June 6, 2012
Moderation as the Sweet Spot for Exercise
By GRETCHEN REYNOLDS
New York Times
Moderate exercise may be more beneficial than vigorous workouts.Thor Swift for The New York Times Moderate exercise may be more beneficial than vigorous workouts.
For people who exercise but fret that they really should be working out more, new studies may be soothing. The amount of exercise needed to improve health and longevity, this new science shows, is modest, and more is not necessarily better.
That is the message of the newest and perhaps most compelling of the studies, which was presented on Saturday at the annual meeting of the American College of Sports Medicine in San Francisco. For it, researchers at the University of South Carolina Arnold School of Public Health and other institutions combed through the health records of 52,656 American adults who’d undergone physicals between 1971 and 2002 as part of the Aerobics Center Longitudinal Study at the Cooper Institute in Dallas. Each participant completed physical testing and activity questionnaires and returned for at least one follow-up visit.
The researchers found that about 27 percent of the participants reported regularly running, although in wildly varying amounts and paces.
The scientists then checked death reports.
Over the course of the study, 2,984 of the participants died. But the incidence was much lower among the group that ran. Those participants had, on average, a 19 percent lower risk of dying from any cause than non-runners.
Notably, in closely parsing the participants’ self-reported activities, the researchers found that running in moderation provided the most benefits. Those who ran 1 to 20 miles per week at an average pace of about 10 or 11 minutes per mile — in other words, jogging — reduced their risk of dying during the study more effectively than those who didn’t run, those (admittedly few) who ran more than 20 miles a week, and those who typically ran at a pace swifter than seven miles an hour.
“These data certainly support the idea that more running is not needed to produce extra health and mortality benefits,” said Dr. Carl J. Lavie, medical director of cardiac rehabilitation and prevention at the Ochsner Medical Center in New Orleans and an author of the study. “If anything,” he continued, “it appears that less running is associated with the best protection from mortality risk. More is not better, and actually, more could be worse.”
His analysis echoes the results of another new examination of activity and mortality, in which Danish scientists used 27 years’ worth of data collected for the continuing Copenhagen City Heart Study. They reported that those Danes who spent one to two and a half hours per week jogging at a “slow or average pace” during the study period had longer life spans than their more sedentary peers and than those who ran at a faster pace.
This decidedly modest amount of exercise led to an increase of, on average, 6.2 years in the life span of male joggers and 5.6 years in women.
“We can say with certainty that regular jogging increases longevity,” Dr. Peter Schnorr, a cardiologist and an author of the study, said in presenting the findings at a clinical meeting organized last month by the European Association for Cardiovascular Prevention and Rehabilitation. “The good news is that you don’t actually need to do that much to reap the benefits.”
“The relationship appears much like alcohol intakes,” he continued. “Mortality is lower in people reporting moderate jogging than in non-joggers or those undertaking extreme levels of exercise.”
There’s further confirmation of that idea in the findings of a large study of exercise habits published last year in The Lancet, which showed that among a group of 416,175 Taiwanese adults, 92 minutes a week of moderate exercise, like walking, gentle jogging or cycling, increased life span by about three years and decreased the risk of mortality from any cause by about 14 percent.
In that study, those who embarked on more ambitious exercise programs did gain additional risk reduction, as seems only fair, but the benefits plateaued rapidly. For each further 15 minutes per day of moderate exercise that someone completed beyond the first 92, his or her mortality risk fell, but by only about another 4 percent.
Whether and at what point more exercise becomes counterproductive remains uncertain. “In general, it appears that exercise, like any therapy, results in a bell-shaped curve in terms of response and benefit,” says Dr. James H. O’Keefe, a cardiologist and lead author of a thought-provoking review article published on Monday in Mayo Clinic Proceedings that examines whether extreme amounts of vigorous exercise, particularly running, can harm the heart.
“To date, the data suggests that walking and light jogging are almost uniformly beneficial for health and do increase life span,” Dr. O’Keefe says. “But with more vigorous or prolonged exercise, the benefits can become questionable.
“I’m a fan of distance running,” he adds. “I run. But after about 45 to 60 minutes a day, you reach a point of diminishing returns, and at some point, you risk toxicity.”
His advice? The study by Dr. Lavie and his colleagues offers excellent guidelines for safe and effective exercise, Dr. O’Keefe says. “Twenty miles a week or less of jogging at a 10- or 11-minute-mile pace can add years to your life span. That’s very good news.” Indeed it is — especially since that routine happens to replicate almost exactly my own weekly exercise regimen.
