Teenagers' odds of developing moderate to severe acne, may largely depend on whether their parents had the problem, suggests a new study.
Most teens have occasional acne breakouts with hormonal shifts of adolescence, especially the increase in testosterone, the main cause. But some teens and adults, develop more-comprehensive acne that requires treatment with appropriate prescriptions, or oral medications such as antibiotics or Isotretinoin, a synthetic form of vitamin A.
It has been unclear why some teenagers are prone to more severe acne.
The new findings from a study of 1,000 Iranian high school students, suggest that family history can be key.
The researchers found that 14 percent of the students had moderate to severe acne, with the prevalence varies considerably, based on family history. Of teenagers who have parents or siblings have had moderate to severe acne, 20 percent had the same problem.
In comparison, the price was 10 percent among adolescents with no such family history, researchers report in the Journal of Investigative Dermatology.
The findings point to the importance of genetics in whether a teenager will have more severe acne, according to senior researcher Dr. Christos C. Zouboulis, in Dessau Medical Center in Germany.
"Therefore, children with parents who have experienced severe acne must be followed up regularly and treated earlier, when acne lesions occur," he told Reuters Health in an e-mail.
And mothers' history may be particularly important, Zouboulis and his colleagues found.
Mom's acne tripled teen risk
Teens whose mothers had moderate to severe acne were three times as likely to develop problems as their peers were. When fathers had skin condition, the children's risk increased twofold.
This, according to the researchers, increases the chance that a genetic characteristic associated with the X-chromosome plays role. (All inherits an X chromosome from their mother, while fathers contributes an X chromosome of female children only.)
Besides family history, there were other suspects in the high school students' acne risk, Zouboulis and his colleagues found.
Teens with oily skin, for example, were more likely than those with "normal" skin to have moderate to severe acne. And for girls, the problem was more likely to flare up shortly before their menstruation.
There was also evidence of a higher risk among teens who often ate greasy or sugary foods.
Most previous studies have suggested that certain foods play little or no role in acne development. But, said Zouboulis, some more-recent research suggests that diet may have an effect on acne severity.
But, he added, it remains unclear which foods or food components may be involved.
Friday, September 25, 2009
Friday, September 18, 2009
The real cause of obesity [2]
The genes that control food intake and metabolism act to keep weight in a stable range by creating a biological force that resists weight change in either direction. When weight is gained, hunger is reduced. When weight is lost, the unconscious drive to eat is stimulated and acts to return weight to the starting point. Moreover, the greater the amount of weight that is lost, the greater the sense of hunger that develops. Thus, when the obese lose large amounts of weight by conscious effort, their bodies fight back even more strongly by increasing hunger and reducing energy expenditure. If you think it is hard to lose 10 to 20 pounds (and it is), try to imagine what it would feel like to lose many tens or even hundreds of pounds.
Anyone who doubts the power of this biologic system should study the case of a young boy in England a few years back. He had a mutation in a critical gene, the one that produces the hormone leptin. Leptin is made by fat tissue and sends a signal informing the brain that there are adequate stores of energy. When leptin drops, appetite increases. Because of a genetic error, this boy could not make this hormone, which left him ravenously hungry all of the time. At age 4 he ate 1,125 calories at a single meal—about half of what a normal adult eats in an entire day. As a result he already weighed 90 pounds and was well on his way to developing diabetes. At the time, his similarly affected cousin was 8 and weighed 200 pounds. After a few leptin injections, the boy's calorie intake dropped to 180 calories per meal, and by the time he was 6 his weight had dropped into the normal range. Nothing changed except the hormone levels: his parents weren't more or less permissive, his snacks did not switch from processed to organic, his willpower was not bolstered. Rather this boy was a victim of a malfunctioning weight-regulating system that led to an uncontrollable drive to eat. This examples illustrates that feeding behavior is a basic drive, similar to thirst and other life-sustaining drives. The key role of leptin and other molecules to control feeding behavior undercuts the common misconception that food intake is largely under voluntary control.
