Glycemic Index and Breakfast
A report in the British Journal of Nutrition1 suggests that serving children a breakfast with a low glycemic index (GI) may make them less hungry during the day and thus lead to a lower total caloric intake.This study tracked total calories consumed each day for a group of 38 children, ages 8 to 11. On some days, they were given a low-GI breakfast (such as oatmeal, whole-grain breads, etc), and on others, a high-GI version. Over the remainder of the day after the low-GI breakfast, the children consumed 60 fewer calories. While 60 calories may not seem like much, the researchers point out that no one becomes obese overnight. It might also be interesting to see how exercise patterns may differ relative to the meal types.
- BJN, Sept. 2007.
Researchers from the RMIT University in Melbourne, Australia, report that they have been able to improve acne in teenagers and young adults by simply reducing the glycemic load in the diet. The low-glycemic diet consisted of 25 percent (by energy content) protein and 45 percent low-glycemic carbohydrates.2 In addition to an improvement in the acne condition, the diet produced reductions in weight and improved insulin sensitivity.
- American Journal of Clinical Nutrition, July 2007.
Vitamin D and Pre-Eclampsia
Researchers from the University of Pittsburgh3 report that there appears to be a strong correlation between blood levels of vitamin D and a resistance to pre-eclampsia during pregnancy. They found that as levels of 25-hydroxyvitamin D decreased in the sample groups of women they studied, the incidence of pre-eclampsia increased. On average, women who developed the condition during early pregnancy tested out at 45.4 nmol/L, as compared to 53.1 nmol/L in the control group.
- Bodnar LM, et al. Journal of Clinical Endocrinology and Metabolism,Sept. 2007.
Air Pollution and Circulation
Living near a high vehicular traffic area is not good for your cardiovascular system, according to three new studies. One study published in the New England Journal of Medicine4 finds that the blood of bicyclists pedaling behind a Volvo diesel engine tended to form more persistent clots, leading to oxygen-starved tissues.
A study from Chicago5 reports that clots are much more likely to form in the blood of mice exposed to the tiny particulate matter common in urban air pollution. The particles stimulated the production of interleukin-6, a compound involved in inflammation, which then leads to an increased tendency for the blood to clot.
Another study6 found that people who live near a lot of traffic have a greater amount of atherosclerosis, measured by the coronary artery calcification seen on CT scans. The amount of calcification was directly proportional to the proximity of a major road in this study of 4,494 people.
- NEJM, Sept. 12, 2007.
- Journal of Clinical Investigation, Sept. 2007.
- Circulation, July 31, 2007.
Vitamin C Review
A new review of 30 published studies of vitamin C supplementation, involving more than 11,000 people taking at least 200 mg a day, reports both good and bad news. The study finds that in the general population, vitamin C has no effect on the likelihood of contracting the common cold, though there was a very slight beneficial effect in the severity and duration of symptoms. High doses during the course of a cold did not show any consistent patterns. The researchers say this is not a definitive answer though, as the related studies were not always well-designed.
However, in people who are exposed to extreme physical stress for short periods of time, it's a different story. Marathon runners, skiers and soldiers involved in subarctic exercises cut their incidence of colds by 50 percent by taking vitamin C.7
- The Cochrane Library 2007. Available at www.cochrane.org/reviews/en/ab000980.html.
A vaccine marketed for protection against pneumonia is being blamed for a number of new cases of ear infections in children that are resistant to all approved drugs.8 Prevnar was approved for use in children in 2000, and contains antigens from the streptococcus pneumoniae bacteria (as well as diptheria toxin, as part of the vaccine complex). An unfortunate side effect is now being reported, however. A number of cases of superbugs causing ear infections are cropping up in children who have been inoculated. These children are being subjected to treatment attempts, ranging from massive doses of antibiotics (most of which have failed) to ear surgery, to drain the infections. The germ is a strept variation that is dissimilar enough to the vaccine to be unrecognized by the body.
The current thinking is that the vaccine sensitizes the body to seven types of strept bacteria, which when eliminated by the body, make room for the drug-resistant and more aggressive types to take control. This results in an infection that cannot be treated effectively with current medications. The vaccine manufacturer apparently anticipated this problem and has been working on a counter-attack, but that won't be ready for a couple more years. Health officials are worried that the new superinfection will, in the meantime, begin spreading through day care centers and schools.
- Associated Press, Sept. 17, 2007.
Fat Is Contagious
A study of more than 12,000 people over three decades reports that obesity behaves, in some ways, like a communicable disease. This research finds that a person's chance to become obese increases up to 57 percent if they are friends with an obese person, even if that person lives hundreds of miles away. It's even worse for best friends, in which case, the risk triples. Siblings and spouses of obese people have an increased risk of 40 percent and 37 percent, respectively.9 Social ties were stronger factors than genetic influences. On average, a friend would gain five pounds for every 17 pounds gained by the more obese individual.
- New England Journal of Medicine, July 25, 2007.
Exercise Instead of Medication
A study from Duke University Medical Center10 reports that regular exercise can indeed (as reported by earlier studies) help patients suffering from depression. The research was designed to counter criticisms that previous studies were invalid because there was no comparison to placebos. This study included patient groups that performed group-based exercise therapy three times a week, home-based exercise, took a typical antidepressant, or took a placebo pill.
The researchers concluded that the group-based exercise worked every bit as well as the drug group. The home-based exercisers fared not quite as well as those in the group setting, but still better than the placebo group. There were 202 men and women ages 40 and up participating in the study, all of whom had been diagnosed with major depression.
- Psychosomatic Medicine, Sept. 2007.
The "Nocebo" Effect
A new study from the Netherlands11 reports that a positive reaction to an allergy test may not necessarily mean you are allergic to the allergen. The researchers performed double-blind, placebo controlled allergy testing of 105 children averaging about 5 years old. About one of every six children (17 total) showed a positive reaction to the procedure, most of which were objectively confirmed rashes, hives, diarrhea and such. The term for this outcome is the "nocebo effect." While the placebo effect, which can improve a patient's condition when he expects good results, the nocebo effect can cause physical manifestations relating to the patient's negative expectations.
- Allergy, Aug. 2007.
The American Journal of Clinical Nutrition12 reports that a diet with lots of high-glycemic carbohydrates may contribute to the development of macular degeneration. This study looked at the dietary habits of more than 4,000 aging adults in comparison to signs of age-related macular degeneration (AMD). The correlation was so significant that the researchers calculated that about 20 percent of the AMD cases could have been prevented if all the diets had been of low glycemic index.
- AJCN, July 2007.
Researchers from the University of Alberta13 have discovered that diet drinks and snacks, at least in juvenile rats, can actually promote weight gain. They found that after a period of being fed such dietary items, they tended to go "hog wild" when presented with normal foods. While the reason for the effect (which was not seen in adult rats) is not clearly understood, the authors suspect that the youngsters' appetite mechanisms were thrown out of kilter by the specialty foods. In light of this study, they recommend that children be fed a diet of well-balanced foods in their natural form.14
- Obesity, Aug. 2007.
- Reuters, Aug. 13, 2007.
Click here for previous articles by Brian Sutton, DC.