Environmental impact of cooking oils

Vegetable oils and fats play a crucial role in our diets, serving as a significant source of dietary polyunsaturated fatty acids, alongside a variety of other essential nutrients. They are not only used extensively in cooking and baking, adding flavor and nutritional value to our meals, but are also utilized in a wide range of non-food goods such as cleaning agents and beauty products.

Chemical use in crop production

Using large amounts of synthetic nitrogen fertilizer contributes to a crop’s overall emissions because fertilizer production is energy-intensive. Synthetic fertilizers also release nitrous oxide, a GHG that is about 300 times more potent than carbon dioxide.

Pesticide use often leads to contamination of soil and water, and is a significant cause of the decreasing populations of vital pollinators such as honeybees and Monarch butterflies.

Go Green: Buy certified organic oil

Note that any certified USDA Organic product is also GMO-free.

Land management & farming practices

Responsible land management and farming practices have a huge impact on crop sustainability. This can include a no tilling strategy instead of conventional tilling, which can create twice as much GHG emissions. Choosing crops suited for the local climate decreases resources required for successful cultivation, as does the selection of crops that are more efficient with their nitrogen use and add nitrogen to the soil naturally.

Monocultures are an especially nefarious farming strategy, which is rampant in palm oil cultivation. This is where only a single species of crop is grown in a large area, disrupting natural ecosystems, discouraging natural biodiversity in local wildlife, which also negatively affects pollinators. The lack of plant diversity leads to soil degradation, in turn creating the need for increased fertilizer usage for adequate production. It also increases a crop’s vulnerability to diseases and pests, as a large population of a single species makes it easier these to spread rapidly.

Go Green: Buy from small farms; Look for sustainability certifications

Shop for oils with certifications such as these that ensure sustainable and ethical farming practices.

Water consumption

As with any crop, vegetable oil species are best grown where appropriate for the local climate.

Sunflower oil has the least impact when it comes to water consumption. On the other hand, olive oil is the worst. Among all food crops, only nuts like almonds require more water than olive oil. In fact, olive oil requires more water per kilogram of food than even beef, eggs, pork, or milk.

Transportation

Cooking oils such as palm, coconut, and avocado grow in subtropical locations, which amount to a fair distance to travel to reach the US. Most of the world’s top oilseed producers are outside of the western hemisphere.

Go Green: Buy locally produced oils as able

Oil Extraction

After first considering the environmental impact of an oil source’s cultivation and harvest, we need to consider the ensuing steps of processing, which affects both the nutritional value and sustainability of the oil. The first step in this process is the extraction of oil from the seeds or fruits. This is achieved by either chemical or mechanical means.

Chemical extraction

Chemical oil extraction is the most commonly utilized method of oil extraction, and is the primary method used for the world’s top commodity oilseeds, including corn, soybean, canola, sunflower seed, cottonseed, and peanut. This is because the process can be utilized on a large scale that results in higher yields, is quicker, and less expensive. In addition, some raw materials do not release oil by expelling, making it necessary to use solvent extraction. Besides using large amounts of chemicals, this process requires high-energy input.

If seeds have not first undergone mechanical processing, they are flaked, cracked, ground or pressed. The oilseeds are then washed with a solvent, which is most commonly hexane, a highly flammable petroleum-derived chemical that is a component in gasoline and has been associated with neurotoxicity in animals.

The hexane separates oilseeds into liquid fat and solid protein, after which it separated from the mixture by evaporation or distillation. Hexane evaporation is achieved by heating the mixture to about 300 °F.

This evaporation process releases hexane into the atmosphere, where it contributes to the formation of photochemical smog. The EPA has designated n-hexane as a hazardous atmospheric pollutant. Most direct exposure is from inhalation, especially by workers or those that live near a facility where this chemical is used. Hexane exposure can lead to a variety of negative health effects; carcinogenicity is unknown.

