NEWSBREAKS INCLUDE:
[check mark] Benefits of Fish Oil in Baby Formula
[check mark] The Acne and GI Connection
[check mark] The New Research on Homocysteine and Kidney Disease
Low-Fat Diet Linked to Lower Risk of Ovarian Cancer
A low-fat diet may decrease the risk of ovarian cancer in postmenopausal women, according to a new analysis of the Women's Health Initiative by Dr Ross Prentice and colleagues at the Fred Hutchinson Cancer Center in Seattle. Previous reports from the Women's Health Initiative Dietary Modification Randomized Controlled Trial examined the effect of a low-fat diet on the risk of breast and colorectal cancer in postmenopausal women. Small but not significant effects were found in its favor for breast cancer, but it was not yet known whether the same diet would alter ovarian cancer risk.
The researchers analyzed data from the dietary modification trial to see if the changes in the women's diets decreased the risk of ovarian and endometrial cancer and invasive cancers overall. In the trial, nearly 20,000 women were randomly assigned to the diet-modification group, and almost 30,000 women ate their normal diet. The women participating in the diet were asked to reduce their fat intake to 20% of their overall diet and eat at least 5 servings of fruits and vegetables a day and at least 6 servings of whole grains. They were followed for an average of 8 years.
Ovarian cancer is a rare cancer, so it took a long time for the number of cases to be enough for analysis. The risk of ovarian cancer was similar in the 2 groups during the first 4 years of follow-up, but it was reduced in the dieting group during the following 4 years. Women who had the highest fat intake before the trial saw the greatest reduction in risk. There was no difference in endometrial cancer risk between the 2 groups, but a trend toward a reduction in invasive cancers overall was suggested in the dieting group. It was not, however, statistically significant. "Ongoing[horizontal ellipsis]follow-up of trial participants may provide additional valuable assessment of the effects of a low-fat dietary pattern on these and other cancer incidence rates," the authors write.
Source: Journal of the National Cancer Institute
Lowering Homocysteine Levels Does Not Improve Outcomes for Patients With Chronic Kidney Disease
Patients with end-stage kidney disease treated with high doses of folic acid and B vitamins to lower homocysteine levels did not have improvement in survival or reductions in the incidence of vascular events, according to a recent study. Although these patients still need these nutrients to replace losses during dialysis, the use of massive doses in the hope that cardiovascular risk will be reduced is not borne out by the evidence.
Many studies have shown that high plasma levels of homocysteine are associated with vascular disease, and folic acid can lower these levels in some cases. Patients with chronic kidney disease or end-stage renal disease (ESRD) have very high homocysteine levels and very extensive vascular disease, as well as many other health problems. Thus, their death rates are as high as 20% per year. Folic acid and B vitamins decrease homocysteine levels somewhat in these patients but cannot bring homocysteine levels to normal levels. Whether the lowering is enough to decrease the rates of death and vascular events was not known, however, and led to this study in patients with advanced chronic kidney disease (ACKD) and ESRD. The randomized controlled trial (2001-2006) involved 36 Veterans Administration medical centers and included patients with ACKD (n = 1,305) or ESRD (n = 751) and high homocysteine levels. Median (midpoint) follow-up was 3.2 years. Participants received a daily capsule containing very high (more than 10 times the recommended dietary allowance) doses of folic acid and vitamins B6 and B12 or a placebo.
After 3 months, the homocysteine levels of patients in the vitamin group decreased by about 26%, whereas this level decreased by only 1.7% in the placebo group. Unfortunately, there was no significant effect of treatment on the rate of death between the 2 groups or on other outcomes such as myocardial infarction, stroke, and amputation. Thus, the findings did not support the administration of very large doses of folic acid and B vitamin supplements to prevent vascular injury or improve survival in patients with ACKD or ESRD.
Source: JAMA. 2007;298(10):1163-1170.
Obesity Increases Colorectal Cancer Risk Among Women
New research suggests that obesity is one of the most important factors that increase colorectal cancer among women. Researchers examined data from 1,252 women who underwent colonoscopy. They classified patients according to their age, smoking history, family history of colorectal cancer, and body mass index (BMI). Obesity was defined as a BMI of 30 kg/m2 or higher. For smoking, patients were divided into 3 groups: heavy exposure, low exposure, and no exposure. Patients who were in the heavy-exposure group included women who had smoked more than 10 "pack years" and who were currently smoking or had quit in the past 10 years. Smokers had a significant increased risk of colorectal cancer, and so did those who were obese. In fact, in this group, obesity was the highest attributable risk factor for developing the disease. One-fifth of all significant polyps detected during colonoscopy was accounted for by BMI. Of those patients who were found to have colorectal cancer neoplasia, 20% were obese and 14% were smokers; thus, clearly, other factors were at work as well in increasing risks. There are many good reasons for achieving or maintaining a healthy weight and for not smoking; this study provides a couple more.
