Saturday, October 31, 2015

Does Exercise Slow the Aging Process? - The New York Times

Almost any amount and type of physical activity may slow aging deep within our cells, a new study finds. And middle age may be a critical time to get the process rolling, at least by one common measure of cell aging.

Dating a cell's age is tricky, because its biological and chronological ages rarely match. A cell could be relatively young in terms of how long it has existed but function slowly or erratically, as if elderly.

Today, many scientists have begun determining a cell's biological age — meaning how well it functions and not how old it literally is — by measuring the length of its telomeres.

For those of us who don't know every portion of our cells' interiors, telomeres are tiny caps found on the end of DNA strands, like plastic aglets on shoelaces. They are believed to protect the DNA from damage during cell division and replication.

As a cell ages, its telomeres naturally shorten and fray. But the process can be accelerated by obesity, smoking, insomnia, diabetes and other aspects of health and lifestyle.

In those cases, the affected cells age prematurely.

However, recent science suggests that exercise may slow the fraying of telomeres. Past studies have found, for instance, that master athletes typically have longer telomeres than sedentary people of the same age, as do older women who frequently walk or engage in other fairly moderate exercise.

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U.S. deaths drop for leading causes - Yahoo News

The U.S. death rate for all causes is continuing to decline, aided by drops in fatalities from leading causes like heart disease, cancer, stroke, diabetes and accidents, new research finds. 

Between 1969 and 2013, the death rate for all causes declined 43 percent from about 1,279 people for each 100,000 individuals in the population to about 730 per 100,000, according to the study published today in JAMA, the journal of the American Medical Association.

Five of the six leading causes of death declined during the study period. Death rates dropped 77 percent for stroke, 68 percent for heart disease, 40 percent for unintended injuries, 18 percent for cancer, and 17 percent for diabetes. 

"The leading causes of death examined in this study – except unintentional injuries – all are chronic conditions," said lead study author Jiemin Ma, director of the surveillance and health services research program at the American Cancer Society. 

"Tobacco control, high blood pressure prevention and management, early detection and screening, and improvements in treating heart disease, stroke and some types of cancer have substantially contributed to reductions in death rates," Ma added by email.

Only one of the six leading causes of death – chronic obstructive pulmonary disease – didn't drop. Rates of death from COPD doubled despite a decline in deaths among men near the end of the study period.

To examine long-term trends in mortality, Ma and colleagues analyzed U.S. national vital statistics to determine the total and annual percent change in age-standardized death rates and years of life lost before age 75 for all causes combined and for the leading causes.

While death rates for five of the six leading causes dropped, the magnitude of the declines recently started to slow for heart disease, stroke and diabetes, the study found.

The progress against heart disease and stroke is due to improvements in controlling high blood pressure and cholesterol, smoking cessation and advances in treatment, the authors conclude.

Reductions in cancer deaths since the early 1990s is also due to tobacco control efforts as well as gains in early detection and treatment, the authors note. 

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Thursday, October 29, 2015

The 'Mall-ification' of Medical Care - The New York Times

Last week I was dashing through O'Hare International Airport in Chicago to catch a flight back to New York. Fifty feet before my gate I noticed a stand offering flu shots. I'd been considering getting a coffee before the flight, but maybe I should get a flu shot instead?

It sure looked tempting. I'd been meaning to get my flu shot at work, but whenever I had a moment the nurse was busy with patients, and whenever she was available I was locked in mortal combat with the electronic medical record system. The pleasant young woman at the airport clinic offered to check my insurance plan to see if it would be covered, and I was about to pull out my insurance card when the paperwork logistics gave me pause.

Because I'm a doctor and am required to get vaccinated, I'd have to get documentation from the airport kiosk, remember to bring it to my hospital, and figure out how to get it incorporated into my official medical record. And who was this white-coated person anyway, I wondered. Was she a nurse, a pharmacist, an airport employee? Who was certifying this kiosk? Were they storing the vaccine in the proper manner? Did they have equipment available to handle allergic reactions?

When retail health clinics started springing up in the early 2000's, many thought it was a passing fad. But these clinics have exploded over the last 10 years, and now it seems like every other big-box store, supermarket and shopping mall has its own clinic. Apparently airports are now getting in on the action.

Between 2007 and 2009, the number of visits to retail clinics quadrupled. Almost half the visits were after hours — on evenings and weekends when doctors' offices are usually closed. Most were for minor acute conditions like flu symptoms, ear infections and back pain, or for simple preventive care like vaccinations and sports physicals.

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Tuesday, October 27, 2015

The science against meat: A look at 5 key studies about cancer risk - The Washington Post

In making its decision to declare bacon, sausages and other processed meats carcinogens, the World Health Organization's research arm looked at 800 epidemiological studies from numerous countries with diverse ethnicities and diets. They gave the greatest weight to studies done in the general population, had a controlled design, large sample sizes, and/or used quantitative dietary data culled from questionnaires.

Below is a look at five of the key studies cited by the scientists in their announcement published in The Lancet Oncology on Monday. Most of the supporting studies focused on colorectal cancer but the panel said it also looked at data for 15 other types of cancer and found positive associations for red meat and pancreatic and prostate cancer and of processed meat for cancer of the stomach.

