Patti Neighmond

It's been clear for many years that vitamin D helps keep bones strong, but studies have been inconclusive and conflicting about the vitamin's value in protecting against certain cancers, including colorectal cancer.

Colorectal cancer is the second-leading cause of cancer death in the United States, most frequently diagnosed among adults over 65. To catch those typically slow-growing malignancies early, when they can often be cured, most doctors' groups recommend colorectal cancer screening starting at age 50.

But the American Cancer Society this week changed its advice and is recommending that screening start five years earlier.

Though Americans spend an estimated $80 billion to $100 billion each year in hopes of easing their aching backs, the evidence is mounting that many pricey standard treatments — including surgery and spinal injections — are often ineffective and can even worsen and prolong the problem.

Research has shown that sharp reductions in the amount of food consumed can help fish, rats and monkeys live longer. But there have been very few studies in humans.

Now, some researchers have found that when people severely cut calories, they can slow their metabolism and possibly the aging process.

Eventually it happens to everyone. As we age, even if we're healthy, the heart becomes less flexible, more stiff and just isn't as efficient in processing oxygen as it used to be. In most people the first signs show up in the 50s or early 60s. And among people who don't exercise, the underlying changes can start even sooner.

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