Even after solvent-extracted oil and meal are processed, they may still contain trace amounts of hexane. However, the U.S. Food and Drug Administration (FDA) does not currently monitor or regulate hexane residue in foods, and the CDC reports that the hexane level in cooking oil is too low to have any effect on people. Any oil processed in this way cannot be considered organic.

Because of environmental and health concerns, some processors are shifting towards more eco-friendly extraction techniques. These include aqueous enzyme extraction (AEE), the use of green solvents such as terpenes from citrus peels and tree oils, or mechanical expeller pressing as alternatives to the traditional hexane extraction method. Other newer green extraction technologies include ultrasonic-aided extraction (UAE), microwave-aided extraction (MAE), subcritical extraction (SWE), and supercritical extraction (SFE).

Mechanical extraction

Environmentally, cold pressing technology produces the most sustainable cooking oils, and is far superior to chemical extraction because of reduced energy use and lack of chemical utilization with resulting exposure and pollution risks. It also results in healthier oils, since no nutrients are lost in the process.

The two main extraction methods you will encounter are expeller pressed and cold pressed.

Expeller pressed oil is extracted by adding raw crops to a corkscrew type machine that applies high pressure in order to squeeze the oil from the seed or fruit. The oil seeps through small openings that filter out fiber solids, which are passed through the machine and collected. As the raw material is pressed, friction causes it to heat. This heat can affect the end flavor of the oil in addition to removing some of the important nutrients.

Cold-pressed oils are defined as being produced “without heating, precleaning, dehulling and milling mechanically. Cold pressed unrefined oil can only be purified by washing with water, precipitating, filtrating and centrifuging.” These oils are made by first grinding the seed or fruit into a paste. The paste is then pressed to separate the oil from the solids, which are then referred to as cake. A significant amount of oil can remain in the cake, and so it might undergo a chemical extraction process or be sold for livestock feed. From there, the resulting unrefined oil can be simply filtered and bottled or be refined if necessary.

• Wood pressed oil is a type of cold press process. The difference is that the pestle used is made of wood, as opposed to steel as with a machine. The wood absorbs any increase in temperature and doesn’t generate any heat through friction, better maintaining a lower temperature. This oil extraction process is often used for coconut, sesame, groundnuts, castor seeds, and mustard seeds.

• Virgin oil, primarily used to define olive oil, indicates that the oil is of high quality and has not been refined or processed, preserving its purity and nutritional properties. Virgin oils can be cold-pressed, but not all cold-pressed oils are considered virgin. The distinction mainly comes down to the type of oil and the specifics of the extraction process. Virgin oils are a subset of cold-pressed oils with an emphasis on minimal processing to maintain the oil’s natural quality. Extra virgin oil denotes a high quality of oil.

Thus, oils that remain in their natural state are designated as unrefined, cold-pressed, raw, virgin, or extra virgin. These oils preserve their natural flavors, along with valuable minerals, nutrients, and enzymes, making them a healthier choice. On the downside, since these unrefined oils contain more than just fats, they have lower smoke points and tend to burn at higher heat. In addition, they become rancid more quickly when stored.

Common cold-pressed oils include avocado, coconut, grapeseed, walnut, flaxseed, and sesame oils. It is possible to cold-press canola and sunflower oil, but may be harder to find.

The cooking oil refining process

After extraction, some types of oils require refining. Many types of oilseeds are not edible without first undergoing a refining process in order to improve shelf life and eliminate free fatty acids and other undesirable compounds, as well as toxic components such as pesticides or trace metals in order to make them fit for human consumption.

Crude oils such soybean, rapeseed (canola), palm, corn, cottonseed, peanut, safflower, and sunflower oils must be purified or refined before consumption. The goals of refining treatments include obtaining a better quality (which is demonstrated by a lighter odor and color and longer stability) and a safe product after pollutants are eliminated. However, the refining process removes some essential nutrients and often generates other undesirable compounds, which can influence the safety level of the finished product.

