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Diet and Fitness Newsletter
May 4, 2009


In This Issue
• Remembrance of Fat May Be at Root of Cravings
• Hidden Salt in Diet Haunts Many With Heart Failure
• A Pre-Workout Meal to Help You Burn Fat
• Wine May Guard Against Lymphoma Recurrence
 

Remembrance of Fat May Be at Root of Cravings


WEDNESDAY, April 29 (HealthDay News) -- When you eat fat-rich foods, your brain forms long-term memories of the experience, says a new study.

The finding adds to knowledge about the link between dietary fats and appetite control and could lead to new ways of treating obesity and other eating disorders, according to researchers from the University of California, Irvine.

In previous studies, they found that oleic acids from fats are transformed into a compound called oleoylethanolamide (OEA) in the upper region of the small intestines. OEA sends hunger-curbing messages to the brain to increase feelings of fullness. Elevated levels of OEA can reduce appetite.

In their new study, the researchers found that OEA also causes memory consolidation, in which superficial, short-term memories are turned into meaningful, long-term memories. OEA does this by activating memory-enhancing signals in the amygdala, the brain area that plays a role in retaining memories of emotional events.

The study was published online in this week's issue of the Proceedings of the National Academy of Sciences.

"OEA is part of the molecular glue that makes memories stick," neuroscientist Daniele Piomelli, a co-author of the study, said in a university news release. "By helping mammals remember where and when they have eaten a fatty meal, OEA's memory-enhancing activity seems to have been an important evolutionary tool for early humans and other mammals."

The ability may have been a survival mechanism for early humans, but things are different today. Because fatty foods are now overly abundant, this ability can cause cravings that lead to excess consumption and obesity, Piomelli said.

More information

The American Academy of Family Physicians offers advice about healthy nutrition  External Links Disclaimer Logo.


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Hidden Salt in Diet Haunts Many With Heart Failure


SATURDAY, April 25 (HealthDay News) -- Eating a low-salt diet is one of the most important lifestyle changes people with heart failure can make, but only a third adhere to the recommendation, a new study has found.

Researchers asked 116 people with heart failure to write down everything they ate for three days. Though the recommended daily intake of sodium for people with heart failure is 2,000 milligrams, participants in the study were consuming an average of 2,671 mg a day.

Many weren't purposefully ignoring doctor's recommendations, said study co-author Carolyn M. Reilly, a postdoctoral fellow at Emory University in Atlanta. Most thought they were taking steps to reduce their sodium by putting less salt on their foods, but she said they were focused on the wrong target.

About 70 percent of the sodium in the American diet comes from processed foods such as canned soups, lunch meats and fast food, not from salt added to home-cooked meals.

Sodium is added to foods to give them a longer shelf life, enhance texture and mask bitterness.

"There is so much salt hidden in foods that patients aren't aware of," Reilly said in a news release from the American Heart Association.

The research was to be presented Saturday at the American Heart Association's 10th Scientific Forum on Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke in Washington, D.C.

The American Heart Association recommends that healthy people try to eat less than 2,300 mg of salt a day. Some people -- including blacks, middle-aged and older adults and people with high blood pressure -- should aim for less than 1,500 mg a day.

"The patients themselves were shocked to find out they were eating more than 2,000 mg of sodium a day," Reilly said.

Some of the highest-sodium foods eaten by the study participants included hot dogs, sausage and bacon, canned soups, salad dressings, condiments, fast food, lunch meat, bread, pizza, processed entrees, prepared grits and cornbread.

More information

The American Heart Association has more on low-sodium diets  External Links Disclaimer Logo.


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A Pre-Workout Meal to Help You Burn Fat


THURSDAY, April 23 (HealthDay News) -- The type of carbohydrates you eat before a workout may influence how much fat you burn during your exercise session, new research suggests.

Women who ate a breakfast rich in carbohydrates that do not cause a spike in blood sugar -- think muesli, yogurt, skimmed milk -- burned 50 percent more fat during a post-breakfast workout than did those who ate a breakfast rich in the kind of carbohydrates known to make blood sugar rise sharply, such as cornflakes and white bread.

Carbs that cause a sharp blood sugar rise are known as high-glycemic index carbs, while those that don't are called low-glycemic index carbs.

