Wednesday, October 27, 2010

Daily Aspirin Lowers Colon Cancer Risk

A low daily dose of aspirin taken for the long term lowers the risk of colon cancer by 25%, according to a new study.

The study, published last week my a multinational team of researchers in the prestigious UK journal The Lancet, followed the outcomes of five randomized trials in the UK, Sweden and the Netherlands for a period of 20 years. Over the follow-up period, after taking low doses (75mg per day) of aspirin for about 6 years, subjects had a 24% lower likelihood to be diagnosed with colon cancer, and a 35% lower likelihood to die of the disease. The use of aspirin was particularly beneficial against upper (proximal) colon cancers, which are typically not caught by colonoscopy or sigmoidoscopy. There was no advantage for larger doses than baby aspirin.

The study was particularly powerful because it had a wide patient sample (over 14,000) over three countries, and because, based on randomized trial, it was able to establish causality between the treatment and the effect.

A commentary in the same issue of the journal proposes that the daily use of a low dose of aspirin become a standard suggestion by family doctors. "Anyone with any risk factors such as a family history (of colon cancer) or a previous polyp should definitely take aspirin," said Peter Rothwell,  professor at the University of Oxford, and one of the study's authors. Professor Rothwell believes that the study also "tips the balance" for anyone considering aspirin to prevent heart attacks and strokes.

Some experts cautioned patients not to start taking daily aspirin doses without consulting a doctor first, as it may cause lesions and bleeding in the stomach and intestines when taken over long periods. Low doses of aspirin in the study were 75mg, while baby aspirin doses in the US are 81 mg.

Another study about aspirin, published almost simultaneously with this one, appeared to show aspirin to have a major effect on prostate cancer treatment survival, possibly reducing death rates by 60%, with an 80% mortality reduction from high risk prostate cancers. A different study, also almost simultaneous, reported that aspirin reduces complication from heart surgery when administered immediately preceding the procedure.

Want to read more about it? Try WebMD, the New York Times, USA Today, the Washington Post, or Medscape.

The study in The Lancet
The commentary in The Lancet

Monday, October 25, 2010

AHA Releases New CPR guidelines

After multiple years of evidence that chest compressions alone are statistically at least as efficient as, if not more than traditional CPR, the American Heart Association (AHA) has updated its CPR guidelines.

The new guidelines put much stronger emphasis on chest compressions, and on the urgency to call emergency services. They separate the case of untrained bystanders from emergency personnel and bystanders trained in CPR. Untrained bystanders are encouraged to deliver compression-only CPR (sometimes called CCR). Trained lay-persons and emergency personnel are requested to start with chest compressions, then to clear the airway, then to alternate between 2 breaths and 30 compressions. The new acronym for trained responders is C-A-B: Compression - Airway - Breathing. The guidelines emphasize that chest compressions should be as uninterrupted as possible, and that the patient not be over-ventilated (too much breathing).

The Red Cross, the largest training organization in CPR, has not adopted the AHA recommendations yet.

The new guidelines are somewhat controversial. The past 5 years have seen many studies show the statistical superiority of CCR over traditional CPR. Some voices complain that the new AHA guidelines do not go far enough: "Why do the Guidelines state that, 'Rescuers should avoid stopping chest compressions and avoid excess ventilations' and yet not advocate chest-compression-only CPR?" asks Dr. Gordon Ewy, of Sarver Heart Center at the University of Arizona, a pioneer of CCR, "the 'Guidelines' have lost or are in danger of losing their credibility."

There is general agreement that, for cardiac arrests only, CCR is superior to CPR. For cardiac arrest following drowning, drug overdose, or for children where cardiac arrest is typically consecutive to breathing problems, the use of breaths is generally believed to be valuable or necessary. The controversy focuses on what the general recommendation for CPR should be, and what untrained bystanders should be directed to do in the general case. In general, however, less than one third of all patients undergoing cardiac arrest outside of a hospital setting get any form of CPR, so any progress on the frequency of administration of CPR or CCR would be better.

We postponed the publication of this post to be able to point at good presentations from the AHA on its new guidelines. Unfortunately, one full week after the publication of the new guidelines, the AHA pages on CPR are still a mess, and provide pitiful clarity on the new process. Surprisingly, the AHA does not make it easy to find out what good CPR is... So, not being able to point you at a very clear summary of the new guidelines from the AHA, we give you our own summary of the new process below.

