Do you like the salad chain Sweetgreen? I do. I eat there, and it's been a lifesaver on occasions where I've wanted a quick and inexpensive salad with fresh, organic ingredients. With locations all over the east and west coasts of the United States, it is also very convenient.
One thing I appreciate about Sweetgreen is their dedication to sustainable sourcing. I also recognize that in many cases, they do have your health in mind. For example, they recently removed Sriracha from all of their salad dressings because sugar is the 2nd ingredient in the hot sauce. (Ingredients are typically listed in descending order of concentration, so in the case of Sriracha, sugar is the 2nd most abundant ingredient.)
However, Sweetgreen still uses an ingredient that I think is deserving of the term "toxic"—much more so than the Sriracha that they (very publicly) removed.
The ingredient in question is called grapeseed oil.
What is grapeseed oil?
Grapeseed oil is a tasteless, odorless, colorless oil extracted from the seeds of grapes using an industrial process similar to how corn, soybean, and canola oil is created. Often times, this process involves heat and harsh chemical solvents, like hexane.
Hexane is classified as an air pollutant by the Environmental Protection Agency (EPA) and as a neurotoxin by the Centers for Disease Control and Prevention (CDC). It's still regarded as safe for food use (the residues found in food are very small), and it's unclear as to what the consequences are of long-term, low level dietary exposure. That said, it's probably best avoiding if possible.
Most grain and seed oils are made using hexane unless they say they are expeller-pressed. I tried to find info on Sweetgreen's website about whether their grapeseed oil is expeller-pressed, and couldn't.
How (and why) does Sweetgreen use this oil?
Nearly every single one of Sweetgreen's "housemade" salad dressings lists grapeseed oil as a major ingredient. It is near the top of the list for many of their dressings, including their yummy Spicy Cashew Dressing (where it's #1). This means that it is in very high concentration in these dressings.
Restaurants and food manufacturers love using grain and seed oils for a very simple reason: They are dirt-cheap. Grapeseed oil is a perfect example of this.
Made as a byproduct of winemaking, grapeseed oil allows manufacturers to take something that used to be thrown away (the seeds of grapes), and turn it into a very high margin product. 100 years ago we didn't have the machinery or chemicals required to do this, but today we do. This is why our consumption of grain and seed oils (like grapeseed oil) has shot up 200-1000% in the past century. (R)
There are numerous problems associated with grapeseed oil. Let's get right into it.
1. Grapeseed oil is extremely high in pro-inflammatory omega-6 fats.
The problems associated with the Western diet—high rates of obesity, type 2 diabetes, heart disease, cancer, and now neurodegenerative disease—are thought to be contributed to (if not altogether fed) by a skewed omega-3 to omega-6 ratio. (R) In a nutshell, both are essential, but while omega-3s are anti-inflammatory, omega-6 fats provide the precursors to our body's inflammation pathways.
Researchers believe that our ancestral diets incorporated omega-6 fats in a ratio of between 1:1 and 4:1 with omega-3s. Today, due to the ubiquity of grain and seed oils like corn, soybean and grapeseed oil, we over-consume omega-6 fatty acids in a ratio of 25:1 with omega-3s. This can cause our bodies inflammation pathways to become chronically activated.
Grapeseed oil has an omega-6-to-omega-3 ratio of 700:1. In relative terms, it contains huge amounts of omega-6 fats and virtually zero omega-3 fats. This may contribute to fat storage (R), heart disease (R, R), cancer (R), hormonal dysfunction (R), autoimmunity (R), and even depression (R).
2. The fat in grapeseed oil is easily damaged, and can thus damage you.
Sweetgreen is weary of saturated fats. This was evident when they removed the bacon from their menus, along with Sriracha. But while saturated fats are highly chemically stable, polyunsaturated fats are the exact opposite: Delicate and prone to a type of chemical damage called oxidation.
85-90% of the fatty acids in grapeseed oil come from these damage-prone polyunsaturated fats. The fact that heat is often used to create grapeseed oil makes it particularly worrisome (R).
When these fats become oxidized, ingesting them can deplete your body's own antioxidant defense mechanisms. Over time, these oxidized fats can set off a cascade that can damage multiple organ systems (independent of whether or not they are omega-3 or omega-6 fats). (R) This may explain why a bounty of recent evidence suggests that it's not saturated fats per se that are harmful to our health, but the polyunsaturated fats that we've been told to trade them in for (R, R).
Note that even when grapeseed oil is "cold-pressed," it is still vulnerable to oxidation, as oxygen exposure, light, storage, and being left out in the warm kitchen environment catalyzes this process.
3. Grapeseed oil—and thus Sweetgreen salad dressings—likely contains trans-fats.
Trans-fats are a type of fat that is often man-made and highly dangerous. The consumption of trans-fats has been associated with poorer cognitive function and risk for early mortality (R).
