Health Experts Really Want You To Eat Less Of This Highly Refined Oil

The term “vegetable oil” can refer to any type of edible oil1 derived from plants, including various types of fruits, nuts, grains, or seeds. These products are produced by extracting the oil from the plant, either by crushing the plant material or by using a chemical solvent.

A few examples of cooking oils that are technically considered vegetable oils include:

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More commonly, however, the term is used to describe a specific type of cooking oil made from soybean oil or a blend of soybean and corn oils.

Often labeled simply as “vegetable oil,” this type of oil is known for its high smoke point, neutral flavor, and budget-friendly price tag. Vegetable oil is also a versatile ingredient and can be used to whip up dips and salad dressings, deep-fry dishes, or ramp up the richness and flavor of baked goods.

Though vegetable oil has been around for centuries, its popularity skyrocketed during the 20th century. In fact, the estimated per-capita consumption of soybean oil2 increased by over 1000-fold between 1909 and 1999, as animal-derived fats like butter and lard slowly fell out of favor.

This is attributed to a few different factors, including the introduction of new processing techniques for seed oils, recommendations from health organizations to eat more polyunsaturated fats, and public policies designed to support soybean production.

Summary

"Vegetable oil" typically refers to highly processed oils made from soybean oil or a blend of soybean and corn oils. Vegetable oil is affordable, neutral in flavor, and has a high smoke point. Over the last century, its use in the food industry has skyrocketed.

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1.

It contains omega-6 fatty acids

According to Jenna Macciochi, Ph.D., an immunologist who specializes in understanding the connection between lifestyle and immune function, vegetable oil tends to be high in omega-6 fatty acids. “These are the raw materials for our cells to make inflammatory mediators like prostaglandins,” she explains.

Macciochi notes that regular consumption of omega-6 fatty acids could theoretically increase inflammation3, which could contribute to chronic conditions like heart disease, cancer, and diabetes.

However, she also points to research in humans4, which suggests that this is not always necessarily the case. “This tells us that data from mechanistic studies doesn't always translate to the complex system of a human,” says Macciochi. “It also shows that context is important. Omega-6 intake in a person who is eating a healthy diet with plentiful omega-3s doesn't seem to be a major issue.”

To break this down and keep things short and sweet: if you’re following a balanced diet and eating plenty of foods rich in heart-healthy omega-3 fatty acids, consuming vegetable oil from time to time is probably just fine.

On the other hand, loading up on omega-6 fatty acids without balancing them out with other healthy fats in your diet could increase inflammation.

2.

It’s typically highly refined.

Some of the processes used to produce vegetable oil could negatively affect its nutritional value, according to Amy Shapiro, MS, RD, CDN, a registered dietitian and founder of Real Nutrition NYC.

“Vegetable oils extracted with chemical solvents are deprived of some of the essential nutrients1 and compounds, such as polyphenols, vitamins, tocopherols, and phytosterols, originally found in the source of extraction,” says Shapiro.

“Chemical extraction may also generate potentially harmful products such as trans fat,” says Shapiro. It’s no secret that trans fats are something you definitely don’t want on your plate. In fact, adding artificial trans fats5 to processed foods was even banned by the FDA in 2020, after studies linked them to a long list of harmful health conditions, including heart disease6.

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3.

It’s often found in less nutritious foods.

Unless you’re in the habit of chugging vegetable oil straight from the bottle, Macciochi points out that you’re probably not consuming it in isolation.

“Foods high in vegetable oils tend to be those which are intrinsically unhealthy for us for a variety of reasons,” says Macchiochi, noting that the high salt, fat, or sugar content coupled with the low amount of fiber found in these foods is not healthy.

Processed foods—a major source of vegetable oil in the typical diet—have been linked to a variety of issues, ranging from increased belly fat7 to a higher risk of heart disease8, metabolic syndrome9, and even depression10. Vegetable oil is also frequently found in fried foods, which can also harm heart health11.

Desiree Nielsen, RD, a registered dietitian and author of Good For Your Gut, points out that certain processing methods (like deep-frying) can also generate harmful compounds in vegetable oils, such as aldehydes12. “However, these concerns don’t really apply to typical cooking at home using a small amount of vegetable oil,” explains Nielsen. “This is more of a concern in eating a dietary pattern high in hyper-processed and fried foods cooked in these oils.”

So, is vegetable oil bad for your health?

Because vegetable oils are typically highly refined, rich in omega-6 fatty acids, and often found in fried or processed foods, it’s best to moderate your intake.

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Macchiochi and Nielsen both recommend olive oil as a healthy substitute for vegetable oil, thanks to its long track record and numerous health benefits.

Besides bringing a bitter or peppery zing to dishes, research suggests that olive oil could also ease inflammation13 and may even protect against chronic conditions14 like heart disease, breast cancer, and type 2 diabetes.

Note that olive oil has a slightly lower smoke point than vegetable oil, which Macchiochi points out might be a concern for some people. “However, the high polyphenol content of olive oil protects the oil during all forms of home cooking,” she says.

Though extra-virgin olive oil (the least processed variety) can also come with a slightly higher price tag than vegetable oil, it’s equally versatile and well worth the investment from a nutritional standpoint.

RELATED READ: 10 Best Olive Oils Of 2023 + How To Find A High-Quality EVOO

Shapiro shares that avocado oil is her top pick for cooking methods like grilling, roasting, or frying.

In addition to its mild yet buttery taste, its higher smoke point makes it a good choice when you’re cooking at high heat. Plus, while some varieties can also be a bit pricey, there are plenty of affordable options on the market if you’re on a tight budget.

While there’s no doubt that whole avocados can fit right into a healthy diet, promising new research suggests that avocado oil may boast some serious health benefits as well.

According to one 2021 review, animal studies have found that avocado oil could aid in the prevention of conditions like heart disease15 and diabetes. Another recent animal study even showed that avocado oil supplementation improved insulin sensitivity16, lowered triglyceride levels, and boosted brain function in mice.

Though it’s been subject to quite a bit of controversy over the years, coconut oil can be a cost-effective alternative to vegetable oil, especially for high-heat cooking.

Refined coconut oil has a high smoke point and a mild taste that works well in a wide range of recipes. Meanwhile, unrefined coconut oil (aka virgin coconut oil) undergoes less processing, giving it a lower smoke point and a coconutty flavor and aroma.

Proponents of this popular cooking oil claim that it could help bolster fat-burning and boost weight loss. “Coconut oil contains medium chain triglycerides (MCTs), which are used quickly as an energy source instead of being stored as fat,” says Shapiro.

While research on coconut oil has been pretty inconsistent, some studies suggest that its unique nutrient profile could help decrease body weight17 and body fat. What’s more, coconut oil is brimming with antioxidants18, which can ward off inflammation and disease.