This debate has been around since margarine was created by a Frenchman fromProvence, France — Hippolyte Mège-Mouriez — in response to an offer by the Emperor Louis Napoleon III for the production of a satisfactory substitute for butter. To formulate his entry, Mège-Mouriez used margaric acid, a fatty acid component isolated in 1813 by Michael Chevreul and named because of the lustrous pearly drops that reminded him of the Greek word for pearl — margarites. From this word, Mège-Mouriez coined the name margarine for his invention that claimed the Emperor’s prize.*

So let’s look at what is in these two foods:

Butter –Ingredients: Cream, salt

Margarine – Ingredients: Liquid Canola Oil, Water, Partially Hydrogenated Soybean Oil, Plant Stanol Esters, Salt, Emulsifiers, (Vegetable Mono- and Diglycerides, Soy Lecithin), Hydrogenated Soybean Oil, Potassium Sorbate, Citric Acid and Calcium Disodium EDTA to Preserve Freshness, Artificial Flavor, DL-alpha-Tocopheryl Acetate, Vitamin A Palmitate, Colored with Beta Carotene.

The problem with margarine can be ingredient number 3, partially hydrogenated soybean oil! Trans fats.

Today, nutritionists say to go easy on both butter (high in saturated fat) and margarine (high in trans fatty acids). TheAmerican Heart Association still recommends margarine over butter but also advises consumers to choose the soft liquid or tub varieties. Look at the ingredients and nutrition facts, AHA says, and buy the variety with no more than 2 g of saturated fat per tablespoon and with liquid vegetable oil (not hydrogenated) as the first ingredient.

Reference: http://www.butteryspreads.org/historyofmargarine.php *