Health Topics


Thursday
Apr172014

Bariatric Surgery Has an Important Side-Benefit in Women

Obesity is, unfortunately, increasingly common in the USA.  And it’s linked to an increased risk of major health problems – heart disease, diabetes, and cancer.  In women, the risk of endometrial (uterine) cancer is high.  It’s estimated that a woman with a Body Mass Index (BMI) of 40 (i.e. ‘morbidly’ or ‘severely obese’) would have roughly an 8 times greater risk of developing endometrial cancer than someone with a normal BMI (less than 25).  Researchers at the University of California-San Diego decided to evaluate the effect of surgical treatment of obesity on the frequency of endometrial cancer.  Their results are published in the journal Gynecologic Oncology.

The University HealthSystem Consortium database contains information on over 7 million patients.  The San Diego researchers identified 103,797 patients who had a history of bariatric surgery for obesity and 44,345 who had a diagnosis of endometrial cancer.  The rates of this cancer per hospital admission were calculated, as well as whether those diagnosed at the time of discharge included a history of bariatric surgery, and further, whether there was a diagnosis of obesity.

Analyses showed that the rate of endometrial cancer was 599 cases per 100,000 patients among who did not have a history of prior bariatric surgery.  The rate was 1,409 per 100,000 patients in those obese women who had not previously undergone bariatric surgery, whereas it was 408 per 100,000 in those who had had bariatric surgery.  Further calculations showed that the relative risk of uterine cancer in women who had bariatric surgery compared with obese women who didn’t have surgery, was 0.29.  Women who were no longer obese during follow-up after bariatric surgery had a relative risk of uterine cancer of 0.19 compared to obese women who had not undergone surgery.  The findings are clear – obese women who have undergone successful bariatric surgery lower their risk of developing endometrial cancer by 71%, and up to 81% if they keep the weight off.

It’s likely that the reduced risk of uterine cancer is related to a reduction in elevated estrogen levels and in chronic inflammation;  both of these are associated with obesity, according to the principal author of the study.  Obese people who lose weight by other means are probably going to have this extra benefit, too.

Monday
Apr142014

Perhaps Saturate Fat Isn’t So Bad for Us

Ever since the 1970s we’ve accepted the mantra: saturated fats cause raised total cholesterol levels, which is associated with coronary heart disease.  This belief was based on a famous study involving 7 countries – it was called the Seven Countries Study – that showed that the rates of heart attack and stroke were related to the level of total serum cholesterol. However, as we know, correlation is not causation.  Recently several cardiologists have pointed out fallacies in the saturated fat/cholesterol/heart attack linkage; and an analysis of published studies has been reported by Cambridge University, UK scientists in the Annals of Internal Medicine

Studies in the medical literature that were pooled for meta-analyses fell into three groups: the effects of fatty acids from dietary intake, information from fatty acid biomarkers, and randomized, controlled trials of fatty acid supplementation.  

In the first two groups - 32 and 17 observational studies, with 512,000 and 26,000 patients, respectively - the top and bottom thirds of baseline dietary fatty acid intake were compared.  Pooled results showed the relative risks for coronary heart disease to be 1.03 for saturated, 1.00 for monounsaturated, 0.87 for long-chain omega-3 polyunsaturated, 0.98 for omega-6 polyunsaturated, and 1.16 for trans fatty acids.  Corresponding estimates for circulating (i.e. serum) fatty acids were 1.06, 1.06, 0.84, 0.94, and 1.05, respectively.  Only two values were statistically significant: higher dietary trans fatty acids were associated with more coronary disease, and higher omega-3 polyunsaturated intake with less coronary disease.   

In the 27 randomized, controlled trials (105,000 participants), the relative risks for coronary heart disease were 0.97 for α-linolenic, 0.94  for omega-3, and 0.86 for omega-6 polyunsaturated fatty acid supplementations;  none of these findings were statistically significant.