For untrained bystanders, the process is:
1. Call 911, or ask someone to do it for you
2. If the victim does not respond, roll him (or her) on his back.
3. Immediately start administering chest compressions, at least 100 per minute (on the rhythm of Staying Alive, by the Bee Gees), to a depth of 2" for adults and 1.5" for children. Allow full chest recoil after each compression before the next. Keep on administering chest compressions without interruption.

For trained lay-persons, the process is:
1. Call 911, or ask someone to do it for you
2. If the victim does not respond, roll him (or her) on his back.
3. Immediately start administering 30 chest compressions, on a rhythm of at least 100 per minute (on the rhythm of Staying Alive, by the Bee Gees), to a depth of 2" for adults and 1.5" for children. Allow full chest recoil after each compression before the next.
4. Open the airway with a head tilt and chin lift
5. Quickly administer two 1-second breaths with a tight seal
6. Go back to uninterrupted cycles of 30 chest compressions followed by 2 breaths. Minimize interruptions to the chest compressions, and do not over-ventilate the patient.

Want to read more about it? Try the Washington PostBBC,WebMD, Chicago Sun Times, CNN, Time Magazine, CBS, USA Today, Business Week HealthDay, KCRG or MedPage Today. You might also want to read our previous post on the state-of-the-art of CPR and CCR.

Thursday, October 21, 2010

Industry Progress on BPA Phase-Out

Responding to major consumer concerns over the use of Bisphenol A (BPA), many large corporations, including ConAgra and General Mills, have made faster progress than expected in phasing BPA out of their product portfolio, according to a recent report.

BPA is an organic compound frequently used in plastic baby products and food packaging. Scientific evidence has raised the concern of significant development danger in human consumption of food or liquids in contact with BPA containers, without proving danger in clinical trials or cohort studies.

The NGO As You Sow, in collaboration with the green tech investment fund Green Century Capital Management, recently published a report grading industry progress in eliminating the use of BPA, company by company. The report shows that, in part due to investment activism, some major companies have made rapid progress in phasing out BPA, as compared with 2009. BPA is present in many plastic products, in general food and liquid containers, and in metal can liners for food packaging.

In particular, Heinz, ConAgra, and Hain Celestial have started using PBA-free packaging, are committed to eliminating BPA, and have a timeline for getting there. General Mills, Nestle, Sarah Lee and McCormick are all committed to eliminating BPAs, and have engaged in large scale tests to identify alternative packaging. Other companies, such as While Foods, Costco, Kellogg, PepsiCo or Smuckers, are making some progress in moving towards PBA-free packaging, but have not demonstrated total commitment or started engaging in alternative packaging tests.

Laggards in the field, who have not committed to eliminating PBAs, include Coca-Cola, Safeway, Del Monte, Kraft, Unilever, Herschey, and Wal-Mart.

BPAs are an unusual case as an environmental concern, because it has not been proven to be nefarious to human consumption in clinical trials. Yet the scientific concerns surrounding it are such that many in the environmental community believe it should be phased out nonetheless. The FDA has recently expressed concern about BPAs, while Canada on October 13 of this year became the first country to officially declare BPA a toxic substance.

We are of two minds about BPA and the controversy around it. On the one hand, all of us at have gotten rid of all of our BPA containers, in particular for those that were in use with our children. At the same time, we are slightly leery of too much legislation being passed before human consequences are proven for BPA. Clearly, it is important to stop the use of potentially nefarious substances before they have a chance to impact a whole generation of children or more, such as what happened with lead paint. And yet, where do you stop before significantly damaging the tissue of our industrial society? We wish we had an answer to that...

Want to read more about it? Try Fast Company and USA Today.

The 2010 BPA Progress report  (PDF) by As You Sow and Green Century Capital Management
The 2009 BPA Progress Report (PDF) by As You Sow and Green Century Capital Management

Wednesday, October 20, 2010

Babies No Smarter From Fish Oil Pills

Use of fish oil supplements during pregnancy does not appear to improve the baby's mental development or decrease the incidence of post partum depression, according to a new study.

This new study, published this week in the prestigious Journal of the American Medical Association (JAMA) by researchers of the University of Adelaide in Australia, reports on the results of a well designed randomized double blind trial correlating the use of fish oil supplements during pregnancy with the baby's cognitive development and the mother's risk of post partum depression.

Some studies in the past have found a link between higher intake of fish oil and improved cognitive development for the baby along with less incidence of post partum depression for the mother. None of these studies, however, were truly authoritative: some were observational (post facto analysis), while others used small sample sizes. As a result of these studies, many national and international health agencies have come out with recommendations for pregnant women to take fish oil supplements. The key fish oil component is assumed to be docosahexaenoic acid, or DHA.

