Friday, December 5, 2014

Keeping Your Heart Healthy During the Holidays

The holidays are a time of celebration with family, friends, and the community. During this time, millions of people change their normal habits of traveling, eating, drinking, and exercising. It also can be a time of increased stress due to travel, family, and work issues. These factors impact your health directly, and also for people with chronic diseases, the hustle bustle of the season may cause inappropriate delays in seeking medical therapy. For people with heart disease, some common sense strategies can help make a big difference in keeping a person at home for the holidays, instead of in an emergency room or a hospital bed or worse.
The first strategy for heart patients to stay healthy during the holidays is to continue with their routine medical doctor visits. It can be a big mistake to put off a scheduled appointment because a family member is flying in that day, or a friend is driving into town that day. Regular office visits can enable heart patients and their doctors to identify any change in medical condition early, while it still can be successfully treated.
Another strategy that can help heart patients during the holidays is to maintain their routine dietary and exercise habits. Excess salt in particular can lead to fluid retention, which can put extra strain on the heart. Also, sudden changes in exercise habits and exertion levels can also shock the heart, and sometimes cause some problems. While exercise is good for just about all of us, gradual changes generally are better tolerated by the body and more successful in getting the results we want. Also, stress reduction through meditation and similar activities also appears to be particularly helpful in heart disease patients.
Finally, remember that there are people in the medical clinics, in the hospitals, and in the emergency rooms during the holidays. They are there to help. Heart patients should not hesitate in seeking medical attention just because it is Christmas Day or New Year's Eve. When it comes to your heart, getting prompt medical attention, when it is necessary, can be life saving.
Discuss all of these issues ahead of time during a routine visit to your doctor. This will help decrease your stress levels and your anxiety, which is good for your heart. Be sure to ask about what you should do if you have a question. Discuss dietary issues, including salty foods such as ham or chips. Making a plan ahead of time can help you stay as healthy as possible during the holidays.
When and why do heart attacks occur? Cardiovascular triggers and their potential role. Schwartz BG, Mayeda GS, Burstein S, Economides C, Kloner RA. Hosp Pract (Minneap). 2010 Aug;38(5):144-52.
Cardiac mortality is higher around Christmas and New Year's than at any other time: the holidays as a risk factor for death. Phillips DP, Jarvinen JR, Abramson IS, Phillips RR. Circulation. 2004 Dec 21;110(25):3781-8. Epub 2004 Dec 13. Review.
Published by Tom Heston MD 12/7/2011
Tom Heston MD is a Johns Hopkins trained physician who practices clinical medicine in the Pacific Northwest.

Tuesday, November 18, 2014

Are Bicycle Lanes Good for Bicyclists?


Researchers have just found that designated bicycle lanes do not effectively increase the distance between a passing car and the bicyclist.

This recent study in an urban environment found that there are more significant variables than the presence of a bicycle lane that affects the overtaking distance between vehicle and bicycle. These important factors are:
  • Absolute width of the road
  • Nearside parking
  • Opposing vehicle traffic
Not surprisingly, the authors identified a larger "unknown factor" that affected how wide of a margin the driver gave the bicyclist. And that factor is (drum roll)..... the driver.

So, what can be done? Possible ways to improve bicycle safety in traffic include:

  • Make roads wide enough to handle both vehicle and bicycle traffic
  • Promote a driving culture that respects bicycle riders
  • Limit parking to side-streets

Cycle Lanes: Their Effect on Driver Passing Distances in Urban Areas

TransportVolume 29, Issue 3, 2014Special Issue: Special Issue on Travel Demand Management

Saturated Fats Bad, Polyunsaturated Fats Better

A recent study from Sweden and published by the American Heart Association has found that a diet rich in saturated fats leads to an unhealthy balance in serum cholesterol levels, whereas polyunsaturated fats have a more beneficial response. J Am Heart Assoc. 2014; 3: e001095

Comment: there are two important issues to consider when evaluating this study. First, adding polyunsaturated fats to the diet tends to lead to weight gain, which in most people will lead to excess weight gain. So, it is important to substitute polyunsaturated fats for calories coming from other sources. Secondly, it  does appear that saturated fats are not very good for you. Based on this study, here's a brief list of the "bad" fats (saturated) and the "better" fats (polyunsaturated).

  • most come from animal sources including meat and dairy products
  • fatty beef
  • lamb
  • port
  • poultry with skin
  • butter
  • most cheeses
  • dairy products made with whole or 2% reduced fat mil.
  • palm oil, coconut oil
  • OILS: soybean, corn, sunflower
  • some fish oils (salmon, mackerel, herring, trout)
  • walnuts, sunflower seeds
  • tofu
  • soybeans
  • flaxseed
 Now, what about "mono" unsaturated fats? These might be the best kinds of dietary fats, but at least they are considered to be better than saturated fats.

  • OILS: olive, canola, peanut, safflower, and sesame
  • Avocados
  • peanut butter (check the label)
  • many nuts and seeds, e.g. macadamia, hazelnuts, pecans, almonds, pistachios, cashews
  • certain types of margarine
  • cheeses: roquefort, monterey jack, parmesan
  • eggs (mostly good fats but also contain saturated fat)

  • Regular exercise and a stable, healthy weight are very important. 
  • High sugar foods are almost always "BAD"

Thursday, November 6, 2014

Colorectal cancer prevention by an optimized colonoscopy protocol

METHODS: retrospective cohort study of an optimized colonoscopy protocol: 
  • telephonic reinforcement of bowel preparation instructions; 
  • active inspection for polyps throughout insertion and circumferential withdrawal; and 
  • timely updating of the protocol and documentation to incorporate the latest guidelines. 
RESULTS: 17,312 patients underwent screening colonoscopies by 59 endoscopists in South Carolina, USA. Over 78,375 person-years of observation, the colorectal cancer mortality reduction was 89% (p < 0.001; four CRC deaths vs. 35.95 expected). 

CONCLUSION: Over 80% reduction in colorectal cancer incidence and mortality is achievable in routine practice by implementing key colonoscopy principles targeting near-complete polyp clearance.

Int J Cancer. 2014 Sep 20. doi: 10.1002/ijc.29228.