“I wouldn’t automatically discourage people from doing more if they really want to” and are not experiencing side effects, like extreme fatigue or repeated injuries, Dr. O’Keefe continued. “But the message from the latest data is that the sweet spot for exercise seems to come with less.”
Gretchen Reynolds is the author of “The First 20 Minutes: Surprising Science Reveals How We Can Exercise Better, Train Smarter, Live Longer” (Hudson Street Press, 2012).
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Sunday, March 3, 2013
Monday, September 3, 2012
Rabbis Will Defy Law on Circumcision Ritual
ABC News
Sep 3, 2012
Ultra-Orthodox rabbis in New York City say if a proposed law requiring parental consent for a circumcision ritual linked to two infant deaths is enacted they will defy it. During the ritual, called metzitzah b’peh, a mohel removes the foreskin and uses his mouth to stop the bleeding. At least 11 New York infants are thought to have contracted herpes from the practice, two of whom died and two of whom have irreversible brain damage, according to the New York City Department of Health and Mental Hygiene.
But rabbis insist 5,000-year-old ritual is safe, and say they refuse to tell parents there are any health risks.
“This is the government forcing a rabbi practicing a religious ritual to tell his congregants it could hurt their child,” said Rabbi David Niederman, executive director of the United Jewish Organization of Williamsburg. “If, God forbid, there was a danger, we would be the first to stop the practice.”
Niederman said the research linking metzitzah b’peh to infant deaths is “full of holes,” adding that the ritual is performed safely “tens of thousands of times a year” worldwide, and that babies who aren’t circumcised can also acquire herpes shortly after birth.
“We are convinced that the data is flawed and there’s no risk whatsoever,” he said, adding that “safeguarding the life of an infant” is one of the Torah’s most important principles.
Most modern mohels remove the blood with a sterile pipette. But about two-thirds of boys born in New York City’s Hasidic communities, who are ultra-Orthodox, are circumcised in the oral suction manner, Rabbi David Zwiebel, executive vice president of the Orthodox Jewish organization Agudath Israel of America, told ABC News in March...
ABC News
Sep 3, 2012
Ultra-Orthodox rabbis in New York City say if a proposed law requiring parental consent for a circumcision ritual linked to two infant deaths is enacted they will defy it. During the ritual, called metzitzah b’peh, a mohel removes the foreskin and uses his mouth to stop the bleeding. At least 11 New York infants are thought to have contracted herpes from the practice, two of whom died and two of whom have irreversible brain damage, according to the New York City Department of Health and Mental Hygiene.
But rabbis insist 5,000-year-old ritual is safe, and say they refuse to tell parents there are any health risks.
“This is the government forcing a rabbi practicing a religious ritual to tell his congregants it could hurt their child,” said Rabbi David Niederman, executive director of the United Jewish Organization of Williamsburg. “If, God forbid, there was a danger, we would be the first to stop the practice.”
Niederman said the research linking metzitzah b’peh to infant deaths is “full of holes,” adding that the ritual is performed safely “tens of thousands of times a year” worldwide, and that babies who aren’t circumcised can also acquire herpes shortly after birth.
“We are convinced that the data is flawed and there’s no risk whatsoever,” he said, adding that “safeguarding the life of an infant” is one of the Torah’s most important principles.
Most modern mohels remove the blood with a sterile pipette. But about two-thirds of boys born in New York City’s Hasidic communities, who are ultra-Orthodox, are circumcised in the oral suction manner, Rabbi David Zwiebel, executive vice president of the Orthodox Jewish organization Agudath Israel of America, told ABC News in March...
Saturday, August 18, 2012
Coffee good for you, but it's OK to hold back
Coffee good for you, but it's OK to hold back
By Elizabeth Landau
CNN
August 18, 2012
A study last year found a lower risk of endometrial cancer in coffee-drinking women. Coffee may prevent type II diabetes and Parkinson's disease, evidence shows It may also have anti-cancer and antidepressant effects
If you can't get through your day without a coffee break or two, here's good news for you: What scientists know so far suggests coffee may help you stay healthy.
As usual with medical research, the operative word is "may."
It's hard to know for sure whether coffee is really causing good effects -- lifestyles or behaviors associated with coffee consumption may also influence health. Also, different people have different tolerances for coffee -- it can have short-term side effects that make people steer clear of morning brews.
So, doctors aren't quite convinced enough to prescribe coffee -- but they probably don't need to, because so many people indulge in it anyway.
The point is: In general, regular coffee drinkers won't be discouraged from continuing the habit, although there are exceptions.
