skin cancers. However, they can minimize these problems away from direct sunlight, using sunglasses and apply a sunscreen with a protection factor (SPF) increased from 15 in the parts of your skin.
Vitiligo
Lack of pigmentation in the skin.
Vitiligo
The vitiligo is a disease in which the loss of melanocytes produce smooth and white plates in the skin.
In some people are only one or two well-defined plaques, in other, the sheets of vitiligo appear on a large part of the body. The changes are more showy in people of darker pigmentation. As with albinism, non-pigmented skin is extremely sensitive to sunburn. The areas of skin affected by vitiligo also produce white hair, because hair follicles lose melanocytes.
The vitiligo may occur after a rare physical trauma, especially trauma to the head, and tends to concur with certain diseases, such as Addison's disease, diabetes, pernicious anemia and thyroid disease. The vitiligo can be psychologically devastating because of the great disfigurement that occurs after the change in pigmentation.
Pityriasis versicolor is a fungal infection of the skin that may resemble the vitiligo, although sometimes produces hyperpigmentation.
Treatment
There is no known cure for vitiligo. Small areas can hide with different dyes that do not soiled clothes and whose effects last for several days. On occasion, treatment with psoralens (photosensitive drugs) combined with ultraviolet A (PUVA) is effective, but treatment requires time and must be continued indefinitely. The sunscreens and protective against exposure to sunlight can prevent burns.
Loss of pigment after skin injury
Sometimes the skin loses its pigment once they are cured some skin diseases such as blisters, sores, burns and skin infections. In this case the skin is not as white as in the vitiligo and with the passage of time may reappear pigmentation cosmetics can hide this kind of stain skin.
Melasma
The melasma appears on the face (usually on the forehead, cheeks, temples and jaws) as plates hyperpigmented dark brown, often well-delineated on both sides of the face so symmetrical.
The melasma appears mostly during pregnancy (pregnancy mask) but may also occur in women taking oral contraceptives. Darkening, usually disappears shortly after birth or the suspension of oral contraceptives.
People suffering from melasma can use sunscreens on the plates dark and avoid sun exposure to prevent the worsening of the disease. If applied regularly for a long time, some ointments that are sold without a prescription can clarify the plates dark.
Monday, December 29, 2008
melanin: aging of the skin and skin cancer
“Ultraviolet (UV) radiation is responsible for 90% of the visible signs of aging on the skin of whites,” says Dr. Michael J. Martin, former Assistant Clinical Professor in the Dept. of Epidemiology and Biostatistics at University of California, San Francisco.
Blacks’ skin, however, ages much slower.
Why are most dark-skinned blacks protected from harmful UV rays? Because compared to whites, blacks possess more melanin, the pigment that gives skin its color.
Melanin
Melanin offers protection against UV rays for blacks and other dark-skinned people. Conversely, fair-skinned people are much less protected and more susceptible to skin cancer. Furthermore, albinos’ skin offers no protection.
Although blacks’ skin produces more melanin than whites’, all skin has the same number of melanocytes, the cells that manufacture the melanin.
Melanocytes manufacture melanin from an amino acid, tyrosin, with the help of an enzyme, tyrosinase. In the bottom layer of the epidermis above the dermis, UV light stimulates the production of melanin in the form of insoluble melanosomes. These surround the epidermal cells, which move up to the surface of the skin. The result is a tan.
Blacks’ skin produce more melanin, even in the absence of sunlight, and their type of melanin, eumelanin, is more effective at blocking solar rays. However, white skin produces melanin only in the presence of sunlight and after the UV rays have penetrated the lower portion of the epidermis and have caused skin damage.
“Melanin also functions as an excellent free radical scavenger. It affects the delicately designed lipids that hold moisture in the stratum corneum (the outermost layer of the epidermis). If the skin loses its moisture, it becomes rigid and cracks,” says Sergio Nacht, PhD., Senior Vice-President of Enhanced Derm Technologies, Inc. in Redwood City.
UV Radiation and Skin
UV-A has the longest wavelength, is not filtered by the ozone and passes through glass. It reaches the earth all year long and the amount is comparatively stable. It can penetrate the skin down to the dermis, beneath the four layers of epidermis. It is responsible for most of the visible signs of aging, due to damage to collagen and elastic fibers of the connective tissue of the dermis.
UV-A radiation also plays a role in the development of sunburns and skin cancer. Tanning salon lamps emit a large amount of UV-A rays to generate tans, so the American Academy of Dermatology does not recommend their use.
UV-B radiation, which is partially filtered by the ozone, penetrates the skin to the bottom layer of the epidermis where the basal cells are produced. UV-B can break the molecular bonds, disturbing the dividing cells and altering their structure. Compared with UV-A, UV-B is responsible for most of DNAs damage. It also causes most sunburns. During a sunburn the reddening of the skin, erythema, is caused by dilation of capillaries.
More UV-B is present during summer months between 10 a.m. and 4 p.m. and at latitudes closer to the equator. Furthermore, at high altitudes the air is thinner and cleaner, so UV-B radiation is more abundant.
UV-C, which is generally filtered by the ozone, has the shortest wavelength and the most energy, or intensity. It can sterilize hospital equipment and kill bacteria.
In addition, UV light that reaches the earth is scattered in all directions, and up to 85% is reflected from surfaces.
