Young adults in their twenties and thirties could boost their chances for better health and a longer life by keeping blood cholesterol levels low, according to new research presented last week at the National Heart Lung and Blood Institute.

The report presents the latest results from the Framingham heart study, a 30-year project that has been tracking the cardiovascular risk of residents of a Massachusetts town.

These most recent results are based on data from 2,000 men between 31 and 65 years old who were screened before entering the study 30 years ago and found to be free of heart disease and cancer.

Results show that keeping blood cholesterol low early in life appears to decrease the risk of death from all diseases -- not just heart disease -- reports statistician Keaven Anderson. Ninety percent of the men aged 31 to 39 who kept blood cholesterol levels 180 milligrams or below when they were in their thirties were alive 30 years later, he said, compared with only 65 percent of men who had blood cholesterol levels 260 milligrams and above when they were in their thirties.

These results were far less striking for men in the 40- to 47-year-old age group and did not show up at all for men who began the study at ages 48 to 55 and 56 to 65 years.

Exactly what accounts for the differences among age groups is not known. One theory, Anderson says, is "that the people who are affected by high cholesterol levels are already dead" before reaching their fifties or sixties. Another theory is that there are other risk factors -- such as increased body weight -- which are so threatening to health that the effect of cholesterol would appear diminished.

"I think the message is for people to take care of themselves in their twenties and thirties," Anderson said. That's often the time when people gain weight and their blood cholesterol levels rise. "You shouldn't be waiting until you're 40 or 50 to take care of yourself," he said. "There seems to be evidence pointing toward that."

While these results are preliminary, Anderson said, they are also helping to answer another important question: Do people who keep their blood cholesterol low face a reduced risk of heart disease but also run an increased risk of developing cancer?

Probably not, Anderson said. When he and his colleages looked at overall mortality, they found "no indication of a higher death rate among the lower blood cholesterol groups."