"For most people, for people who don't experience the side effects, the benefits far outweigh the risks," said Dr. Donald Hensrud of the Mayo Clinic.
Why would coffee be good?
More is known about the overall association between coffee and positive health effects than about the mechanism behind it, said Dr. Alberto Ascherio, professor of epidemiology and nutrition at the Harvard School of Public Health.
Antioxidants are one potential reason that good outcomes are seen from coffee. Our bodies produce oxygen radicals, which are damaging to DNA. Antioxidants prevent them from doing damage, Ascherio said.
Although antioxidants are found in fruits and vegetables, research has shown that coffee is the top source of antioxidants for Americans.
Caffeine itself may also contribute to coffee's positive effects on brain health. That may be because caffeine is an antagonist to adenosine receptors. These receptors normally slow down neural activity when the chemical adenosine binds to them, producing a sleepy feeling. But if caffeine binds to the receptors, the activity of neurons speeds up.
Coffee also appears to lower levels of insulin and estrogen, which is perhaps why a study last year found a lower risk of endometrial cancer in coffee-drinking women. Insulin also plays a role in prostate cancer, another disease coffee may help stave off.
What good it may bring
The evidence is fairly strong for coffee preventing type II diabetes and Parkinson's, and reasonably good for antidepressant effects, too, doctors say.
Just in the last few months, several new studies have been published highlighting other possible benefits of coffee. Again, none of them prove that coffee causes any effects at all; they are just associations.
People who drink two 8-ounce cups of coffee daily appear to have an 11% lower risk of developing heart failure, compared to noncoffee drinkers. That's according to a meta-analysis published in June in the American Heart Association's journal Circulation: Heart Failure, based on pooling the results of five studies. The researchers did not take into account the strength of coffee, what time of day it was drunk, or whether it was caffeinated -- factors that could be related.
Coffee drinkers may also be protecting themselves against basal cell carcinoma, the most common form of skin cancer, according to a July report in the journal Cancer Research. Other caffeinated beverages also seemed to reduce the risk of this slow-growing cancer. But scientists don't yet know why this effect was observed.
Increased coffee consumption also is associated with longer life, according to Research in the New England Journal of Medicine. Again, no one knows what about coffee would make people live longer, but Ascherio theorizes it could be the protection against type II diabetes, Parkinson's, depression and suicidal tendencies.
Some of the strongest evidence comes from studies on type II diabetes. According to a 2009 meta-analysis, the risk of type II diabetes goes down with each cup of coffee consumed daily. Additionally, a 2007 meta-analysis found a correlation between increased coffee consumption and lower risk of liver cancer. But it's not enough to tell anyone who doesn't already drink coffee to start.
There have not been any large randomized controlled trials regarding coffee's health benefits, or even to see whether caffeinated or decaf is better for you. Without this kind of research, there will be uncertainty.
While perhaps scientifically interesting, such an investigation hasn't happened because of the economics involved, Ascherio said. A trial could cost in the tens of millions of dollars. Pharmaceutical companies aren't in the business of selling coffee, and coffee makers don't need a study to market their products -- people who like coffee buy it anyway.
How much coffee a person can drink daily varies widely; some people don't feel any side effects.
The optimal daily dose of coffee varies widely, depending on the person. Some can't drink it at all. Others tolerate six to eight cups a day.
As common sense might suggest, the greatest overall benefits appear to be in people who drink coffee at moderate levels: two to three cups a day. But there are exceptions: A May 2011 study found that men who drink six or more cups a day had a decreased risk of fatal prostate cancer.
The bad stuff
Coffee hasn't always been hailed as such a great thing. It's also not for everyone. Doctors may never consider coffee a standard recommendation because of individuals' varying susceptibility to side effects, said Hensrud.
Those include headaches, insomnia, heartburn and palpitations, not to mention urinary urgency. People who get fast heartbeats may need to steer clear of caffeinated coffee, too. Others don't drink coffee because it irritates their stomachs.
Famously, coffee got a bad reputation from research in the early 1980s connecting it to pancreatic cancer. But more recent studies have not found the same link, according to the American Cancer Society.
Some studies in the past did not take into account the connection between drinking coffee and smoking cigarettes, which do contain carcinogens, Hensrud said. Different people metabolize caffeine differently, so some people can have a cup of coffee at night and fall asleep right away, while others need to keep their distance from java for several hours before bedtime to avoid insomnia.
Coffee that's boiled -- popular in Scandinavia, for instance -- will increase bad cholesterol; espresso has the same effect, Hensrud said. But filtering regular coffee reduces those cholesterol-raising substances...
