Fortunately there are still a few tasty things for us gourmands to enjoy in relative security. Their numbers, however, are depleted almost daily, it seems, by ruthless proclamations from the ever-vigilant Food and Drug Administration and its allies, our doctors. The latest felon to face prosecution is the salt of life, sodium chloride. Ostensible, overuse of salt causes high blood pressure and hypertension, the cause of half the deaths in the United States every year. A few years ago the anti-salt campaigners raised such a rumpus that salt was banned from baby food. Currently pressure is being ap- plied to food manufacturers to oblige them to label their products to show sodium content. Because doing so would cost mercenary manufacturers money, they argue that they have no idea how much salt remains on such things as potato chips and how much sticks to the bag. Furthermore, salt isn't the only harmful ingredient in food. If the manufacturer has to pro- vide sodium content, why not require him to list every ingredient and specify which are detrimental to our health? Cigarettes have a warning printed on them. Shouldn't the same type of warning appear on canned foods that are notoriously oversalted? There are endless ifs and buts in the controversy, but the most telling of these is the questionable proof of salt's diabolic effect upon the blood pressure. True, people who cut their salt intake lowered their blood pressure but where is the scientific proof that something other than salt didn't to the trick? The most common means of providing dubious proof that salt causes hypertension is to compare societies that use little salt with those that use mountains of salt in their daily diets. Which group has the higher rate of hypertension? Whose blood pressure is lower? What happens when salt is introduced into a group where salt is a novelty? Does the blood pressure rise significantly? Studies of the Japanese indicate that as the world's greatest salter, they suffer the most from hypertension. On the other hand, the simple, salt-free cuisine of several tribes in the Solomon Islands has kept older tribesmen and women from developing hypertension and high blood pressure, ailments traditionally killing their peers in America. No account is taken of the effects of inflation, recession, pollution, crime, and sundry other ills to which Americans, unlike people on primitive islands, are exposed. To salt or not to salt? That is the question. Now that the question had arisen, it must not be treated with levity but, rather, with searching scientific investigation so that those of us who are preoccupied with both savory food and longevity may decide which of the two is worth its salt. Food manufacturers don't want to label packages with sodium content because______.