Monday, October 20, 2014

College Student Health: UK versus the US

A recent study found that compared to UK college students, US college students live a healthier lifestyle. As a percentage, UK students smoke twice as much as US college students (39% vs 16%). This in part may be due to the 1,478 smoke-free campuses in the US, of which 976 are 100 percent tobacco-free and 292 prohibit the use of e-cigarettes anywhere on campus. US students also self-reported greater fruit & vegetable consumption and greater physical activity. Read More

Thursday, October 16, 2014

The Prevention of Breast Cancer

Breast cancer continues to be a prevalent, and deadly cancer. It is the most common cancer in women and next to lung cancer, the second most common cause of death from cancer in women. 
A recent column in the Times Colonist lamented that with all the focus on screening and the use of mammography, what gets lost in the story is the need to pursue aggressive prevention strategies such as a health diet and adequate exercise. With the recent U.S. and Canadian governments issuing major guidelines on the use of a technology, and another recent U.S. Food and Drug Administration change in approval for a pharmaceutical, one has to wonder why isn't more attention being paid to prevention? 
There are strong evidence based recommendations on how to prevent breast cancer. One is to eat a healthy diet. This means maintaining a healthy weight and for most of us eating more vegetables. A major goal is to increase the fiber-to-sugar ratio in the diet. 
Exercise has been shown consistently to positively affect the healthy life span. This is also true when it comes to breast cancer. Not only is exercise a preventive strategy, it likely is also of benefit to increase the percentage of otherwise health, cancer survivors. 
The situation with alcohol usage is not as clear. It appears to increase the rate of breast cancer but when taken in moderation, also decrease the risk of an adverse cardiovascular event. Smoking, because of its strong association with other severe diseases, namely lung cancer and heart disease, is not recommended. Greater emphasis toward smoking cessation, or ideally never starting, would thereby make an enormous impact upon women's health. 
Alberta Physical Activity and Breast Cancer Prevention Trial: Inflammatory Marker Changes in a Year-long Exercise Intervention among Postmenopausal Women. Friedenreich C, Neilson HK, Woolcott CG, Wang Q, Stanczyk FZ, McTiernan A, Jones CA, Irwin ML, Yasui Y, Courneya KS. Cancer Prev Res (Phila). 2011 Oct 7. [Epub ahead of print]
Effect of supervised and home exercise training on bone mineral density among breast cancer patients. A 12-month randomised controlled trial. Saarto T, Sievänen H, Kellokumpu-Lehtinen P, Nikander R, Vehmanen L, Huovinen R, Kautiainen H, Järvenpää S, Penttinen HM, Utriainen M, Jääskeläinen AS, Elme A, Ruohola J, Palva T, Vertio H, Rautalahti M, Fogelholm M, Luoto R, Blomqvist C. Osteoporos Int. 2011 Sep 3. [Epub ahead of print]
Vegetables, but not pickled vegetables, are negatively associated with the risk of breast cancer. Yu H, Hwang JY, Ro J, Kim J, Chang N. Nutr Cancer. 2010;62(4):443-53. Erratum in: Nutr Cancer. 2010 Jul;62(5):700.
Published by Tom Heston MD 11/30/2011
Tom Heston MD is a Johns Hopkins trained physician who practices clinical medicine in the Pacific Northwest.

Wednesday, October 15, 2014

Thus Came the Opportunity

A villanelle on the meaning of community

The important thing was integrity.
Especially at first, from the start.
Thus came the opportunity.

As he joined the crowd in gaiety
acting together came music and art,
the important thing was integrity.

Who was he, what was destiny?
A shadow, yes, but unique and a lark.
Thus came the opportunity.

So venture adventure, ride calamity
he thought. This was his truth, his art.
The important thing was integrity.

Then came the curious trip, a bold serenity
coming from his spirit and deep in his heart.
Thus came the opportunity.

This is the strength of community:
the people together yet uniquely apart.
The important thing was integrity.
Thus came the opportunity.

Going Home for Christmas

All she wanted was to go home for Christmas.
As I looked down upon her, laying there on the hospital bed as she constantly gasped for another breath, it was clear that there was no cure. There was no earthly salvation that would bring her back to what she used to be, many years ago, in her youth.
She once was a lively, young and energetic woman. Got married. Had kids, even grand kids. But for some reason, a long time ago, she started smoking. Now she was paying the final price. End-stage emphysema with a constant air hunger that nobody could satisfy.
In between short breaths, she spoke one or two words at a time.
"Please.... help me.... I want.... to go.... home.... for.... Christmas."
I nodded in assent. Sometimes a physician cannot cure, cannot heal, and the chance for prevention long past. But this wish of hers, maybe I could help give her some comfort.
The family came in later that day and we talked. They understood that the number of mom's days were coming down to the single digits. They knew there was nothing more that medical science could do for their mother. And they agreed. Mom would spend her Christmas at home! Not in a hospital ward. Not in her hospital bed. Home.
Then, later, when doing my evening rounds on my patients, the nurse told me the family had changed their mind. Taking care of their mom at home would be simply too much, they said. It would ruin Christmas, for years to come. We need to leave her here so she can have a nurse, a doctor, and all the medical equipment nearby, they said.
So along came Christmas, and it was my turn to cover the hospital for the group of physicians I worked with. I had two young boys at home, a loving wife to go back to. But they understood. Today would not be my last Christmas spent at the hospital.
My patient again looked at me with pleading eyes, gulping in small bites of air. It was clear to all of us that her number was now down not to days, but to hours. Terminal disease, that's what we called it. We had done absolutely everything we could medically. Those damn cigarettes, we'd say. But nevertheless, the time was close. Maybe yet I could do something for her. Maybe my calling was not to simply apply medical technology, but to give of my spirit, and share my soul. Maybe.
So I sat with her. We held hands. And the time, well it came peacefully. Without drama or fanfare, but with serenity and calmness. Our hands clasped, we spent the moment together in that empyrean realm beyond words.
She got her Christmas wish.
Peace. Friendship. And going home.

~ Tom Heston MD

The New Idea Out West

Old doc Clarence filled his black medical bag back up with the tools of his profession: several knives, his glasses, some bandages, a few potions, some whiskey, and needle and thread. It was over. Now things fall into the hands of nature, whether to take its course towards death or turn back towards life.
"I've done everything possible, Ma'am." he said to Mrs. Turner. He had forgotten her name so just said Ma'am.
With that, he wrapped up in his coat, hat, and gloves, bracing himself for the cold outside. Doc Clar was practical, no-nonsense, and effective. From his boots, to his horse, to his medical bag, his way was simple practicality. 
"And you might want to clean things up with some soap and water" he said as leaving the warmth of the hearth and the seriousness of the family emergency. He was asked to help, he had done his best. 
His not-so-close neighbor, Franklin Turner, farmed barley to support his wife and two young boys, both of whom were under 3 years of age. It was when riding out into the field that his horse got startled, jumped, and threw Frank off the saddle and onto that craggy tree root. His head was headed straight at the twisted shard of thick tree roots, but at the last split-second he was able to throw an arm in front of his eye, saving his vision but causing a deep gash into the meat of his arm. His right arm. His dominant hand. His work hand. He was thinking about the survival of his family. What would this injury mean? 
What good could he do without the use of his right arm? Plenty, yes, but it would slow him down, and he even knew of some people who would die of such a wound. What he could do in an hour with both arms now would take two hours, or three hours, or even longer. A good thing doc Clarence was nearby.
"I'll keep it clean, just like you say, doc."