This study was the first clinical trial of significant size to actually test the causality link between taking fish oil supplements and assumed health and cognitive benefits. It used a double blind randomized trial approach with a statistically large population of subjects. The researchers followed 2,320 women, who were randomly assigned to take 1,500 mg of fish oil pills or of vegetable oil pills (control group), starting on the 21st week of pregnancy. After giving birth, mothers took standard evaluation test for depression 6 weeks and 6 months after giving birth, while 694 children were evaluated at age 6 months.

The conclusions were disappointing. The children's cognitive, language, motor development and social emotional behavior scores were the same across both groups. Of the women in the trial, 9.67% of those who took DHA supplements developed post partum depression, while 11.02% of those in the trial group did. The conclusions of the authors were that DHA supplements did not influence either the baby's cognitive development, of the mother's risk to develop post partum depression, although there appeared to be some positive influence for women at high risk. The researchers conclude: "The results of [this trial] do not support routine DHA supplementation for pregnant women to reduce depressive symptoms or to improve cognitive or language outcomes in early childhood."

Why is the outcome of this study so unexpected to many? Some experts, such as Dr. Emily Orken of Harvard Medical School, suggest that dosage might be a possibility. Some mention that eating fish may be better than taking supplements. The study authors suggest that previous observational studies have other impacting factors, and that past clinical trials might have used too small population samples. Finally, some, like Dr. William Barth of Massachussetts General Hospital, were skeptical all along: “I wish it were so simple, that there was a pill we could take to make our children smarter.”

The study was considered important enough by the Journal of the American Medical Association to warrant an editorial. This editorial recognizes the value of the study, yet suggest that, for now, recommendations to pregnant women not be changed: "For now, pregnant women should take care to get the recommended intake of 200 mg/d of DHA, either by including low-mercury, high-DHA fish in their diets or by taking a daily n-3 PUFA supplement," write Dr. Emily Orken of Harvard Medical School and Dr. Many Belfort of Children's Hospital in Boston for Editorial Board of JAMA.

Want to read more about it? Try Medical News TodayReuters, WebMDFood Consumer, International Federation of Gynecology and Obstetrics, The Age, the New York Times, US News, Time Magazine, Medscape, the LA Times, and ABC News.

Monday, October 18, 2010

Vitamin B12 May Lower Alzheimer's Risk

A diet heavy in vitamin B12 may lower your risk of developing Alzheimer's disease.

A study published today in Neurology by researchers from Karolinska Institute in Sweden indicates that subjects who consume higher amounts of Vitamin B12 may be better protected from the development of Alzheimer's disease. The researchers followed 271 patients aged 65 to 79, none of which had dementia at the start of the study, for 7 years. 17 of them developed Alzheimer's disease over the duration of the study. After correcting for gender, weight, blood pressure, age, smoking habits, and educations, the study concluded that higher vitamin B12 concentration in the patient's blood was correlated with a lower risk of Alzheimer's disease. The study also found that higher concentrations of the amino-acid homocysteine was associated with a higher likelihood of developing Alzheimer's disease.

Both the authors of the study and specialists commenting on it agreed on the fact that the study was small, preliminary, and by no means definitive. Previous studies on the links between Vitamin B12 and Alzheimer's diseased have had mixed results.

Want to read more about it? Try Medical News Today, WebMD, Medscape, BBC, Medpage Today, hc2d UKCNN, BusinessWeek HealthDay, or MSNBC.

Wednesday, October 13, 2010

Three Healthy Habits Lower Breast Cancer Risk

Three healthy habits contribute to lowering the risk of breast cancer in post-menopausal women, according to a recent study: engaging in regular physical activity,  maintaining a healthy weight, and consuming alcohol in moderation.

The American Cancer Society has long maintained healthy lifestyle recommendations for cancer prevention, concerning diet, exercise and alcohol consumption:
  • maintain a body mass index of 18.5 to under 25
  • engage in 30 minutes of vigorous exercise at least 5 days per week (45-60 minute sessions are preferable)
  • drink no more than one alcoholic beverage per day
A large retrospective study, published this week in Breast Cancer Research by researchers from the University of Rochester, followed more than 85,000 post-menopausal women for over 5 years, and surveyed how well they followed the American Cancer Society recommendations listed above, where the vigorous exercise requirement was lowered to 20 minutes at least 5 days per week. The conclusion? "Whether or not you have a family history, the risk of breast cancer was lower for women engaged in these three sets of behavior compared to women who were not," says principal author Dr. Robert Gramling.