While mutations in the leptin gene like the cases described above are rare, nearly 10 percent of morbidly obese individuals carry defects in genes that regulate food intake, metabolism, and body weight. The evidence further indicates that the rest of the obese population carries genetic alterations in other, as yet unidentified, single genes or combinations of genes (polygenes) interacting with environmental factors.
So if you are thin, it might be more appropriate for you to thank your own "lean" genes and refrain from stigmatizing the obese. A broad acceptance of the biologic basis of obesity would not only be fair and right, but would also allow us to collectively focus on what is most important—one's health rather than one's weight. There is no evidence that obese individuals need to "normalize" their weight to reap health benefits. In fact, it is not even clear whether there are enduring health benefits to weight loss among obese individuals who do not suffer from diabetes, heart disease, hypertension, or liver disease. What is known is that the obese who do suffer from these conditions receive a disproportionately large benefit from even modest weight loss, which together with exercise and a heart-healthy diet can go a long way toward improving health.
While research into the biologic system that controls weight is moving toward the development of effective therapies for obesity, we are not there yet. In the meantime we must change our attitudes toward the obese and focus less on appearance and more on health. In their efforts to lose weight they are fighting against their biology. But they also are fighting against a society that wrongly believes that obesity is a personal failing.
Anyone who doubts the power of this biologic system should study the case of a young boy in England a few years back. He had a mutation in a critical gene, the one that produces the hormone leptin. Leptin is made by fat tissue and sends a signal informing the brain that there are adequate stores of energy. When leptin drops, appetite increases. Because of a genetic error, this boy could not make this hormone, which left him ravenously hungry all of the time. At age 4 he ate 1,125 calories at a single meal—about half of what a normal adult eats in an entire day. As a result he already weighed 90 pounds and was well on his way to developing diabetes. At the time, his similarly affected cousin was 8 and weighed 200 pounds. After a few leptin injections, the boy's calorie intake dropped to 180 calories per meal, and by the time he was 6 his weight had dropped into the normal range. Nothing changed except the hormone levels: his parents weren't more or less permissive, his snacks did not switch from processed to organic, his willpower was not bolstered. Rather this boy was a victim of a malfunctioning weight-regulating system that led to an uncontrollable drive to eat. This examples illustrates that feeding behavior is a basic drive, similar to thirst and other life-sustaining drives. The key role of leptin and other molecules to control feeding behavior undercuts the common misconception that food intake is largely under voluntary control.
While mutations in the leptin gene like the cases described above are rare, nearly 10 percent of morbidly obese individuals carry defects in genes that regulate food intake, metabolism, and body weight. The evidence further indicates that the rest of the obese population carries genetic alterations in other, as yet unidentified, single genes or combinations of genes (polygenes) interacting with environmental factors.
So if you are thin, it might be more appropriate for you to thank your own "lean" genes and refrain from stigmatizing the obese. A broad acceptance of the biologic basis of obesity would not only be fair and right, but would also allow us to collectively focus on what is most important—one's health rather than one's weight. There is no evidence that obese individuals need to "normalize" their weight to reap health benefits. In fact, it is not even clear whether there are enduring health benefits to weight loss among obese individuals who do not suffer from diabetes, heart disease, hypertension, or liver disease. What is known is that the obese who do suffer from these conditions receive a disproportionately large benefit from even modest weight loss, which together with exercise and a heart-healthy diet can go a long way toward improving health.
While research into the biologic system that controls weight is moving toward the development of effective therapies for obesity, we are not there yet. In the meantime we must change our attitudes toward the obese and focus less on appearance and more on health. In their efforts to lose weight they are fighting against their biology. But they also are fighting against a society that wrongly believes that obesity is a personal failing.
Tuesday, September 15, 2009
The real cause of obesity
Despite receiving a MacArthur genius award for her work in Alabama "forging an inspiring model of compassionate and effective medical care in one of the most underserved regions of the United States," Regina Benjamin's qualifications to be surgeon general have been questioned. Why? She is overweight. "It tends to undermine her credibility," Dr. Marcia Angell, former editor of The New England Journal of Medicine, said in an interview with ABC News. "I do think at a time when a lot of public-health concern is about the national epidemic of obesity, having a surgeon general who is noticeably overweight raises questions in people's minds."
