THURSDAY, Feb. 14 (HealthDay News) -- Older smokers are more likely than younger ones to deny they smoke when asked about it by doctors and others.

That's the conclusion of a study that analyzed data on 15,182 self-reported "nonsmokers" in the United States who took part in the third National Health and Nutrition Examination Survey. The researchers found that 8 percent of those self-reported nonsmokers actually were smokers and that smoking denial increased with age.

"Denying smoking overall increased with age from 6 percent of 18 to 34 year olds to 25 percent of the elderly over the age of 75," lead author Monica Fisher, an associate professor at Case Western Reserve University's School of Dental Medicine, said in a prepared statement.

When she and her colleagues analyzed race and gender data, they found that non-Hispanic white men and women followed the overall pattern and had increased denial with age. Smoking denial rates decreased with age among older Mexican-American women, and remained stable over age for Mexican-American men and non-Hispanic black men and women.

In some cases, social taboos may cause older people to deny that they smoke, Fisher said.

She and her colleagues said the findings challenge the validity of utilizing self-reported tobacco use in research projects, surveys of tobacco use in the general public, or in the care of people with chronic diseases related to smoking.

The study was published in the Journal of Health Care for the Poor and Underserved.

More information

The U.S. Centers for Disease Control and Prevention has more about tobacco use and smoking.

MONDAY, Feb. 11 (HealthDay News) -- Among Americans living to the ripe old age of 100 and counting, it is the ability to delay the onset of disability, and not the onset of disease, that seems to secure a long life.

A new study reveals that 32 percent of centenarians struggle with age-related illness for 15 years or more before hitting the 100 mark. Yet mental or physical disability is no more prevalent among this group than among centenarians who stave off disease until later in life.

"One would have guessed that to get to extreme old age, you'd have to avoid or delay disease," said study co-author Dr. Thomas Perls, director of the New England Centenarian Study at Boston Medical Center. "But some very old people with significant illness still live independently. And the message here is that one shouldn't jump to the conclusion that disease equals disability."

Perl's study is published in the Feb. 11 issue of the Archives of Internal Medicine.

In it, he and his colleagues noted that men and women over the age of 85 are the fastest-growing segment of the American population.

A 2001 U.S. Census Bureau report further reveals that, as of 2000, a little more than 50,000 centenarians were living in the United States -- roughly one in every 5,578 people. By 2050, this figure will rocket up to 834,000 Americans living past 100.

To explore this phenomenon, the authors analyzed health history questionnaires regarding 739 men and women between the ages of 97 and 119. A little more than 70 percent of the participants were women, and almost all were white.

Almost one-third of the centenarians indicated that they had initially developed at least one age-related disease before the age of 85.

Yet the researchers found that by the time they reached the 100-year mark, these so-called "survivors" of heart or lung disease, osteoarthritis, diabetes, high blood pressure, dementia, and/or Parkinson's were generally no more disabled or functionally dependent than seniors who remained disease-free until after age 85.

Stark gender differences were apparent, however. While noting that women are far more likely to reach 100 than men, the authors found that male centenarians function significantly better physically and mentally than female centenarians.

Among "survivors" alone, 72 percent of men were considered functionally "independent", compared with 34 percent of women. And among all centenarians, 67 percent of men had normal or mildly impaired cognitive function, compared with just 42 percent of women.

The researchers floated the explanation that men are generally far less resilient than women, so that those men who do make it to 100 are the cream of the crop.

Overall, Perls and his team concluded that for many elderly people, disability, rather than disease, determines longevity.

"This is just a first step of what I think is a pretty cool finding," said Perls. "And what we need to do now is try to discover what enables these people to markedly delay their disability. We have to go over all the possible factors -- socioeconomic, genetic -- and see what plays a role. Where do they get their functional reserve, resilience, capacity? We don't know the answers yet."

Meanwhile, Dr. James S. Goodwin, director of the Sealy Center on Aging at the University of Texas Medical Branch in Galveston, expressed little surprise at the findings.

"What this study shows is that disease is not the best way to assess the health of older people," he said. "If you live long enough, you're going to pick up a lot of them -- diabetes, high cholesterol, high blood pressure, heart disease -- but, by themselves, they don't immediately make people feel bad."

"But when people go on to become disabled, that's the bad sign," he added. "Because it's disability that interferes with your life and your ability to thrive -- to be physically and mentally able to reach your potential. So really, these things we call diseases could be thought of as risk factors for disability. Because when people become disabled, that's when they become truly sick. And that's when they stop living long."

A separate study in the same journal from Brigham and Women's Hospital in Boston revealed that men who do not smoke and practice a healthy lifestyle -- involving regular, vigorous exercise and weight control -- are more likely to live to age 90 and beyond.

The finding was based on questionnaires completed in the early 1980s by almost 2,400 men (average age 72), 40 percent of whom went on to live past 90. The analysis also suggested that men aged 90 plus have better physical and mental function then men who die at a younger age.

More information

For additional information on centenarians in the United States, visit the U.S. Census Bureau.

THURSDAY, Jan. 17 (HealthDay News) -- Despite some reports that statins might slow or prevent Alzheimer's disease, a new study finds no evidence for the theory.

While some animal studies have suggested this possibility, whether the same benefit translates to humans hasn't been clear, the researchers said.

"We didn't find a relation between statin use and the risk of Alzheimer's disease or a decline in thinking ability," said lead researcher Dr. Zoe Arvanitakis, an associate professor of neurology at Rush University Medical Center in Chicago.

In addition, brain autopsies found no effect of statins on the two main causes of dementia, Alzheimer's and stroke, Arvanitakis said.

In the study, Arvanitakis' team collected data on 929 Catholic clergy who took part in the Religious Orders Study, which looks at aging and Alzheimer's disease. At the start of the study, all the participants were around 75 years old and had no signs of dementia. All had a brain autopsy after death, and each had yearly cognitive exams for up to 12 years.

The findings were published in the Jan. 16 online edition of Neurology.

When the study started, 119 people were taking statins. Over the 12 years of the study, 191 people developed Alzheimer's. Of these, only 16 had been taking statins.

Moreover, brain autopsies on more than 250 people who died during the study failed to find any evidence that taking statins had an effect on pathology of Alzheimer's disease or strokes, the scientists found.

"This study adds to the growing evidence that statins don't lower the risk of Alzheimer's disease," Arvanitakis said.

However, one expert thinks this study is not conclusive, and clinical trials that are under way should provide a definitive answer on the issue. "We will see the results of these trials fairly soon," said William Thies, vice president of medical and scientific affairs for the Alzheimer's Association.

"This finding fits in with a great deal of other work that has been done on statins," said Thies. "Most of these studies show a benefit, but this is not the first one to show there isn't a benefit."

Statins are excellent drugs for lowering cholesterol, Thies said. "But there is no recommendation that you take statins for Alzheimer's disease," he added.

Larry Sparks, director of the Roberts Laboratory for Neurodegenerative Disease Research at the Sun Health Research Institute in Arizona and one of the first to link statins with Alzheimer's prevention, doesn't think the study was large enough to give a definitive result.

In his own work, Sparks has found a benefit from statins in treating patients with mild to moderate Alzheimer's disease. However, he thinks the type of statin makes a difference.

"Research suggests that statins that don't get into the brain may prevent or slow the progression of Alzheimer's," Sparks said. "This is a continuing story."

More information

For more on Alzheimer's disease, visit the Alzheimer's Association  .