By Elizabeth Landau
CNN
August 18, 2012
A study last year found a lower risk of endometrial cancer in coffee-drinking women. Coffee may prevent type II diabetes and Parkinson's disease, evidence shows It may also have anti-cancer and antidepressant effects
If you can't get through your day without a coffee break or two, here's good news for you: What scientists know so far suggests coffee may help you stay healthy.
As usual with medical research, the operative word is "may."
It's hard to know for sure whether coffee is really causing good effects -- lifestyles or behaviors associated with coffee consumption may also influence health. Also, different people have different tolerances for coffee -- it can have short-term side effects that make people steer clear of morning brews.
So, doctors aren't quite convinced enough to prescribe coffee -- but they probably don't need to, because so many people indulge in it anyway.
The point is: In general, regular coffee drinkers won't be discouraged from continuing the habit, although there are exceptions.
"For most people, for people who don't experience the side effects, the benefits far outweigh the risks," said Dr. Donald Hensrud of the Mayo Clinic.
Why would coffee be good?
More is known about the overall association between coffee and positive health effects than about the mechanism behind it, said Dr. Alberto Ascherio, professor of epidemiology and nutrition at the Harvard School of Public Health.
Antioxidants are one potential reason that good outcomes are seen from coffee. Our bodies produce oxygen radicals, which are damaging to DNA. Antioxidants prevent them from doing damage, Ascherio said.
Although antioxidants are found in fruits and vegetables, research has shown that coffee is the top source of antioxidants for Americans.
Caffeine itself may also contribute to coffee's positive effects on brain health. That may be because caffeine is an antagonist to adenosine receptors. These receptors normally slow down neural activity when the chemical adenosine binds to them, producing a sleepy feeling. But if caffeine binds to the receptors, the activity of neurons speeds up.
Coffee also appears to lower levels of insulin and estrogen, which is perhaps why a study last year found a lower risk of endometrial cancer in coffee-drinking women. Insulin also plays a role in prostate cancer, another disease coffee may help stave off.
What good it may bring
The evidence is fairly strong for coffee preventing type II diabetes and Parkinson's, and reasonably good for antidepressant effects, too, doctors say.
Just in the last few months, several new studies have been published highlighting other possible benefits of coffee. Again, none of them prove that coffee causes any effects at all; they are just associations.
People who drink two 8-ounce cups of coffee daily appear to have an 11% lower risk of developing heart failure, compared to noncoffee drinkers. That's according to a meta-analysis published in June in the American Heart Association's journal Circulation: Heart Failure, based on pooling the results of five studies. The researchers did not take into account the strength of coffee, what time of day it was drunk, or whether it was caffeinated -- factors that could be related.
Coffee drinkers may also be protecting themselves against basal cell carcinoma, the most common form of skin cancer, according to a July report in the journal Cancer Research. Other caffeinated beverages also seemed to reduce the risk of this slow-growing cancer. But scientists don't yet know why this effect was observed.
Increased coffee consumption also is associated with longer life, according to Research in the New England Journal of Medicine. Again, no one knows what about coffee would make people live longer, but Ascherio theorizes it could be the protection against type II diabetes, Parkinson's, depression and suicidal tendencies.
Some of the strongest evidence comes from studies on type II diabetes. According to a 2009 meta-analysis, the risk of type II diabetes goes down with each cup of coffee consumed daily. Additionally, a 2007 meta-analysis found a correlation between increased coffee consumption and lower risk of liver cancer. But it's not enough to tell anyone who doesn't already drink coffee to start.
There have not been any large randomized controlled trials regarding coffee's health benefits, or even to see whether caffeinated or decaf is better for you. Without this kind of research, there will be uncertainty.
While perhaps scientifically interesting, such an investigation hasn't happened because of the economics involved, Ascherio said. A trial could cost in the tens of millions of dollars. Pharmaceutical companies aren't in the business of selling coffee, and coffee makers don't need a study to market their products -- people who like coffee buy it anyway.
How much coffee a person can drink daily varies widely; some people don't feel any side effects.
The optimal daily dose of coffee varies widely, depending on the person. Some can't drink it at all. Others tolerate six to eight cups a day.
As common sense might suggest, the greatest overall benefits appear to be in people who drink coffee at moderate levels: two to three cups a day. But there are exceptions: A May 2011 study found that men who drink six or more cups a day had a decreased risk of fatal prostate cancer.
The bad stuff
Coffee hasn't always been hailed as such a great thing. It's also not for everyone. Doctors may never consider coffee a standard recommendation because of individuals' varying susceptibility to side effects, said Hensrud.