It is not enough, it seems, that the obese must suffer the medical consequences of their weight, consequences that include diabetes, heart disease, and cancer, and that cause nearly 300,000 deaths in the United States each year. They must also suffer the opprobrium heaped on them by people like Angell or Rep. James Sensenbrenner (R-WI), who advised the obese to "Look in the mirror because you are the one to blame." In our society, perhaps no group is more stigmatized than the obese.
The abuse is nothing new, of course. Four hundred years ago, Shakespeare had Prince Hal hurl a barrage of insults at Falstaff, calling him "fat-witted," "horseback-breaker," and a "huge hill of flesh." But Shakespeare had an excuse. In his time essentially nothing was known about the real reasons that people are fat. Today we have no such excuse. Modern medical science has gone a long way toward explaining the causes of obesity, and the bottom line is clear: obesity is not a personal choice. The obese are so primarily as a result of their genes.
Genetic studies have shown that the particular set of weight-regulating genes that a person has is by far the most important factor in determining how much that person will weigh. The heritability of obesity—a measure of how much obesity is due to genes versus other factors—is about the same as the heritability of height. It's even greater than that for many conditions that people accept as having a genetic basis, including heart disease, breast cancer, and schizophrenia. As nutrition has improved over the past 200 years, Americans have gotten much taller on average, but it is still the genes that determine who is tall or short today. The same is true for weight. Although our high-calorie, sedentary lifestyle contributes to the approximately 10-pound average weight gain of Americans compared to the recent past, some people are more severely affected by this lifestyle than others. That's because they have inherited genes that increase their predisposition for accumulating body fat. Our modern lifestyle is thus a necessary, but not a sufficient, condition for the high prevalence of obesity in our population.
Over the past decade, scientists have identified many of the genes that regulate body weight and have proved that in some instances, different variants of these genes can lead a person to be fat or thin. These genes underlie a weight-regulating system that is remarkably precise. The average person takes in a million or more calories per year, maintaining within a narrow range over the course of decades. This implies that the body balances calorie consumption with calorie expenditure, and does with a precision greater than 99.5 percent. Even the most vigilant calorie counter couldn't compete, if for no other reason than that the calorie counts on food labels are often off by 10 percent or more.
The genes that control food intake and metabolism act to keep weight in a stable range by creating a biological force that resists weight change in either direction. When weight is gained, hunger is reduced. When weight is lost, the unconscious drive to eat is stimulated and acts to return weight to the starting point. Moreover, the greater the amount of weight that is lost, the greater the sense of hunger that develops. Thus, when the obese lose large amounts of weight by conscious effort, their bodies fight back even more strongly by increasing hunger and reducing energy expenditure. If you think it is hard to lose 10 to 20 pounds (and it is), try to imagine what it would feel like to lose many tens or even hundreds of pounds.
It is not enough, it seems, that the obese must suffer the medical consequences of their weight, consequences that include diabetes, heart disease, and cancer, and that cause nearly 300,000 deaths in the United States each year. They must also suffer the opprobrium heaped on them by people like Angell or Rep. James Sensenbrenner (R-WI), who advised the obese to "Look in the mirror because you are the one to blame." In our society, perhaps no group is more stigmatized than the obese.
The abuse is nothing new, of course. Four hundred years ago, Shakespeare had Prince Hal hurl a barrage of insults at Falstaff, calling him "fat-witted," "horseback-breaker," and a "huge hill of flesh." But Shakespeare had an excuse. In his time essentially nothing was known about the real reasons that people are fat. Today we have no such excuse. Modern medical science has gone a long way toward explaining the causes of obesity, and the bottom line is clear: obesity is not a personal choice. The obese are so primarily as a result of their genes.
