oilsNutritionist Joy Bauer, RD, tells you which ones are healthiest, how to store them – and when butter is better

Are there any oils I should avoid totally?
Yes: The worst type of oil is an ingredient in packaged foods including some stick margarines, baked goods, chips, crackers and candy. I’m talking about partially hydrogenated oils – or trans fats, which is how they’re listed on Nutrition Facts panels on labels. Partially hydrogenated oil is vegetable oil that has been chemically altered so it’s less likely to spoil. Food manufacturers often add it to their products because it can help foods stay fresh longer.

But even in very small amounts, partially hydrogenated oil can wreak havoc on your heart health. It lowers levels of HDL (“good”) cholesterol and raises LDL (“bad”) cholesterol and it even increases your risk for diabetes. The American Heart Association recommends that no more than 1% of your total daily calories come from trans fat. This translates to less than 2 grams for women, who typically need fewer than 2,000 calories per day. If a food contains trans fat, it’ll be listed below Saturated Fat in the “Total Fat” column.

For the record, which is better: butter or olive oil?
From a health standpoint, olive oil is the better choice. But butter still has its place. All oils are a mixture of fats including monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA) and saturated fatty acids (SFA) – but in each oil (and in butter, too, which is basically a solidified oil), one type of fat dominates.
Olive oil is predominantly rich in heart-healthy monounsaturated fat, which decreases your risk for cardiovascular disease by lowering LDL cholesterol and increasing HDL cholesterol. On the other hand, butter is mostly saturated fat, which increases LDL cholesterol and causes inflammation in your body. So generally, it’s best to use olive oil (or another healthy oil; check the “Healthy Oils at Glance” chart).

However, the distinctive smell, flavor and consistency of butter works best in certain baked goods – including cakes, cookies and pastries – so it’s OK to oils1make these occasionally and enjoy the butter. Another butter-vs-oil difference: Because butter is solid at room temperature, you have more control over how much (or how little) of it you spread on bread; with olive oil, it’s difficult to gauge how much oil is absorbed. So dip lightly!

What’s the difference between regular olive oil, virgin and extra-virgin?
Simply put, olive oil is made by crushing olives to make a paste that’s then put under a press. If the oil that comes out has a low acidity and a good taste and smell, it’s labeled extra-virgin or virgin. (Virgin is slightly lower quality than extra-virgin.) These types are ideal to use for bread dunking, drizzling on veggies and other foods, and making salad dressings, since their delicate flavor and aroma will be lost when heated (some chefs still prefer to use extra-virgin for cooking). The deeper the color. The more intense the olive flavor.

If the oil is highly acidic or not great quality, it’s refined and mixed with virgin or extra-virgin oil to make “regular” olive oil; this all-purpose oil is good for cooking.

The heart-health benefits of all types of olive oil are pretty much the same, although the virgin and extra-virgin ones have extra antioxidants. Oils may be oils2“fattening” in the sense that they’re pretty high in calories compared with other foods. All oils have around 120 calories per Tbsp, so you can easily gain weight if you use too much. Even butter has fewer calories than oil (100 per Tbsp of butter) because of its water content. What’s more, “whipped” butter sold in a tub has even fewer calories – about 60 to 70 per Tbsp, thanks to the air that’s been incorporated into the mix and tub “light” margarine spreads have only 30 to 50 calories per Tbsp.

But since oils contain fats that are good for you, you’re better off getting that 120 calories from a healthy oil rather than stick or tub butter. By the way, if you’re inclined to cut out fats entirely, don’t; We do need some fat to be healthy. Without it, our bodies can’t absorb fat-soluble vitamins like A, D, E and K, and we miss out on fatty acids that are essential for the health of your skin, hair, heart and brain – and just about every other part of your body.

How should I store oils?
Heat, light and oxygen degrade oils, which makes them turn rancid more quickly and actually promotes the formation of cancer-causing compounds called free radicals. The more polyunsaturated fats an oil contains, the more susceptible to rancidity it becomes.

 

Oils rich in PUFAs, such as walnut and flaxseed, are best stored in the fridge in tightly capped containers. MUFAs, such as those found in olive oil, are a bit more hardy, but you should still protect oils that contain them by keeping the lid on tightly and storing them in a dark place far from the stove or other heat source. Saturated fats, such as butter, can withstand more heat, light and oxygen, but you should still refrigerate sat-fat-rich butter, because it contains milk solids which can go rancid. If you store oils correctly, most will last about six months to one year.

When you’re shopping for oils, reach for bottles at the back of the shelf, since that’s where they are more protected from harsh lighting that can make them go bad. Check the bottle for an expiration date (most oils have one), and every time you open a bottle, give it a whiff to make sure it doesn’t smell rancid.

hoHEALTHY OILS AT A GLANCE
Olive and canola oil are my two favorite kitchen staples because they’re so versatile. I also recommend the other picks in this chart for cooking and baking; they’re healthier than the corn, soybean and vegetable oil blends that so many of us grew up with .
TYPE OF OIL WHY IT’S HEALTHY WHAT IT’S GOOD FOR
almondAlmond Has MUFAs, which help lower cholesterol Salad dressings and marinades. Try it as a dip for apple slices or on an apple and arugula salad.
Canola Contains MUFAs and omega-3s, which have been linked to a lower risk of diabetes as well as stroke. Since it's flavorless, this oil can be used for many things, especially stir-frying and panfrying.
Flaxseed Rich in omega-3s. Dressings. Do not heat.
Hazelnut Has a high MUFA content. Drizzling over steamed vegetables or whisking into salad dressings and sauces, since it has a strong nutty flavor. Try it on roasted broccoli.
oliveOlive Contains MUFAs as well as anti-inflammatory compounds that can help lower your risk of heart disease, diabetes and arthritis pain. Roasting and sautéing. Flavorful extra-virgin oils are best for dipping, drizzling and dressings. (Will lose flavor when heated.)
Toasted sesame* Has MUFAs, which help lower cholesterol. Dressings, sauces, dips and drizzling, thanks to its deep, nutty flavor. It's also great in stir-fries.
sunflower Sunflower Contains MUFAs. Choose one labeled high monounsaturated or high oleic, which means it's mostly monounsaturated fat. All-purpose, since it has a neutral taste.
Walnut* A good source of omega-3s. Drizzling on roasted or steamed vegetables and whisking into salad dressings.