Health Updates 30 August 2012

  • New study finds  calorie restriction does not affect survival: “Scientists have found that calorie restriction – a diet comprised of approximately 30 percent fewer calories but with the same nutrients of a standard diet – does not extend years of life or reduce age-related deaths in a 23-year study of rhesus monkeys.  However, calorie restriction did extend certain aspects of health.  The research, conducted by scientists at the National Institute on Aging (NIA) at the National Institutes of Health, is reported in the August 29, 2012 online issue of Nature.  Calorie restriction research has a long history.  The first finding came in the 1930s, when investigators observed laboratory rats and mice lived up to 40 percent longer when fed a calorie-restricted diet.  Subsequent research has cited calorie restriction as extending lifespan of yeast, worms, flies and some strains of mice.  But other studies have not shown a longevity benefit.  For example,  in studies of certain strains of mice, calorie restriction on average had no effect on lifespan.  Some of these mice actually had a shorter lifespan when given a calorie-restricted diet.  The survival results in the study reported today by NIA researchers differ from those published in 2009 by NIA-supported investigators at the University of Wisconsin-Madison.  The Wisconsin study followed two groups of rhesus monkeys for 20 years and found that monkeys on a calorie-restricted diet lived longer than those on a standard diet.  Beyond longevity, the parallel NIA and Wisconsin studies have reported similar beneficial health effects of calorie-restriction.  Both studies found that certain age-related diseases – including diabetes, arthritis, diverticulosis and cardiovascular problems – occurred at an earlier age in monkeys on the standard diet compared to those on calorie restriction.  However, this observation was not statistically significant in the NIA study.  NIA researchers did find that monkeys started on calorie restriction at an early age had a statistically significant reduction in cancer incidence.”  The NIA’s food had a natural ingredient base, while the Wisconsin study featured a purified diet.  Purified diets generally lack trace dietary chemicals and minerals that could affect an animal’s health.  The groups also used different sources for proteins, fat and carbohydrates.  The NIA monkeys also had a greater genetic diversity, originating from China and India. (NIH News)
  • Driver’s seat safer than sidewalk for older adults: “Driving gets more dangerous with age, but older adults may be more vulnerable while walking on the sidewalk than behind the wheel, says a new study.  Researchers who reviewed data on road accident deaths in the UK found that pedestrians over 70 were five times more likely to die from being hit by a car each time they went out than those age 21 to 29.  But elderly drivers were no more likely to die on the road than those in their twenties.  ‘The focus is usually on older drivers as a danger to themselves and other drivers,’ said Jonathan Rolison, who led the study at the University of Plymouth in the UK.  But, he added, ‘the real issue isn’t really safeguarding older drivers, it’s making the road environment safer for pedestrians.’  There has been a shift in recent years in both the UK and the US toward more demanding license renewal processes for older adults.  As eyesight and cognitive abilities decrease with age, older adults are often assumed to be more dangerous on the road than younger drivers.  But previous research suggests that’s not necessarily the case.  In one US study, researchers found male drivers were less of a risk to other road users at 70 years old than they were at 40.  For the new study, Rolison and his colleagues reviewed UK police records on all fatal road accidents reported between 1989 and 2009.  They found the risk of dying behind the wheel was similar for older adult drivers and young people every time they got in the car: 13 in 100 million driving rips ended in fatality among those under 29, compared to 14 in 100 million trips for people over 70.  The elderly still accounted for fewer driver deaths overall.  In 2009, when 1,138 people died behind the wheel, one in 10 was over age 70, while younger drivers accounted for one in four of those deaths….But when researchers looked at figures for pedestrians, they found the risk of being killed when traveling on foot was five times higher for older people than for the young.  Among older adults, 23 trips in every 100 million were fatal.” (Reuters Health)