The results from these analyses of over half a million patients show that increased fat intake (dietary, shown in blood levels, or resulting from supplements) had virtually no effect on the development of coronary heart disease.  They support the contention of leading cardiologists, that the mantra that saturated fat should be removed from the diet is false  Obesity rates have increased lately in the face of a concurrent reduction in fat consumption – because we’ve replaced dietary fat by increased carbohydrate intake, which itself leads to fat formation in the body.  So go ahead – enjoy that bacon-and-fries breakfast.

PS  The above meta-analysis study has been criticized by some nutritionists, but the linked publication is a corrected version, in which the investigators stick to their same sconclusions.

Thursday
Apr102014

The 5-Second Rule Is Not a Complete Myth . . .

For once, it’s nice to be able to report that something that’s been pooh-poohed for years may, in fact, be true.  Students at Aston University, Birmingham, UK, have conducted a study that led  to a press release, and quite a lot of comment, a couple of weeks ago.  The “5-second rule” is the theory that if food is retrieved within 5 seconds after being dropped on the floor, it is safe to eat, because there has not been enough time for harmful bacterial contamination. 

The researchers monitored the transfer of the common bacteria Escherichia coli (E. coli) and Staphylococcus aureus from a variety of indoor floor types (carpet, laminate and tiled surfaces) to toast, pasta, biscuit and a sticky candy when contact was made from 3 to 30 seconds. 

Analysis of the results showed that time is a significant factor in how many bacteria are transferred.  But the type of floor surface plays an important role, carpet actually posing the lowest risk of the three types tested. If the food is moist, the transfer risk is greater.

A survey of participants in the study showed that 87% of them had already eaten food dropped on the floor, or would do so. And most said they would adopt the 5-second rule. 

Hopefully this experiment will be published in a peer-reviewed journal, to help resolve a lot of the criticism leveled at the result.  The leader of the study stated: “Consuming food dropped on the floor still carries an infection risk as it very much depends on which bacteria are present on the floor at the time.”  And “The findings of this study will bring some light relief to those who have been employing the 5-second rule for years.”

One of the comments on the press release is apposite:  “Our culture now has become germophobic and we are less healthy for it. We were made to live in a dirty world. We have an immune system to combat that world but it has to be exercised. We wash our hands whenever we touch anything now. Get dirty folks. Fight off some microbes naturally. You'll be healthier in the end.”  That makes sense to me.

Monday
Apr072014

Progress of MCI to Dementia Is Not Necessary Fast or Inevitable

In 2007 I wrote briefly about Mild Cognitive Impairment, or MCI.  I described it as the half-way house between normal brain function and dementia, and subsequent research has confirmed this view.  Now German clinical researchers have analyzed progress (or lack thereof) in MCI, trying to determine the likelihood and speed with which MCI continues on to dementia.  They published their results in the Annals of Family Medicine.  

The German Study on Ageing, Cognition, and Dementia in Primary Care Patients (AgeCoDe) recruited 357 people aged 75 or older from primary care practices across Germany. 

Analysis of the data gathered over repeated visits in the first 3 years after enrollment allowed the subjects to be sorted into 4 groups.  The largest group, 42%, had a remittent course – relief of symptoms with normal cognitive function tests – at 18 months and 3 years after enrollment.  21% of the subjects showed a fluctuating course, with changing test results between normal and MCI status during the 3-year study.  15% had stable cognitive function tests, i.e. their cognitive state remained unchanged at each test during the study.  Finally, 22% of the subjects had progressed to dementia during the 3 years.  In general, progress along the course towards dementia was more likely if the subjects had symptoms of depression, more severe or widespread cognitive impairment, or were older. 

