………CLICK & SEE The two doctors note that no matter how the story spins from the denizens of the anti-fat camp, one piece of their advice remains staunchly constant: “You should sharply limit your intake of saturated fats.” But will saturated fats really increase your risk of heart disease and raise your cholesterol? In a word, no. In fact, humans need them, and here are just a few reasons why:
1) Improved cardiovascular risk factors
Saturated fat plays a key role in cardiovascular health. The addition of saturated fat to the diet reduces the levels of a substance called lipoprotein (a) that correlates strongly with risk for heart disease. Research has shown that when women diet, those eating the greatest percentage of the total fat in their diets as saturated fat, lose the most weight.
2) Stronger bones
Saturated fat is required for calcium to be effectively incorporated into bone. According to one of the foremost research experts in dietary fats and human health, Dr. Mary Enig, Ph.D., there’s a case to be made for having as much as 50 percent of the fats in your diet as saturated fats for this reason.
3) Improved liver health
Saturated fat has been shown to protect the liver from alcohol and medications, including acetaminophen and other drugs commonly used for pain and arthritis.
4) Healthy lungs
For proper function, the airspaces of the lungs have to be coated with a thin layer of lung surfactant. The fat content of lung surfactant is 100 percent saturated fatty acids. Replacement of these critical fats by other types of fat makes faulty surfactant and potentially causes breathing difficulties.
5) Healthy brain
Your brain is mainly made of fat and cholesterol. The lion’s share of the fatty acids in the brain are actually saturated. A diet that skimps on healthy saturated fats robs your brain of the raw materials it needs to function optimally.
6) Proper nerve signaling
Certain saturated fats, particularly those found in butter, lard, coconut oil, and palm oil, function directly as signaling messengers that influence metabolism, including such critical jobs as the appropriate release of insulin.
7) Strong immune system Saturated fats found in butter and coconut oil (myristic acid and lauric acid) play key roles in immune health. Loss of sufficient saturated fatty acids in white blood cells hampers their ability to recognize and destroy foreign invaders, such as viruses, bacteria, and fungi.
It is recomended to use olive oil, but recommend against the use of canola oil, despite its widely perceived healthful reputation. In order to be fit for human consumption, rapeseed oil (which is canola oil) requires significant processing to remove its objectionable taste and smell. Processing damages the oil, creating trans fats. Also, the oil is sensitive to heat, so if used at all, it should never be used to fry foods.
90 percent of melanoma growths are curable if caught early and removed; untreated, survival rates are worse than for lung cancer. When it comes to melanoma, vanity may be a virtue. The most direct method for detecting this deadly skin cancer is to face a mirror, clothes off, and check for suspicious moles from head to toe.
Moles at least the size of a pencil eraser are of greatest concern, since smaller spots are rarely cancerous, said Dr. David Polsky, a dermatologist at New York University School of Medicine. “To get hung up on the real small stuff is missing the bigger picture,” he said.
But changes to the color, size or shape of any mole may be an early indication of trouble, especially for someone who has a family history of melanoma or lots of unusual moles.
And while sun-drenched areas on the head or legs are likely sites for other forms of skin cancer, melanoma can develop anywhere on the body.
About 90 percent of melanoma growths are curable if caught early and surgically removed, putting the impetus on people at home to look for cancerous spots. When growths are left unchecked, the chances of surviving the disease for long are worse than for lung or colon cancer.
But in the push to make everyone better skin cancer detectives, tough obstacles — and questions — remain.
To locate the first signs of danger requires studious attention, and few people seem willing to bother. Nine to 18 percent of Americans regularly examine their own skin for melanoma, surveys show. Dermatologists, typically the first responders for skin cancer, may be quicker to schedule a Botox appointment than to verify a patient’s concern about changing moles, research shows.
Furthermore, there is no proof so far that such screening will ultimately help save any of the estimated 8,400 lives lost to melanoma each year in the United States.
“It’s still an open question,” said Dr. Marianne Berwick, a melanoma specialist at the University of New Mexico who led the largest and most rigorous investigation so far on skin self-exams. That study found that fastidious skin watchers had no better chance of surviving cancer after five years than those who did not check for moles. Two decades of follow-up have failed to show any improvement, she said.
The stakes are high. The chance of surviving melanoma turns sharply for the worse once the tumors have spread beyond their original site on the skin, making it critical to find changes early.
