TUESDAY, June 16 (HealthDay News) -- Antioxidants play an important role in semen quality, according to new research from Spain.

The study found that "men with good semen quality ate more vegetables and fruit (more vitamins, folic acid and fiber and less protein and fats) than those men with low seminal quality," the lead author, Jaime Mendiola, a researcher at the University of Murcia, said in a news release.

Antioxidants, found mainly in fruits and vegetables, lower the level of oxidative stress that can affect semen quality, the researchers explained, and also improve sperm concentration and mobility.

The study included 61 men -- 30 with reproductive problems and 31 who did not have such issues. It appears online in the journal Fertility and Sterility.

An earlier study by the same team "showed that men who eat large amounts of meat and full-fat dairy products have lower seminal quality than those who eat more fruit, vegetables and reduced-fat dairy products," Mendiola said.

But the new study "found that people who consume more fruits and vegetables are ingesting more antioxidants, and this is the important point," Mendiola said. "A healthy diet is not only a good way of avoiding illness but could also have an impact on improving seminal quality."

"What we still do not understand is the difference between taking these vitamins naturally and in the form of supplements," the researcher added. "In the studies we are going to carry out in the United States (where the consumption of vitamins in tablet form is very common), we will be looking at the role of supplements."

More information

The U.S. National Institute of Child Health and Human Development has more about reproductive health.

FRIDAY, June 5 (HealthDay News) -- Parents' eating habits don't seem to influence their children's food choices as much as experts have thought, new research suggests.

"We found that the resemblance in dietary intake between parents and children is weak," said study senior author Dr. Youfa Wang, an associate professor of international health and epidemiology at Johns Hopkins Bloomberg School of Public Health in Baltimore. However, he added, "there is some effect."

Wang found that children whose parents ate a healthier diet -- and that was a small minority -- were three times more likely to have a healthy diet compared to the kids whose parents did not have a very healthy diet.

Overall, however, he said that "it seems that parents' influence is quite moderate, much weaker than what many people have believed."

The study is published online in Social Science & Medicine.

The findings suggest that other factors, such as peer influence and television viewing, may be more powerful influences on what children eat.

For the study, Wang and study co-author May Beydoun evaluated two 24-hour dietary recalls from the U.S. Department of Agriculture (USDA) Continuing Survey of Food Intake by Individuals 1994-96. In all, they looked at the food intake of nearly 5,000 persons -- 1,061 fathers, 1,230 mothers, 1,370 sons and 1,322 daughters.

The researchers compared intake and assessed diet quality based on the USDA Healthy Eating Index Score. A perfect score is 100, and the index takes into account a person's intake of fruits, vegetables, whole grains, dairy products, meat, beans, oils, saturated fat and sodium.

The average scores of the parents and children were about 48 to 50, well below the score of above 80 that the USDA deems a good diet. Only 10 percent of Americans got a score greater than 80 in 2000, according to the USDA.

Wang looked at the overall correlation between children's and parents' intake. The correlation measure range is between minus 1 and 1, with zero reflecting no resemblance and 1 perfect resemblance. The correlation, overall, ranged from 0.26 to 0.29, using various combinations such as mother-daughter and father-son.

Put more simply: "The variation in children's diet that could be explained by their parent's diet was less than 10 percent," Wang said, "[and] 90 percent of the variation in the children's diet were explained by factors other than the parent's diet."

The results are something of a surprise, said Connie Diekman, director of university nutrition at Washington University in St. Louis and past president of the American Dietetic Association.

So what's a parent to do? After brushing up on your own diet, "take the kids to the store, let them see and smell the produce," Diekman suggested. "Talk about how you choose meat and how you decide which dairy foods to buy."

Let them help you cook healthy foods, too, she said.

Wang agreed that parents should aim to eat healthier themselves and encourage their children to follow similar habits. Schools, too, need to make a stronger commitment to getting the healthy diet message out, Wang said.

More information

To learn more about healthy eating for kids, visit the U.S. Department of Agriculture.

FRIDAY, June 5 (HealthDay News) -- One reason many people don't stick with exercise is that it's often not that interesting. But what if you could dance your way to improved health?

Two new studies suggest that you just might be able to do that.

Presented recently at the American College of Sports Medicine meeting in Seattle, one study found that salsa dancing could improve cardiovascular fitness, and the other found that less vigorous ballroom dances such as the fox trot or tango -- although not as much of a workout as salsa -- can add 2,000 steps or so to a person's daily walking total.

"Learning to dance can be a fun, social, local and friendly way to enjoy low-intensity physical activity and skill learning," said the author of the second study, Stephen Cobley, a senior lecturer in skill acquisition and sport/exercise psychology at Leeds Metropolitan University in the United Kingdom.

Dancing, or at least watching dancing on TV, has soared in popularity recently. In the United States, "Dancing with the Stars" draws a significant audience each week, and its British counterpart, "Strictly Come Dancing," has more than 8 million viewers, according to Cobley.