The researchers sounded a fairly optimistic note when interpreting their findings.  They pointed out that their study showed that three-quarters of patients with MCI stay cognitively stable or even improve within 3 years.  Many people will be less sanguine, and weigh the possibility of having cognitive testing at a relatively early age.  At present, however, there’s little point in this approach – there isn’t a satisfactory treatment to stop dementia in its tracks.  My best advice is to lead a healthy lifestyle, have many friends and social activities, and practice exercises for the body and the brain.  And don’t get misled by reports of a new blood test for predicting the likely development of dementia; it’s not accurate in more than 60% of subjects!

Thursday
Apr032014

Getting Faster Treatment for Stroke

For someone who’s had the most common sort of stroke – thrombosis, or a clot lodging in a brain blood vessel – treatment with a “clot-buster” type of drug can help limit the extent of brain damage, and even be life-saving.  But the effectiveness of clot-busters is related to the time interval between the event and starting the treatment.  Doctors are trying to reduce the critical time spent in the hospital (“door-to-needle time”), and their latest suggestion involves a considerable change – skipping the usual visit to the emergency department, or ED.  New Jersey neurologists have reported on their experience using this shortcut in the journal Neurosurgery.  

A critical step before a clot-buster drug (e.g. tPA) can be given is to determine, using a CT (computed tomography) scan, whether the patient has had an ischemic stroke (blockage of a cerebral artery), or has cerebral hemorrhage or some other condition, which could be worsened by such a drug.  The study involved evaluation of door-to-CT and door-to-needle times in patients reaching the hospital with an emergency medical service (EMS) assessment as being a ‘pre-hospital stroke alert’ subject.  (EMS technicians had received special training in recognizing such patients.)  For one year (July 2012 to July 2013) all stroke-alert patients were delivered directly to the CT suite, bypassing the usual ED routines.  There, the neurological emergency team performed a quick assessment and CT scan of the brain.  If stroke was confirmed within the appropriate timeframe (4.5 hours since onset of symptoms), tPA treatment was started immediately.  

Of the 141 pre-hospital stroke alert patients, stroke was confirmed in 66%, i.e. the EMS personnel had made an accurate assessment in two-thirds of the cases.  The average door-to-CT time was 11.8 minutes. Twenty-six of the patients went on to receive intravenous tPA; the average door-to-needle time for them was 44 minutes.  The average for door-to-CT time was 35 minutes in 2011, i.e. it underwent a 67% reduction in time from then to now; and the average door-to-needle time in 2009 was 56.5 minutes, showing a 22% reduction by 2013.

These time-saving steps are impressive.  But as a potential patient (or caregiver) you should do your part to reduce the time to optimal treatment, too.  This means being aware of the first signs of a stroke: one side of the face seems droopy or numb (ask the patient to smile); the arms may be numb or weak (lift both hands); speech may be slurred or even absent (ask for a simple reply).  Don’t wait to see if these signs get better on their own.  Call 911 immediately and wait for the EMS – it’s better than just about any other form of transport to hospital.

Monday
Mar312014

No Need to Add Flavanol to Dark Chocolate

By now, we all know that dark chocolate has health benefits on the cardiovascular system. However, the mechanism of effect is unknown, and it is uncertain which component of the chocolate is responsible.  New work by Dutch nutritional scientists, published in the March FASEB Journal, helps to clarify both these points. Attention is focused on flavanol, which belong to a class of chemicals called flavonoids. (Flavanols are not to be confused with flavonols, a similar but different type of chemicals with different functions.)

The researchers used a randomized, double-blind, crossover study design to examine the effects of dark chocolate on the function of the blood vessel walls, in particular the inner lining layers. Forty-four overweight middle-aged men took part in a 4-week study in which they consumed 70 grams daily of either high or low (i.e. normal) flavanol-containing chocolate, followed by a 4-week washout period and then crossover to four weeks of the other kind of chocolate.

Both types of chocolate increased the fasting flow-mediated dilatation of the small blood vessels by approximately 1%, and decreased the blood pressure therein to a similar extent; these changes have been suggested in previous studies to represent a 13% reduction in cardiovascular-event risk. Additional examinations showed that 4 weeks of chocolate consumption significantly lowered circulating white blood cell counts, suggesting a possible decrease in body inflammatory activity.

