A new study following the dietary habits of over 200,000 people suggests that diets high in a specific type of polyunsaturated fat called linoleic acid may have much higher incidence of a painful disease called ulcerative colitis. While red meat contains some linoleic acid, you will also find it in many margarines and cooking oils including safflower, hemp, sunflower, corn, wheat germ, cottonseed, soybean, walnut, and sesame oil. EMaxHealth points out “Given that many foods, especially fast foods, are fried in such oils, it can be easy for individuals to consume high levels of linoleic acid.”

The working theory is that “Once in the body, linoleic acid is converted to arachidonic acid, which is a component of the cell membranes in the bowel. Arachidonic acid can then be converted into various inflammatory chemicals, high levels of which have been found in the bowel tissue of patients with ulcerative colitis.” Should linoleic acid turn out to actually cause ulcerative colitis (instead of just being associated with it), it will be responsible for almost a third of total cases.

Conjugated Linoleic Acid, or CLA, is sold as a supplement in health food and vitamin stores, and is thought to have cancer-fighting properties in addition to aiding weight loss.

The same study found that people who ate diets high in the omega-3 fatty acid known as docosahexanoic acid had much lower incidence of ulcerative colitis. This fatty acid is found in fish such as salmon and herring. Moreover, an unrelated study also new this week shows that diets high in omega-3 fatty acids may prevent a leading cause of blindness among the elderly.

Her Take: We’ve talked about how fake sweeteners are bad. Now we have some actual evidence that fake butter — margarine — is bad for you as well. Granted, it’s not news that fast food cooked in lots of oil is bad for you. Better to enjoy a small quantity of quality food prepared well than to eat fake food and pretend it is somehow more than a culinary chemistry set.