Because this show was drawing so many viewers in the U.K., Cobley and his colleagues thought to capitalize on its popularity and conducted a study by offering a 12-week series of introductory ballroom dancing lessons to a group of sedentary adults.

The average age of the 27 study participants was 53, and most -- 22 -- were women. The once-a-week, two-hour classes were led by an instructor and included dances such as the tango, fox trot and cha-cha.

The classes replaced what was usually sedentary time for the participants and added about 2,000 steps to their daily total, the researchers said. Experts recommend 10,000 steps a day for good health.

"Ten thousand steps per day is the recommendation, but how many seniors are getting that?" asked sports and lifestyle nutritionist Molly Kimball, from the Ochsner Health System in New Orleans. "Two thousand steps is still good, and every little bit helps."

But, she said, different dances, such as the salsa, would provide a much greater aerobic workout.

Salsa was the focus of the other study, in which Italian researchers measured heart rate and oxygen consumption in dancers who were doing a typical salsa during lessons, salsa dancing at a night club or doing a group dance called rueda de casino.

The study included 11 pairs of dancers who were, on average, 36 years old. Maximum heart rate increased between 58 and 75 percent for those doing any of the three dances, and oxygen consumption went up between 41 percent and 56 percent, depending on the dance. Nightclub salsa dancing appeared to be the most aerobic of the three dances, though all increased heart rate and oxygen consumption, the study found.

"Salsa is a spirited dance," study author Gian Pietro Emerenziani, from the University of the Studies of Rome, in Italy, said in a statement. "With this form of dance, you are clearly getting a workout. All three types of salsa in our study, practiced frequently, will have a positive impact on health and fitness."

And dancing has other things going for it, fitness-wise.

"With dancing, you don't necessarily have to go to the gym, you don't have to run in the heat, but you're still benefiting," Kimball said. The trick, however, is to make sure you're not swapping dancing for a higher-intensity exercise, she said.

She suggests that new dancers check their heart rate while dancing to make sure they're getting the same workout they got from a spinning class or a run.

Another caveat, she said, is to make sure you don't negate the benefits of all your two-stepping by having high-calorie drinks or snacks while you're out sashaying the night away.

More information

The AARP has more on dancing your way to good health  .

MONDAY, May 11 (HealthDay News) -- Exercise helps increase insulin sensitivity and ward off diabetes, but taking supplemental antioxidants such as vitamins C and E actually blunts that benefit, researchers report.

Exercise helps increase the body's sensitivity to insulin by making reactive oxygen species, or "free radicals," which antioxidants work against. These free radicals are thought to damage cells and speed the aging process, but they are also used by the body to prevent cell damage after exercising, the researchers say.

"When you exercise you do improve your insulin sensitivity, and if you are at risk for diabetes improving insulin sensitivity is good," said researcher Dr. C. Ronald Kahn, the Mary K. Iacocca Professor at the Joslin Diabetes Center and Harvard Medical School.

Part of the reason that exercise improves insulin sensitivity is that it causes oxidative stress on the muscles. The muscles respond to this stress by creating free radicals, Kahn said.

"If you take antioxidants like vitamins C and E, you block the oxidative stress response, but you also block the beneficial effects of exercise on insulin sensitivity," he said.

The report is published in this week's online edition of the Proceedings of the National Academy of Sciences.

For the study, Kahn's team looked at the benefit of exercise in increasing insulin resistance in 39 young men, roughly half of whom were taking supplemental vitamins C and E.

Kahn's group found that men taking vitamin supplements had no change in their insulin resistance, but men not taking vitamins had an increase in free radicals, which increases insulin resistance. A month after stopping the vitamin supplements insulin sensitivity was restored, the researchers noted.

"If you are exercising, in part, to reduce diabetes risk, you shouldn't take vitamin C and E, because you are going to block some of the beneficial effect of the exercise to prevent the diabetes," Kahn said.

Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine, thinks this study raises doubts about the benefits of taking antioxidant supplements, but not about the value of these vitamins in the foods people eat.

"We have long held out hope that antioxidant supplements, among them vitamin C, vitamin E, beta carotene, and more recently lycopene and others, would help prevent diseases from the common cold to cancer, heart disease to diabetes," Katz said. "But to date, virtually all of the best research evidence is contrary to this hope."

This study has a counter-intuitive conclusion, namely that antioxidant supplements may actually interfere with the beneficial effects of exercise on insulin sensitivity, Katz said.

"This is a small and short-term study, and thus cannot tell us definitively that antioxidant supplements are harmful in diabetes or the insulin-resistant state that often precedes it. But that is precisely what the study suggests may be true," Katz said.

For now, there is substantial uncertainty about any health benefits and the potential harms of antioxidants as supplements, Katz said. "But we have no such confusion about the powerful health-promoting effects of wholesome, mostly plant-based diets and regular physical activity."

More information

For more information on antioxidants, visit the U.S. National Library of Medicine.