Like a janitor sweeping the halls after the lights go out, major changes occur in the brain during sleep to flush out waste and ward off disease, researchers said Thursday.

The research in the journal Science offers new answers to explain why people spend a third of their lives asleep and may help in treating dementia and other neurological disorders.

The World Health Organization (WHO) on Thursday classified outdoor air pollution as a leading cause of cancer in humans.

"The air we breathe has become polluted with a mixture of cancer-causing substances," said Kurt Straif of the WHO's International Agency for Research on Cancer (IARC).

A Brazilian company said Wednesday it was bringing to market a garlic capsule designed to tackle flatulence.

"This garlic oil is rich in antioxidants and deodorants and combats intestinal dysbiosis, a colon malfunction that increases flatulence," Polias chemist Joseth Gimenes told Agence France Presse.

An experimental blood test has shown promise toward detecting early lung cancer and may offer a more accurate tool than scans and invasive biopsies, researchers said Wednesday.

Only about one in five patients who undergo surgery or a biopsy for a small lung mass found during a computerized tomography (CT) scan actually have cancer, and experts say there is a great need for better technology.

Some of the most haunting victims of the two decades of conflict ravaging eastern Democratic Republic of Congo are the starving children -- and with the World Food Program struggling to fund its operations here, their fate looks likely to get worse.

At the Mugunga I refugee camp, where more than 50,000 displaced people live crowded together under white tents, hundreds of mothers line up at the health center to get a special liquid called "premix" -- a porridge of maize meal, soy, oil and sugar that provides their children 1,057 precious calories.

More than 2,500 children under five have died of malnutrition in Niger this year, the U.N. Children Fund said Wednesday.

The child mortality rate has declined over recent years but still stands at one percent and UNICEF said the impoverished west African was one of the world most aid-reliant countries.

The United Nations marked World Food Day on Wednesday, warning against food waste as 842 million people go hungry and stressing the importance of healthy diets amid rising obesity.

Around a third of food produced globally currently goes to waste -- some 1.3 billion tonnes a year according to the Rome-based U.N. Food and Agriculture Organization (FAO).

Elton John has honored Hillary Rodham Clinton for her work to help those affected by HIV/AIDS at an annual event for his foundation.

Clinton was excited as she accepted the first founders award from the Elton John AIDS Foundation Tuesday night in New York City.

The Dalai Lama weighed in on Mexico's marijuana legalization debate on Tuesday, telling an audience that he backs the drug's use for medicinal purposes.

The Tibetan spiritual leader, speaking at an event hosted by former Mexican president Vicente Fox, said that "the exception" for smoking marijuana would be if it has pharmaceutical virtues.

A Japanese doctor infected with tuberculosis examined more than 600 patients without wearing a mask, an official said Wednesday.

The doctor, who is in his 50s and runs a clinic in central Ito city, began displaying symptoms of the potentially lethal airborne disease in mid-August, but brushed them off as a common cold, the health authority official said.