Refining is achieved by one of two methods: physical or chemical. The steps in both types refining are largely similar, with the exception of the neutralization process where free fatty acids are removed.

Chemical refining consists of removing free fatty acids by adding caustic soda and separating the soap by centrifugation (mechanical separation), while physical refining, in the last step, removes free fatty acids and other compounds by steam distillation (also known as steam refining).

Steps in refining of cooking oil

1. Degumming removes phospholipids, which are often linked with heavy metals. This is a vital proess to allow for successful subsequent refining steps; incomplete removal of phospholipids affects oil clarity, color, and flavor. Degumming is achieved by one of four variations of this process, depending on the oil being refined.
2. Neutralization is the method in which free fatty acids (FFA) are eliminated, as well as any remaining phospholipids and metals. The presence of FFA in oil creates many problems for the storage and stability, and results in an undesirable color and odor in the final product. The method of neutralization is the main difference between mechanial and chemical refining. In chemical refining, this involves washing the solution with a caustic soda (sodium hydroxide), which neutralizes the FFA and converts them into soapstock, which can be used for a variety of applications such as animal feed or in the production of fertilizer and biodiesel fuel. The oil is washed with hot water and centrifuged to remove the remaining soap and soda. Mechanical neutralization is achieved during the deodorizing process, described below.
3. Bleaching is done to reduce the levels of colored pigments (carotenoids and chlorophylls). Bleaching earth is the most widely used adsorbent to achieve the removal of these pigments, which are not eliminated in any other refining stage. Bleaching clays such as bentonite is the most popular adsorbent used, while activated carbon, special silica, or a combination of these are also options.
4. Dewaxing, also known as winterization, concerns a few types of oils rich with waxes, such as rice bran, canola, corn germ oil, and sunflower. This step is only utilized when oil appears cloudy at room temperature due to waxes or saturated triacylglycerols. It’s worth mentioning that these substances don’t compromise the oil’s performance or functionality. However, consumers find the oil’s appearance less appealing. In this process, oil is heated until completely liquid and then slowly cooled to allow crystallization of the waxes. The oil and wax is then separated by centrifugation.
5. Deodorizing is the final stage of refining, and eliminates volatile compounds and contaminants, as well as odors and different off-flavor components, while being the primary method of removing FFA in mechanical refining. This step improves the stability and color of the oil, but unfortunately may also destroy valuable nutrients. This is achieved with steam distillation, also known as steam refining, which involves high temperatures and pressures. A deodorized oil lacks any taste, even pleasant ones.

Refined oils have a neutral flavor, high smoke point, and long shelf life.

Mechanical refining

As noted, physical refining of oil follows the same steps as chemical refining, with the main difference being neutralization included in the deodorization stage. In addition, dewaxing is not always necessary.

Mechanical refining is a less expensive and more eco-friendly process which uses less chemicals, requires less energy and creates less emissions, and reduces the production of polluting effluent wastewater.

However, physical refining is not suitable for all types of oils. It is limited for use with oils with high acidity. Palm, coconut, canola, soybean, and sunflower oils may be processed in this way.

Sources:

• Gharby, S. (2022) ‘Refining Vegetable Oils: Chemical and Physical Refining.’ ScientificWorldJournal.
• AOCS Lipid Library : Oil Refining
• Durazzo, Ramadan, Di Stefano, and Lucarini. (2023). ‘Editorial: Cold Pressed Oils: A Green Source of Specialty Oils, volume II‘

Which cooking oil is the most environmentally friendly?

At last, we can answer the million dollar question.

Ok, maybe not. Nothing in the world of sustainability is that straightforward. When you combine the attributes of crop cultivation, extraction, refining, and transportation, it gets a little complicated. Almost every single type of cooking oil has significant cons to counter the positive attributes. As is the case with nearly everything else in going green(er), it’s often a matter of choosing the lesser of the evils, with only a couple obvious answers.

