Dear Dr. Blonz: I have purchased some wild turbot fillets, and the nutrition chart reads: “Total fat 6 grams, saturated fat 2 grams, trans fat 0 grams.” Please explain the breakdown of the fat content in this fish, as I had thought it was a good source of unsaturated fat. Obviously, it is not the same as the fat in red meat, but is it “good” fat? It also has 210 calories per serving, which seems like a lot. — F.S., Concord, California
Dear F.S.: Naturally occurring fats and oils tend to be mixtures of saturated, monounsaturated and polyunsaturated fatty acids. The most prevalent fat is the one that generally gets associated with the identity of the food.
For example, olive oil is considered monounsaturated, but about 10 percent of its fat is saturated and 13 percent is polyunsaturated. The same goes with fish, which is generally thought of as polyunsaturated, some with omega-3s, but they also contain saturated and monounsaturated fatty acids. And then there’s lard. We might classify it as saturated, but in actuality, it is approximately 45 percent monounsaturated, 11 percent polyunsaturated and only about 39 percent saturated fat — much of it stearic acid, a saturated fat that has been found to have a neutral effect on blood lipid levels.
My point here is to not get all worked up about such labels and focus instead on the overall quality and variety of the foods you eat. Generally, fish are good food, but your question about whether the fats in this particular fish are “good” relates more to personal taste than anything else.
The calories provided seem quite modest. You can also compare this with other fish or food options. Check out nutritiondata.self.com, where you can compare the nutrient contents of foods and portion sizes and see a Nutrition Facts label for your selection. It also provides a breakdown of the different types of fatty acids and other nutrients in your selected foods. Another option is the USDA database (ndb.nal.usda.gov), which provides a library of branded and generic options.
Dear Dr. Blonz: Why is there palmitate in powdered milk? — M.B. San Jose, California
Dear M.B.: When a compound has “palmitate” as part of its name, it means that it is made with palmitic acid, a saturated fatty acid found in palm oil.
In milk fortified with vitamin A, or retinol, that nutrient is combined with palmitic acid, and the resulting compound is called either “vitamin A palmitate” or “retinol palmitate.” The amount of palmitate in powdered milk is negligible. It is only there as an “escort” for the vitamin A added to the product. You might see palmitate in other compounds as well, such as ascorbyl palmitate, which is a combination of palmitic acid and vitamin C (ascorbic acid).
Consider also that the human body can synthesize its own palmitic acid. Palmitate makes up about 25 percent of the fats found in breast milk, and it’s also present in human lung surfactant — a substance that coats the inside of our lung surfaces and allows us to breathe.
(Ed Blonz, Ph.D., is a nutrition scientist and an assistant clinical professor at the University of California, San Francisco. He is the author of the digital book “The Wellness Supermarket Buying Guide” (2012), which is also available as a free digital resource at blonz.com/guide.)
Send questions to: “On Nutrition,” Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.