The most well-known type of trans-fat found in the diet comes from oils that have undergone a process called hydrogenation. This is when manufacturers pump vegetable oils with hydrogen to make them behave more like saturated fats and to give products a longer shelf-life. These fats are so damaging that the FDA has recently banned them.
But hydrogenation isn't the only way to produce trans-fats. They are formed in the production process used to create grain and seed oils like grapeseed oil. This is independent of whether or not these oils are hydrogenated.
I'll repeat: The mere creation of these oils generates trans-fats.
To be produced, grain and seed oils (like canola, corn, and grapeseed oil) undergo a process called deodorization. This removes any scent and odor from the oils so that they become tasteless and can thus be used in a wide range of processed foods. Even organic, non-GMO canola oil contains small amounts of trans-fats.
The trans-fat content of industrially-produced oils range from .5%-4%. (This includes grapeseed oil, canola oil, corn oil, soybean oil, and even regular olive oil, which is why you should always stick to extra-virgin.) Unfortunately, nutrition labels are only required to disclose the trans-fat content if it's over 0.5 grams for a serving. "Despite this claim, virtually all vegetable oils sold in the supermarket contain small amounts of trans-fat," wrote Dr. Guy Crosby on a recent blog at the Harvard School of Public Health.
There is no safe level of trans-fat consumption.
4. Grapeseed oil may contain dangerous carcinogens.
Polycyclic Aromatic Hydrocarbons, or PAHs, constitute over 100 different chemicals that are formed during the incomplete burning of coal, oil and gas, and garbage. They are also found widely in the food supply. (R, R) The problem is, PAHs are known carcinogens. (R)
Although some degree of exposure to them is unavoidable (and we detoxify and excrete them accordingly), grapeseed oils and other vegetable oils have been found to contain very high levels of them. (R) This, compounded by the fact that we consume so much vegetable oil these days, has made it a major PAH contributor in the diet. (Grains are also a large contributor. R)
In a recent review, the Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Committee on Food Additives (JECFA), determined that the effect of dietary PAHs on human health are likely to be insignificant under normal circumstances.
However, they still recommended that efforts should be made to minimize the intake of PAHs (R). Avoiding grapeseed oil makes following this instruction very easy.
5. Grapeseed oil may promote brain fog.
Diets that are very high in omega-6 fatty acids can change the structure of your brain. This is because the brain is composed primarily of fat and predominantly these delicate, damage-prone polyunsaturated fats. The polyunsaturated fats that we consume can easily cross the blood-brain barrier where they can integrate into our brain cells, and determine how well they are able to function. (R)
Important aspects of our cognition may be particularly vulnerable to a skewed omega-6/omega-3 ratio, such as executive function. Executive function is the ability to think clearly and we rely on it to "get stuff done," and we call on it when planning, making decisions, and tuning out distractions.
In one cross-sectional study, children with ADD had worse symptoms when their diets contained higher levels of omega-6 fatty acids relative to omega-3 fatty acids. Researchers wrote, "Executive functions may be particularly affected by omega-6 to omega-3 imbalances.” (R)
While a cross-sectional study can not determine causality, trials in many age groups involving omega-3 supplementation (to correct the omega-6/omega-3 balance) have yielded positive results, strengthening the link between excessive omega-6 consumption and compromised brain function. (R, R, R)
6. Grapeseed oil is nutritionally poor.
While the whole grape seed may contain some important phytonutrients, the oil that is extracted from them is nutritionally quite poor. (R) It does contain vitamin E, an antioxidant, but there are much better sources of vitamin E including extra-virgin olive oil which also contains other compounds that have a strong supportive research base.
Of course, being "nutritionally poor" doesn't make something toxic, but one of the hallmarks of a health-promoting diet is the consumption of nutrient-dense foods. Grapeseed oil is calorie-rich, while not containing very many nutrients.
Easy fix: Make your own dressing
Sweetgreen is one of the healthiest food chains out there, so I hope they do change the oils in their dressings. In the meantime, there is a really simple solution to their dressing problem: Avoid using them completely, and create your own custom dressing instead.
All Sweetgreen locations have (usually organic) extra-virgin olive oil. When a server asks you if you'd like your dressing "light, medium, or heavy," simply say "None of the above! I'd like a custom dressing," and ask for these ingredients:
- extra-virgin olive oil
- balsamic vinegar (optional)
This custom dressing, unlike Sweetgreen's own dressings, is actually extremely healthy. Extra-virgin olive oil consumption has been associated with improved cognitive function, cardiovascular health, and weight. Part of this has to do with the fact that unlike grapeseed oil (which promotes inflammation), extra-virgin olive oil is anti-inflammatory. It also may help block fat storage due to its ability to block an enzyme called fatty acid synthase which helps store carbs as fat. (R)
In the end, this switch will very likely leave you feeling better, with more energy and less brain fog throughout the day. Win-win!