Let’s quickly highlight the pros and cons of each common cooking oil in order to determine that most sustainable cooking oils, including which are the healthiest options.

Avocado oil

Not surprisingly, there’s not really a way for us as consumers to verify whether the avocados we purchase are funding criminal enterprises who are also destroying the environment.

This is especially unfortunate for avocado lovers as only about 16% of the avocados Americans consume are from California.

And what we purchase might not even be authentic avocado oil, or at least of poor quality. A 2020 study by UC Davis found that 82% of avocado oil sold in the U.S. is of poor quality, having gone stale or rancid prior to the expiration date, or mislabeled as being pure when actually adulterated (mixed) with other oils. Some samples didn’t contain any avocado oil at all.

Pros

• Avocado oil is high in polyunsaturated fatty acids, in addition to having one of the highest monounsaturated fat contents among cooking oils, and contains vitamin E as well as carotenoid and polyphenol antioxidants, which may benefit heart health. It contains the same amount of saturated fat as olive oil. This makes it one of the healthiest oils available.

Cons

• Expensive
• Chosen Foods estimates that on average, it takes 15 to 22 avocados to produce a 500ml bottle of avocado oil.
• Deforestation has become an widespread solution in Mexico in order to clear land for increased cultivation as the evergrowing demand for this superfood rises.
• Avocado cultivation requires a lot of water: On average, about 528 gallons of water are needed to produce a kilo of avocados (2.2 pounds). In the Mexican state of Michoacán, which produced half of all avocados globally, around 9.5 billion liters of water are used daily for avocado growing. This massive extraction of water from local aquifers has led to unexpected environmental consequences, such as creating small earthquakes.
• According to the World Economic Forum, “Intensive avocado production has caused biodiversity loss, extreme weather conditions, extensive soil degradation of the soil and is on the brink of causing an entirely human-made environmental disaster.”

Go Green: California grown cold-pressed avocado oil with sustainability certifications

Try to purchase avocado oil that’s organic and fair-trade certified, if you can find it. And a partridge in a pear tree. This healthy oil might best be avoided unless it you can find one that checks all the boxes.

Best avocado oil brands

Avocado oil should be green, not light yellow or clear. It should taste “grassy, buttery and a little bit like mushrooms,” according to UC Davis. If rancid, it will start to smell stale, a bit like play dough. Store in a dark, cool place.

Canola (Rapeseed) oil

Go Green: Organic, non-GMO, expeller-pressed canola oil

Coconut oil

Pros

• High in lauric acid, a saturated medium-chain fatty acid (also found in breast milk) which may have antimicrobial properties and other potential health benefits. It also contains antioxidants with anti-inflammatory properties.
• When desired, unrefined/cold-pressed coconut oil imparts its flavors into foods.

Cons

• Very high in saturated fat, 80-90%, which is twice that of butter. The American Heart Association recommends skipping tropical oils as a result.
• The coconut craze has been fueled by a variety of health claims, however many of these are based on studies done with a special formulation of coconut oil which lacks long-chain triglycerides. This differs from the coconut oil available to consumers. Current studies have yet to confirm many of the alleged health benefits of coconut oil.
• Coconut oil has demonstrated an ability to elevate levels of both beneficial (HDL) and harmful (LDL) cholesterol more than other vegetable oils, including olive or canola oil. Other oils such as olive, canola, and avocado, as well as foods high omega-3 fatty acids like nuts and seafood, have been shown to be more beneficial in studies.
• Grows in tropical areas near equator, therefore transported over long distances to the US.
• Coconut cultivation can face the same environmental woes as palm oil, such as deforestation and monoculture farming. In fact, a controversial 2020 study found that the production of coconut oil threatens five times more species per ton of oil produced palm oil and more than any other cooking oil.

