Showing posts with label Study. Show all posts
Showing posts with label Study. Show all posts

Friday, 22 February 2013

Human Teeth Healthier in the Stone Age Than Today: Study

News Picture: Human Teeth Healthier in the Stone Age Than Today: Study

TUESDAY, Feb. 19 (HealthDay News) -- Something to think about next time you're in the dentist's chair: Ancient humans had healthier teeth than people do today, researchers say.

This decline in oral health over the past 7,500 years is the result of changes in oral bacteria due to human evolution and industrialization, the study authors said. These changes have led to chronic oral and other health problems, according to the report published Feb. 18 in Nature Genetics.

"The composition of oral bacteria changed markedly with the introduction of farming, and again around 150 years ago," explained study leader Alan Cooper, a professor and director of the University of Adelaide's Australian Centre for Ancient DNA, in a center news release. "With the introduction of processed sugar and flour in the Industrial Revolution, we can see a dramatically decreased diversity in our oral bacteria, allowing domination by caries [cavities]-causing strains. The modern mouth basically exists in a permanent disease state."

The international team of researchers examined DNA that had been preserved in tartar -- calcified dental plaque -- found on 34 prehistoric northern European human skeletons. They used these samples to analyze how oral bacteria changed from the Stone Age to the last hunter-gatherers, medieval times and later with the introduction of food manufacturing in the Industrial Revolution.

The evolution of human behavior and diet have had a negative impact on oral health, the investigators said.

"This is the first record of how our evolution over the last 7,500 years has impacted the bacteria we carry with us, and the important health consequences," Cooper said. "Oral bacteria in modern man are markedly less diverse than historic populations and this is thought to contribute to chronic oral and other disease in post-industrial lifestyles," he pointed out.

Study lead author Christina Adler, now at the University of Sydney, added that "dental plaque represents the only easily accessible source of preserved human bacteria." And, she said in the news release, "Genetic analysis of plaque can create a powerful new record of dietary impacts, health changes and oral pathogen genomic evolution, deep into the past."

The researchers said their research is being expanded to include other periods in time, other areas of the world and other species, such as Neanderthals.

-- Mary Elizabeth Dallas MedicalNews
Copyright © 2013 HealthDay. All rights reserved. SOURCE: Australian Centre for Ancient DNA, news release, Feb. 18, 2013



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Wednesday, 20 February 2013

Statins Plus Exercise Best at Lowering Cholesterol, Study Finds

By Steven Reinberg
HealthDay Reporter

TUESDAY, Nov. 27 (HealthDay News) -- People who exercise along with taking statins to lower their high cholesterol levels can dramatically reduce their risk of dying, a large new study suggests.

"The reduction in death is independent; whatever statins do is independent of what exercise does," said lead researcher Peter Kokkinos, a professor in the cardiology department at the Veterans Affairs Medical Center in Washington, D.C.

"When you combine the two, you get even better results," he said. "If you are taking statins, your mortality is about 35 percent lower versus not taking statins, but if you exercise, your mortality level decreases as your fitness level increases to the point where you can reach a 70 percent reduction in mortality."

Kokkinos is talking about regular moderate exercise -- not vigorous workouts. "Thirty minutes a day of brisk walking -- not a whole lot," he said.

Statin drugs include Lipitor (atorvastatin), Lescol (fluvastatin), Pravachol (pravastatin), Crestor (rosuvastatin) and Zocor (simvastatin).

Some people can't take statins because of side effects, Kokkinos said. "For these people, exercise alone reduces your risk just as much, if not more, than statins," he said. However, he stressed, "we do not recommend that people do not take their statins."

Exercise works by stressing the body making it stronger, Kokkinos said. It's an evolutionary adaptation to protect the body from being overcome by changing stressors, he said.

"Get off the couch -- walk," Kokkinos said. "About 150 minutes a week of brisk walking is all you need."

The report was published online in the Nov. 28 edition of The Lancet.

For the study, Kokkinos' team analyzed the medical records of more than 10,000 veterans with high cholesterol levels treated in Veterans Affairs hospitals in Washington D.C., and Palo Alto, Calif. Of these, 9,700 were men and 343 were women.

The researchers judged the fitness levels of the participants by looking at the results of standard treadmill exercise tolerance tests, which were given between 1986 and 2011.

Fewer deaths occurred among participants who were taking statins and were physically fit. Over 10 years of follow-up, those who were the most physically fit had the lowest risk of dying, the researchers noted.

These fittest people actually reduced their risk of dying by about 60 percent regardless of whether they were taking statins, according to the study.

These difference in death risk could not be explained by age, weight, ethnicity, gender, history of cardiovascular disease, risk factors for cardiovascular disease or medications, the researchers said.

According to the U.S. Centers for Disease Control and Prevention, about 71 million Americans have high cholesterol, which is an important risk factor for heart disease, the authors pointed out.

One expert familiar with the new findings cautioned that exercise is not a replacement for statins in those with high cholesterol. The best results are among those taking statins and who are the fittest, he emphasized.

"Cardiovascular disease remains the leading cause of death and disability in men and women in the United States," said Dr. Gregg Fonarow, a spokesman for the American Heart Association and a professor of cardiology at the University of California, Los Angeles.

"Statin therapy has been proven in multiple clinical trials to substantially reduce cardiovascular events and all-cause mortality in men and women with or at risk for cardiovascular disease," he said.

Some people have assumed that if they are engaging in regular exercise and are physically fit that they may not benefit from statin treatment and some physicians consider statin therapy only for patients who have failed attempts at lifestyle modification, Fonarow said.

This new study shows that at all levels of physical fitness, statin therapy was independently associated with lower risk of dying. The very best 10-year outcomes were among men and women taking statins with the highest fitness levels, he noted.

"These findings further reinforce the remarkable real-world clinical effectiveness and safety of statin therapy to prevent and treat cardiovascular disease," Fonarow said.

MedicalNewsCopyright © 2012 HealthDay. All rights reserved. SOURCES: Peter Kokkinos, Ph.D., professor, Veterans Affairs Medical Center, Washington, D.C.; Gregg Fonarow, M.D., spokesman, American Heart Association, and professor, cardiology, University of California, Los Angeles; Nov. 28, 2012, The Lancet, online



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