Those include headaches, insomnia, heartburn and palpitations, not to mention urinary urgency. People who get fast heartbeats may need to steer clear of caffeinated coffee, too. Others don't drink coffee because it irritates their stomachs.
Famously, coffee got a bad reputation from research in the early 1980s connecting it to pancreatic cancer. But more recent studies have not found the same link, according to the American Cancer Society.
Some studies in the past did not take into account the connection between drinking coffee and smoking cigarettes, which do contain carcinogens, Hensrud said. Different people metabolize caffeine differently, so some people can have a cup of coffee at night and fall asleep right away, while others need to keep their distance from java for several hours before bedtime to avoid insomnia.
Coffee that's boiled -- popular in Scandinavia, for instance -- will increase bad cholesterol; espresso has the same effect, Hensrud said. But filtering regular coffee reduces those cholesterol-raising substances...
Thursday, December 8, 2011
Some men can delay prostate cancer treatment: panel
Some men can delay prostate cancer treatment: panel
By Julie Steenhuysen
Dec 7, 2011
(Reuters) - Men with low-risk prostate cancer may wait to see if their disease progresses before treating it, an independent panel of experts convened by the U.S. National Institutes of Health (NIH) said on Wednesday.
The panel backed the so-called active monitoring approach to prostate cancer treatment as a way to help men avoid the potential health consequences of treatment, which include impotence and incontinence.
The NIH is considering dropping the name "cancer" from this very early stage of the disease because it may make it easier for men to accept that carefully monitoring for changes is a better approach for them than immediate treatment.
Prostate cancer is the most common non-skin cancer in men in the United States. Some 240,000 U.S. men will be diagnosed with prostate cancer this year, and about 33,000 will die of the disease. More than half of these cancers are confined to the prostate and unlikely to become life-threatening.
Even so, about 90 percent of men who are diagnosed with prostate cancer get immediate treatment, such as surgery or radiation therapy.
"It's clear that many men would benefit from delaying treatment," said Dr. Patricia Ganz, a cancer prevention expert at the University of California Los Angeles, who chaired the NIH's state-of-the-science panel on prostate cancer.
The problem, said Ganz, is there is no consensus on the best strategies for monitoring the progress of prostate cancer and what benchmarks should be used to determine when treatment is needed. The panel urged NIH for more research to clarify this matter.
Many doctors already use a variety of monitoring strategies for men whose low-grade prostate cancer was detected through PSA screening, a blood test that detects levels of a protein made in the prostate gland known as prostate-specific antigen.
Elevated levels of this protein can indicate prostate cancer, but it can be caused by other things as well..
Several studies have suggested many men are over-screened for prostate cancer, and this over-screening has in many cases caused more harm than good, leading men to chose a biopsy and treatment for a slow-growing cancer that may have never caused them harm during their lifetimes.
Alternative strategies for men with low-risk prostate cancer typically fall into two camps: observation with and without the intent to cure.
In the observation without intent to cure approach, sometimes called watchful waiting, doctors treat symptoms if they develop.
In observation with intent to cure, often called active surveillance, patients undergo frequent testing and are offered curative treatment if the cancer progresses.
Ganz said it is not yet clear which approach is best.
"Prostate cancer affects some 30-40 percent of men over the age of 50. Some of these men will benefit from immediate treatment, others will benefit from observation. We need to standardize definitions, group patients by their risks and conduct additional research to determine the best protocols for managing low-risk disease," she said in a statement.
(Editing by Todd Eastham)
Wednesday, December 7, 2011
Why Working the Night Shift May Boost Your Risk of Diabetes
Why Working the Night Shift May Boost Your Risk of Diabetes
By Alice Park
Time
December 7, 2011
The night shift isn't usually anyone's first choice, but in some professions — and in this economy — it can't be avoided. About 26% percent of the American workforce, including health-care workers and sanitation staff, clocks in after dark, and the schedule may be taking a toll on their health.
Past research has shown that working when you're supposed to be in bed disrupts your circadian rhythm, raising the risk of heart disease, obesity, ulcers and even depression. Now, reporting in the journal PLoS Medicine, scientists also find that rotating night-shift work can increase the risk of developing Type 2 diabetes. The backward schedule can mess with the body's ability to use insulin properly to break down sugars in the blood, according to Dr. Frank Hu, a professor of nutrition and epidemiology at Harvard School of Public Health.