“There’s no really good proven therapy for advanced disease,” said Dr. Martin Weinstock, a professor of dermatology at Brown University Medical School.
Researchers have tested various treatments, including chemotherapy, radiation and the drug interferon, which show only modest effects against the later stages of melanoma. Newer drugs and vaccines are undergoing testing now. But the main reasons that melanoma survival rates have improved at all over the past 30 years are earlier detection and better screening.
Yet in the rush to get the cancer out fast, experts say they are noticing a relaxing of standards in diagnosing melanoma. Doctors these days are more likely to take out any suspicious mole out of fear of missing a cancerous one, and possibly getting sued for a missed diagnosis, these experts say.
A separate study conducted by Dr. Berwick found that 40 percent of the melanomas detected in 1988 would not have been considered cancerous 10 years earlier.
This could mean that surgeons are removing a fair share of lesions that aren’t melanoma, though even pathologists examining the same skin biopsy samples often disagree on whether the diagnosis is melanoma. At the same time, doctors who aren’t trained in spotting may be leaving harder-to-detect, slow-growing tumors behind.
“Unless you’re specifically trained as a clinician to do a skin exam, you can’t necessarily do a good one,” said Dr. Cockburn of U.S.C.
Nonetheless, like many doctors, Dr. Cockburn still believes that the odds can improve by teaching “your average Joe” to look for melanoma spots, a view shared by the American Cancer Society and other medical groups.
Enlisting the help of a spouse or partner may make it easier to track evolving moles on the body. A camera may also help. One study found that people who took photos of their skin improved their chances of detecting possible melanomas by 12 percent.
The only downside to home screening is in creating a nation of skin cancer hypochondriacs who further tilt the balance to unnecessary operations, experts warn.
But in this age of plastic surgery, the chance to overcome a deadly, but treatable, cancer is worth the risk, Dr. Cockburn said. “With the amount of stuff that gets chopped off these days,” he said, “I don’t really think there’s a problem.”
Sources: The New York Times:Oct.19.’08
Leaves of three, let them be.â€ No doubt youâ€™ve heard this warning about poison ivy, a weedy plant that each year causes more than 350,000 reported cases of human contact dermatitis, and probably many thousands more unreported cases.
Anecdotes from doctorâ€™s offices indicate that this year is shaping up as a particularly nasty one for poison ivy, or Toxicodendron radicans, and evidence suggests that increased concentrations of carbon dioxide in the air have contributed to bumper crops with a more potent toxin.
But the rising risk of developing an extremely itchy, blistering rash from poison ivy is only one of the recent changes in human exposures to toxic or harmful plants.
Many homes and gardens play host to an increasing number of hazardous plants, and children are most often at risk. In 2003, according to an authoritative new book, poison control centers nationwide received more than 57,000 calls relating to exposure to potentially harmful plants, and 85 percent of them involved children under age 6. Most, however, were considered simply exposures; either no toxin was ingested or the amount consumed was too small to be harmful.
The book, â€œHandbook of Poisonous and Injurious Plantsâ€ by Dr. Lewis S. Nelson, Dr. Richard D. Shih and Michael J. Balick, was produced under the auspices of the New York Botanical Garden, where Dr. Balick is director of the Institute of Economic Botany. While its primary mission is to help health care professionals identify and treat plant-caused injuries, this lavishly illustrated book can be a helpful guide to ordinary people. It highlights hundreds of troublesome plants, providing photographs and written descriptions, common names, geographic distributions, toxic parts and toxins, effects on the body and information on medical management.
I was stunned to realize just how many of these potentially dangerous plants were in my own home and garden, including aloe, elephantâ€™s ear, jade, peace lily (Spathiphyllum), philodendron and dumbcane (Dieffenbacchia), as well as foxglove (Digitalis purpurea), hellebore, vinca, rhododendron and chrysanthemum. I count my blessings that none of my children or grandchildren tried to chomp on one of them.
Of course, plant-based poisons have an important role to play, especially in discouraging predators. And through the ages and into modern times, many have served important medicinal roles. Vinca, for example, was the original source of the anticancer drug vincristine, and foxglove gave us the valuable heart stimulant digitalis.
Deer, which have become a horrific horticultural nuisance in the Northeast, somehow know to avoid dining on several of the toxic plants, like vinca and foxglove, enabling gardeners to plant them in unfenced areas. If only our children were equally knowledgeable.
