Health experts across the country are sounding the alarm about the evils of trans fat, the saturated fat heaped into much of the fast-food, baked goods and spreads consumed by far too many Americans.

In studies released earlier this year, researchers at the Harvard School of Public Health showed the disturbing link between trans fatty acids and the increased risk of cardiovascular and heart disease.

Virtually unheard of five years ago, today trans fat is the new villain of the health-conscious world.

In January, the U.S. Food and Drug Administration (FDA) began requiring food manufacturers to list trans fat content greater than half a gram on nutrition facts label. Restaurants are not required to list their contents, but many of them (especially large fast-food chains) are voluntarily taking the trans fat out. Many restaurants are also getting the message from consumers and eliminating or cutting back on trans fat.

What are trans fats? They are substances produced when hydrogen is added to vegetable oil – called hydrogenation. This process makes some foods tastier and keeps them fresher longer on store shelves.

Trans fats are used extensively in making cakes, pies and cookies and are the basis of many lards, spreads and solid cooking oils. You might think yummy, but there’s a down side. Trans fats also raise the low-density lipoprotein (LDL) blood levels in the body. That’s the bad cholesterol responsible for clogging arteries and causing strokes and heart attacks. Trans fats also reduce the level of good cholesterol (HDL) in the blood. A double whammy. The Harvard study found that eating just 5 grams of trans fat a day could increase the risk of heart disease by 25 percent. Researchers concluded that eliminating trans fat from the American diet could prevent nearly 228,000 heart attacks.