Cholesterol and Changing Facts

The constantly changing news about diet and health embarrasses science. Experts no sooner announce some discovery than other experts come up with a contradictory one. The situation evokes Alice's plight in Wonderland, as nutrition scientists keep moving labels saying "Eat me" and "Drink me" from one food to another.

Partly that's caused by people like me---joumalists who pounce on studies of food's effects and swiftly turn the technical into the popular. Sometimes dull but crucial details vanish in the process; inaccuracies creep in. "Preliminary study suggests" in the original becomes "Research proves" in the popularized version.

But more important, this shove and push of fact replacing fact as study supersedes study is exactly how science usually progresses. Here at the Geophysical Institute, for example, dozens of ideas have appeared about the configuration of earth's electromagnetic environment. Sometimes a once-discredited theory gains new life as a rocket flight brings back fresh data; sometimes a well-accepted view fades quickly away after a better computer analysis shows that ion streaming (or some such phenomenon) actually couldn't work that way.

However, ion streaming isn't a life and death matter. The scientists debating it feel little pressure to publicize their partial studies. Writers don't feel compelled to stay on top of the shifting results. And the public, by and large, doesn't give a hoot which theory prevails. Ions can stream however they please.

The public does give a very loud hoot indeed about food that may be silently clogging arteries. People want to know---and are better off knowing---as soon as possible, even if the knowledge comes from preliminary studies.

With the foregoing firmly in mind, you may now read about recent work on cholesterol. Science News sent a reporter to the National Conference on Cholesterol and High Blood Pressure, and she picked up some interesting highlights.

Niacin has been used successfully to lower blood cholesterol since 1955, but many people can't tolerate the high doses required (up to 3000 milligrams; a vitamin pill providing the full daily requirement contains 20 milligrams of niacin). They get upset stomachs and whole-body blushes. A Minnesota physician has found a way to embed niacin in a non-digestible wax to slow its absorption, and that seems to do the trick---at least for the 201 people who participated for 16 weeks in this experiment.

Exercise increases high-density lipoproteins (HDL), the so-called good component of cholesterol that carries the bad low-density lipoproteins (LDL) out of the system. That is the implication, at least, of a study in which a dozen healthy women exercised on treadmills for 45 minutes on each of two successive Sundays. The 6.2 percent elevation in their measured HDL was considered small but significant, and lasted about 90 minutes after the exercise.

Palm oil is high in saturated fat, so high that "Contains no tropical oils" has become a mark of quality on mass-market baked goods. Now it turns out that palm oil also contains some potent cholesterol-reducing agents. Fifteen men and women who participated in an eight-week study of these agents averaged a 20 percent decline in overall serum cholesterol levels and a 28 percent reduction in the especially unwelcome LDL.

The foregoing are all respectable bits of research, and their implications are not trivial. But note the absolute numbers involved: 201 people, twelve, and fifteen; studied for four months, or two, or two days. Different results might appear with different numbers and kinds of people, studied perhaps for decades instead of weeks.

Maybe the best course of action is to heed such studies, but check further before you change your life to conform to the research results.

For example: another study at the conference concerned substances that increase the amount of HDL in the bloodstream. Listed among them was alcohol. Alcohol? I'm going to discuss that one with my doctor---probably over a beer.