Dr. Nelson, of New York University School of Medicine and the New York City Poison Control Center, said the problem often began with the fact that many toxic plants are beautiful and colorful, prompting people to pick them to adorn their homes and gardens. But their very attractiveness is what creates a hazard for small children, who may be tempted to put toxic berries, flowers or foliage in their mouths.
A second risk involves adults, who pick what they think are edible or medicinal plants but mistakenly choose a toxic look-alike. In a recent incident cited by Dr. Nelson, a group of people picked what they thought were wild leeks, or ramps, cooked and ate them. What they really consumed was the cardiac toxin from young false hellebore. Fortunately, they survived the resulting heart rhythm disturbance.
Other cases have involved people who picked foxglove before it flowered, thinking it was a helpful herb that could be made into a medicinal tea. And sometimes herbal teas that should be safe are not because they were accidentally contaminated by a toxic plant. Thus, it is best to stick to well-known commercial brands packaged in the United States.
While ingested plant poisons are the most common hazard for small children, for adults and older children the usual sources of misery are plants that create problems on physical contact, like poison ivy. I asked Dr. Nelson what people do wrong after coming into contact with poison ivy, and the answer was simple: â€œThey donâ€™t wash their hands quickly and thoroughly enough. If you wash off the toxin with soap and water within 10 or 15 minutes, itâ€™s unlikely to cause a reaction.â€
This can be a particular problem for outdoor sports enthusiasts, landscapers and other outdoor workers who may not notice their contact with the plant or may not have a means of quickly washing away the toxin, called urushiol. Even those who do wash may fail to scrub off the urushiol that gets under fingernails and then spread it to other parts of the body, Dr. Nelson said.
Over the course of hours or days, urushiol causes a slowly developing rash characterized by pain, itchiness, redness, swelling and blisters. Contrary to what many people think, the rash itself does not spread. Rather, people spread the toxin around their bodies through scratching and contact with contaminated clothing.
Other Problem Plants
Poison ivy is hardly the only source of urushiol, a class of toxins with varying potencies. It is also found in the skin of mangoes, as I sadly learned after eating a mango off the rind. It was still winter when I called my dermatologist and said, â€œIf I didnâ€™t know better, Iâ€™d say I had poison ivy of the mouth.â€ His immediate response: â€œYouâ€™ve been eating mangoes.â€
Why, I wondered, had this not happened years ago? The answer was that after repeated exposures to urushiol that caused no reaction, I had become sensitized to the allergen and thereafter any contact with it could cause the same miserable reaction. Dr. Nelson said 85 percent of the population has the potential to develop sensitivity to urushiol. So if you think you can safely traipse through poison ivy, think again. Sooner or later you are likely to suffer as I did.
Treatment of a poison ivy rash typically involves relieving the itch with calamine lotion and taking an oral antihistamine or, in more serious cases, a corticosteroid.
Another common source of contact dermatitis involves the stinging nettle, a weedy plant that also seems to be thriving in our carbon dioxide-enriched environment, Dr. Balick said. These plants are a source of mechanical irritants. They have fragile hypodermic-like tubules containing a mixture of irritant chemicals that are injected when bare skin brushes against the plant and stinging hairs from the stems and leaves break the skin. Unlike poison ivy, the burning, itchy rash caused by stinging nettles is short-lived.
Still other problem plants contain chemical irritants, like capsaicin from chili peppers. This chemical is a mucous membrane irritant that causes the release of a substance that stimulates pain fibers and inflammation. This is especially painful when contaminated fingers transfer the chemical to the eyes or genitalia. To relieve the discomfort, it takes thorough and repeated washing, an analgesic to relieve the pain and, in some cases, anti-inflammatory medication.
Some plants, including agave, snow-on-the-mountain, crown-of-thorns, marsh marigold and buttercup, contain an irritant sap or latex, which can cause a chemical burn on the skin.
Finally, there are plants that contain phototoxins â€” substances that increase the sensitivity of the skin to ultraviolet light and can result in a blistering sunburn. Among these are yarrow, rue and Queen Anneâ€™s lace.
T.V. Jayan explains, with the help of a new study: It’s often been said that there is no engineer quite like Mother Nature. A living organism ” with all its parts that fit in so smoothly is after all an engineering marvel. But this near-perfect manufacturing skill of Nature has often fanned the debate on whether life was created, or evolved.