In a study involving nearly 177,000 middle-aged women enrolled in two Nurses' Health Studies, women who worked rotating night shifts for 1 to 2 years increased their risk of developing diabetes by 5% over a 20-year follow-up period, compared with women who didn't get assigned these shifts. Women who kept up night work for 10 to 19 years increased their risk by 40%. Working on and off at night for more than 20 years boosted the risk of diabetes by 60%.
Certainly, body weight is part of the problem, since excess weight is a risk factor for diabetes. People who work at night may snack more when they should be sleeping — and our bodies are metabolically trained to slow down as the sun sets. So the calories we take in during the evening and night hours are less likely to get burned off efficiently, and more likely to be stored as fat.
It's not just night work that causes a problem. Simply not sleeping when you're supposed to, or not getting enough sleep, can also wreak havoc with your metabolism, by pushing up levels of the appetite-stimulating hormone ghrelin and suppressing the appetite-curbing hormone leptin. Our circadian clocks also regulate body weight indirectly, by controlling body temperature and blood glucose levels. "The bottom line is there are probably multiple mechanisms through which disrupted sleep patterns or long term rotating night shift work can influence the risk of Type 2 diabetes," says Hu.
The study focused on people who rotated night shift work, so they weren't working nights routinely, but perhaps once every few days or weeks. Hu says it's not clear whether those who regularly work at night (and therefore sleep during the day) can adjust their body clocks to avoid this increased risk of diabetes.
What intrigued Hu and his team the most was the cumulative effect that night work had on diabetes risk. The longer people worked irregular hours at night, the higher their risk of developing the disease. "It's something people should keep in mind," he says. "If they minimize or reduce the time they work on night shifts, they may be able to attenuate their risk."
That's an important lesson for those who have to work at night. They might not be able to avoid the late hours, but they should remember that sticking with a night shift schedule for too long can be harmful for their health. And because these individuals may be at higher risk of developing diabetes, they should pay more attention to things that can lower their risk, such as watching their diet, exercising and getting screened for the disease more regularly.
By Alice Park
Time
December 7, 2011
The night shift isn't usually anyone's first choice, but in some professions — and in this economy — it can't be avoided. About 26% percent of the American workforce, including health-care workers and sanitation staff, clocks in after dark, and the schedule may be taking a toll on their health.
Past research has shown that working when you're supposed to be in bed disrupts your circadian rhythm, raising the risk of heart disease, obesity, ulcers and even depression. Now, reporting in the journal PLoS Medicine, scientists also find that rotating night-shift work can increase the risk of developing Type 2 diabetes. The backward schedule can mess with the body's ability to use insulin properly to break down sugars in the blood, according to Dr. Frank Hu, a professor of nutrition and epidemiology at Harvard School of Public Health.
In a study involving nearly 177,000 middle-aged women enrolled in two Nurses' Health Studies, women who worked rotating night shifts for 1 to 2 years increased their risk of developing diabetes by 5% over a 20-year follow-up period, compared with women who didn't get assigned these shifts. Women who kept up night work for 10 to 19 years increased their risk by 40%. Working on and off at night for more than 20 years boosted the risk of diabetes by 60%.
Certainly, body weight is part of the problem, since excess weight is a risk factor for diabetes. People who work at night may snack more when they should be sleeping — and our bodies are metabolically trained to slow down as the sun sets. So the calories we take in during the evening and night hours are less likely to get burned off efficiently, and more likely to be stored as fat.
It's not just night work that causes a problem. Simply not sleeping when you're supposed to, or not getting enough sleep, can also wreak havoc with your metabolism, by pushing up levels of the appetite-stimulating hormone ghrelin and suppressing the appetite-curbing hormone leptin. Our circadian clocks also regulate body weight indirectly, by controlling body temperature and blood glucose levels. "The bottom line is there are probably multiple mechanisms through which disrupted sleep patterns or long term rotating night shift work can influence the risk of Type 2 diabetes," says Hu.
The study focused on people who rotated night shift work, so they weren't working nights routinely, but perhaps once every few days or weeks. Hu says it's not clear whether those who regularly work at night (and therefore sleep during the day) can adjust their body clocks to avoid this increased risk of diabetes.
What intrigued Hu and his team the most was the cumulative effect that night work had on diabetes risk. The longer people worked irregular hours at night, the higher their risk of developing the disease. "It's something people should keep in mind," he says. "If they minimize or reduce the time they work on night shifts, they may be able to attenuate their risk."
That's an important lesson for those who have to work at night. They might not be able to avoid the late hours, but they should remember that sticking with a night shift schedule for too long can be harmful for their health. And because these individuals may be at higher risk of developing diabetes, they should pay more attention to things that can lower their risk, such as watching their diet, exercising and getting screened for the disease more regularly.