Frank would follow that crazy man's advise, and use plenty of soap and water to keep things clean. Doc Clar wasn't the fanciest dresser, or the most talkative person around, but he did seem to get results. It was Frank's best chance.
"Uh-huh" the doc grunted as he went out to his horse.
He was going to miss dinner again, not that he was hungry anyway. The country roughened doctor's thoughts were consumed with that new idea from Europe, that a clean wound heals better. Made sense. He just hoped that crazy Hungarian Semmelweis was correct, and that it would help.
Frank Turner was a good man, a good father, and although they weren't that close, Clarence considered him a friend. Maybe hand washing really did work. Maybe. At least that's what his buddy told him over a beer at the tavern. Maybe it would even work for Frank.
"Come on, Ginny" he said to his horse, as they started the long, night, ride. Back on the trail, back home.

What's Inside

I fear becoming my patient.
Positron emissions where they shouldn't be,
x-ray deflections that aren't quite right.

On the outside he smiles,
with only the faintest hint
of the terrible, tragic, and
deathly wrong.

I give the radioactivity
- yes I'm helping! -
then, bad news comes,
the disease progresses,
and pain happens.

The wife, the child at home,
the things left undone.
The great beyond of forever.
An unstoppable tsunami,
not far off.

So I smile warmly.
We share a laugh.
We still have this moment.
We still have this joy.

The burst of light we share can't be seen,
yet it shines brighter
than the photon flux,
that hits the crystal,
inside my camera.

The scan is real,
but what does it reveal,
about what's inside?

The Power of Snow (Haiku)

The coughs and the colds
and all the runny noses
cured by winter's snow.

The ABC's of Heart Health

Although many heart problems cannot be prevented, there are a few principles that will at least lower your risk of getting heart disease or suffering from complications of existing heart disease. While you should always consult your personal health care provider first, my patients have found that this simple ABC plan helps them focus on what is important. 
A- stay ACTIVE. This is perhaps the most important principle of good health. Science has consistently shown that regular exercise not only helps you stay healthy, it also helps prevent the development of many heart diseases. Regular exercise can lower the risk of heart disease and evens some forms of cancer. In addition, it seems to be helpful in lowering the risk of diabetes, obesity, and high blood pressure which all can contribute to heart disease.
B- regularly check your BLOOD PRESSURE. In most cases, high blood pressure occurs slowly, and does not cause any symptoms. You could easily have high blood pressure, but not even know it! Be sure to get your blood pressure checked using a machine that is regularly calibrated so that the results are accurate. Good blood pressure control helps reduce the risk of heart disease and stroke.
C- control your CHOLESTEROL levels. High cholesterol levels, over time, can increase the risk of coronary artery disease, peripheral vascular disease, and stroke. High cholesterol levels are almost always entirely asymptomatic, meaning that you need to get a blood test in order to know if your levels are increased. Although cholesterol levels typically go up with increasing weight, in some people there is a genetic predisposition, and their cholesterol levels may be increased even though they have a normal body weight. If your cholesterol levels are high, there are several different options of getting it back into the healthy range, so feel comfortable getting medical treatment for this. High cholesterol levels do not necessarily mean a lifetime of taking a prescription medication.
D- consume a healthy DIET. Perhaps the most important component of a healthy diet is to maintain a healthy weight. So eat a wide variety of foods, but be particularly careful about controlling your calories so your weight is in a desirable range. Most people could benefit from eating more green vegetables and less sugar. It sometimes seems like there are millions of different diet programs available, but the major objective is to control your calories with a healthy diet that you enjoy and can follow for a long period of time. A good start is the MegaSimple Diet which emphasizes more fiber and less sugar. Of course, a healthy diet means that you DON'T SMOKE and don't abuse alcohol or other drugs.
E- make sure you ENJOY LIFE. A happy and positive outlook seems to help the heart stay healthy and strong. Although there are many things you cannot control, having an optimistic view of your life can improve your situation. We cannot prevent all heart disease, and cannot control our genetics. Accidents and sporadic illnesses occur, and even if we live a perfect life we are still vulnerable to random diseases and accidents. So enjoy the present moment, today.
That's it ! Stay ACTIVE, control your BLOOD PRESSURE, control your CHOLESTEROL, eat a healthy DIET and DON'T SMOKE, and finally ENJOY LIFE. By focusing on these simple, fundamental principles you can help lower your risk of heart disease, help prevent complications of existing disease, and stay healthy.
Tom Heston MD is a Johns Hopkins trained physician and a Fellow of the American Academy of Family Practice and a Fellow of the American Society of Nuclear Cardiology. He practices medicine in the Pacific Northwest.

Saturday, August 30, 2014

Wednesday, April 30, 2014

Dyspnea during daily activities predicts all-cause mortality

Dyspnea during light daily activities can be used as an indicator of exercise intolerance and low fitness. Persistent or developing dyspnea reveals an increased risk of death. Read More

Saturday, March 29, 2014

TV linked to poor snacking habits, cardiovascular risk in middle schoolers

Middle school kids who park themselves in front of the TV for two hours or more each day are more likely to consume junk food and have risk factors for cardiovascular disease, even compared to those who spend an equal amount of time on the computer or playing video games, according to research. Read More

Friday, March 21, 2014

Measles Outbreak Alert: Information and Photos from the CDC

Whatcom County, located in northwestern Washington State, has just had its first case of measles since 1995. In addition, there is a measles outbreak occurring presently in British Columbia, Canada.

Given that vaccination rates are not 100%, the return of measles has triggered an aggressive public health alert in order to contain any new outbreaks that may occur.

In the pre-vaccine era, measles regularly affected a large percentage of the population in the U.S., primarily children. It killed about 1 to 3 people out of a thousand infected, and caused permanent brain damage in about 1 to 2 people out of a thousand people infected.

