How to figure out the amount of trans fat in cooking oil

Trans fat labeling can be misleading.

On the label of a bottle of cooking oil, you read "Trans fat: 0 gram" per serving. Does that mean there is no trans fat in the cooling (vegetable) oil? Not necessarily so.

The FDA allows food manufacturers to claim "trans fat: 0 gram" when trans fat does not exceed 0.5 gram per serving.

The government permission does not mean less than 0.5 gram per serving of trans fat is safe. According to Harvard nutritionists and epidemiologists, there is no safe threshold for trans fat. And trans fat consumption may be involved in 100,000 deaths each year.

How could consumers figure out whether or not there is any trans fat in a cooking oil for which the nutrition facts label claims "trans fat: 0 gram"?

What you can do is actually some simple math. For example, on the label for a bottle of olive oil, you read

Total fat 14 g

Saturated fat: 2g
Trans fat: 0g
Polyunsaturated fat: 1.5g
Monounsaturated fat: 10g

Now add all non-trans fat (saturated, polyunsaturated fat and monounsaturated fat) and you get 13.5g

Subtract non-trans fat (13.5g) from total fat (14g) and you get 0.5g. This means 14 g of olive oil or one serving of olive oil contains 0.5g of trans fat. If the difference is 0, then there is indeed no trans fat in the oil.

Often times, trans fat in vegetable oils is not added. It forms during the processing. Food chemists know when vegetable oils are subject to thermal processing, some percentage of oil is transformed into trans fat.

Cooking oil processors and packers know this. That is why, some manufacturers/packers claim that their oils are cold pressed, implying that nutrients are maximally retained and no trans fat is formed in their oils.

Sue Mueller