The Theory of Melanin for Environmental Adaptation
Originally, people of a particular race resided in a particular area. As time went on, their skin adapted to the environment. For instance, people who lived geographically close to the equator had darker skin, and people who lived far from the equator had lighter skin.
In Scotland, which lies at a northern latitude, descendants of the Britons have white skin. When their skin is exposed to the meager sunlight, the scant amount of melanin their skin produces is unable to block the sunlight. Therefore, their bodies are able to make Vitamin D with the help of sunlight. Vitamin D, a vitamin found in fish oil, is necessary to prevent rickets, a bone disease caused by too little calcium.
In contrast, in Africa, which is near the equator, blacks require intense sunlight to penetrate their dark skin to make Vitamin D. This is all well and good. However, when blacks lived in England during the Industrial Revolution, they were the first to develop symptoms of rickets, such as retarded growth, bowed legs and fractures because not enough sunlight was available.
Fortunately, in 1930, Vitamin D was discovered and dispensed as a supplement to add to the diet.
On the other hand, the skin of whites in Australia are in complete opposition to their climate. Consequently, intense UV radiation has been the major cause of skin damage and skin cancer Down Under.
Sunday, December 28, 2008
Melanin Production Discovered In Fat Tissue May Protect Some Individuals Against Chronic Diseases Associated With Obesity
A two-year study conducted by researchers at George Mason University, INOVA Fairfax Hospital and the National Cancer Institute may open the door to new therapies for combating chronic diseases associated with obesity, a condition that affected more than 33 percent of American adults in 2005-06 according to the Centers for Disease Control and Prevention.
While analyzing samples taken from morbidly obese patients undergoing weight loss surgery, the researchers discovered that substantial quantities of melanin—a pigment that gives the skin, the hair and the iris of the eye their natural color—were being produced in the study participants’ fat tissue.
Ancha Baranova, assistant professor in George Mason University’s Department of Molecular and Microbiology and the paper’s lead author, explains that melanin production has never before been identified in fat tissue. She believes that the antioxidant, which has been shown to have anti-inflammatory properties, could be the body’s natural defense against obesity-related conditions such as type 2 diabetes, coronary heart disease, fatty liver disease, polycystic ovary syndrome and some cancers.
“Stockpiling extra calories is difficult even for specialized fat cells; having too much lipid molecules takes its toll on the fat cells, producing oxidative stress,” says Baranova. “It’s not unthinkable that these cells would adapt and produce melanin as a form of self-protection. As a side benefit, melanin may suppress inflammatory properties of the extra pounds of the fat.”
Baranova notes that a larger study is needed in order to confirm the role that the body’s production of this compound plays in fat tissue. However, the discovery suggests that melanin-based therapies may one day be used to reduce the incidence of chronic diseases among the morbidly obese.
“This opens an entirely new avenue for medical interventions because the process of biosynthesis of melanin is relatively easy to meddle with,” says Baranova. “We hope that this study will spur the development of preventive medications aimed at curtailing devastating metabolic complications in obese and overweight populations.”
The paper was co-authored by Manpreet Randhawa, Tom Huff and Vikas Chandhoke of George Mason University; Julio C. Valencia and Vincent J. Hearing of the National Cancer Institute; and Zobair Younossi of INOVA Fairfax Hospital. The study was funded by the Thomas F. Jeffress and Kate Miller Jeffress Memorial Trust and by the Intramural Research Program of the National Cancer Institute at the U.S. National Institutes of Health.
While analyzing samples taken from morbidly obese patients undergoing weight loss surgery, the researchers discovered that substantial quantities of melanin—a pigment that gives the skin, the hair and the iris of the eye their natural color—were being produced in the study participants’ fat tissue.
Ancha Baranova, assistant professor in George Mason University’s Department of Molecular and Microbiology and the paper’s lead author, explains that melanin production has never before been identified in fat tissue. She believes that the antioxidant, which has been shown to have anti-inflammatory properties, could be the body’s natural defense against obesity-related conditions such as type 2 diabetes, coronary heart disease, fatty liver disease, polycystic ovary syndrome and some cancers.
“Stockpiling extra calories is difficult even for specialized fat cells; having too much lipid molecules takes its toll on the fat cells, producing oxidative stress,” says Baranova. “It’s not unthinkable that these cells would adapt and produce melanin as a form of self-protection. As a side benefit, melanin may suppress inflammatory properties of the extra pounds of the fat.”
Baranova notes that a larger study is needed in order to confirm the role that the body’s production of this compound plays in fat tissue. However, the discovery suggests that melanin-based therapies may one day be used to reduce the incidence of chronic diseases among the morbidly obese.
“This opens an entirely new avenue for medical interventions because the process of biosynthesis of melanin is relatively easy to meddle with,” says Baranova. “We hope that this study will spur the development of preventive medications aimed at curtailing devastating metabolic complications in obese and overweight populations.”
The paper was co-authored by Manpreet Randhawa, Tom Huff and Vikas Chandhoke of George Mason University; Julio C. Valencia and Vincent J. Hearing of the National Cancer Institute; and Zobair Younossi of INOVA Fairfax Hospital. The study was funded by the Thomas F. Jeffress and Kate Miller Jeffress Memorial Trust and by the Intramural Research Program of the National Cancer Institute at the U.S. National Institutes of Health.
Subscribe to:
Posts (Atom)