Indeed, the study shows that adherence to these recommendations resulted in approximately 24% lower incidence of breast cancer for women with no family history of breast cancer, and in approximately 14% lower incidence of breast cancer for women with a family history of breast cancer. Dr. Susan Gapstur, vice president of the epidemiology research program of the American Cancer Society, believes that breast cancer risk reduction might be even more significant if vigorous exercise sessions are increased to 45-60 minutes at least 5 days per week.

Want to read more about it? Try CBC NewsHealthDay, NIH Medline, or HealthLine.

The Study in Breast Cancer Research
Body Mass Index Calculator at the National Heart and Blood Institute
American Cancer Society cancer prevention guidelines

Thursday, October 7, 2010

Compression-Only CPR is Better

Using a simpler CPR resuscitation technique which only uses chest compressions saves more lives than traditional CPR, according to a new study.

The study, published by researchers from the Arizona Department of Health Services  in yesterday's edition of the prestigious Journal of the American Medical Association (JAMA), reviewed over 4,400 incidents where patients experienced cardiac arrest outside of a hospital setting, and where only bystanders were available to administer CPR. 849 patients received compression-only CPR, while 666 patients received traditional CPR. The other patients did not receive any CPR. Of the patients who received compression-only CPR, 13.3% survived, while 7.8% of those receiving traditional CPR survived. Only 5.2% of those who received no CPR at all survived. The differential between traditional CPR and compression-only CPR shows a 60% advantage for compression-only CPR.

The compression-only CPR process involves calling emergency services and immediately administering at least 100 compressions per minute to the chest - equivalent to the beat of the song Staying Alive, by the Bee-Gees. No breaths are given, and compressions are not interrupted. The traditional CPR process involves calling emergency services, opening the airway and clearing it, then administering in alternance 30 chest compressions and 2 breaths, where chest compressions are given at a rhythm of approximately 100 compressions per minute.

This conclusion of this study only reinforces findings that have been common to many other recent studies:
  • In September, a study published in the journal  BMC Medicine by researchers from the University of Michigan concluded that patients who experience sudden cardiac arrest outside of a hospital setting do as well when treated with compression-only CPR as they do when getting immediate defibrillation. 
  • In July, two studies testing compression-only CPR were published in the New England Journal of Medicine. One was conducted in Sweden, and covered more than 1,200 incidents. The other one, conducted in Seattle and in London, covered more than 1,900 incidents. Both studies found that chest compression-only CPR was as effective as traditional CPR when dealing with people experiencing a heart attack.
  • In 2009, data from the Arizona Center for Health Services from almost 5,000 incidents over 4 years showed that people treated with compression-only CPR were more likely to survive by a margin of 68% compared to regular CPR.

In 2008, on the heels of several years of studies showing the benefits of compression-only CPR, the American Heart Association published a statement recommending that bystanders not confident or trained in CPR call 911 and immediately start chest compression-only CPR. The statement followed the publication, in 2007, of three large studies, each one of which surveyed the outcomes of thousands of instances of CPR practiced by bystanders. Two large scale studies from Sweden and Japan were published in the journal Circulation, the Swedish study covering nearly 10,000 incidents, and the Japanese study covering 4,900 cases. Another Japanese study was published in the journal The Lancet, and covered more than 4,000 cases. All studies showed that the use of compression-only CPR had no worse, and sometimes much better results than that of traditional CPR.

The American Heart Association is expected to soon announce a significant change to its CPR guidelines.

Want to read more about it? Check Medscape, USA Today, iVillage, San Jose Mercury News, Science Daily, ABC News, CBC News, Wall Street Journal, and NIH Medline.

10/15/2010 Update: a new study published yesterday in the prestigious UK journal The Lancet confirms further the findings of the studies listed above, by analyzing the results of over 3,000 instances of CPR administered by bystanders guided by emergency dispatchers. Survival rates were 22% higher for compression-only CPR than for traditional CPR. More information in  NIH Medline, MedPage Today or Business Week HealthDay.

Wednesday, October 6, 2010

Light Drinking in Pregnancy OK?

Drinking up to one to two glasses of alcohol per week during pregnancy does not appear harmful to the baby, according to a new study.

