It's no secret that staying physically active and eating healthy may help people live longer.

But a person's attitude also has a lot to do with how long a person lives and the quality of those years.

According to research, lifestyle and outlook can help extend life up to seven and a half years longer.

Research shows 25 percent of aging is determined by genetics.

Heart disease risk

Overweight Americans with risk factors for heart disease should be offered "intensive" counseling on diet and exercise, according to new guidelines released this week.

The recommendations come from the U.S. Preventive Services Task Force, an independent panel that reviews medical research and makes recommendations on preventive care.

The group's latest guidelines are aimed at a large swath of the U.S. population: overweight adults who have at least one risk factor for heart disease and stroke, such as high blood pressure, high cholesterol or current smoking.

According to the task force, doctors should offer intensive lifestyle counseling, or referrals for counseling, to all of those patients. Nearly half of all U.S. adults have at least one risk factor for cardiovascular disease while roughly 70 percent are overweight or obese, according to the task force.

Mothers to be and tuna

Pregnant women should stop eating all forms of tuna, even the canned light variety, due to risks of mercury exposure, according to Consumer Reports.

The Yonkers, N.Y.-based organization's new report, "The Great Fish Debate," which appears in the October issue of the magazine — and is currently available online at www.consumerreports.org — is based on its own analysis of the FDA's data on mercury in fish, said Dr. Michael Crupain, Consumer Reports' associate director of consumer safety and sustainability.

According to the March of Dimes, babies who are exposed to mercury in the womb can have brain damage, vision and hearing problems.

However, the FDA stands by its recommendation that mothers to be can eat tuna.

Doctors say pregnant women shouldn't avoid all fish, including tuna, because they won't get enough Omega 3 fatty acids.

Omega 3 is vital for the neurological development of the fetus.