What are cold pressed oils?

What is the best cooking oil? Unrefined, cold pressed (or centrifugal) oils made from plants are the healthiest cooking oils for your kitchen. Learn more about these less refined vegetable oils in this expert guide.

It used to be that you had a few cooking oil options on the supermarket shelves, like corn oil, soybean oil, and canola oil — all clear, pale, odorless, and tasteless. Then came the popularity of olive oil, which added delicious, unrefined, extra virgin oil to the options. But today, the group of unrefined vegetable oils has risen significantly. You can find unrefined and cold pressed avocadoAnd the almondsAnd the PeanutsAnd the grape seedsAnd the chopsticksAnd the linenAnd red palms, walnuts and Coconut In supermarkets – especially in natural food stores.

Consumers clearly have a wide range of oils to use in cooking, salad dressing, and pasta garnish. But what are the nutritional effects of these unrefined, cold-pressed oils?

What are unrefined and cold pressed oils?

Refined oils are those that have been heated and used chemical solvents to extract the oil, producing the best synthetic yield from a plant, such as soybeans, sunflower seeds, or corn. However, this process results in the oils with the worst health properties, according to Janet Bond Brill, Ph.D., RDN, FAND, LDN, a heart health and dietary fat expert, and author of Low cholesterol. In contrast, unrefined vegetable oils are those that are defined as “virgin,” that is, the oil is mechanically extracted without heat or chemical solvents. The word “cold” refers to those oils that do not use heat during the extraction process. When high temperatures are applied to plants, such as olives, there can be a loss of volatile odors, as well as polyphenols, antioxidants, and vitamins. The term “pressed” refers to crushing in a mill in order to obtain oil.

“Unfortunately, there is no regulation that guarantees that unrefined oils are not actually refined,” Brill says. The only exception is olive oil. In the European Union, “cold” and “pressed” labels are regulated for olive oil, Brill explains, but outside the EU, regulations for these terms regarding olive oil do not apply, so consumers have no guarantee that these statements are correct. To be sure, Brill suggests looking for an olive oil that has the highest polyphenol content (above 500), a free fatty acid level of 0.2 percent or less, and peroxides well below 10 mEq/kg. Additionally, you can search for certification seals, such as a Protected Designation of Origin (PDO), Protected Geographical Identification (PGI), the Australian Olive Society, the California Olive Oil Council, and the 3E Association.

What are the health benefits of unrefined, cold-pressed oils?

In general, we know that vegetable oils rich in unsaturated fatty acids, such as sunflower, rapeseed, corn, soybean, and olive, are associated with lowering LDL and total cholesterol and triglyceride levels, and raising HDL cholesterol levels, compared with lower. Healthy fats are like butter. (1) In theory, unrefined vegetable oils should exceed the benefits of fatty acid formation, because they contain more phytochemical compounds and micronutrients than the original plant. Unfortunately, there isn’t a whole lot of scientific evidence on the range of unrefined vegetable oils on shelves today to support this theory, other than that of an unrefined vegetable oil: extra virgin olive oil.

Unrefined vegetable oil with the lion’s share of evidence-based benefits Extra virgin olive oil. “Scientific data supporting the health benefits of extra virgin olive oil, as well as the presence of olive oil regulators make choosing olive oil your best option. At least until other oils can compete in terms of data and regulation,” Brill advises. In fact, hundreds of studies have documented the health benefits of extra virgin olive oil, an essential part of the Mediterranean diet. In 2018, the International Olive Oil Council invited experts from around the world at the Robert Mondavi Institute in California to summarize data on the effects of olive oil consumption on human health. They highlighted the benefits of this oil on cardiovascular disease, breast cancer, Alzheimer’s disease and diabetes, as well as lifestyle, taste, and cultural benefits related to Mediterranean food traditions. (2)

Brill, who ranks this oil as its second best choice after olive oil, explains it’s another immersive, unrefined avocado oil, which has an oil extraction process similar to that of olive oil. Avocado oil extraction involves removing the skin and pit, grinding the pulp into a paste, fermenting (slow stirring) for 40-60 minutes at 45-50°C, and separating with a centrifuge to obtain the oil. Slightly higher temperature does affect the quality of the oil, says Brill, which contains 76% monounsaturated, 12% polyunsaturated, and 12% saturated — very similar to olive oil. The main antioxidant is a-tocopherol, with a slight presence of d-tocopherol and components such as chlorophyll and carotenoids.