Go Green: Sustainably certified coconut oil

• Nutiva Organic Virgin Coconut Oil – non-GMO, Fair Trade certified; a refined version is available if a neutral flavor is desired. Buy at Amazon

Corn oil

Pros

• Very high smoke point, ideal for deep frying.
• Contains a high amount of phytosterols, which are anti-inflammatory and may help reduce cholesterol. Also has vitamin E and linoleic acid.
• Produced in the US.

Cons

• Corn oil is very highly processed.
• The omega-6 to omega-3 fat ratio in corn oil is very high, 46:1.
• When corn oil is heated, it produces the acrylamide, which has been linked to nerve, hormone, and muscle dyfunction.
• A 2019 study found that corn farming is responsible for significant amounts of air pollution, mainly from fertilizer use, which emits ammonia into the atmosphere and is responsible for 4,300 air pollution-related deaths annually in the US. Ammonia and other components of fertilizer also pollute waterways. High amounts of pesticides are typically used in corn production.
• Corn is often farmed in monocultures.

Go Green: Skip it for healthier, less processed oils

Grapeseed oil

Go Green: Cold-pressed grapeseed oil

Spain produces half of the world’s olive oil, followed by Italy and Greece. The US has approximately 40,000 acres of olives for oil planted in California, Arizona, Texas, Georgia, Florida, Oregon and Hawaii. This results in about 5% of the olive oil consumed by Americans each year.

Oil is produced by taking freshly picked olives and crushing them in a hammer mill, then grinding the crushed olives to form a paste. This paste is softened by stirring, a process referred to as malaxation or paste beating. Following this, centrifugation is used to divide solids from the liquid mixture, and the resulting liquid undergoes vertical centrifugation to further purify the oil by removing water and fine particles. After resting for 24 to 48 hours to allow for settling, the oil undergoes filtration to eliminate any residual particulate matter before being stored in containers.

Olive oil is classified into grades, which are set by the International Olive Council (IOC). In the United States, while the Department of Agriculture and the North American Olive Oil Association have IOC-based standards, adherence to these standards is voluntary. Moreover, olive oils imported into the U.S. are not obligated to comply with IOC regulations. The state of California does have mandatory standards and testing which are stricter than the IOC’s. This applies for companies that produce at least 5,000 gallons per year from locally-grown olives.

The IOC defines virgin olive oil as, “the oils obtained from the fruit of the olive tree (Olea europaea L.) solely by mechanical or other physical means under conditions, particularly thermal conditions, that do not lead to alterations in the oil, and which have not undergone any treatment other than washing, decantation, centrifugation and filtration.”

From there the grades are further determined by level of acidity, or level of free oleic acid.

• Virgin olive oil has an acidity level of 0.8 to 2%. This type of oil is not commonly sold in the US.
• Extra virgin olive oil (EVOO) denotes a high quality of oil, and in the case of extra virgin olive oil, refers to amount of free fatty acids, which is less than or equal to 0.8%. It has no defects, such as particulate matter, and has a fruity flavor.
• Refined olive oil, which has a free fatty acid content of 0.3% or less and is flavorless and odorless.
  • If a bottle is simply labeled Olive Oil, it means it is a lesser quality olive oil, which has been refined and then blended with 5% to 15% extra virgin or virgin olive oil.
  • Pure and Light olive oils are labels indicating that the oil has undergone refining and is blended with a small quantity of extra virgin or virgin olive oil. “Light” or “Extra Light” olive oils have a milder taste, scent, and often a lighter color compared to extra virgin olive oil, yet their calorie content remains unchanged.

The University Institute of Research on Olive and Olive Oils (INUO) states that, “The EVOO (Extra Virgin Olive Oil) organic production model might be the most sustainable, as long as it uses short distribution channels. However, organic production alone does not guarantee sustainable. Sustainable olive and olive oil production involves: improving the structural and nutritional quality  of the soil; reducing dependence on external chemical inputs; increasing the agroecosystem’s biodiversity and landscape quality; integrating practices and technologies to reduce energy consumption and waste generation (which will enhance the sector’s medium-and long-term profitability).” 