If the advocates of creationism are ready to swallow, however grudgingly, the theory that life originated from the amoeba eons ago, science has not been able to give convincing answers to a number of sub-questions. How does, for instance, a tiny, fragile fertilised egg grow into a body of full-blown organs without any â€œexternalâ€ guidance? Why are the shapes of organs in a human being as they are? Why are our legs longer than our arms?
Ardent proponents of evolutionary biology, however, may no longer have to fumble for answers to many such questions. A team of scientists from the Skirball Institute of Biomolecular Medicine, affiliated to the New York University School of Medicine, recently proved that logic could explain some of these difficult questions. Led by Deborah Yelon, the scientists unravelled the factors governing the complex process of the formation of the heart, which is a simple tube in early development, growing into a four-chambered, intricate organ with a characteristic pear shape. The researchers published their study in the February 20 issue of PLoS (Public Library of Science) Biology.
The heart, like many other organs, undergoes dramatic changes in its three-dimensional form as the embryo develops and functional demands intensify. Before it becomes a multi-chambered organ, it exists as a simple tube made up of myocardium (muscle) lined by endocardium (endothelium). As this thin-walled tube bulges outward, the chambers emerge and eventually acquire the characteristic dimensions of curvature and thickness.
In an article in Current Biology (September 2005), Sheffield University scientist David Strutt wrote that in order to control the shape and size of an organ, it is necessary that the dimensions be measured as the organ grows, and growth stops in each axis at the appropriate time.
But how this is achieved largely remains a mystery.
Developing organs acquire a specific three-dimensional form that ensures their normal functioning. The unique shape of the heart in higher-order animals, too, is critical for proper functioning. It is composed of a series of chambers that rhythmically drive blood circulation. Each of the chambers is designed for its optimal functional capacity. The organ, which commences beating from approximately 21 days of conception, is responsible for pumping blood via blood vessels through repeated, rhythmic contractions. In the process, it picks up carbon dioxide from the blood and drops it off in the lungs in exchange for oxygen which is in turn circulated through the blood.
Organs acquire their characteristic shapes not simply as a consequence of the accumulation of cells that profusely divide and multipl Shape is also a physical process during which tissues are pressed, pulled and moved, the scientists said.
In the experiments using transgenic (containing genes transferred from another species) zebra fish in which individual cardiac cells can be watched, Deborah Yelon, her student Heidi Auman and others demonstrated that cells change size and shape, enlarging and elongating to form bulges in the heart tube and eventually the chambers. The big question was whether the function of the heart â€” that is, blood flow â€” too influences cell shape.
Their studies using zebra fish genetically modified so that each fish has a functional defect â€” helped them to find out that both blood flow and contraction of the cardiac tissues play a role in shaping cardiac cells. The unique tools the researchers used helped to clearly show that blood flow affects form. Further, they could define this at the cellular level.
The contribution of individual cell morphology to the overall shape was not previously shown, particularly in relation to the impact on chamber morphogenesis (formation and shape), said Deepak Srivastava, director of the Gladstone Institute of Cardiovascular Disease, University of California, San Francisco.
â€œThis is an important advance as although it has long been thought that blood flow does affect morphogenesis, the two have been difficult to isolate in a cause-and-effect manner,â€ Srivastava told KnowHow.
Moreover, the work is more rigorous and detailed than previous such exercises, he said.
However, Larry Taber, professor of biomedical engineering at Washington University, feels that the researchers are missing some key points. For example, he says, they talk about curvature (of the heart chambers) but never explicitly discuss looping, which causes the greatest changes during heart development. Looping, it may be mentioned, involves the bending and twisting of the heart tube to create asymmetry of the chambers as is required for optimal functioning.
There are a lot of misconceptions about looping among developmental biologists, including some propagated in this paper, Taber, who has been studying heart formation in chicks for a couple of decades, told KnowHow.
He, however, said that the Skirball teamâ€™s conclusion that contraction and blood flow are important for chamber expansion seems plausible. He also said that cell shape changes can cause curvature changes as well. What he disagrees with is their implication that contraction and blood flow regulate looping.
The use of zebra fish with minor induced genetic defects helped the Skirball Institute scientists to show that slight abnormalities in cell morphology may lead to substantial changes in the shape and functioning of the cardiac chambers. This could probably explain aberrations observed in some types of heart disease.