CHECKUP : NEWS, TIPS AND TRENDS COUPLES THINK ALIKE WHEN IT COMES TO DENTAL HYGIENE.

Couples often share similar dental hygiene practices, research shows.

People who neglect their teeth are 32 times more likely than others to be paired with someone who also has poor dental hygiene, a recent study of married people found. Similarly, people without signs of dental neglect are nearly 5.5 times as likely as other people to have a partner with the same level of dental hygiene.

The findings suggest that social and environmental factors - not just genetics - influence whether ``having good teeth'' runs in the family, according to the Academy of General Dentistry (AGD) in Chicago.

``When people live together, they have a tendency to adopt similar dental habits,'' Dr. J. Nick Russo, an AGD spokesperson stated in the December issue of Dentalnotes, the group's newsletter.

``However, while living together is an important factor involved, there are other factors that influence their oral hygiene habits, including where they live, their social and financial status, and hereditary factors,'' he said.

Fitness in five: Exercise seems to bestow its benefits on people even when done only five minutes a day, a Cornell University study has found.

Such a modest exercise regimen does not work wonders - it does not cause weight loss - but it can increase muscle flexibility and mental attitude, said Toni McBride, director of Cornell's Wellness Program.

A 12-week study of 25 people showed that those who did sit-ups and leg and back exercises for five minutes a day increased flexibility and improved abdominal strength and endurance, she said.

When the people leave...: Nuclear pollution such as that seen in the area of the Chernobyl disaster 11 years ago may not be the total environmental catastrophe one would think, reports Robert Baker, a geneticist from Texas Tech University who recently spent seven weeks visiting the area to assess wildlife there.

Baker was amazed to find that moose, deer, wild boars, foxes, river otters, rabbits and other animals were thriving near Chernobyl. Indeed, the closer he went to the plant itself, the denser the animal population was. Such a finding puzzled the scientist.

``It finally dawned on me,'' Baker said. ``The answer is simple: Man has left. Radioactivity at the level associated with the Chernobyl meltdown does have discernible, negative impacts on plant and animal life. However, the benefit of excluding humans from this highly contaminated ecosystem far outweighs any negative factor associated with radiation.''

Clean hands, well body: Frequent, proper hand washing can help children and adults avoid colds, Indiana researchers report.

In a study of 60 children ages 3 to 5 and 20 teachers at a child-care center, those who followed certain hand-washing techniques caught fewer colds during cold and flu season than the group who took no special precautions.

The youngsters and adults in the special-care group followed a strict hand-washing regimen that included washing their hands for 10 to 15 seconds upon arrival at the center and drying them thoroughly. Those in this group were encouraged to sneeze into their elbows instead of their hands. If they forgot, they were instructed to wash their hands. Parents were encouraged to follow the same practices at home.

Almost 19 percent of the children and teachers in the special-care group caught colds compared to nearly 28 percent in the other group, reported lead researcher Joann Niffenegger, an assistant professor of early child development at Purdue University in West Lafayette, Ind.

While it takes some time to change a child's behavior, ``eventually children understand the importance of hand washing and become very interested in doing it properly with the help of the adults around them,'' she said.

Though persistent washing can dry out the hands, a little moisturizing lotion can counteract the drying, Niffenegger said.

Arming the immune system: Asthma may be on the rise in modern countries because childhood infections - which activate the immune system - have declined, a new study suggests.

Researchers say the report raises the intriguing possibility that doctors one day may be able to give a vaccination of sorts that could mimic an infection and therefore help protect against the chronic lung disease.

An asthma attack is caused when the airways become inflamed and constrict, usually because of an allergic sensitivity to pollution, dust mites or other airborne substances. However, deaths from asthma have risen in industrialized countries, even though the air in major cities has generally become cleaner. Also, research has found that asthma is just as common in arid cities with low dust-mite infestations.

These enigmas have prompted a hunt for other culprits, including stress, nutritional deficiencies and exposure to household pests.