Source: Annual Scientific Meeting of the American College of Gastroenterology
Does Drinking Skimmed Milk After Exercise Promote Recovery and Rehydration?
Writing in the British Journal of Nutrition, researchers report that volunteers in their trial remained hydrated after drinking milk but remained dehydrated after drinking other drinks. In the United States, the sports drinks market generates almost 3 billion sales. Gatorade (PepsiCo) dominates the market with an 82% share. Powerade (Coca-Cola) is second with a reported 13% share of the market.
In the British study, researchers recruited 11 healthy volunteers (average age, 24 years) for the randomized crossover trial. Lactose-intolerant people were excluded from participating. The participants exercised to lose 1.8% of their body weight and then consumed 1 of the beverages-the volume drunk was equivalent to 150% of the sweat lost. Drinks included skimmed milk (0.2%), skimmed milk with added sodium chloride, water, or Powerade. Urine samples were taken 5 hours after exercise.
Urine excretion during the recovery period was unchanged as a result of drinking the milk, whereas excretion increased between 1 and 2 hours after drinking the water and sports drink. No additional benefit on fluid levels was observed when the milk contained additional salt. It is likely that the presence of sodium along with a relatively large quantity of potassium (approximately 45 mmol/L) in milk accounts for the effectiveness of milk at restoring fluid balance after exercise-induced dehydration.
Source: British Journal of Nutrition / http://nutraingredients.com
Potential Health Benefits of Fish Oil in Baby Formula
Infant formula's composition is not a perfect match with breast milk, so the nutritional content of infant formula is altered and refined as more is discovered. Recent improvements include the addition of long-chain n-3 fatty acids, which, it is claimed, can improve brain and visual development. But they may have other roles as well. To better understand the role of these n-3 fatty acids in the early development of babies, researchers at Laval University in Quebec and the Rowett Research Institute in Scotland affiliated with University of Aberdeen and the North of Scotland College of Agriculture in the United Kingdom investigated how these fatty acids affect protein metabolism in neonatal pigs. The scientists weaned 28 piglets at 2 days of age and raised them for a month on either a control formula that did not contain the fatty acid or a "test" formula that contained 3.5% of the fatty acid from fish oil.
The researchers noticed that in the piglets that were fed the control formula, fewer proteins were produced in their body over time, and at the same time, their insulin became less effective at lowering blood sugar levels. However, piglets that drank the test formula showed increased protein production, and their insulin was as effective at using the proteins in the test formula for their growth as when they were born.
In piglets, increased amounts of long-chain n-3 fatty acid have beneficial effects on early development and may help babies in regulating muscle growth that affect early development and future metabolic health. Whether such amounts are safe in babies and whether they help babies regulate muscle growth await other more definitive research on humans.
Source: Journal of Lipid Research. November 2007
Do Low-Fat, Low-Sugar Diets Clear up Acne-Marked Faces Better Than Junk Food Does?
In a randomized study, adolescent boys deprived of a high-glycemic-index junk food diet and who ate a low-glycemic-load diet cleared their mild-moderate acne vulgaris better in 3 months than did their peers who kept to the usual teen diet, and researchers claim that effects were as great as those of pimple medications.
The low-glycemic-load diet was composed of 25% energy from protein, 45% from low-glycemic-index carbohydrates, and 30% energy from fats and was also apparently lower in energy than the junk food diet.
All the boys used food scales and kept food records, and their adherence to diet was monitored. At 12 weeks, urea excretion relative to urinary creatinine was assessed. They were also given a mild facial cleanser, which contained no antiacne medication. At the end of the study, the decrease in total mild-moderate acne vulgaris lesion counts in the low-glycemic-load diet group was significantly greater than among controls, at -21.9 (95% confidence interval, -26.8 to -9.0) versus -3.8 (95% confidence interval, -19.1 to -8.5; P = .01), respectively. However, the boys on the low-glycemic-load diet had significantly greater weight loss (P < .001), lower body mass index (P = .001), reduced body fat (P = .006), reduced waist circumference (P = .04), reduced free androgen indices (P = .04), and increased levels of insulinlike growth factor binding protein-1 (P = .001) than did those eating usual diets. Because there was no group that was put only on a reducing diet, it is difficult to say whether a weight loss diet and a facial cleanser would not do the trick just as well.
There is every reason for teens to maintain or achieve healthy weights, and it may have additional effects in reducing acne lesion burden and severity. As for the low-glycemic-load diets, until other studies show that they have different and better effects than weight loss alone, it is premature to recommend them as acne remedies.
Source: MedPage Today/Smith RN, Mann NJ, Braue A, Makelainen H, Varigos GA. The effect of a high-protein, low glycemic-load diet versus a conventional, high gycemic-load diet on biochemical parameters associated with acne vulgaris: A randomized, investigator-masked, controlled trial. J Am Acad Dermatol. 2007;2:247-256