Genetic studies have shown that the particular set of weight-regulating genes that a person has is by far the most important factor in determining how much that person will weigh. The heritability of obesity—a measure of how much obesity is due to genes versus other factors—is about the same as the heritability of height. It's even greater than that for many conditions that people accept as having a genetic basis, including heart disease, breast cancer, and schizophrenia. As nutrition has improved over the past 200 years, Americans have gotten much taller on average, but it is still the genes that determine who is tall or short today. The same is true for weight. Although our high-calorie, sedentary lifestyle contributes to the approximately 10-pound average weight gain of Americans compared to the recent past, some people are more severely affected by this lifestyle than others. That's because they have inherited genes that increase their predisposition for accumulating body fat. Our modern lifestyle is thus a necessary, but not a sufficient, condition for the high prevalence of obesity in our population.
Over the past decade, scientists have identified many of the genes that regulate body weight and have proved that in some instances, different variants of these genes can lead a person to be fat or thin. These genes underlie a weight-regulating system that is remarkably precise. The average person takes in a million or more calories per year, maintaining within a narrow range over the course of decades. This implies that the body balances calorie consumption with calorie expenditure, and does with a precision greater than 99.5 percent. Even the most vigilant calorie counter couldn't compete, if for no other reason than that the calorie counts on food labels are often off by 10 percent or more.
The genes that control food intake and metabolism act to keep weight in a stable range by creating a biological force that resists weight change in either direction. When weight is gained, hunger is reduced. When weight is lost, the unconscious drive to eat is stimulated and acts to return weight to the starting point. Moreover, the greater the amount of weight that is lost, the greater the sense of hunger that develops. Thus, when the obese lose large amounts of weight by conscious effort, their bodies fight back even more strongly by increasing hunger and reducing energy expenditure. If you think it is hard to lose 10 to 20 pounds (and it is), try to imagine what it would feel like to lose many tens or even hundreds of pounds.
Wednesday, September 9, 2009
8 Things in Your Home That May Be Harming You [5-8]
Your laundry
Nobody thinks of the washing machine as a germ magnet—that’s where clothes get clean, right? Not if you’re using a public machine, and especially if that machine uses water that’s not hot enough, says Tierno.
Here’s why: Lower temperatures can encourage the spread of germs. Researchers at the University of Arizona found that intestinal viruses such as hepatitis A can be easily transferred from underwear to other garments during the washing process. Even worse, some germs can lurk in public washing machines and find their way to your clothes.
What to do
Wash your underwear and towels separately, using bleach if possible, and wash all towels in water that’s at least 155 degrees, which will kill most germs. Not sure if your apartment’s water temperature is hot enough? Talk to the building manager.
Your humidifier
Watch out for the humidifier, say germ experts. “If it’s not cleaned properly, a humidifier can become a repository for legionella and other pathogens that cause respiratory infections,” says Tierno.
What to do
If you like sleeping with a humidifier in your room, be sure to clean it often—at least a few times a week—by mixing a solution of one-part bleach to 19 parts water (for most humidifiers, this would equal about a half or full cup of bleach) and letting it sit for a few minutes before rinsing well.
Your doorknob
Think of the people who have touched your front doorknob in the past 48 hours: the UPS man, a neighbor, a solicitor, your friends—it’s easy to lose count. Now think of all the places they’ve been—the subway, public restrooms, grocery stores. Those germs are all on your doorknob right now, says Tierno.
Most people let their guard down when it comes to their own door handles, he says, but we shouldn’t: “Viruses can survive for days on doorknobs, and you can easily get cross contamination from them,” he says.
What to do
Make a habit of wiping down your doorknob frequently with sanitizing wipes or sprays. Have a copper doorknob? You may be in luck. Researchers in England found that copper door handles had 95 percent fewer microorganisms on them compared with other doorknobs. Scientists believe that many germs, including MRSA, may not be able to survive on copper.
Your salt and pepper shakers
When’s the last time you cleaned your salt and pepper shakers? Exactly. These unassuming little items get touched in all parts of the meal-prep process. Example: You give your sauce a dash of salt after touching raw chicken (oops) and then later set the shaker on the table.
What to do
Nobody thinks of cleaning their salt and pepper shakers, says Elizabeth Scott, Ph.D., assistant professor and co-director Simmons Center for Hygiene and Health in Home and Community at Simmons College, but to avoid cross-contamination and food poisoning, you should. “Best to wipe them with an EPA-registered disinfectant,” she says. “But better still, always wash your hands after handling raw foods and before touching anything else.”
by Sarah Jio
Nobody thinks of the washing machine as a germ magnet—that’s where clothes get clean, right? Not if you’re using a public machine, and especially if that machine uses water that’s not hot enough, says Tierno.