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The Black-White Sleep Gap

In 2005, re­search­ers at the Uni­versity of Cali­for­nia, San Diego, began an ex­per­i­ment that would last five years. One by one, they brought 164 study par­ti­cipants to a sleep lab at the U.C. San Diego Med­ic­al Cen­ter, a room with a sweep­ing view of the city and the sur­round­ing val­ley. There, par­ti­cipants un­der­went poly­so­m­no­graphy, the most com­pre­hens­ive sleep test known to sci­ence. A poly­so­m­no­graphy ma­chine is an oc­topus of a med­ic­al device: It has scalp sensors to re­cord brain-wave pat­terns; eye track­ers to as­sess rap­id eye move­ments; breath­ing sensors that are placed on the nose, mouth, and around the chest; a blood-oxy­gen sensor for the fin­gers; and sensors on the legs to track move­ment. The ma­chine pro­duces a chart—re­sem­bling a cross between a mu­sic­al com­pos­i­tion and a seis­mo­gram—that traces the brain and body minute by minute through the night.

"I think it's quite beau­ti­ful per­son­ally," says Li­anne Tom­fohr, who was the lead au­thor on the study and is now a psy­cho­logy pro­fess­or at the Uni­versity of Cal­gary. "We can put [sensors] on their head and, through the elec­tri­city in their brains, see how deeply they are sleep­ing. It's a little bit mys­tic­al to me that it is even pos­sible."

The San Diego re­search­ers planned to use the poly­so­m­no­graphy ma­chine to doc­u­ment slow-wave sleep—the phase of sleep "when it's really hard to wake you up," as Tom­fohr de­scribes it. Slow-wave sleep is thought to be the most res­tor­at­ive peri­od of sleep, and it's im­port­ant to good health: Ex­per­i­ments where people are denied slow-wave sleep on pur­pose have shown that bod­ies quickly change for the worse. (One pa­per, pub­lished in the Pro­ceed­ings of the Na­tion­al Academy of Sci­ences in 2007, found that study par­ti­cipants who were denied slow-wave sleep for three nights—re­search­ers would sound an alarm in their ears when they entered this sleep phase—be­came less sens­it­ive to in­sulin, a pre­curs­or to dia­betes.)

But it wasn't just slow-wave sleep in gen­er­al that in­ter­ested the re­search­ers; they spe­cific­ally hoped to com­pare how blacks and whites ex­per­i­enced slow-wave sleep. And what they found was dis­turb­ing. Gen­er­ally, people are thought to spend 20 per­cent of their night in slow-wave sleep, and the study's white par­ti­cipants hit this mark. Black par­ti­cipants, however, spent only about 15 per­cent of the night in slow-wave sleep.

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Costs for Dementia Care Far Exceeding Other Diseases, Study Finds - The New York Times

Three diseases, leading killers of Americans, often involve long periods of decline before death. Two of them — heart disease and cancer — usually require expensive drugs, surgeries and hospitalizations. The third, dementia, has no effective treatments to slow its course.

So when a group of researchers asked which of these diseases involved the greatest health care costs in the last five years of life, the answer they found might seem surprising. The most expensive, by far, was dementia.

The study looked at patients on Medicare. The average total cost of care for a person with dementia over those five years was $287,038. For a patient who died of heart disease it was $175,136. For a cancer patient it was $173,383. Medicare paid almost the same amount for patients with each of those diseases — close to $100,000 — but dementia patients had many more expenses that were not covered.

On average, the out-of-pocket cost for a patient with dementia was $61,522 — more than 80 percent higher than the cost for someone with heart disease or cancer. The reason is that dementia patients need caregivers to watch them, help with basic activities like eating, dressing and bathing, and provide constant supervision to make sure they do not wander off or harm themselves. None of those costs were covered by Medicare.

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Monday, October 26, 2015

Unexpected Honey Study Shows Woes of Nutrition Research - The New York Times

Just a few weeks ago, a study was published in the Journal of Nutrition that many reports in the news media said proved that honey was no better than sugar as a sweetener, and that high-fructose corn syrup was no worse.

This shocked people on all sides of the sweetener debate. It has become an article of faith among many that natural sweeteners like honey are better for you than engineered sweeteners like high-fructose corn syrup, especially for people concerned about diabetes.

Not so fast. A more careful reading of this research would note its methods. The study involved only 55 people, and they were followed for only two weeks on each of the three sweeteners. Sure, glucose and insulin levels and measures of insulin resistance were no different for honey, sugar and high fructose corn syrup. But should we really place so much faith in such a small, short-lived trial?

The truth is that research like this is the norm, not the exception. I've written about nutrition quite often here at The Upshot — about weight loss, dietary guidelines, healthy food choices, the role of exercise in weight loss, the potential benefits of coffee — and a fair amount of the time, it's to counter conventional wisdom, for example about milk, red meat or artificial sweeteners. Just a short while ago, I argued that while more recent nutritional guidelines are, perhaps, more evidence-based, they may still be straying from what we can glean from studies. Readers often ask me how myths about nutrition get perpetuated and why it's not possible to do conclusive studies to answer questions about the benefits and harms of what we eat and drink.

Almost everything we "know" is based on small, flawed studies. The conclusions that can be drawn from them are limited, but often oversold by researchers and the news media. This is true not only of the newer work that we see, but also the older research that forms the basis for much of what we already believe to be true. I'm not ignoring blockbuster studies because I don't agree with their findings; I'm usually just underwhelmed by what I can meaningfully conclude from them.

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