  • West Nile cases jump 40% in a week; 66 deaths reported, CDC says: “One of the worst outbreaks of West Nile virus to ever hit the United States continues to expand, with 66 deaths and 1,590 illnesses reported as of Tuesday, according to the US Centers for Disease Control and Prevention.  Cases have jumped 40 percent nationwide since just last week, the agency added.  Cases have now reached their highest level since the mosquito-borne virus was first found in the United States in 1999, agency officials said in a Wednesday press briefing.  While almost all states have reported at least once case of West Nile illness, over 70 percent of cases have come from six states — Texas, South Dakota, Mississippi, Oklahoma, Louisiana and Michigan.  The outbreak has hit hardest in Texas, where nearly half (45 percent) of the total US cases have been reported.  ‘The number of people reported with West Nile virus continues to rise,’ said Dr. Lyle Petersen, director of the CDC’s Division of Vector-Borne Infectious Diseases.   ‘We have seen this trend in previous West Nile epidemics, so the increase is not unexpected,’ he added.  ‘In fact, we think the reported numbers will get higher through October.’  According to Peterson, of the cases reported so far, 56 percent are what is called neuroinvasive disease, when the virus enters the nervous system causing conditions such as meningitis or encephalitis.  The remaining cases (44 percent) are non-neuroinvasive….Neuroinvasive disease is the most serious…and these patients usually are hospitalized, Peterson said.  The size of the outbreak is based on these cases since they are  the ones easily identifiable….The only states that have not reported cases are Alaska and Hawaii….The reason for a major outbreak this year aren’t clear…The drought in Texas may have played a role, but there are probably other factors as well, he added.  The best way to avoid the virus is to wear insect repellent and support local programs to eradicate mosquitoes.  There is currently no treatment for West Nile virus and no vaccine to prevent it, [Peterson] added….People older than 50 and those with certain medical conditions, such as cancer, diabetes, hypertension, kidney disease and organ transplants, are at greater risk for serious illness according to the CDC….The CDC recommends the following steps to protect yourself:
    • Use insect repellents when outside.
    • Wear long sleeves and pants from dawn to dusk.
    • Don’t leave standing water outside in open containers, such as flower pots, buckets and kiddie pools.
    • Install or repair windows and door screens.
    • Use air conditioning when possible.” (HealthDay)
  • Really?  During a heart attack, dial 911 and chew an aspirin: “Last week the entertainer Rosie O’Donnell surprised fans when she announced that she recently had a heart attack.  Ms. O’Donnell wrote on her blog that she felt an ache in her chest and soreness in her arms, followed by nausea and a ‘clammy’ feeling.   She took an aspirin, she said, but decided against calling 911.  The next day, she went to a hospital, where she learned one of her coronary arteries was 99 percent blocked, requiring a stent.  ‘I am lucky to be here,’ she wrote.  ‘Know the symptoms, ladies’.  Studies show that for men and women, the symptoms can differ.  Men are more likely to experience the classic signs, like chest pain, shortness of breath and radiating pain in the neck and arms.  Women are more likely to experience severe fatigue, indigestion and cold sweats.  Despite the differences, the response should be the same: Immediately call 911, then chew an aspirin, said Dr. Noel Bairey Merz, director of the Barbra Streisand Women’s Heart Center at the Cedars-Sinai Heart Institute in Los Angeles.  Some people may suspect that chewing an aspirin, which inhibits platelet activity that could block arteries during at attack, makes little difference.  But a study in The American Journal of Cardiology highlighted its importance.  In a group of 12 subjects tested in a laboratory, chewing an aspirin tablet for 30 seconds before swallowing on an empty stomach prompted a 50 percent reduction in platelet activity in five minutes.  It took 12 minutes to achieve the same effect when the aspirin was swallowed whole.  Dr. Merz said people who suspect they are having an attack should chew one full-strength tablet, which is 325 milligrams.  But most important, she added, is to ‘get to an emergency room’.  The Bottom Line: If you experience symptoms of a heart attack, dial 911 first, then chew on an aspirin.” (Anahad O’Connor, NY Times)

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