Are you fed up with learning one day that Vitamin E will cure everything from athlete’s foot to cancer only to find out the next day that it will cause you to have a massive stroke?

You’re not alone–a new report indicates something very important about all those authoritative scientific studies: A third of them are…wrong.

“New research highlights a frustrating fact about science: What was good for you yesterday frequently will turn out to be not so great tomorrow.

“The sobering conclusion came in a review of major studies published in three influential medical journals between 1990 and 2003, including 45 highly publicized studies that initially claimed a drug or other treatment worked.

“Subsequent research contradicted results of seven studies — 16 percent — and reported weaker results for seven others, an additional 16 percent.

“That means nearly one-third of the original results did not hold up, according to the report in Wednesday’s Journal of the American Medical Association.”

This has implications beyond whether you should drink green tea or go on the Atkins diet.

As our iconoclastic friend Wendy McElroy of ifeminist points out, bad studies make for bad laws and wasteful spending of the taxpayer’s money: 

“If a relatively ’hard’ science (like medicine) has such difficulty with accuracy,” writes McElroy, “then the results offered by the so-called ’soft’ sciences (like sociology) should be approached with a high degree of skepticism. This is especially necessary since public policy and laws are often formed by such studies.

“Consider the ‘feminist’ issues of rape or domestic violence. Studies that address these areas are often released in combination with policy recommendations. Indeed, they sometimes appear to be little more than a springboard from which advocates can launch a campaign for more law.”

This doesn’t mean that information from scientific or sociological studies should be dismissed out of hand–but, when confronted with them, we must evaluate them critically. Some studies, as McElroy notes, are intentionally dishonest:

“The scientific community is still reeling from recent revelations about Eric T. Poehlman, a leading researcher on aging and obesity. Poehlman simply faked the data on 17 applications for federal grants that totaled near $3 million. His ‘findings,’ published in prestigious medical journals, helped to define how medicine approaches the effects of menopause on women’s health.”

And, as McElroy also points out, some studies are unintentionally biased:

“The soft sciences share all these research vulnerabilities. But, because they are less constrained by research controls, the most common answer there to what motives bias may well be ’political belief.’”