WEDNESDAY, March 3 (HealthDay News) -- Eating plenty of potassium-rich foods such as leafy greens, potatoes and bananas may reduce the risk of stroke and coronary artery disease, according to Italian researchers.

The new analysis was based on 10 studies published between 1966 and 2009 that included almost 280,000 adults. During follow-ups that ranged from five to 19 years, there were over 5,500 strokes and almost 3,100 coronary heart disease events, the investigators found.

Higher potassium intake was associated with a 19 percent lower risk of stroke and an 8 percent lower risk of coronary heart disease. The findings support global recommendations for people to increase their consumption of potassium-rich foods in order to prevent vascular disease, said Dr. Pasquale Strazzullo, of the University of Naples, and colleagues.

Other foods high in potassium include soybeans, apricots, avocados, plain non-fat yogurt, prune juice, and dried beans and peas.

The findings were presented Wednesday at the American Heart Association's Nutrition, Physical Activity and Metabolism conference in San Francisco.

Another study presented at the meeting found that a diet high in raw fruits and vegetables may help protect against stroke.

In that study, the researchers examined the incidence of stroke among more than 20,000 men and women, aged 20 to 65, who were free of cardiovascular disease at the start of the study. During 10 years of follow-up, there were 233 strokes among the participants.

After they adjusted for a number of factors, the researchers found that people with a high intake (more than 262 grams per day) of raw fruits and vegetables were 36 percent less likely to suffer a stroke than those with a low intake (less than 92 grams per day) of raw fruits and vegetables.

However, there was no association between stroke risk and a high intake (more than 233 grams per day) or low intake (less than 113 grams per day) of processed fruits and vegetables, said Linda Oude Griep of Wageningen University, the Netherlands.

More information

The U.S. National Library of Medicine has more about dietary potassium.

THURSDAY, March 4 (HealthDay News) -- Healthy eating habits lead to longer survival for ovarian cancer patients, U.S. researchers say.

In a study of 351 women with incident epithelial ovarian cancer, the researchers found that higher total fruit and vegetable consumption, higher vegetable consumption alone, and healthy grain consumption were associated with longer survival. High consumption of "less-healthy" meats was associated with shorter survival.

The findings "suggest that food patterns three to five years prior to a diagnosis of epithelial ovarian cancer have the potential to influence survival time," Therese A. Dolecek, research associate professor of epidemiology at the University of Illinois at Chicago, and colleagues wrote in their report published in the March issue of the Journal of the American Dietetic Association.

"The pre-diagnosis food patterns observed to afford a survival advantage after an epithelial ovarian cancer diagnosis reflect characteristics commonly found in plant-based or low-fat diets. These diets generally contain high levels of constituents that would be expected to protect against cancer and minimize ingestion of known carcinogens found in foods," the researchers wrote.

"The authors provide new evidence that dietary factors, particularly total fruit and vegetable, red and processed meat, and milk intakes may influence ovarian cancer survival," Cynthia A. Thomson, an associate professor of nutritional sciences at the University of Arizona, Tucson, and Dr. David S. Alberts, director of the Arizona Cancer Center in Tucson, wrote in an accompanying editorial. "These findings corroborate earlier work . . . and are among only a select few studies of dietary associations with ovarian cancer recurrence and/or prognosis despite a significant and growing body of literature suggesting diet may influence ovarian cancer risk."

According to background information in a news release about the study from the journal's publisher, 21,550 new diagnoses of ovarian cancer and 14,600 deaths from the disease were estimated to occur in the United States in 2009. Ovarian cancer is often diagnosed in the late stages and the five-year survival rate is about 45 percent.

More information

The American Cancer Society has more about ovarian cancer  .

WEDNESDAY, March 3 (HealthDay News) -- People who watch more television in their 20s and 30s are more apt to develop heart disease risk factors by the time they reach their mid-40s than people who spent less time in front of the screen, a new study finds.

And while that's worrisome enough for many, the worse news is that you can't exercise the risk away.

The findings are to be presented Wednesday at the American Heart Association's Joint Conference: Nutrition, Physical Activity and Metabolism, in San Francisco.

"When we took into account physical activity, the negative effects of TV viewing persisted," confirmed Emmanuel Stamatakis, lead author of the paper and a senior research associate at University College London. "A likely explanation is that the harmful effects of prolonged sitting cannot be simply compensated by doing some physical activity. In other words, the mechanisms of action of the harms of sitting are not the opposite of the benefits of exercise."

And there may be another negative twist to staying glued to a screen.

"We also would expect that, to some extent specifically, TV viewing harms through increased caloric intake [of unhealthy foods]. There is some evidence to support such an explanation but our study could not take into account food intake," Stamatakis said.

Dr. Eugene Storozynsky, assistant professor of medicine at the University of Rochester Medical Center, believes the association might come from behaviors other than sitting.

"I suspect it's not so much the TV watching but other behaviors that go along with TV watching -- specifically, were the study subjects eating lots of carbohydrate-rich foods or drinking carbohydrate-rich drinks at the time they're TV watching?" he said.

"It would be interesting to see if there is a similar association with other sedentary lifestyles with the caveat that these individuals are not able to eat or drink all the time," Storozynsky added. "Has anyone done a study on people who spend a lot of time in libraries and just read and then exercise? After all, every elliptical trainer and treadmill in the gym has a TV above it."

The study was also unusual in that it looked at people in post-adolescence and early adulthood, he added, and it also focused on a specific type of sedentary behavior, said Dr. Robert Scott III, assistant professor of internal medicine at Texas A&M Health Science Center College of Medicine and senior staff cardiologist at Scott & White in Temple, Texas.