Measles information from the CDC

  • Measles is a highly contagious rash illness that is transmitted from person to person by direct contact with respiratory droplets or airborne spread. 
  • About 90% of susceptible exposed individuals will get infected.
  • The average incubation period for measles is 10 to 14 days from exposure to rash (range: 7–21 days).
  • Persons with measles are infectious 4 days before through 4 days after rash onset.
  • Commonly reported complications are pneumonia (6%), otitis media (7%), and diarrhea (8%)
  • In low to middle income countries where malnutrition is common, measles is often more severe and the case-fatality ratio can be as high as 25%
  • Measles can be severe and prolonged among immunocompromised persons, particularly those who have leukemias, lymphomas, or HIV infection. Among these persons, measles can occur without the typical rash and a patient can shed measles virus for several weeks after the acute illness. However, a fatal measles case without rash also has been reported in an apparently immunocompetent person.
  • A persistent measles virus infection can result in subacute sclerosing panencephalitis (SSPE), a rare and usually fatal neurologic degenerative disease.Signs and symptoms of SSPE appear an average of 7 years after measles infection, but might appear decades later.
  • Widespread use of measles vaccine has led to the virtual disappearance of SSPE in the United States, but imported cases still occur.

CDC - Measles: Photos

From the Whatcom County department of health:

Precautions To Take When Scheduling Visits for Measles Assessment
  • Instruct telephone and triage staff to assess for rash illnesses prior to the patient coming to the facility
  • Patient MUST wear a mask before they enter the facility. (surgical masks are sufficient). Examine patients in their vehicle if necessary.
  • Rapidly isolate persons with suspected measles in a private room and call the Health Department. In hospital settings, patients with suspected measles should be placed immediately in a negative-pressure isolation room if one is available and, if possible, should not be sent to other parts of the facility.
  • Only staff who have documented immunity to measles should be present in the room with the patient.
  • Airborne precautions must be implemented during the exam. (N-95 masks are preferable, when available, for staff to use while in the room).
  • The exam room should not be occupied for at least two hours after the patient leaves.
More information:

Wednesday, March 19, 2014

Links explored between physical activity, learning

The association between physical activity and learning has been evidenced in many studies. The results have suggested that being physically active produces positive effects on many cognitive functions, such as memory, attention, information processing and problem solving. Unfortunately, these previous studies have used fairly small datasets and have yielded fairly little information on the actual underlying mechanisms. Read More

Smokers lack motivation

While the results of smoking may be expected to decrease fitness, new research has found that smokers are less physically active, lack motivation and are more likely to suffer symptoms of anxiety and depression. Read More

Monday, March 17, 2014

Older adults: Build muscle and you'll live longer

The more muscle mass older Americans have, the less likely they are to die prematurely, new research shows. The findings add to the growing evidence that overall body composition -- and not the widely used body mass index, or BMI -- is a better predictor of all-cause mortality. "In other words, the greater your muscle mass, the lower your risk of death," said the study's co-author. "Thus, rather than worrying about weight or body mass index, we should be trying to maximize and maintain muscle mass." Read More

Exercise in older patients improves health

This 12-week fitness program increased motivation and encouraged people to continue with regular physical activity even after they completed the program.  Read More

Even a 5% weight loss can prevent and treat obstructive sleep apnea

This is no surprise - even a small amount of weight loss helps prevent and treat obstructive sleep apnea. Read More

Thursday, March 13, 2014

Abdominal fat accumulation prevented by unsaturated fat

New research shows that saturated fat builds more fat and less muscle than polyunsaturated fat. This is the first study on humans to show that the fat composition of food not only influences cholesterol levels in the blood and the risk of cardiovascular disease but also determines where the fat will be stored in the body. Gaining weight on excess calories from polyunsaturated fat appears to cause more gain in muscle mass, and less body fat than overeating a similar amount of saturated fat. Read More

Large waist linked to poor health, even among those in healthy body mass index ranges

Having a big belly has consequences beyond trouble squeezing into your pants. It's detrimental to your health, even if you have a healthy body mass index (BMI), a new international collaborative study has found. Men and women with large waist circumferences were more likely to die younger, and were more likely to die from illnesses such as heart disease, respiratory problems, and cancer after accounting for body mass index, smoking, alcohol use and physical activity. Read More

Wednesday, March 12, 2014

The Obese Get Less Than One Minute of Vigorous Activity per Day

This research found that in the U.S. most people spend more than 15 hours per day sleeping and sitting. Obese people were found to spend less than one minute per day in vigorous activity. Read More

The Effect of Moderate Exercise on Strok Risk in Women

This study found that moderate exercise, e.g. brisk walking, may decrease a woman's stroke risk by a full 20 percent.  Read More

Monday, March 10, 2014

Self-rated physical fitness in midlife an indicator of dementia risk

How would you rate your own physical fitness? Is it good, satisfactory or maybe even poor? Surprisingly, your answer may reveal your future risk of getting dementia. A recent collaborative study from Finland, involving the follow-up of 3,559 adults for 30 years, has found that a simple question about self-rated physical fitness in midlife may reveal individuals who are at an increased risk of developing dementia. Those who reported poor self-rated physical fitness in midlife, at the mean age of 50 years, were four times more likely to get dementia during the next three decades compared to those with good self-rated physical fitness. Read More

Lower IQ and poorer cardiovascular fitness in teen years increase risk of early-onset dementia

Men who at the age of 18 years have poorer cardiovascular fitness and/or a lower IQ more often suffer from dementia before the age of 60. This is shown in a recent study encompassing more than one million Swedish men. Read More

Attitude during pregnancy affects weight gain, research shows

Overweight or obese women with the mentality that they are 'eating for two' are more likely to experience excessive weight gain while pregnant, according to research. Researchers interviewed 29 post-partum women who were overweight or obese before pregnancy. Participants in the study were asked about their diet habits, experience with morning sickness and physical activity habits during pregnancy. Those who gained the appropriate amount of weight stuck to a meal plan and chose foods carefully. These women also had little or no increase in the amount of calories they consumed during pregnancy and exercised as much or more than they had before the pregnancy. Women who gained excessive weight described the experience as "eating for two." They had fewer goals and exercised less than usual during their pregnancy. They also made less healthy food choices and ate more as a result of cravings. Read More

Sunday, March 9, 2014

Exercise, surgically removing belly fat improves cognition in obese, diabetic mice

Cognitive decline that often accompanies obesity and diabetes can be reversed with regular exercise or surgical removal of belly fat, scientists report. A drug already used to treat rheumatoid arthritis also helps obese/diabetic adult mice regain their ability to learn and comprehend, while transplanting belly fat to a normal mouse reduces those abilities. Studies in humans and animals indicate that obesity and diabetes -- which often go hand in hand -- essentially triple the risk of mild cognitive impairment as well as Alzheimer's.Read More

Dangers of ... sitting? Regardless of exercise, too much sedentary time is linked to major disability after 60

If you're 60 and older, every additional hour a day you spend sitting is linked to doubling the risk of being disabled -- regardless of how much exercise you get, reports a new study. The study is the first to show sedentary behavior is its own risk factor for disability, separate from lack of moderate vigorous physical activity. In fact, sedentary behavior is almost as strong a risk factor for disability as lack of exercise. Read More

Thursday, March 6, 2014

A repeated measures experiment of green exercise to improve self-esteem in UK school children.

