How many glasses of cranberry juice per day does it take to keep the cardiologist at bay? Three glasses, suggests a small study presented at the annual meeting of the American Chemical Society. The nutrients found in cranberry juice may reduce the risk of heart disease by as much as 40 percent, mostly by increasing high-density lipoprotein cholesterol levels. Cranberry juice also increases blood levels of antioxidant nutrients by as much as 121 percent. Because sweetened cranberry juice can increase triglyceride levels, the best way to get full benefit may be to include fresh cranberries in the daily diet.

Eating breakfast every day can help prevent obesity and type 2 diabetes. As reported by Reuter's Health, a recent study of 2,681 young adults (25 to 37 years of age) and their eating habits found that breakfast cuts the risk of obesity by controlling appetite, thereby reducing the chance of overeating later in the day. Young adults who reported eating breakfast every day were 35 to 50 percent less likely to develop obesity and insulin resistance than those who ate breakfast less often. The quality of the breakfast was also important: risk reduction was associated with eating whole-grain or bran cereals, but not refined-grain cereals. The findings of this eight-year study were presented at the American Heart Association's 43rd Annual Conference on Cardiovascular Disease Epidemiology and Prevention.

Are sugar and fat addictive? As reported on The Age Web site, a study conducted at Albert Einstein College of Medicine found that high-fat diets in rats quickly resulted in resistance to leptin, a substance secreted by fat cells that influences the area of the brain moderating eating behavior. In another study conducted at Rockefeller University, rats that were fed a constant diet of sugars and then suddenly taken off this diet experienced tremor-like symptoms, much like those in people who are withdrawing from nicotine and morphine. However, an Australian nutritionist questions proof based on tests in rats and suspects that habit has a more important role in human overeating.

Regular rest breaks have some effect in preventing accidents during sustained activities, according to a study published in The Lancet. Records from a database of all on-duty accidents that occurred during a three-year period at a car assembly plant showed that accident risk increased over the four half-hour segments that made up a two-hour period of continuous work. Immediately after a work break, the risk decreased almost to the level in the first section after the preceding break, but restorative effects were short lived. The investigators note that although frequent short breaks have been shown to improve work performance, the breaks should fit in with the work routine. Risk may increase if the rest breaks involve shutting down and starting up equipment.

What's with “know-it-alls”? As reported in Psychology Today, a study of 211 students that was conducted at the University of British Columbia in Vancouver found that those with narcissistic character traits were more likely to overstate their knowledge of real and even fake events. A psychologist at the university noted that these students are probably not aware of their behavior, that memory bias may play a part, and that the overstating behavior becomes habitual over time.