Here’s why: Lower temperatures can encourage the spread of germs. Researchers at the University of Arizona found that intestinal viruses such as hepatitis A can be easily transferred from underwear to other garments during the washing process. Even worse, some germs can lurk in public washing machines and find their way to your clothes.
What to do
Wash your underwear and towels separately, using bleach if possible, and wash all towels in water that’s at least 155 degrees, which will kill most germs. Not sure if your apartment’s water temperature is hot enough? Talk to the building manager.
Your humidifier
Watch out for the humidifier, say germ experts. “If it’s not cleaned properly, a humidifier can become a repository for legionella and other pathogens that cause respiratory infections,” says Tierno.
What to do
If you like sleeping with a humidifier in your room, be sure to clean it often—at least a few times a week—by mixing a solution of one-part bleach to 19 parts water (for most humidifiers, this would equal about a half or full cup of bleach) and letting it sit for a few minutes before rinsing well.
Your doorknob
Think of the people who have touched your front doorknob in the past 48 hours: the UPS man, a neighbor, a solicitor, your friends—it’s easy to lose count. Now think of all the places they’ve been—the subway, public restrooms, grocery stores. Those germs are all on your doorknob right now, says Tierno.
Most people let their guard down when it comes to their own door handles, he says, but we shouldn’t: “Viruses can survive for days on doorknobs, and you can easily get cross contamination from them,” he says.
What to do
Make a habit of wiping down your doorknob frequently with sanitizing wipes or sprays. Have a copper doorknob? You may be in luck. Researchers in England found that copper door handles had 95 percent fewer microorganisms on them compared with other doorknobs. Scientists believe that many germs, including MRSA, may not be able to survive on copper.
Your salt and pepper shakers
When’s the last time you cleaned your salt and pepper shakers? Exactly. These unassuming little items get touched in all parts of the meal-prep process. Example: You give your sauce a dash of salt after touching raw chicken (oops) and then later set the shaker on the table.
What to do
Nobody thinks of cleaning their salt and pepper shakers, says Elizabeth Scott, Ph.D., assistant professor and co-director Simmons Center for Hygiene and Health in Home and Community at Simmons College, but to avoid cross-contamination and food poisoning, you should. “Best to wipe them with an EPA-registered disinfectant,” she says. “But better still, always wash your hands after handling raw foods and before touching anything else.”
by Sarah Jio
Friday, September 4, 2009
8 surprising home health risks [1-4]
Home sweet home, right? Well, sort of. You may be unaware of the potential health dangers lurking in your abode—from critters in the kitchen to bugs in the bedroom. Here’s what you need to know and what to do.
Your kitchen sponge
Maybe you’ve heard about the germs on your kitchen sponge (gross news flash—there may be as many as 20 million microbes on it right now). But here’s the deal: Your method for “cleaning” that sponge may be leaving it loaded with potentially hazardous bacteria that can make you ill. Researchers at the USDA’s Agricultural Research Service found that some common cleaning methods for sponges—soaking them in a bleach solution, lemon juice or water—did not eradicate the germs.
What to do
The best ways to clean a dirty sponge, they say, are in the microwave (on high for one minute) and in the dishwasher, which will kill 99.9 percent of all germs.
Your bed
Have you been on a trip recently? If so, you may have brought home some hitchhikers—of the creepy-crawly variety. Bedbugs, tiny bloodthirsty insects, are hosts to organisms that cause hepatitis B and Chagas disease, say health experts. But the real problem seems to be the infections and allergic reactions that can sometimes result from bedbug bites.
According to the Environmental Protection Agency, bedbugs are on the rise and becoming an increasing health problem. The insects, which hide in the crevices of mattresses and bedding, are showing up everywhere, from hostels to the swankiest hotels, and they often find their way into people’s luggage, transporting themselves to unsuspecting homes.