Monday, November 28, 2011
A form of autism called regressive autism is linked to brain overgrowth in males
Larger brains linked with regressive autism
By Shari Roan
Los Angeles Times
November 28, 2011
Autism symptoms can appear in babies, however some children with the disorder develop normally until about age 2 when they suddenly regress. A new study has linked this second type of autism -- regressive autism -- with larger brain size in boys.
Other studies have suggested some association between overgrowth of the brain and autism. The new study, led by researchers at the UC Davis MIND Institute, demonstrates that there are multiple biological subtypes of autism including likely differences between males and females.
Researchers looked at 114 children with autism spectrum disorder between the ages of 2 and 4 and compared them with 66 healthy children of the same age. Of the 114 with the disorder, 54% had regressive autism and 46% had non-regressive autism.
Brain scans of the children showed that abnormal head growth and brain enlargement was identifiable in 22% of males with regressive autism compared with 5% of males with the non-regressive type. Girls with autism did not show brain enlargement. The data suggest that the abnormal brain growth occurred at around 4 to 6 months of age, much earlier than the symptoms of regression -- such as a decline in speech -- actually appear.
The study, published Monday in the Proceedings of the National Academy of Sciences, adds to a growing body of evidence showing autism likely has various biological underpinnings. Researchers are particularly interested in understanding the disorder in girls. "[I]t is likely that the pattern of pathology is different in females than in males," they wrote.
By Shari Roan
Los Angeles Times
November 28, 2011
Autism symptoms can appear in babies, however some children with the disorder develop normally until about age 2 when they suddenly regress. A new study has linked this second type of autism -- regressive autism -- with larger brain size in boys.
Other studies have suggested some association between overgrowth of the brain and autism. The new study, led by researchers at the UC Davis MIND Institute, demonstrates that there are multiple biological subtypes of autism including likely differences between males and females.
Researchers looked at 114 children with autism spectrum disorder between the ages of 2 and 4 and compared them with 66 healthy children of the same age. Of the 114 with the disorder, 54% had regressive autism and 46% had non-regressive autism.
Brain scans of the children showed that abnormal head growth and brain enlargement was identifiable in 22% of males with regressive autism compared with 5% of males with the non-regressive type. Girls with autism did not show brain enlargement. The data suggest that the abnormal brain growth occurred at around 4 to 6 months of age, much earlier than the symptoms of regression -- such as a decline in speech -- actually appear.
The study, published Monday in the Proceedings of the National Academy of Sciences, adds to a growing body of evidence showing autism likely has various biological underpinnings. Researchers are particularly interested in understanding the disorder in girls. "[I]t is likely that the pattern of pathology is different in females than in males," they wrote.
Thursday, November 10, 2011
Happiness linked to longer life
Happiness linked to longer life
By Amanda MacMillan
Health.com
October 31, 2011
A new study suggests that happiness in older people may lead to a longer life.
(Health.com) -- Being happy doesn't just improve the quality of your life. According to a new study, it may increase the quantity of your life as well.
Older people were up to 35% less likely to die during the five-year study if they reported feeling happy, excited, and content on a typical day. And this was true even though the researchers took factors such as chronic health problems, depression, and financial security out of the equation.
"We had expected that we might see a link between how happy people felt over the day and their future mortality, but we were struck by how strong the effect was," says Andrew Steptoe, Ph.D., the lead author of the study and a professor of psychology at University College London, in the United Kingdom.
Health.com: Boost your mood naturally
Previous studies on happiness and longevity have largely relied on the participants' ability to recall how they felt during a certain period of time in the past. These recollections aren't always accurate, though, and to get around this problem Steptoe and his colleagues asked more than 3,800 people to record their levels of happiness, anxiety, and other emotions at four specific times over the course of a single day.
The participants, who were between the ages of 52 and 79 when the study began, were divided into three groups according to how happy and positive they felt. Although the groups differed slightly on some measures (such as age, wealth, and smoking), they were comparable in terms of ethnic makeup, education, employment status, and overall health.
Five years later, 7% of people in the least happy group had died, compared with just 4% in the happiest group and 5% in the middle group.
When the researchers controlled for age, depression, chronic diseases, health behaviors (such as exercise and alcohol consumption), and socioeconomic factors, they found that the happiest and medium-happy people were 35% and 20% less likely to have died, respectively, than their gloomier counterparts.