What’s important in this study is that results with both high and low-flavanol dark chocolate were extremely similar, indicating that flavanol is unlikely to be the critical component that confer health benefits. This tells scientists they have to look elsewhere in their search for the relevant constituent, and it tells us not to be duped into paying more for flavanol-enriched chocolate.  Just enjoy regular dark chocolate as it is – the study participants found that it has a less pleasant taste when flavonol is added.

Thursday
Mar272014

How’s Your Reaction Speed?

A new study has found that reaction time is related to mortality; those with slower reaction times are linked to an increased risk for premature death.  The study was conducted by researchers from universities in London, Edinburgh, and Glasgow, UK, and is reported in the online journal PLoS ONE.

Data were derived from the Third National Health and Nutrition Examination Survey (NHANES III), in which participants were enrolled between 1988 and 1994. Over 5,000 of them, aged 20 to 59, had their reaction times recorded at the start of the study;  this was done by  timing their response – pressing a button – to a light flashed on a computer screen.  The average reaction time across 50 trials was determined.  Deaths were then recorded over a 15-year period.

The participants were classified into groups according to their reaction times at enrollment. After adjustments were made for known influences on longevity – e.g. male sex, smokers, heavy drinkers, and physical inactivity – mortality rates of different groups were compared.  Those with slight to moderately slower reaction times were 25% likely to die of any cause, and 36% more likely to die of cardiovascular disease, than those with faster reactions.  There was no relationship between reaction times and cancer mortality.

Greater variability of reaction times amongst the 50 records at baseline testing was also associated with a greater risk of all-cause (36% greater) and cardiovascular mortality (50% greater). 

While there are several well-established risk factors for premature death and heart disease (e.g. high blood pressure, high cholesterol, smoking, overweight), slow reaction time is a candidate risk factor, based on the results of this study.  However, the authors stress that more work is needed to establish the possible mechanism that slow reaction times may exert on the cardiovascular system before too much importance is attached to their findings.

Monday
Mar242014

How to Stop Muscle Loss in Old Age

As we age, our muscles lose strength and bulk, so that the end result is actual disability.  Australian researchers at Deakin University, Victoria, have studied how to keep muscles strong during the aging process.  They examined the effects of progressive resistance training, with and without a protein-enriched diet, on age-related muscle loss in older women.  Their report is published in the American Journal of Clinical Nutrition.

A randomized controlled trial was done using 100 women aged 6 to 90 who were living in 15 retirement villages.  All of them underwent a resistance-training program and took 1,000 IU vitamin D3 daily.  Half of them ate a protein-enriched diet – 160 grams of lean red meat, cooked, 6 days a week – and the other half (the controls) ate an additional serving of pasta or rice, daily.  The resistance training was done twice a week, using increasing weights over time.  The study lasted 4 months.  Lab measurements included estimations of lean muscle mass, serum insulin-like growth factor I and interleukin-6, blood lipids and blood pressure.  

After 4 months the protein-rich diet group had a significantly greater increase in muscle strength (+18%) over the exercise-only group, and had an additional 0.45 kg of total body lean muscle mass.  They also had a 10% greater increase in serum insulin-like growth factor I, and a 16% reduction in serum interkeukin-6.  (Insulin-like growth factor I is known to block muscle atrophy, among other effects, while interleukin-6 is a marker for chronic inflammatory diseases.)  There were no other significant differences between findings in the two groups. 

The authors of the report conclude that a protein-enriched diet in elderly women can enhance the effects of resistance strength training on lean tissue mass and muscle strength, at the same time reducing interleukin-6 levels.  The observed increase in serum insulin-like growth factor I could indicate a possible benefit on cognitive function, but this was not measured in this study.  The protein in this study was lean red meat, but then the study was partially sponsored by Meat and livestock Australia.  I guess any good source of protein would work, too.