It’s been drilled into your head that trans fats, found in fried foods and packaged foods, are bad for your health. Unfortunately, the processed food industry is touting a “safe” replacement that could be even worse for you.

Ever heard of interesterified fat? Brace yourself. It is in supermarkets and restaurants. And the dirty little secret of the food industry is that this type of fat often contains trans fats! Even worse, this Frankenstein of fats — “Franken fat,” as I call it — appears to increase the risk for diabetes because it increases blood sugar levels after a meal and also lowers insulin levels.

FAKE FATS

Trans fats first came into our diets around 1911, as a replacement for butter, which is rich in saturated fats. (Studies now show that saturated fats might not be the heart disease culprit that they were originally believed to be.) Back then, trans fats, found in “partially hydrogenated vegetable oils” made from soybean oil and other types of vegetable oils, seemed like the ideal solution. Food makers found trans fats easy to work with from a manufacturing standpoint — they have a long shelf life, and they have a “mouth feel” similar to that of butter.

But by the early 1990s, scientists at Harvard University and other major research centers were looking closely at trans fats, and they were troubled by how these fats increased levels of the “bad” low-density lipoprotein (LDL) form of cholesterol, a major risk factor for coronary heart disease. Trans fats are now believed to cause as many as one in five deaths from heart disease (anywhere from 30,000 to 100,000 each year in the US).

When New York City banned the use of trans fats in restaurants, the food industry let out a collective shriek — it had no substitute that had the same properties. The industry was in a bind.

Indeed it was — until one of the largest food ingredient manufacturers in the world, Illinois-based Archer Daniels Midland (ADM) came up with an industry-friendly solution — interesterified fats. These fats have similar manufacturing properties and taste to trans fats. And unfortunately, as we are learning, they have similar unhealthy effects on our bodies.

DANGERS IN THESE FATS

The evidence: Several years ago, a team of researchers compared the health effects of three different types of fats on healthy adults. The diets each contained 30% of daily calories from either palm-oil-derived saturated fat, partially hydrogenated soybean oil or interesterified soybean oil.

The results of the study, published in the journal Nutrition & Metabolism, showed that interesterified fats, just like trans fats, raised levels of the LDL cholesterol and lowered the “good” HDL cholesterol. But here’s the kicker: People who consumed interesterified fats had a 20% increase in their fasting blood sugar… and their post-meal blood sugar jumped by 40%, compared with people who were eating large amounts of saturated fats. The interesterified fats also depressed levels of insulin — the hormone needed to manage blood sugar levels. And this was just in one month! Long term, it seems clear that these changes would significantly increase the subjects’ risk for type 2 diabetes.

This study was criticized by some because it was funded by the Malaysian industry that produces and markets palm oil as an alternative to trans fats and interesterified fats. But I have read his study several times, and it looks solid from a scientific standpoint.

For many consumers, seeing trans fats listed on a food label has become tantamount to seeing a skull and crossbones. And this has caused a public relations and labeling nightmare for companies that make their living selling junk foods and fast foods. ADM’s marketing of interesterified fats is nothing if not clever. ADM sells several types of interesterified fats (trade name NovaLipid) for different applications in food processing. Significantly, the ADM brochures point out that using interesterified fats may enable companies to avoid listing trans fats on their products’ labels.

Buyer beware: This deceptive type of marketing amounts to a dangerous shell game for consumers. When you look at the sales literature from ADM, as I have done, it is clear that many of their interesterified fat products do in fact contain trans fats… some providing one gram per serving… and some providing a vague “less than” one gram per serving. By law, any food that contains more than one-half gram of trans fats per serving must list the amount in the package’s “Nutrition Facts” box — but foods with 0.49 gram or less trans fats per serving can list their trans fat content as zero.

MY ADVICE FOR SAFE EATING

When you buy any type of packaged food, take the time to carefully read the list of ingredients printed on the label. Interesterified fats may be identified by a variety of terms, including interesterified soybean oil, interesterified vegetable oil, partially or fully hydrogenated oil, high in stearic acid or stearate rich. While you’re at it, watch out for foods that contain partially hydrogenated vegetable shortening, which is a code word for trans fats. To be safe, don’t buy foods containing any of these ingredients.

Unfortunately, it is more difficult to know what you are ordering in restaurants. Most fast-food companies list nutrition information on their Web sites — but it generally is not easy to find or easy to read (it is usually written in tiny type on big charts). Other restaurants don’t even do that — and many (perhaps most) chefs aren’t even aware of the dangers of interesterified fats.

There is a simple solution: You can avoid interesterified and trans fats by avoiding most commercial baked sweets and fried foods (which aren’t good for you anyway!) and sticking with healthy fresh foods — fruits, vegetables, fish, chicken and legumes. Bonus: Fresh foods are almost always more nutritious than those that come in boxes, cans, bottles and jars.