Health.com: How to live to 100
It may seem far-fetched that a person's feelings on one particular day would be able to predict the likelihood of dying in the near future, but these emotional snapshots have proven to be a good indication of overall temperament in previous studies, says Sarah Pressman, Ph.D., a professor of psychology at the University of Kansas, in Lawrence.
"There is always room for error, of course; if I get a parking ticket or stub my toe on the way to the study, I'm not going to be particularly happy," says Pressman, who was not involved in the study but researches the impact of happiness on health. "But given that the study worked, it suggests that, on average, this day was fairly typical for the participants."
Unlike the happiness measures, depression symptoms were not associated with mortality rates once the researchers adjusted for overall health. According to the study, this finding suggests that the absence of happiness may be a more important measure of health in older people than the presence of negative emotions.
Health.com: The secrets to a super-happy winter
Positive emotions could contribute to better physical health in a number of ways. Regions of the brain involved in happiness are also involved in blood-vessel function and inflammation, for instance, and studies have shown that levels of the stress hormone cortisol tend to rise and fall with emotion.
The study doesn't prove that happiness (or unhappiness) directly affects lifespan, but the findings do imply that doctors and caregivers should pay close attention to the emotional well-being of older patients, the researchers say. "We would not advocate from this study that trying to be happier would have direct health benefits," Steptoe says.
However, this study and others like it should help establish happiness as a legitimate area of concern for health professionals, Pressman says. "There are still some people who see happiness as something fluffy and less scientific -- not something they should be worried about like, say, stress or depression," she says...
By Amanda MacMillan
Health.com
October 31, 2011
A new study suggests that happiness in older people may lead to a longer life.
(Health.com) -- Being happy doesn't just improve the quality of your life. According to a new study, it may increase the quantity of your life as well.
Older people were up to 35% less likely to die during the five-year study if they reported feeling happy, excited, and content on a typical day. And this was true even though the researchers took factors such as chronic health problems, depression, and financial security out of the equation.
"We had expected that we might see a link between how happy people felt over the day and their future mortality, but we were struck by how strong the effect was," says Andrew Steptoe, Ph.D., the lead author of the study and a professor of psychology at University College London, in the United Kingdom.
Health.com: Boost your mood naturally
Previous studies on happiness and longevity have largely relied on the participants' ability to recall how they felt during a certain period of time in the past. These recollections aren't always accurate, though, and to get around this problem Steptoe and his colleagues asked more than 3,800 people to record their levels of happiness, anxiety, and other emotions at four specific times over the course of a single day.
The participants, who were between the ages of 52 and 79 when the study began, were divided into three groups according to how happy and positive they felt. Although the groups differed slightly on some measures (such as age, wealth, and smoking), they were comparable in terms of ethnic makeup, education, employment status, and overall health.
Five years later, 7% of people in the least happy group had died, compared with just 4% in the happiest group and 5% in the middle group.
When the researchers controlled for age, depression, chronic diseases, health behaviors (such as exercise and alcohol consumption), and socioeconomic factors, they found that the happiest and medium-happy people were 35% and 20% less likely to have died, respectively, than their gloomier counterparts.
Health.com: How to live to 100
It may seem far-fetched that a person's feelings on one particular day would be able to predict the likelihood of dying in the near future, but these emotional snapshots have proven to be a good indication of overall temperament in previous studies, says Sarah Pressman, Ph.D., a professor of psychology at the University of Kansas, in Lawrence.
"There is always room for error, of course; if I get a parking ticket or stub my toe on the way to the study, I'm not going to be particularly happy," says Pressman, who was not involved in the study but researches the impact of happiness on health. "But given that the study worked, it suggests that, on average, this day was fairly typical for the participants."
Unlike the happiness measures, depression symptoms were not associated with mortality rates once the researchers adjusted for overall health. According to the study, this finding suggests that the absence of happiness may be a more important measure of health in older people than the presence of negative emotions.
Health.com: The secrets to a super-happy winter
Positive emotions could contribute to better physical health in a number of ways. Regions of the brain involved in happiness are also involved in blood-vessel function and inflammation, for instance, and studies have shown that levels of the stress hormone cortisol tend to rise and fall with emotion.
The study doesn't prove that happiness (or unhappiness) directly affects lifespan, but the findings do imply that doctors and caregivers should pay close attention to the emotional well-being of older patients, the researchers say. "We would not advocate from this study that trying to be happier would have direct health benefits," Steptoe says.
However, this study and others like it should help establish happiness as a legitimate area of concern for health professionals, Pressman says. "There are still some people who see happiness as something fluffy and less scientific -- not something they should be worried about like, say, stress or depression," she says...
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