Have you ever had peanut butter with whipped cream and honey? My parents never bought into low-fat anything. They’d trade vitamins for raw cream and pastured eggs. I felt sorry for my friends who had to eat margarine instead of butter.
Eating real, whole foods sounds like such a simple concept, but it can be a little confusing at times, and I get asked a lot of questions about fat nutrition.
Nutritional scientists never thought that fat was bad for you, or eggs for that matter. We just haven’t been very good at communicating what science knows and doesn’t know. When your parents’ doctor told them to eat fat-free salad dressing and not to eat eggs, that wasn’t based on science. There’s a yin and yang to fats, and although they are complicated in a way, it’s really not that difficult to learn to use them wisely.
THE HEALTHY-FAT BASICS
- Any kind of fat will give you slow, steady energy (and work for a ketogenic diet).
- Olive oil that is not extra virgin has a higher smoke point than EVOO, so it’s good for most frying.
- Use EVOO and walnut oil in salads to lower your blood cholesterol.
- Walnut oil and other plant oils become oxidized, rancid, and unhealthy after too long in the cupboard—store them in the fridge.
- Coconut oil and dairy fat are good at increasing blood cholesterol, sadly.
- Seafood isn’t the only way to get the omega-3s that your brain and eyes need.
BURNING FAT AND KETONE BODIES
There’s no one best fat—what’s best depends on what you’re using it for. If you just want a steady, dependable source of energy, any kind of fat will do. Fat is digested and absorbed more slowly than carbs, so you don’t get sugar spikes followed by crashing, which is even more significant for people who tend to have low blood sugar. And most cells in the body are very happy to burn fat for energy instead of carbs.
Fat is also used to make ketone bodies, another good fuel that cells—especially brain cells—are happy to use instead of carbs. There’s even evidence from a few studies that providing the brain with ketone bodies can improve test scores in people with dementia. To get the liver to make ketone bodies, the only option used to be a very low-carb, high-fat diet. A new option is to eat medium-chain triglycerides (MCTs), which are made by concentrating “ketogenic” fatty acids from coconut and palm kernel oils. Taking a prescription MCT product improved scores on tests of cognition in people with Alzheimer’s disease.
OLIVE OIL AND MONOUNSATURATED FAT
Olive oil is considered the most perfect fatty food in large part because it’s used in Mediterranean countries where people live long, healthy lives. One of the good things olive oil does in the body is lower blood cholesterol. This surprises people—that eating fat would lower blood cholesterol—but it has been so exhaustively researched that even the most conservative public health agencies won’t disagree.
For salads, use EVOO—it’s cloudy and peppery because it contains all sorts of valuable plant components. For frying, these plant components are not desirable—they smoke and burn—so you want olive oil with a clearer appearance. When you look at a nutrition facts panel, you’ll notice that olive oil has a high percentage of monounsaturated fat, which resists a lot of the oxidizing, fat-damaging effects of heat and air. Some other plant oils do as well.
(To learn more about picking an olive oil, see this goop Q&A with journalist Tom Mueller, the author of Extra Virginity. And while you’re at it, check out this guide to cooking oils.)
COCONUT OIL AND SATURATED FAT
Coconut oil is similar to olive oil as far as frying. It has a high smoke point, is very resistant to heat and oxygen, and doesn’t become rancid easily. (Most hard fats are resistant to oxidation—that’s why McDonald’s used to fry its French fries in beef tallow.) As extra virgin olive oil does, unrefined, extra virgin coconut oil may smoke and burn.
Coconut oil is a great example of the yin and yang nature of fats. It’s easily absorbed and burned for energy or made into ketone bodies, all of which are great. On the other hand, there is a downside to solid fats. Somewhat similar to the way bacon grease can solidify and clog a drain, hard fats can also cause clogged arteries. They do this indirectly by making your blood cholesterol go up. Will a little bit hurt you? No. Should someone with high cholesterol eat a ton of coconut oil? No.
The cholesterol-raising fats are the saturated fats in coconut oil, palm kernel oil, and dairy fat. In contrast, the saturated fat in cocoa butter is pretty neutral. In nutrition facts panels, you’ll see saturated fat, which includes cholesterol-raising and more-neutral fats.
Meats are not bad, especially if they are grass-fed. It’s all about moderation and context. Eating moderate amounts of beef as part of a healthy diet with lots of veggies does not raise blood cholesterol.
SEED AND NUT OILS, PLUS POLYUNSATURATED FATS
EVOO is not the only kind of oil you can use for salads. My favorite salad oil is roasted walnut oil. There’s a wonderful walnut oil made in California—La Tourangelle—that has a rich flavor just right for beet salads or just about any other salad. It’s so good for you that there is absolutely no reason to skimp on salad dressing.
Walnut oil and most other seed and nut oils contain essential nutrients. Two polyunsaturated fatty acids are essential for life: linoleic acid (an omega-6), and alpha-linolenic acid (ALA, an omega-3). They are found in every membrane of every cell, with an especially important role in skin health.
So look for polyunsaturated fats in the nutrition facts panel. Or just eat nuts and seeds. These essential fats feed your skin and are even better than olive oil at lowering blood cholesterol.
Polyunsaturated fats and vegetable oils do have a downside, though. They tend to become oxidized. Have you ever taken a bottle of oil out of the cupboard and caught an unpleasant, rancid smell? The first time I helped make dinner at my future mother-in-law’s, I told her that we couldn’t use her oil and that it needed to be thrown away. Needless to say, not a smart way to begin a relationship. Once oil with a lot of polyunsaturated fat is opened and exposed to air, unless you go through it quickly, store it in the fridge to prevent oxidation. Heat and oxygen are the worst combination, so don’t cook with these oils.