A repeated measures experiment of green exercise to improve self-esteem in UK school children.
PLoS One. 2013;8(7):e69176
Authors: Reed K, Wood C, Barton J, Pretty JN, Cohen D, Sandercock GR

Exercising in natural, green environments creates greater improvements in adult's self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called 'green exercise' affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run) and self-reported physical activity (PAQ-A) in 11 and 12 year olds (n = 75). Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE) and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74), = 12.2, p<0.001), for the increase in self-esteem following exercise but there was no condition by exercise interaction (F (1,74), = 0.13, p = 0.72). There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = -0.26, p = 0.04) between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = -0.07, p = 0.55). Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise.

Read More

Tuesday, March 4, 2014

Can exercise-related improvements in immunity influence cancer prevention and prognosis in the elderly?

Can exercise-related improvements in immunity influence cancer prevention and prognosis in the elderly?
Maturitas. 2013 Sep;76(1):51-6
Authors: Bigley AB, Spielmann G, LaVoy EC, Simpson RJ

Cancer incidence increases with advancing age. Over 60% of new cancers and 70% of cancer deaths occur in individuals aged 65 years or older. One factor that may contribute to this is immunosenescence - a canopy term that is used to describe age-related declines in the normal functioning of the immune system. There are multiple age-related deficits in both the innate and adaptive systems that may play a role in the increased incidence of cancer. These include decreased NK-cell function, impaired antigen uptake and presentation by monocytes and dendritic cells, an increase in 'inflammaging', a decline in the number of naïve T-cells able to respond to evolving tumor cells, and an increase in functionally exhausted senescent cells. There is consensus that habitual physical exercise can offer protection against certain types of cancer; however the evidence linking immunological mechanisms, exercise, and reduced cancer risk remain tentative. Multiple studies published over the last two decades suggest that exercise can mitigate the deleterious effects of age on immune function, thus increasing anti-cancer immunity. The potential ameliorative effect of exercise on these mechanisms include evidence that physical activity is able to stimulate greater NK-cell activity, enhance antigen-presentation, reduce inflammation, and prevent senescent cell accumulation in the elderly. Here we discuss the role played by the immune system in preventing and controlling cancer and how aging may retard these anti-cancer mechanisms. We also propose a pathway by which exercise-induced alterations in immunosenescence may decrease the incidence of cancer and help improve prognosis in cancer patients.

Read More

Associations between vitamin D receptor polymorphisms and breast cancer risk.

Associations between vitamin D receptor polymorphisms and breast cancer risk.
Tumour Biol. 2013 Dec;34(6):3823-30
Authors: Wang J, He Q, Shao YG, Ji M, Bao W

Many epidemiologic studies have investigated the association between vitamin D receptor (VDR) gene polymorphisms and breast cancer risk, but the results were inconsistent. We performed a meta-analysis of 31 studies on VDR polymorphisms, including FokI, BsmI, TaqI, and ApaI, and breast cancer risk published before May 2013. For FokI, the allele of f was found to be associated with increased risk of breast cancer compared with F (OR, 1.19; 95% CI, 1.03-1.36). Patients with ff genotype were at significantly higher risk of breast cancer compared with those with FF genotype (OR, 1.95; 95% CI, 1.66-2.29). In subgroup analysis by race, Fok1 polymorphism was significantly associated with breast cancer risk for Caucasian population (f vs. F: OR, 1.35; 95% CI, 1.14-1.59; ff vs. FF: OR, 2.18; 95% CI, 1.86-2.54; ff vs. FF + Ff: OR, 1.16; 95% CI, 1.03-1.30). For ApaI, aa genotype was associated with increased breast cancer risk in Asian population based on four studies (aa vs. Aa + AA, OR, 1.49; 95% CI, 1.12-1.98). No significant association was found between breast cancer risk and ApaI and TaqI polymorphism in different models and populations. Our updated meta-analysis showed that Fok1 polymorphism is associated with breast cancer risk both in general population and in Caucasian population. ApaI polymorphism might be associated with breast cancer risk in Asian population. Large well-designed epidemiological studies are necessary to clarify the risk identified in the current meta-analysis.

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Sunday, March 2, 2014

Predictors of short-term outcome to exercise and manual therapy for people with hip osteoarthritis.

Predictors of short-term outcome to exercise and manual therapy for people with hip osteoarthritis.
Phys Ther. 2014 Jan;94(1):31-9
Authors: French HP, Galvin R, Cusack T, McCarthy GM

BACKGROUND: Physical therapy for hip osteoarthritis (OA) has shown short-term effects but limited long-term benefit. There has been limited research, with inconsistent results, in identifying prognostic factors associated with a positive response to physical therapy.
OBJECTIVES: The purpose of this study was to identify potential predictors of response to physical therapy (exercise therapy [ET] with or without adjunctive manual therapy [MT]) for hip OA based on baseline patient-specific and clinical characteristics.
DESIGN: A prognostic study was conducted.
METHODS: Secondary analysis of data from a multicenter randomized controlled trial (RCT) (N=131) that evaluated the effectiveness of ET and ET+MT for hip OA was undertaken. Treatment response was defined using OMERACT/OARSI responder criteria. Ten baseline measures were used as predictor variables. Regression analyses were undertaken to identify predictors of outcome. Discriminative ability (sensitivity, specificity, and likelihood ratios) of significant variables was calculated.
RESULTS: The RCT results showed no significant difference in most outcomes between ET and ET+MT at 9 and 18 weeks posttreatment. Forty-six patients were classified as responders at 9 weeks, and 36 patients were classified as responders at 18 weeks. Four baseline variables were predictive of a positive outcome at 9 weeks: male sex, pain with activity (<6/10), Western Ontario and McMaster Universities Osteoarthritis Index physical function subscale score (<34/68), and psychological health (Hospital Anxiety and Depression Scale score <9/42). No predictor variables were identified at the 18-week follow-up. Prognostic accuracy was fair for all 4 variables (sensitivity=0.5-0.58, specificity=0.57-0.72, likelihood ratios=1.25-1.77), indicating fair discriminative ability at predicting treatment response.
LIMITATIONS: The short-term follow-up limits the interpretation of results, and the low number of identified responders may have resulted in possible overfitting of the predictor model.
CONCLUSIONS: The authors were unable to identify baseline variables in patients with hip OA that indicate those most likely to respond to treatment due to low discriminative ability. Further validation studies are needed to definitively define the best predictors of response to physical therapy in people with hip OA.