Olive oil certifications

Go Green: Organic, cold-pressed olive oil; locally-produced if possible

Be sure to read the bottles to ensure that your olive oil is coming from a reputable source that consistently passes testing.

Olive oils labeled as extra virgin have a history of being adulterated with cheaper seed oils like canola, hazelnut, or refined olive oil. In 2010, UC Davis conducted a study where they tested 14 imported olive oil brand and 5 California brands. 69% of imported olive oil samples and 10% of California olive oil samples labeled as extra virgin olive oil failed to meet the IOC/USDA sensory (organoleptic) standards for extra virgin olive oil. Then in 2015, the National Consumers League (NCL) tested 11 different olive oils from 4 different retailers, and only five of them met the standards that classify them as extra virgin. Even as recently as December 2023, CNN reported large-scale fraudulent labeling.

Look for the harvest date on bottles, as EVOO is best consumed within two years of harvest. This date is typically not going to be found on grocery store olive oils, as they most likey have a blend of oils from various locations. Also look for EVOO bottled in dark glass or tin; clear glass will go rancid faster. Plastic should also be avoided because it’s plastic, and also plastic bottles are not airtight and oils stored inside will oxidize and degrade faster than glass or tin. A strong, unpleasant odor that smells ‘off’ is the best sign that EVOO has gone rancid.

Palm oil

Palm oil is considered healthier than palm kernel oil due to its lower saturated fat content and higher levels of antioxidant activity, attributed to its considerable vitamin E content. Additionally, palm kernel oil, which is extracted from the seeds, cannot be produced organically.

Palm oil is approximately 50% saturated fat, including palmitic acid, which has a controversial role in cardiovascular disease. The remaining oil composition is 40% monounsaturated fat, and 10% polyunsaturated fats.

Environmental impact of palm oil

Palm oil has developed a bad reputation, and deservedly so. The farming practices used to produce this oil are largely damaging to the environment and often exploitative to workers.

One of the biggest sources of GHG emissions from palm oil production is the palm oil mill effluent (POME), the wastewater produced during the oil pressing stages. For every metric ton of palm oil produced, 2.5 metric tons of POME is generated, which releases huge amounts of methane. There is potential to capture and use this gas as a source of energy, however most palm oil processing mills have yet to adopt this technology.

Last, but definitely not least, the Associated Press investigated rampant exploitation of workers in the palm oil industry. These include people like women, children, and migrant workers who are subjected to horrific conditions, including trafficking, forced labor, child labor, dangerous and difficult working conditions, beatings, sexual assault, and more.

Learn more about the palm oil industry in this Bloomberg article.

Why to not boycott palm oil

Despite the numerous ills of palm oil production, there are still significant positives to consider.

According to the World Wildlife Fund, boycotting palm oil could create worse consequences by taking support away from the producers that are working hard to operate responsibly and ethically. It could also potentially encourage other companies to utilize other oils that actually might have more negative impact on the environment.

Go Green: Sustainably certified palm oil

Palm oil can be produced sustainably and ethically. Look for the RSPO Certified or the Palm Done Right labels to ensure you purchase products made with certified sustainable palm oil. This label verifies that the palm oil was produced in a socially and environmentally responsible way.

• Nutiva Organic Red Palm Oil – (CURRENTLY UNAVAILABLE) USDA organic, non-GMO, Fair for Life certified. Sourced from small organic and fair trade certified family farms in Ecuador. Through a partnership with Natural Habitats, Nutiva supports local environmental and community efforts with Palm Done Right. Buy at Whole Foods / Amazon

Peanut oil

Pros

• Peanut oil has one of the highest monounsaturated fat contents among cooking oils
• High in protein, vitamin E, and phytosterols
• Does not absorb food flavors and has a high smoke point.
• Like other legumes, peanuts are a nitrogen-fixing plant, which means they have the ability to restore nutrient depleted soils, and require little fertilizer to grow.
• Peanut plants have a significant root system which can reach more than two meters deep, reducing the need for irrigation.