The study, published yesterday in the Journal of Epidemiology and Community Health, by researchers from the University College London, is a retrospective study, which followed more than 11,500 children born between September 2000 and January 2002, using data from the UK Millennium Cohort Study. Mothers were classified as non-drinkers altogether, non-drinkers during pregnancy (but drinkers otherwise), light drinkers during pregnancy (i.e. one to two glasses of alcohol per week), moderate drinkers during pregnancy (3 to 6 glasses per week), and binge or heavy drinkers (7 or more glasses per week) during pregnancy. Mothers were interviewed about their child's behavior at age 3, and children were tested for behavior and cognitive development at age 5.

Children of mothers who were light drinkers during pregnancy were 30% less likely to show behavior problems than children of mothers who stopped drinking during pregnancy. When the study was corrected for socio-economic status and other factors, they effect still showed 23% advantage for children of light drinking mothers. Cognitive development was also higher for children of light drinking mothers, even after fully adjusting the study results for mediating factors. "There appears to be no increased risk of behavioral or intellectual problems in their children [at age 5]," says Dr. Yvonne Kelly, study investigator. In fact, says Dr,. Kelly, ""children born to light drinkers seemed to have fewer behavioral problems and higher cognitive scores than those born to moms who didn't drink during pregnancy."

What are the limitation of the study?
  • The study is observational only (cohort study), and cannot prove causality - only a randomized double-blind trial could do that.
  • There may be mediating factors that were not taken into account when compensating for other factors in the study.
  • Subjects self reported their drinking, which may subject this measure to some self reporting bias.
Nevertheless, the sample was large (more than 11,500 children), and the methodology so far has in general not been criticized by outside experts.  In fact, a similar study published in June 2010 in the British Journal of Obstetrics and Gynecology, and  using 14 years' worth of data from the Western Australian Pregnancy Cohort (Raine) Study, reported similar results, not only for children of light drinkers, but also for children of moderate drinkers during the first trimester of pregnancy. "Children of light and moderate drinkers had less emotional and behavioral problems through childhood and adolescence," said Dr. Monique Robinson, from Telethon Institute for Child Health Research in West Perth, Western Australia, as reported in Reuters

These studies are not the only ones reporting no harm from light drinking in pregnancy. As early as 1991, Dr. Joel Alpert and Dr. Barry Zuckerman of the Boston University School of Medicine wrote, in the journal Pediatrics in Review, in an analysis of other studies: "Our conclusion is that there is no measurable or documented risk from this level [two or fewer drinks per day] of drinking during pregnancy."

Experts, however, were quick to point out that this study should not be seen as an invitation to drink. "I do not believe we want to establish a precedent that any level of alcohol consumption is okay, because in truth, we really don't know the long-term effects of even light drinking," commented Dr. Marc Lewis, service chief for Women's Health Services at Henry Ford Hospital in Detroit, Michigan, adding: "We know that in the United States, the leading cause of mental retardation is related to fetal alcohol syndrome." Dr. Timothy Naimi, an alcohol expert with Boston University School of Medicine, criticized the study: “These findings are highly implausible, given that ethanol is the world's leading fetal neurotoxin." "Fetal alcohol syndrome has been described in mothers who had a single episode of binge drinking," commented Dr. Ron Jaekle, professor of clinical obstetrics and gynecology at the University of Cincinnati.

What to conclude of all this? You should talk to your doctor before deciding what your drinking behavior should be during pregnancy. The general recommendation in the US is to fully abstain from drinking during pregnancy. It seems, however, from a preponderance of evidence, that light drinking, consisting of one to two glasses of wine or beer per week during pregnancy, is unlikely to cause any development or behavior problem to the child.

Want to read more about it? Try USA TodayMedscape, CNN, SFGatemsnbc, FoxNews, iVillage, Montreal Gazette, Bloomberg, the London Times, Business Week/ HealthDay, National Post, Time Magazine, or WebMD.  

Friday, October 1, 2010

Medical Imaging Radiation Over-Exposure Update

On September 7, we reported a dramatic story discussing numerous incidents of over-exposure to radiation through routine diagnostic CT scans, documented across 3 hospitals in the US, but probably endemic across most radiology departments in the nation. Since that date, over-exposure to radiation has been discovered in 5 additional hospitals.

Today Governor Schwarzenegger of California signed a bill requiring radiology departments to record radiation from CT scans and report to patients and prescribing doctors in cases of over-exposure. The FDA has also broadened it investigation, and is expected to publish its conclusions soon. Congratulations to the New York Times for breaking this important story.

Original New York Times story
Original ConsumerPla.Net story