Can insoles prevent back pain?

There had been a theory that insoles might reduce the impact on spinal discs therefore protecting the back.

According to a new review of 6 studies published in the Cochrane Database of Systematic Reviews 2007, Issue 4, the use of insoles does not prevent back pain. The researchers concluded that "there is limited evidence that insoles alleviate back pain or adversely shift the pain to the lower extremities".

Source: "Insoles for prevention and treatment of back pain" Cochrane Database of Systematic Reviews 2007, Issue 4.

Vitamin C does not prevent common cold

Vitamin C is the most widely used supplement against common colds, but a new analysis of 30 studies in the latest issue of The Cochrane Library has found that the doses of 200mg per day had little effect on reducing the length or severity of colds.

However, the Cochrane researchers acknowledge that vitamin C supplements might have health benefits other than keeping adult colds at bay.