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Exercise and Smell

Association of exercise with lower long-term risk of olfactory impairment in older adults.
JAMA Otolaryngol Head Neck Surg. 2013 Oct;139(10):1061-6
Authors: Schubert CR, Cruickshanks KJ, Nondahl DM, Klein BE, Klein R, Fischer ME

IMPORTANCE: The prevalence of olfactory impairment is high in older adults, and this decline in olfactory ability may pose health and safety risks, affect nutrition, and decrease quality of life. It is important to identify modifiable risk factors to reduce the burden of olfactory impairment in aging populations.
OBJECTIVE: To determine if exercise is associated with the 10-year cumulative incidence of olfactory impairment.
DESIGN, SETTING, AND PARTICIPANTS: Observational longitudinal population-based Epidemiology of Hearing Loss Study. Participants without olfactory impairment (n = 1611) were ages 53 to 97 years at baseline and were followed for up to 10 years (1998-2010).
MAIN OUTCOMES AND MEASURES: Olfaction was measured with the San Diego Odor Identification Test at 3 examinations (1998-2000, 2003-2005, and 2009-2010) of the Epidemiology of Hearing Loss Study. The main outcome was the incidence of olfactory impairment 5 (2003-2005) or 10 (2009-2010) years later and the association of baseline exercise with the long-term risk of developing olfactory impairment.
RESULTS: The 10-year cumulative incidence of olfactory impairment was 27.6% (95% CI, 25.3%-29.9%) and rates varied by age and sex; those who were older (hazard ratio [HR], 1.88 [95% CI, 1.74-2.03], for every 5 years) or male (HR, 1.27 [95% CI, 1.00-1.61]) had an increased risk of olfactory impairment. Participants who reported exercising at least once a week long enough to work up a sweat had a decreased risk of olfactory impairment (age- and sex-adjusted HR, 0.76 [95% CI, 0.60-0.97]). Increasing frequency of exercise was associated with decreasing risk of developing olfactory impairment (P value for trend = .02).
CONCLUSIONS AND RELEVANCE: Regular exercise was associated with lower 10-year cumulative incidence of olfactory impairment. Older adults who exercise may be able to retain olfactory function with age.

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Thursday, February 27, 2014

The Women's Health Initiative Randomized Controlled Dietary Modification Trial: an inconvenient finding and the diet-heart hypothesis.

The Women's Health Initiative Randomized Controlled Dietary Modification Trial: an inconvenient finding and the diet-heart hypothesis.
S Afr Med J. 2013 Nov;103(11):824-5
Authors: Noakes TD

One goal of the US$700 million Women's Health Initiative Randomized Controlled Dietary Modification Trial was to determine whether post-menopausal women who adopted what was regarded as a 'heart healthy' low-fat diet, high in vegetables, fruits and grains, reduced their risk of developing cardiovascular disease. The trial substantially favoured the outcome in the intervention group, who also received an intensive nutritional and behaviour education programme not offered to the control group. These studies neatly disprove the diet-heart hypothesis since adoption of 'heart healthy' eating not only failed to influence future cardiac events in the healthy but it increased such events in the unhealthy and worsened diabetic control in those with type 2 diabetes mellitus. 

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Tuesday, February 25, 2014

Correlation between physical activity and sedentary behavior with healthy and unhealthy behaviors in Italy and Tuscan region: a cross sectional study.

Correlation between physical activity and sedentary behavior with healthy and unhealthy behaviors in Italy and Tuscan region: a cross sectional study.
J Prev Med Hyg. 2013 Mar;54(1):41-8
Authors: Lazzeri G, Azzolini E, Pammolli A, De Wet DR, Giacchi MV

INTRODUCTION: Regular physical activity (PA) has associated with various positive health aspects such as a decreased risk of chronic or generic illnesses, furthermore, a sedentary lifestyle has been associated with health problems such as obesity. To examine the relationship between patterns of PA, screen-based media use (SBM) and social health indicators within a specific demographic group and highlight the regional vs. national differences in these relationships.
METHODS: The data is drawn from the Health Behaviour in School-Aged Children (HBSC) database, a national cross-sectional survey in a representative sample (N = 3920) of students aged 11-13-15 years and compared to those of the Tuscan region (N = 3381). Variables considered other than PA and SBM use includes positive health indicators such as physical health status, quality of family and peer relationships, fruit consumption, breakfast consumption as well as negative health indicators, such as health complaints, smoking and alcohol use.
RESULTS: Some positive health indicators showed a positive correlation with PA. Students adopting healthy behaviours often met the Physical Activity Guide Line (PAGL). On the contrary, negative health indicators were associated with PAGL in a negative way. In general SBM was positively related to several of the negative health indicators and vice versa. SBM was related in a positive fashion to tobacco use that represents a protective factor.
DISCUSSION: The results show that met PAGL is associated with positive health indicators and that high levels of SBM use is associated with negative health indicators. The study also emphasizes the relationship between PA, SBM use and socialfactors. Increasing PA and decreasing SBM use should be an aim in general health behaviour promotion.

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comment: more physical activity is good for your health. 

Diet and the microbial aetiology of dental caries: new paradigms.

