By Bonnie Liebman
"The past few months have provided an especially rich flow of confusing-and often contradictory-discoveries," said the New York Times last March. An example:
"Earlier this month, a study said low-salt diets might be dangerous. Five days later, another said they're great, lowering blood pressure enough to help elderly people get off medication."
It was confusing, all right... because neither the Times nor most other media outlets bothered to look closely at the studies. One was flawless. The other was junk science.
But confusion may be part of someone’s game plan. This isn’t the first time a shoddy study on salt and hypertension hit the press the same week as a major well designed study.
Junk Science Researchers at the Albert Einstein College of Medicine in New York-including Michael Alderman, a former consultant to the industries Salt Institute-studied the diets that 11,346 people reported eating during a 24-hour period in the early 70's. Then they compared the sodium intakes of the 3,923 participants who died over the next two decades with the intakes of the survivors. The death rate was slightly higher among the people who reported eating the least sodium. But the study was riddled with flaws: The low-sodium eaters were more likely to have high blood pressure, which would have raised their risk of dying (and might explain why they ate less salt). The low sodium eaters also reported eating an implausibly low number of calories-fewer then 1,000 a day for the average women-but they weighed no less. That means the group was "contaminated" with people who didn't-or couldn't-comply with the instructions to report everything they ate. Non-compliers typically have a higher risk of dying. When the researchers "adjusted" for the low calorie intake by looking at how much salt people were eating for each 1,000 calories, heavy sodium users had a higher risk of dying (as one would expect). "No good researcher would even publish the unadjusted data," says Lawrence Appel of Johns Hopkins University in Baltimore. "I don't know how this study got published. It's outrageous"
"Salt: Coincidence or Conspiracy" is Copyright 1998 CSPI. Reprinted/Adapted from Nutrition Action Healthletter (1875 Connecticut Ave. N.W., Suite 300, Washington DC 20009-5728. $24.00 for 10 issues.)