What to do
If you’ve done some traveling recently, and especially if you’ve noticed any mysterious bug bites, wash everything in your luggage and consider scrubbing your suitcase with a stiff brush before giving it a good vacuuming.
Your laptop
You’re the only one who uses it, so how dirty can it be? In a word: filthy. A study by researchers at the University of North Carolina Health Care System found that keyboards were loaded with germs.
Even more disgusting, the average public toilet bowl contains 41 germs per square inch. The average personal keyboard? Some 21,000 germs per square inch. “Toilet bowls get cleaned,” says Philip M. Tierno Jr., Ph.D., director of clinical microbiology and immunology at New York University Langone Medical Center, “but keyboards rarely do.”
What to do
Tierno says the best way to keep your laptop or computer’s keyboard clean is to gently wipe it down daily with disinfecting wipes.
Your shower curtain
According to research by the Center for Health, Environment & Justice, shower curtains and liners made from polyvinyl chloride (PVC) may be harmful to your health.
Their study suggests that PVC releases potentially harmful chemicals into your bathroom. While there is still some debate among health experts about how much of these chemicals could be deemed harmful, many believe that limiting your exposure to chemicals, wherever possible, makes sense.
What to do
Check your shower curtain’s label to see if it’s made of vinyl or PVC. While not all manufacturers disclose this information, some retailers, like Ikea, have banned PVC shower curtains altogether, and Target has promised to phase out the material in its shower-curtain products in the months ahead.
Your kitchen sponge
Maybe you’ve heard about the germs on your kitchen sponge (gross news flash—there may be as many as 20 million microbes on it right now). But here’s the deal: Your method for “cleaning” that sponge may be leaving it loaded with potentially hazardous bacteria that can make you ill. Researchers at the USDA’s Agricultural Research Service found that some common cleaning methods for sponges—soaking them in a bleach solution, lemon juice or water—did not eradicate the germs.
What to do
The best ways to clean a dirty sponge, they say, are in the microwave (on high for one minute) and in the dishwasher, which will kill 99.9 percent of all germs.
Your bed
Have you been on a trip recently? If so, you may have brought home some hitchhikers—of the creepy-crawly variety. Bedbugs, tiny bloodthirsty insects, are hosts to organisms that cause hepatitis B and Chagas disease, say health experts. But the real problem seems to be the infections and allergic reactions that can sometimes result from bedbug bites.
According to the Environmental Protection Agency, bedbugs are on the rise and becoming an increasing health problem. The insects, which hide in the crevices of mattresses and bedding, are showing up everywhere, from hostels to the swankiest hotels, and they often find their way into people’s luggage, transporting themselves to unsuspecting homes.
What to do
If you’ve done some traveling recently, and especially if you’ve noticed any mysterious bug bites, wash everything in your luggage and consider scrubbing your suitcase with a stiff brush before giving it a good vacuuming.
Your laptop
You’re the only one who uses it, so how dirty can it be? In a word: filthy. A study by researchers at the University of North Carolina Health Care System found that keyboards were loaded with germs.
Even more disgusting, the average public toilet bowl contains 41 germs per square inch. The average personal keyboard? Some 21,000 germs per square inch. “Toilet bowls get cleaned,” says Philip M. Tierno Jr., Ph.D., director of clinical microbiology and immunology at New York University Langone Medical Center, “but keyboards rarely do.”
What to do
Tierno says the best way to keep your laptop or computer’s keyboard clean is to gently wipe it down daily with disinfecting wipes.
Your shower curtain
According to research by the Center for Health, Environment & Justice, shower curtains and liners made from polyvinyl chloride (PVC) may be harmful to your health.
Their study suggests that PVC releases potentially harmful chemicals into your bathroom. While there is still some debate among health experts about how much of these chemicals could be deemed harmful, many believe that limiting your exposure to chemicals, wherever possible, makes sense.
What to do
Check your shower curtain’s label to see if it’s made of vinyl or PVC. While not all manufacturers disclose this information, some retailers, like Ikea, have banned PVC shower curtains altogether, and Target has promised to phase out the material in its shower-curtain products in the months ahead.
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