Altered genes may give longer life but not necessarily healthier one: New Study Monday, 2 February 2015 - In a new study, scientists have suggested that if you alter you genes to have a longer lifespan, it doesn't necessarily mean that it would be a healthier one too. In a new study, scientists have suggested that if you alter you genes to have a longer lifespan, it doesn't necessarily mean that it would be a healthier one too. A study of long-lived mutant C elegans by scientists at the University of Massachusetts Medical School shows that the genetically altered worms spend a greater portion of their life in a frail state and exhibit less activity as they age then typical nematodes. Principal investigator of the study Heidi A Tissenbaum, PhD, said that to find the genes that help people remain physically active during ageing, they may have to look beyond longevity as the sole criteria, and start looking at new genes that might play a part in 'healthspan'. Dr Tissenbaum and colleagues sought to investigate how healthy long-lived C elegans mutants were as they aged. Identifying both frailty and movement as measurable physical attributes that declined in the nematode with age and that could be tested, Ankita Bansal, PhD, , took four different C elegans mutant specimen (daf-2, eat-2, ife-2 and clk-1) known to live longer than typical nematodes and measured their resistance to heat stress, oxidative stress and activity levels on solids and in liquids as they aged. They compared these results with wild-type nematodes they found that all the animals--wild-type and mutants--declined physically as they aged. And depending on the mutant specimen and trait being measured, each declined at different rates. Overall they found that the mutant worms, despite having longer lifespans, spent a greater percentage of their lives at less than 50% of measured maximum function when compared to wild-type nematodes. The increased lifespan experienced by the mutants was spent, instead, in a frail and debilitated state. The results are published in the Proceedings of the National Academy of Sciences.
U.S. Lifespan Surges, 'Healthspan' Not So Much: CDC Jan 6, 2014 06:12 PM By John Ericson As the average life expectancy continues to rise in developed nations across the globe, Americans are enjoying longer lives than ever, with federal health officials reporting a 0.6-year increase between 2008 and 2009. Experts from the Centers for Disease Control and Prevention (CDC) said on Monday that children born in 2009 can expect to die just shy of their 80th birthday –– 78.7 years, to be exact. In 2008, the figure was 78.1. The positive trend, which has remained steady for the past 50 years, is thought to be the result of better treatment strategies against cardiovascular disease and other global killers."Improvements in heart disease and stroke mortality have had a big impact," Robert Anderson, chief of the Mortality Statistics Branch at the CDC's National Center for Health Statistics, told reporters. "That's a large proportion of total deaths and that's where the action really is in terms of improved life expectancy. That's really what's driving the trend." According to David Katz, director of the Yale University Prevention Research Center, the increase is not limited to a particular demographic set. "To the extent that we all want a bounty of years in life, this report conveys encouraging news," he said, speaking to HealthDay. "Life expectancy at birth in the U.S. is rising for all groups." Better disease control notwithstanding, the gender discrepancy is expected to persist. While the increase is virtually the same for both sexes, men born in 2009 will still die a little earlier than their female counterparts, who can expect to live well into their 80th year. Similar differences were observed across ethnical groups, with data from African-Americans and Hispanics indicating a new life expectancy of 74.5 and 81.2 years respectively.
Good News And Bad News However, Katz and other experts are quick to point out that a longer life does not necessarily mean a better life. "More importantly, this report is only about years in life, not about life in years," he said. "A long life with a high burden of chronic disease — such as diabetes, heart disease, and chronic obstructive pulmonary disease (COPD) — means more time living with illness and disability." In fact, the rising life expectancy is currently considered the primary factor behind the growing number of dementia cases and other age-related disorders. At the G8 dementia summit in London last December, researchers projected a threefold increase in Alzheimer's diagnoses by 2050, driving the number of patients up from 44 million to 135 million. "It's a global epidemic and it is only getting worse," he said, speaking to BBC News. "If we look into the future the numbers of elderly people will rise dramatically."
Lifespan Vs. Healthspan It follows that life expectancy may no longer be the best indicator of public health. While advancements in medicine and technology may have resulted in an increased overall lifespan, a widespread adherence to exercise, dieting, and other healthy lifestyle elements may be necessary to obtain a comparable increase in "healthspan." "The next chapter in medical advance will need to be as much about lifestyle as medicine if we are to add life to years along with years to life," Katz told reporters.
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