While other researchers have also found that a low-glycemic menu is beneficial to fat-burning, the new study has some unique points, noted lead author Emma Stevenson, a senior lecturer at Northumbria University, Newcastle Upon Tyne, U.K. She conducted the study while at the University of Nottingham.

"Most of the research in the effects of the glycemic load of pre-exercise feeding has been carried out in male subjects," Stevenson said. Most of it also has focused on endurance athletes, which doesn't describe the bulk of the population.

Instead, the new study included eight women of a typical healthy weight who averaged 24 years of age. On two different occasions, the women ate either a high- or the low-glycemic index breakfast, then walked on a treadmill for 60 minutes three hours later. Stevenson's group drew blood samples before the breakfast and also during and after the exercise to measure parameters such as free fatty acids, which are a marker for fat burning.

The average amount of fat oxidized during the exercise was 7.4 grams after the low-glycemic meal but just 3.7 grams the higher glycemic index meal, a nearly 50 percent difference.

Why the disparity? High-glycemic index carbs are known to spur a big spike in blood sugar, and the researchers believe that a meal rich in low-glycemic carbs, which elicit a lower blood sugar response, may boost the body's use of body fat for burning rather than for blood sugar.

Each breakfast totaled about 265 calories, but the low-glycemic meal had more fiber, the team noted.

The study was funded by Mars UK, the food and candy company. It is published in the May issue of The Journal of Nutrition.

The take-home message, according to Stevenson: To burn more fat, focus on the low-glycemic foods. "LGI foods tend to be whole grains, porridge, some whole grain cereals, soy and linseed bread," she said.

The new study makes sense and builds on previous research, said Barry Braun, director of the Energy Metabolism Laboratory at the University of Massachusetts, Amherst, who has done his own research on post-workout eating.

While Stevenson's study findings are limited to healthy-weight women, Braun said he suspects it will also hold true for those hoping to shed excess pounds. "Eating large amounts of high-glycemic carbs right before exercise is probably as detrimental for overweight people as it is for normal-weight," he said.

Like Stevenson, he said he is talking about pre-exercise meals for those who work out at less than triathlon intensity. "There may be a place for these high-glycemic carbs" when an athlete needs high energy immediately, such as before running a marathon, Braun said.

Last year, Braun's own research found that the type of food eaten after exercise can make a difference in weight control for everyday exercisers.

Based on his studies, Braun suggests that eating a meal low in carbohydrates after working out at moderate intensity, is potentially better for weight control than eating a meal high in carbs.

More information

There's more on carbohydrates at Harvard University  External Links Disclaimer Logo.


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Wine May Guard Against Lymphoma Recurrence


TUESDAY, April 21 (HealthDay News) -- Patients with non-Hodgkin lymphoma who drank wine before their diagnosis appeared to have a reduced risk of relapse or death, according to a study that's the first to identify this connection.

The researchers looked at more than 500 women with non-Hodgkin lymphoma and found that, overall, those who drank wine before their diagnosis had a 76 percent five-year survival rate, compared with 68 percent for those who didn't drink wine. The five-year, disease-free survival rate was 70 percent for wine drinkers and 65 percent for non-wine drinkers.

Further analysis by the Yale School of Public Health team revealed that patients who drank wine for at least 25 years before their diagnosis had a 25 percent to 35 percent reduced risk of relapse, secondary cancer or death.

The strongest link between wine consumption and improved outcomes was among patients with diffuse large B-cell lymphoma. Overall, they had a 40 percent to 50 percent reduced risk of relapse, secondary cancer or death, while those who drank wine for 25 years or more had about a 60 percent reduced risk.

Drinking beer or liquor had no beneficial effect, according to the researchers, who were to present the findings Tuesday at the American Association for Cancer Research (AACR) annual meeting, in Denver.

The findings need to be replicated before any public health recommendations are made, but the study offers further evidence that moderate consumption of wine has health benefits, wrote first author and doctoral candidate Xuesong Han.

"This conclusion is controversial, because excessive drinking has a negative social and health impact, and it is difficult to define what is moderate and what is excessive. However, we are continually seeing a link between wine and positive outcomes in many cancers," Han said in an AACR news release.

More information

The American Cancer Society has more about non-Hodgkin lymphoma  External Links Disclaimer Logo.


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