Transfat

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Grocery store aisles need to be wider than ever because so many of us stand there reading food labels.

Twenty years ago we just grabbed the foods that we knew the family liked, or that we felt strongly they should learn to like. Now we check for salt content and sugar content. Those are easy. But how about fats?

There are several kinds of fats and they all seem to do different things to our bodies.

We’ve been told for years that trans fats are bad for us, and that people with heart conditions or diabetes shouldn’t eat them. I was happy when, a couple years ago, margarines began appearing highlighting “No Trans Fatty Acids” in large type. I now buy those, but did not know what trans fats are. I did know that hydrogenation, the process that turns oils into solids like margarine, isn’t healthy.

Now my trusty Science News has provided an article on the subject, saying it’s the trans fats that do the hydrogenating. The different kinds of fats get their names from the pattern of hydrogen atoms in the fat molecules. All fats contain chains of carbon atoms with hydrogen atoms attached to some or all. How about saturated fats like butter, and mono- or poly-unsaturated fats? What’s the difference?

Unsaturated fats like corn and soy oil have double bonds at various positions along their carbon chains. In those spots, each carbon atom bonds to a hydrogen atom and the next carbon atom in the chain. Fats with just one double bond are monounsaturated; those with more double bonds are polyunsaturated. Saturated fats such as butter don’t have any double bonds, and that’s supposed to be the least healthy for our hearts.

What of trans fats? We’ve read that they raise our LDLs or bad cholesterol, and lower our HDLs, good cholesterol. In trans fats, the double bonds are in a special configuration. The most recent research on 667 elderly men in the Netherlands indicated a link between consumption of trans fats and heart health. They had eaten twice as much trans fat as we do. The study suggested that every additional 2 percent of trans fats the men ate, made them 25 percent more likely to develop heart disease within ten years. We in the U.S. commonly average only two percent of trans fats in our total diet.

A much larger survey still needs to be done, say the cautious scientists. In another, much smaller study, researchers found that in people on a low trans-fat diet, concentrations of good cholesterol in the blood did indeed rise. In the blood of people whose diet was rich in trans fats, good cholesterol fell. The results were reversible when the people switched diets, which is reassuring.

Researcher Walter C. Willett says, “The more you look, the more problems you see with trans fats.” We need to remember to look beyond butter and margarine: many prepared foods, such as cookies and crackers, are high in trans fats.

This is Ruth Page, trying to help decode some labels on grocery-store items.

–Ruth Page is a writer and former editor of a weekly newspaper and a national gardening magazine.

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