Low-carbohydrate Versus Low-fat Diet

breadLow-carbohydrate diets were initially popularized by the late Dr. Robert Atkins, who published the fundamentals of this diet in his book Dr. Atkins’ New Diet Revolution. He also founded Atkins Nutritional to commercialize and further evangelize the low-carbohydrate diet. Following Dr. Atkins’s death, however, the popularity of the diet subsided and his company filed for Chapter 11 bankruptcy in 2005.

Despite its controversial nature, the low-carbohydrate diet may still have health benefits. A group at the Center for Health Services Research in Primary Care, Department of Veterans Affairs Medical Center (Durham, North Carolina), recently published their findings in the Archives of Internal Medicine, where they compared the low-carbohydrate, ketogenic diet (LCKD) with a low-fat diet (combined with the weight-loss medication orlistat) regarding their effects on several health parameters: weight loss, blood pressure, cholesterol levels, and glycemic parameters.
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Does Green Tea Prevent Hematologic Cancers?

green tea flowerTea consumption began in China around 2737 B.C. and has since become a staple among Asian and English cultures. The use of tea for medicinal purposes have prevailed for centuries in traditional Chinese medicine, but only recently gained prominence in the modern “alternative medicine” community. There has been increased interest and active biomedical research on tea extracts, with dozens of peer-reviewed scientific articles published each month exploring the health properties of green tea. Through in vitro and animal studies, green tea (derived from the Camellia sinensis plant) and its polyphenol compounds — in particular, epigallocatechin-3-gallate (EGCG) — have been associated with possible risk reductions in some cardiovascular, neurologic, and oncologic disorders. Human trials are however sparse or equivocal.

I previously reported on a Japanese study correlating green tea consumption with a lower prevalence of cognitive dysfunction. A similar research group from the Tohoku University School of Medicine (Sendai, Japan) has continued to analyze the benefits of green tea with other health outcomes: causes of mortality, cardiovascular disease, pneumonia, and cancers. Their most recent study, published in the American Journal of Epidemiology, evaluated the influence of green tea consumption on the development of hematologic malignancies.

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New & Interesting (13 July 2009)

stock_new-textThe “New & Interesting” series is a biweekly compilation of select research findings, news articles, and random tidbits in bullet-point format. The entries are highly abbreviated, but provide links to the original articles or abstracts if you desire to read further.

General Interest Articles

  • Caffeine may lower Alzheimer’s risk … in mice. More studies are however necessary to evaluate whether these findings translate to humans. The news report also poses the question of how many cups one would need to drink in a day (CBS News)
  • The first ever 16-patient “domino donor” kidney transplant takes place between June 15 and July 6, 2009. The kidney paired donation (KPD) system involves multiple incompatible donors and recipients, and matching them in a way to accommodate all participants. This system maximizes the chances of being able to donate and receive a kidney transplant (Johns Hopkins Medicine)
  • Obesity is linked to the behavior of same-sex their parents and not due to genetics. That is, obese mothers were more likely to have obese daughters. Sons take after their fathers. This study was performed on 226 families by researchers at the Peninsula Medical School. (BBC)
  • Heavy drinking is associated with an increased of developing prostate cancer, according to scientists at the University of California, San Francisco (Reuters)

Technical Articles

  • Withdrawal of proton-pump inhibitors (PPI) after at least 8 weeks on therapy can result in rebound acid hypersecretion (RAHS) (Gastroenterology)
  • [FAMOUS trial] Famotidine is effective in preventing gastric and duodenal ulcers, and erosive esophagitis in patients on chronic low-dose aspirin (Lancet)
  • NIH publishes their final guidelines on human stem cell research (NIH)
Comparing Strategies for Weight Loss Maintenance

tape measureIt almost seems that a million-and-one books are published everyday touting the secret to rapid and sustained weight loss. But, how many of these diet schemes have been verified to produce the results they advertise? In the latest JAMA (Journal of the American Medical Association) issue, a group of academic centers involved in the Weight Loss Maintenance (WLM) initiative published their results from a three-year study comparing strategies for sustaining weight loss. The project is sponsored by the National Heart, Lung, and Blood Institute (NHLBI), and includes four clinical centers: Duke University, Johns Hopkins University, Pennington Biomedical Research Center, and the Kaiser Permanente Center for Health Research.

The design of the WLM clinical trial involves two phases. Phase 1 comprises a 6-month period where all participants undergo similar intervention to obtain weight loss. Working closely with a trained interventionist, the group strives to achieve a weekly weight loss goal of 1-2 pounds per week through a combination of strategies, such as caloric reduction, dietary modification, and increased physical activity. After having lost weight in phase 1, participants in the 30-month phase 2 trial are randomly divided into three groups, each with a different level of intervention to encourage maintenance of weight loss: 1) minimal intervention; 2) technology-based intervention, with use of an interactive website which sets personal goals, action plans, and provides an online support community; and 3) personal-contact intervention, involving monthly contact with a weight-loss interventionist.

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Inaccurate Alcohol Breath Test

red wineImagine this far-fetched hypothetical scenario where an overworked, sleep-deprived, and hypoglycemic post-call resident is driving home (unbelievable, huh?). During a brief moment of weakness, he drifts to the right, but rapidly corrects his driving trajectory. However, a highway patrolman, Officer Poelis, is sitting along the shoulder of the road and notices the momentary lapse in the driver’s control. Sirens blare and the resident stops his car. Given the circumstances, the resident’s erratic driving behavior probably resulted from his prolonged lack of food and sleep. Officer Poelis, however, suspects that alcohol is involved and asks the resident to take a breath test. To the resident’s shock and surprise, he tests positive for alcohol despite not having had any alcoholic beverages since the last Residents Night Out party two weeks earlier.

Although a seemingly stretched hypothetical scenario, it is not beyond the realm of possibility. A Swedish group recently published a case report of a 59 year-old non-drinker who was unable to start a motor vehicle equipped with an alcohol ignition interlock device. A second breath-alcohol test revealed a blood alcohol level of 0.01-0.02 g/dL. These results were shocking, considering the gentleman has remained abstinent from alcohol his entire life.

There is nevertheless a biochemical explanation for the false alcohol reading. In an attempt to lose weight, the patient was on a very low calorie diet (VLCD). People on such diets or prolonged fasting states depend on fat metabolism for energy. Three forms of ketone bodies (acetone, acetoacetate, beta-hydroxybutyrate) subsequently accumulate in the body. The acetone can be metabolized by the liver to form isopropanol. A drawback of the breath-alcohol analyzer is that it cannot differentiate isopropanol from ethanol (the form of alcohol found in liquor). Consequently, despite the lack of substance use, he was recorded to have had an elevated concentration of alcohol in his breath.

Fortunately, blood alcohol tests utilize gas chromatography, which generate more specific results. This method could be used to verify false positives, but I doubt we will see bulky gas chromatograms in squad cars anytime in the near future.

Since this is the first case report of its kind, it is still unclear whether prolonged fasting states relate to a false positive reading. Besides the obvious warning to not drink and drive, I would strongly discourage the use of this excuse if caught. It would be much easier and safer to just find a designated driver. In the case of a resident on q4 call, finding a willing volunteer may be more difficult to accomplish.

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