Scientists Learning More Why Aging Cells Fail to Repair Themselves
Why Aging Cells Lose Ability to Repair Themselves Study finds defect that could lead to new treatments for disease
FRIDAY, Sept. 5 (HealthWire) — A defect in the body’s self-defense mechanism against age-related genetic mutations has been identified by researchers at the University of Texas Medical Branch at Galveston.
The finding may help explain why the aging human body can’t defend itself against DNA damage in the mitochondria, the power plants that fuel the growth and activity of cells.
Finding ways to help aging cells repair their own damaged DNA could possibly lead to ways to prevent or treat cancer, Alzheimer’s disease, Parkinson’s disease and other health problems caused by genetic defects.
As cells age, they experience continuous genetic mutations, some of which are caused by the harmful byproducts of the oxygen we inhale. But the body’s repair mechanism is constantly at work fixing this DNA damage. However, this repair activity becomes less efficient as cells age.
In this study, the researchers analyzed why this DNA repair activity becomes less effective in the mitochondria as cells age. They found a biochemical “”roadblock”" that prevents much of the repair enzyme activity from reaching the site of the DNA damage in the mitochondria of aging cells.
In old cells, about half of the repair enzyme activity can’t reach the mitochondria DNA to repair it.
The study was published online this week in the Proceedings of the National Academy of Sciences.
Vitamin D More Essential for Bone Health Than Calcium
Vitamin D More Important Than Calcium For bone Health November 9, 2005 Consuming more than 800 mg of calcium per day may be unnecessary for bone health if the body has enough vitamin D, say Icelandic researchers.
Using food consumption records from more than 900 adults, the researchers determined that sufficient vitamin D levels can ensure an ideal level of parathyroid hormone (PTH) – a measure of calcium metabolism – even when calcium intake is less than 800 mg per day. But consuming more than 1200 mg of calcium daily is not enough to maintain ideal PTH if the vitamin D status is insufficient. The study is part of a growing body of work that points to the important role of vitamin D, and not just calcium alone, in bone health. Bone health is a growing concern as the numbers affected by osteoporosis continue to rise, and an increasing elderly population suggests that these will grow further in the future. In Europe, osteoporosis causes around 1.1 million fractures each year. In light of recent research, and predicting future health problems, some researchers have called for recommended intake of vitamin D to be raised but the adequate amounts needed in the diet are still not known. The new study, published in today