Diet and the microbial aetiology of dental caries: new paradigms.
Int Dent J. 2013 Dec;63 Suppl 2:64-72
Authors: Bradshaw DJ, Lynch RJ

The microbial and dietary factors that drive caries have been studied scientifically for 120 years. Frequent and/or excessive sugar (especially sucrose) consumption has been ascribed a central role in caries causation, while Streptococcus mutans appeared to play the key role in metabolising sucrose to produce lactic acid, which can demineralise enamel. Many authors described caries as a transmissible infectious disease. However, more recent data have shifted these paradigms. Streptococcus mutans does not fulfil Koch's postulates - presence of the organism leading to disease, and absence of the organism precluding disease. Furthermore, molecular microbiological methods have shown that, even with a sugar-rich diet, a much broader spectrum of acidogenic microbes is found in dental plaque. While simple sugars can be cariogenic, cooked starches are also now recognised to be a caries threat, especially because such starches, while not 'sticky in the hand', can be highly retentive in the mouth. Metabolism of starch particles can yield a prolonged acidic challenge, especially at retentive, caries-prone sites. These changes in the paradigms of caries aetiology have important implications for caries control strategies. Preventing the transmission of S. mutans will likely be inadequate to prevent caries if a sufficiently carbohydrate-rich diet continues. Similarly, restriction of sucrose intake, although welcome, would be unlikely to be a panacea for caries, especially if frequent starch intake persisted. Instead, approaches to optimise fluoride delivery, to target plaque acidogenicity or acidogenic microbes, to promote plaque alkali generation, to increase salivary flow or replace fermentable carbohydrates with non-fermentable alternatives may be more promising.

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comment: Simply rinsing out the mouth with plain water, in addition to fluoride, will greatly decrease dental cavities

Sunday, February 23, 2014

Exercise Helps You Smell

This study found that exercise seems to help people keep their sense of smell as they age.

Association of exercise with... [JAMA Otolaryngol Head Neck Surg. 2013] - PubMed - NCBI

Friday, February 21, 2014

Physical activity and sedentary behaviors in postpartum Latinas: Madres para la Salud.

Physical activity and sedentary behaviors in postpartum Latinas: Madres para la Salud.
Med Sci Sports Exerc. 2013 Jul;45(7):1298-306
Authors: Ainsworth BE, Keller C, Herrmann S, Belyea M, Records K, Nagle-Williams A, Vega-López S, Permana P, Coonrod DV

PURPOSE: To describe the physical activity (PA) and sedentary behaviors of postpartum Latinas who are overweight or obese before initiating Madres para la Salud, a social support-mediated walking intervention to promote postpartum weight loss.
METHODS: One hundred thirty-nine postpartum women (13.6 ± 7.7 wk since childbirth, age = 28.3 ± 5.6 yr, BMI = 29.7 ± 3.5 kg · m(-2); mean ± SD), recruited from organizations serving Latino residents in the Phoenix, Arizona, area completed the Stanford Brief Activity Survey and concurrently wore an accelerometer (ActiGraph) and a pedometer for 7 d and kept a PA record.
RESULTS: Most were classified as inactive and lightly active on the Stanford Brief Activity Survey (51% inactive, 37% light, 11% moderate). Most time was spent in sedentary (512.0 ± 169.9 min · d(-1)) and light-intensity PA (242.4 ± 51.4 min · d(-1)) with less time in moderate-intensity lifestyle (78.3 ± 39.9 min · d(-1)), moderate-intensity walking (16.6 ± 14.4 min · d(-1)), and vigorous-intensity PA (0.34 ± 1.5 min · d(-1)). Pedometer steps per day were low (total = 4973 ± 2202 steps, aerobic = 412 ± 774 steps), with most participants rated as sedentary (61%) or low active (28.1%). Consistent with objective PA measures, PA records showed more time spent in light-intensity PA such as home care, cooking, child care and self-care tasks, occupation, religious events, and watching television.
CONCLUSION: By and large, the postpartum Latinas enrolled spent most of their day in low-intensity activity levels with little time spent in health-enhancing PA levels/behaviors. This demographic should be the focus of PA interventions to increase PA to health-enhancing levels.

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Wednesday, February 19, 2014

Exercise and coronary heart disease risk markers in South Asian and European men.

Exercise and coronary heart disease risk markers in South Asian and European men.
Med Sci Sports Exerc. 2013 Jul;45(7):1261-8
Authors: Arjunan SP, Bishop NC, Reischak-Oliveira A, Stensel DJ

PURPOSE: South Asians have a higher-than-average risk of CHD. The reasons for this are unclear, but physical inactivity and/or poor responsiveness to exercise may play a role. This study compared the effect of prior exercise on postprandial triacylglycerol (TAG), glucose, insulin, interleukin-6, and soluble intercellular adhesion molecule-1 concentrations in South Asian and European men.
METHODS: Ten healthy South Asian men (i.e., nine Indian men and one Pakistani man) and 10 healthy European men age 20 to 28 yr completed two 2-d trials (exercise and control) in a randomized crossover design. On the afternoon of day 1 of the exercise trial, participants ran on a treadmill for 60 min at approximately 70% of maximal oxygen uptake. Participants rested on day 1 of the control trial. On day 2 of both trials, participants rested and consumed high-fat (57% of energy content) test meals for breakfast (0 h) and lunch (4 h). Fourteen venous blood samples were collected from a cannula between 0 and 9 h for metabolic measurements.
RESULTS: Three-way ANOVA identified higher (P < 0.05) postprandial TAG and insulin concentrations in South Asian versus European men. Exercise lowered postprandial TAG and interleukin-6 and elevated soluble intercellular adhesion molecule-1 concentrations. An interaction effect indicated a greater decrease (22% vs 10%) in TAG area under the concentration versus time curve after exercise in South Asian than in European men.
CONCLUSIONS: Postprandial TAG and insulin responses to high-fat meals were elevated in these South Asian men, but acute exercise was equally, if not more, effective for reducing postprandial lipemia in South Asian than in European men.

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Monday, February 17, 2014

Vitamin D deficiency in early life and the potential programming of cardiovascular disease in adulthood.

Vitamin D deficiency in early life and the potential programming of cardiovascular disease in adulthood.
J Cardiovasc Transl Res. 2013 Aug;6(4):588-603
Authors: Gezmish O, Black MJ

Vitamin D deficiency is a major worldwide public health problem affecting people of all ages, from infants to the elderly. Of particular concern is the high incidence of vitamin D deficiency in women during pregnancy and lactation, leading to the exposure of the growing fetus/infant to inadequate levels of vitamin D, which is essential for normal development. Vitamin D deficiency in adulthood is linked to the etiology of hypertension and to a multitude of adverse cardiovascular outcomes. It is now well-established that the antecedents of cardiovascular disease can originate very early in life. The purpose of this review is to highlight how maternal vitamin D deficiency, and its effects in upregulating the fetal renin-angiotensin system and altering cardiomyocyte growth in the fetal heart, has the potential to program long-term vulnerability to cardiovascular disease.

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Sunday, February 16, 2014

Prevalence of and associations with reduced exercise capacity in peritoneal dialysis patients.