The researchers looked at the TV watching and exercise habits of more than 5,600 men and women born in Britain in 1958. Initial measurements were taken in 1981, when the participants were 23 years of age, with additional follow-up done when they reached age 44.

The researchers unearthed three factors that, together, explained 57 percent of the risk difference between those who watched more TV and those who watched less.

One had to do with metabolism -- triglycerides, HDL ("good") cholesterol, body mass index, waist circumference and blood pressure -- which explained 28 percent of the variance.

The second was an inflammatory component including levels of (inflammation-linked) C-reactive protein, which explained 16 percent of variance. The third component involved total cholesterol and LDL ("bad") cholesterol, which explained 13 percent of the variance.

The associations remained evident even after adjusting for physical activity, the team found.

"It was still better if they exercised versus not exercising but the more you watched TV, even if you exercised, increased these risk factors," Scott said.

But it still comes back to the same bottom line people have been told before.

"Sitting in front of the TV for long periods of time should be avoided. In the U.K. and U.S., adults watch TV for around three to four hours a day on average," Stamatakis said. "This is simply too much, given that most of us have sedentary jobs, drive or commute by motorized transport and have lots of other opportunities (that we usually do not miss) to sit," he explained.

"Humans are not made to be sitting for the 10 to 11 hours that, on average, we do (and these 10 to 11 hours are in addition to sleeping)," he added. "Our evolution teaches us that our bodies are made to hunt and run away from our predators, not sit in front of a screen. We have completely ignored this side of our nature; therefore, it is not surprising that our bodies accumulate too much fat, get heart disease, cancer and type 2 diabetes. All these are direct consequences of too much sitting and not enough physical activity -- both, not either/or."

More information

There's more on heart disease at the U.S. Centers for Disease Control and Prevention.

WEDNESDAY, March 3 (HealthDay News) -- Wondering if you'd do better to cut carbs or fats to lose weight? A DNA test using a cheek swab may reveal which approach would work best for you, new research suggests.

Researchers from Stanford University used data on a study from 2007 in which 138 overweight or obese women were assigned to one of four popular diets for a year. The diets included: the Atkins diet (very low carbohydrate), the Zone diet (low carbohydrate), the Ornish diet (very low fat) or a health professional's diet (a low-fat diet that generally follows the U.S Agriculture Department's Food Pyramid). The women also had the inside of their cheeks swabbed to collect a DNA sample.

Researchers used the genetic information to assign women to a "genotype-appropriate" diet, an eating plan that would seem to be the most effective for them given their particular genetic makeup.

Women assigned to the correct diet based on their genotype lost two to three times more weight at 12 months than those who were assigned to a diet that was inappropriate. When the researchers looked at only the most extreme diets (Atkins versus Ornish), the results were even more stark. Women assigned to their correct diet for their genotype lost five times as much weight as those on the incorrect diet, the study found.

The women on the correct diets also showed improvements in their "good" (HDL) cholesterol and decreases in harmful triglycerides.

"The weight loss differences between the various diets were not that dramatic, but the weight loss difference within a particular diet was," said lead study author Mindy Dopler Nelson, a Stanford postdoctoral research fellow. "On each diet, there were a lot who lost weight, there were a lot who didn't lose weight and there were even some that gained weight. By looking at the genetics we were able to see it was less the particular diet than the individual's response to the diet."

The study was to be presented Wednesday at the American Heart Association's Nutrition, Physical Activity and Metabolism Conference 2010, in San Francisco.

The DNA test, made by Interleukin Genetics in Waltham, Mass., sells for $149. It works by honing in on certain genes that play a role in the way people metabolize food, said Lew Bender, CEO of Interleukin Genetics.

From among hundreds of genes believed to be involved with obesity, researchers from Interleukin Genetics identified three genes that had been implicated in multiple clinical studies to play a role in weight management. The genes include fatty acid binding protein 2, peroxisome proliferator- activated receptor gamma, and beta 2 adrenergic receptor, Bender said.

"We went through a rigorous scientific process to find those that were the most validated and the most functional, and these were the three," he said.

In those genes, a so-called single nucleotide polymorphism -- or a variation of a DNA sequence within a gene fragment -- causes the gene to produce a form of protein that changes the way it functions. In the case of fatty acid binding protein 2, for example, the polymorphism leads to the production of a protein that can cause a greater absorption of fat, Bender said.

"If you look at someone who has a polymorphism that causes them to absorb more fat, combined with another polymorphism that causes them to not burn fat well, they would be more prone to obesity from diets that are high in fat," he said. "In those cases, we would recommend they go on a low-fat diet."

Dr. Robert Eckel, past president of the American Heart Association and a professor of medicine at University of Colorado School of Medicine, said the study results were very preliminary and had to be confirmed by larger studies before he would recommend that anyone have their diet genotyped.

"The three genes they have identified are all genes that could affect energy balance, and the idea that polymorphisms in these genes could affect energy balance is of interest scientifically," Eckel said. "This could explain small differences in the way people respond to diet. But right now the most important predictor of successful dieting is compliance."

Stanford's Nelson, a nutritional scientist, said she was encouraged by the findings but not surprised. During her career, she's seen wide variations in weight loss among people assigned to identical diets. Some results could be explained by how well people adhered to the diet, but not all, she said.

"You do need to be on a reduced-calorie diet. You still need to eat healthy. But there is a difference in how people process calories," Nelson said. "Knowing your genotype is just one more tool to help the weight-loss process."

Interleukin Genetics has applied for a patent on the DNA test, Bender said.

More information

For tips on losing weight, visit the U.S. National Library of Medicine.