Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

Company Says it has 'Safer' Smokeless Tobacco

A Virginia tobacco maker is seeking U.S. Food and Drug Administration approval to sell a moist smokeless tobacco with the claim that it is safer than its competitors.

Star Scientific Inc. says its Stonewall Moist-BDL product has 90 to 99 percent fewer cancer-causing chemicals than other smokeless tobacco products and should carry the "modified risk" label being developed by the FDA, the Associated Press reported.

If the FDA agrees, the product would be among the first to marketed as less harmful than other forms of tobacco. The agency is currently considering similar applications for two of Star's dissolvable tobacco products.

A 2007 report from the Royal College of Physicians in the U.K. suggests that some smokeless tobacco products are less dangerous than cigarettes. However, the U.S. Centers for Disease Control and Prevention says smokeless tobacco contains 28 cancer-causing agents and is not a safe substitute to smoking, the AP reported.

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Americans' Diets Aren't as Healthy as They Believe: Poll

The majority of Americans believe their diet is healthier than it actually is, according to a new survey.

The Consumer Reports Health poll of 1,234 adults found that about 90 percent of respondents said their diet is somewhat, very, or extremely healthy, even though many admitted that they consumed large amounts of fat, sugar and carbohydrates, The New York Daily News reported.

The survey also found that 43 percent of respondents said they drank at least one soda or sugar-sweetened coffee or tea a day, and that vegetables and fruits weren't popular food choices.

"Americans have a tendency to give themselves high marks for healthy eating," said Nancy Metcalfe, a senior program editors with Consumer Reports Health, the Daily News reported. "We found their definition of healthy eating was somewhat questionable."

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Estrogen May be Linked to Head and Neck Cancer: Study

The hormone estrogen may promote head and neck cancers in young women, according to a new study.

The team at Fox Chase Cancer Center in Philadelphia found that estrogen helps precancerous cells move and divide by triggering the activity of an enzyme called CYP1B1, BBC News reported.

"CYP1B1 could be a wonderful target in pre-cancerous lesions of the head and neck, because by attacking it, we might stop these lesions from progressing or moving to a more advanced stage," said study leader Dr. Margie Clapper.

The study appears in the journal Cancer Prevention Research.

"This research has been carried out using cancer cells grown in the lab, and while it's an interesting finding, more work is needed before we know for sure what role estrogen plays in head and neck cancers," Dr. Kat Arney, a spokeswoman for Cancer Research U.K., told BBC News.

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Gene Variant Linked to Depression Risk

A gene variant that influences the risk of developing depression has been identified by U.S. researchers.

They analyzed data from 54 studies and concluded that a gene called 5-HTTLPR accounts for between five and seven percent of a person's chances of becoming clinical depressed, ABC News reported.

While previous research has suggested that other gene variants also influence depression risk, 5-HTTLPR is the one one "we can confidently say is real," said study co-author Dr. Srijan Sen, an assistant professor of psychiatry at the University of Michigan Medical School.

The study was published Monday in the journal Archives of General Psychiatry.

Learning more about how genes affect depression risk could lead to better treatments, Sen said.

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Some Young People With STDs Say They've Never Had Sex: Study

Ten percent of young adults who tested positive for one of three common sexually transmitted diseases (STDs) said they hadn't had sex in the previous year, including six percent who said they never had sex, finds a new study.

The researchers said their findings from 14,000 participants who were screened for chlamydia, gonorrhea, and trichomoniasis held even after they factored in variables such as race, age, gender and education, the Washington Post reported.

The study was published in the journal Pediatrics.

The researchers said their findings suggest that doctors should use lab tests to screen all teens and young adults for STDs, instead of focusing only on those who admit to being sexually active, the Post reported.

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