1. Beneficial omega-3 fats are so called because:
a) There are three types
b) They are three times as healthy as other types of fat
c) Both (a) and (b)
d) None of the above
2. The key beneficial fats found in fish oil are:
d) DHA and ALA
e) EPA and DHA
f) All of the above
3. Only omega-3 fats are essential for human health.
4. These plant foods contain healthy omega-3 fats:
a) Flax seeds
b) Chia seeds
e) a, b, and c
f) All of the above
5. Which of these fats should NOT be used for high-heat cooking?
a) Coconut oil
b) Olive oil
c) Corn oil
e) All of the above
6. When a food label lists zero trans fats, the food contains no trans fats.
1. d) There are, in fact, three types of omega-3 fats: EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), and ALA (alpha-linolenic acid). But this is not how they get their name. Omega-3 fats are so called because of their chemical structure. (If you aren't a chemistry fan, you might want to stop here.) Each molecule of fat is a chain of atoms. "Omega," the last letter of the Greek alphabet, refers to the tail end of the chain. Three types of atoms make up the molecule: carbon, hydrogen, and oxygen, and some of the atoms are joined by double bonds. The "3" indicates that a double bond occurs 3 carbon atoms away from the omega end. (In an omega-6 fat, a double bond occurs 6 carbons away from the omega end.)
2. e) EPA and DHA are found in fish oil. ALA is found in plant foods, and can be converted to EPA and DHA in the human body to varying degrees. DHA and EPA originate in certain types of algae, which are eaten by fish, and vegan supplements of EPA and DHA from algae are available.
3. b) Two types of fats-omega-3 and omega-6-are essential, meaning we must obtain them from food because our bodies can't make them. However, the Western diet typically contains too much omega-6 fat, and much of it is inflammatory-especially oils found in processed and fast foods. Certain types of omega-6 fats, such as borage oil, evening primrose oil, and black currant seed oil, are anti-inflammatory.
4. f) Dark leafy greens, such as kale, spinach, purslane, mustard greens, and collards, contain omega-3 fats, but in very small quantities. Flax and chia seeds and oils, and walnuts, are more concentrated sources. Hemp seeds and hempseed oil, pumpkin seeds, Brazil nuts, and sesame seeds are other plant sources of omega-3s.
5. c) Corn oil, although widely used for frying, breaks down and forms aldehydes when exposed to high heat. Aldehydes, which also form when the oil turns rancid, are harmful substances that have been linked to higher risk for cancer and heart disease. Coconut oil, olive oil, and ghee (clarified butter) are much more stable when heated and don't pose the same risk.
6. b) Trans fat, meaning any "partially hydrogenated" oil, is more damaging than any other type of fat, and regularly eating any amount can contribute to heart disease, stroke, and diabetes. By law, if a food contains less than 0.5 grams of trans fat per serving, the Nutrition Facts section of a label lists "0 grams." However, if partially hydrogenated oil is listed among the ingredients, the food does contain trans fat.