Other unrefined oils, such as hemp seed and flaxseed, may have potential benefits related to the plant’s omega-3 fatty acid content. Hemp oil contains 2 grams of omega-3 fatty acids in each tablespoon, and flaxseed oil contains about 7 grams per tablespoon. However, these oils are often used as a dietary supplement instead of as a cooking oil.

Not all cold pressed oils are created equal

Just because the oil is unrefined, it doesn’t mean the oil has a healthy lipid profile. “Two of my pet peeves are coconut oil and palm oil,” Brill says. She asserts that the claim that coconut oil is a healthy food stems from the misconception that coconut oil contains mostly medium-chain triglycerides (MCTs), so the oil is supposed to have a neutral effect on the level of bad cholesterol in the blood. Additionally, the high amount of lauric acid in coconut oil is assumed to increase HDL cholesterol. “This is simply not the case,” says Brill, who reported that over 40 years ago, saturated fatty acids, lauric acid, myristic acid, and palmitic acid were shown to have hypercholesterolemia. (3) “Approximately 92% of the fat in coconut oil is saturated, consisting primarily of the three major saturated fatty acids: about 49% lauric acid, 18% myristic, and 9% palmitate.”

Red palm oil can be marketed as another healthy, unrefined oil, but it is also high in saturated fatty acids – about 50% of the total fatty acids are saturated, with a high content of palmitic acid (44%). (4) “It is clear that the high content of saturated fatty acids in palm oil makes this a poor choice for heart health, regardless of how it is treated,” Brill says.

What is the whole point of these oils? “Claiming that the oil is unrefined doesn’t automatically make it a healthy food. Just because it’s from a plant doesn’t automatically make it a healthy oil,” Brill says.

In the kitchen

One of the main culinary benefits of unrefined vegetable oils is the aroma and flavor that is still present in the oil. So, if you want a quick frying to the taste of peanuts, add unrefined peanut oil. If you want your cookies to taste nutty, use unrefined nut oil. Heaven is the limit for the flavor characteristics that you can gain in many dishes, such as salad brothAnd the salty waterAnd the delicious recipesAnd the baked goodsFrench fries side dishesAnd the pasta dishes.

But how do unrefined vegetable oils work in the kitchen? “The more refined the oil, the higher the burning point,” Brill says. This means that unrefined oils may lose their quality as the cooking temperature rises. In fact, some unrefined oils have very low smoke points – flaxseed oil is around 225 degrees Fahrenheit, however, many of them have higher smoke points. For example, the burning point of olive oil is 410 degrees Fahrenheit, which should cover most cooking operations performed in a home kitchen.

Unrefined vegetable oils often come at a hefty price tag, further highlighting the option to use these oils as a special cooking ingredient, rather than as a substitute for all the fats in a traditional recipe. The higher price and sensitivity to many unrefined oils may make them better choices for no-heat cooking uses, such as salad brothfinishing pastaThe glaze finishes delicious dishes. While we wait for science, use extra virgin olive oil as your number one cooking oil, and other heart-healthy options to complement the health and flavor of a vegan diet.

For recipes using healthy, unrefined oils, check out the following:

Pasta sauce with tomato and eggplant
Fresh cranberry cereal with pasta and vegetables
Balsamic Nut Squash and Brussels Sprouts with Farro
Homemade Peanut Butter
Quinoa and Waldorf salad with walnut vinaigrette

References:

1. Schwingshackl L, Bogensberger B, Bencic A., Knuppel S, Boeing H., and Hoffman G. Effects of oils and solid fats on blood lipids: a systematic review and network meta-analysis. Lipid Research Journal. 59 (9): 2018 1771-1782. Taken from: http://www.jlr.org/content/early/2018/07/13/jlr.P085522.full.pdf
2. Visioli F, Franco M, Toledo E., et al. Olive oil and chronic disease prevention: summary of an international conference. Nutrition, metabolism and cardiovascular disease. 2018. 28(7): 649–656. retrieved from: https://www.sciencedirect.com/science/article/pii/S0939475318301261.
3. Minsink R. Effects of stearic acid on plasma lipids and lipoproteins in humans. Fats. 2005. 40 (12): 1201–1205.
4. Mancini A, Emberlini E, Negro E et al. Biological and nutritional properties of palm oil and palmitic acid: effects on health. Molecules. 2015. 20(9): 17339-17361. retrieved from: https://www.ncbi.nlm.nih.gov/pubmed/26393565.