Prevalence of and associations with reduced exercise capacity in peritoneal dialysis patients.
Am J Kidney Dis. 2013 Nov;62(5):939-46
Authors: Zuo ML, Yue WS, Yip T, Ng F, Lam KF, Yiu KH, Lui SL, Tse HF, Siu CW, Lo WK

BACKGROUND: Exercise capacity is reduced in patients with end-stage renal disease on maintenance home peritoneal dialysis therapy, although the potential mechanisms and clinical implications remain unclear.
STUDY DESIGN: Cross-sectional study.
SETTING & PARTICIPANTS: 95 ambulatory prevalent and incident peritoneal dialysis patients in a well-established renal dialysis center (mean age, 58.26 ± 12.6 [SD] years; 63% men; mean duration of peritoneal dialysis therapy, 3.2 ± 4.1 years).
PREDICTOR: Estimated volume status using spectral bioelectrical impedance, echocardiography-derived hemodynamic parameters.
OUTCOME: Exercise capacity measured as peak oxygen consumption using symptom-limiting treadmill exercise testing.
RESULTS: Exercise capacity was reduced in 96% of patients and severely reduced in 65%. Extracellular to intracellular fluid volume ratio showed the strongest correlation with reduced exercise capacity (R = -0.63; P < 0.001) and was superior to age, pulmonary capillary wedge pressure (E:E' ratio), lean tissue mass index, and hemoglobin and albumin levels in predicting exercise intolerance.
LIMITATIONS: Relatively small sample size and echocardiogram that was performed only at rest.
CONCLUSIONS: There was a strong relationship between body extracellular to intracellular fluid volume ratio and exercise capacity in peritoneal dialysis patients. These findings provide new evidence for a connection between fluid distribution, muscle mass, and exercise capacity. Therapeutic strategies targeting fluid status and muscle mass may improve the exercise capacity of patients on peritoneal dialysis therapy.

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Physical activity in people with COPD, using the National Health and Nutrition Evaluation Survey dataset (2003-2006).

Physical activity in people with COPD, using the National Health and Nutrition Evaluation Survey dataset (2003-2006).
Heart Lung. 2013 Jul-Aug;42(4):235-40
Authors: Park SK, Richardson CR, Holleman RG, Larson JL

BACKGROUND: People with chronic obstructive pulmonary disease (COPD) are sedentary but the extent of the problem is not fully understood.
PURPOSES: This study examines sedentary time and physical activity (PA) and the relative effects of demographic and clinical characteristics on sedentary time and PA in a population-based sample of people with COPD and a comparison group from the general population.
METHODS: Subjects were drawn from the National Health and Nutrition Examination Survey dataset (2003-2006). Physical activity was measured by accelerometry.
RESULTS: People with COPD were sedentary and spent less time in most levels of PA. Age, gender, race, level of education, working status, shortness of breath, self-reported health, and body mass index were significantly associated with sedentary time or level of PA.
CONCLUSION: Findings emphasize the need to decrease sedentary time and increase PA in people with COPD.

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Diet, nutraceuticals and the tear film.

Diet, nutraceuticals and the tear film.
Exp Eye Res. 2013 Dec;117:138-46
Authors: Jalbert I

Nutrition disorders and their correlates such as obesity are increasingly prevalent worldwide. A number of studies to date have suggested numerous potential associations between diet and tear film health; this paper will provide a summary of the available literature. The tear film is characterized through its protein and lipid content and through clinical measurements of characteristics such as osmolarity, volume and stability. Malnutrition, protein and vitamin-A deficiencies are extremely deleterious to tear film health and supplementation with oral vitamin A in this setting is of clear benefit. The relative impact of diet on tear film within what would be considered normal ranges of consumption is less clear. A number of population studies have suggested that hyperlipidemia and a diet low in omega-3 fatty acids are risks factor for dry eye disease. Numerous studies have investigated the effectiveness of oral supplementation with antioxidants, omega-3 (e.g. fish oil and linseed oil) and omega-6 (e.g. evening primrose oil) fatty acids in the last 10 years. Taken together, these suggest a small benefit of oral supplementation on tear film volume, stability and decreased ocular symptoms in patients previously diagnosed with diseases involving the ocular surface (e.g. Sjögren's syndrome, meibomian gland dysfunction, dry eye disease) and contact lens wearers suffering from dry eye. More research is required to determine the exact composition, dosage and indications for their use and to fully characterize how these nutraceuticals modulate the tear film.

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Physical activity, diabetes, and risk of thyroid cancer: a systematic review and meta-analysis.

Physical activity, diabetes, and risk of thyroid cancer: a systematic review and meta-analysis.
Eur J Epidemiol. 2013 Dec;28(12):945-58
Authors: Schmid D, Behrens G, Jochem C, Keimling M, Leitzmann M

Thyroid cancer incidence has been increasing more rapidly over time than the occurrence of cancers of other sites, and interest in potential adverse relations of diabetes and lack of physical activity to thyroid cancer risk is accumulating. We conducted a systematic review and meta-analysis of published epidemiologic studies on the relations of physical activity and diabetes to thyroid cancer according to the Meta-analysis of Observational Studies in Epidemiology guidelines. Published studies were identified through a search in MEDLINE and EMBASE. Random-effects models were used to summarize thyroid cancer risk estimates comparing high versus low levels of physical activity, and separately, comparing individuals with diabetes versus those without diabetes. Meta-regression analyses were performed to evaluate potential effect modification by study design and thyroid cancer risk factors. Information was extracted from seven studies of physical activity and thyroid cancer and from six studies of diabetes and thyroid cancer. The number of individuals from studies on physical activity was 939,305 (yielding 2,250 incident thyroid cancer cases) and from studies on diabetes it was 960,840 (yielding 1,230 cases). The summary relative risk (RR) estimate from cohort and case-control studies combined indicated no association between physical activity and thyroid cancer (summary RR 1.06, 95 % confidence interval (CI) 0.79-1.42). Subgroup-analyses revealed a significant positive association between physical activity and thyroid cancer in cohort studies (summary RR 1.28; 95 % CI 1.01-1.63), whereas the relation was suggestively inverse in case-control studies (summary RR 0.70; 95 % CI 0.48-1.03; p for heterogeneity = 0.005). Individuals with diabetes showed a borderline statistically significant increased risk of thyroid cancer compared with those without diabetes (summary RR 1.17; 95 % CI 0.99-1.39). The relations of physical activity and diabetes to thyroid cancer were not modified by sex, number of adjustment! factors, and adjustments for adiposity, smoking, and study quality. In this comprehensive systematic review and meta-analysis, no significant association between physical activity and thyroid cancer was found. Diabetes showed a suggestive positive relation with risk of thyroid cancer.

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