Cons

• High in omega-6 fatty acids
• Higher risk of oxidation than other cooking oils, where exposure to heat, air, sunlight or moisture can cause harmful compounds, including free radicals, to form.

Go Green

• Spectrum Organics Peanut Oil – expeller-pressed, unrefined, non-GMO. Buy at Whole Foods
• La Tourangelle Roasted Peanut Oil – non-GMO. Buy at Amazon

Sesame oil

A staple of Asian cooking, sesame oil is one of my personal favorite flavors. The largest producers of sesame in the world are Sudan, India, Myanmar and Tanzania. In the United States, production is mostly limited to Texas and Oklahoma. The country consumes twice as much as is produced nationally. Sesame oil is extracted by mechanical expeller and has a low tolerance of heat by the extraction process. Oil made from toasted sesame seeds is used to add flavor to dishes but is not good for frying; cold-pressed sesame oil is a better choice for this purpose.

Go Green: Cold-pressed sesame oil

• Spectrum Organic Sesame Oil, Unrefined – USDA organic, non-GMO; toasted and refined options also available. Buy at Amazon / Whole Foods
• La Tourangelle Toasted Sesame Oil – non-GMO, expeller-pressed. Buy at Amazon / Whole Foods

Soybean oil

Pros

• Mostly consists of polyunsaturated fat
• High in Vitamin K, which supports bone health
• Contains omega-3
• Versatile, high smoke point
• Efficient crop yield per hectare

Cons:

• Rich in omega-6
• Land for soybean cultivation in South America has grown from the equivalent size of Washington state to the approximate size of California. To accomodate for this, deforestation has become the prime tactic and has grown into a significant environmental issue. Soybean farming, along with other oilseeds, are the second leading cause of deforestation in the world after beef, especially in South America. This leads to loss of habitat, land degradation, and displacement of indigineous people.

Go Green: U.S. produced organic soybean oil

• Shay and Company organic, non-GMO certified soybean oil; produced in US
• US Organic certified organic soybean oil

Sunflower oil

Pros

• All parts of sunflowers can be used: for every 100 pounds of sunflower seeds, about 40 pounds of oil, 35 pounds of high-protein meal, and 20-25 pounds of other by-products are produced. For example, the petals of the sunflower are also edible.
• Sunflower plants are relatively tolerant to drought and are good pollinator plants.
• Sunflowers produce substances that directly impact the growth of surrounding plants, which naturally suppresses weed growth and decreases the need for herbicides.
• High in unsaturated fats and Vitamin E

Cons

• High linoleic sunflower oil is very high in omega-6 fats
• Some studies have found that regardless of cooking method, but especially at high heat, sunflower oil releases a higher amount of aldehydes in cooking fumes than other oils. These toxic chemicals that can damage DNA and cells and lead to conditions like Alzheimers, heart disease, and cancer.

Go Green: Organic, non-GMO high oleic sunflower oil

• La Tourangelle Organic High Oleic Sunflower Oil – non-GMO, expeller-pressed. Buy at Amazon / Whole Foods
• Spectrum Organics Refined Organic Sunflower Oil – non-GMO, expeller-pressed. Buy at Amazon

Vegetable oil

Most vegetable oils on the market are a blend of canola, corn, soybean, safflower, palm and sunflower oils. Vegetable oils are refined and processed, which means they not only lack flavor, but also nutrients. According to Lisa Howard, author of The Big Book of Healthy Cooking Oils, “Vegetable oil is guaranteed to be highly processed. It’s called ‘vegetable’ so that the manufacturers can substitute whatever commodity oil they want—soy, corn, cottonseed, canola—without having to print a new label.”

Go Green: Opt for healthier pure oils

Alternative oils

Zero Acre Oil

Launched in August 2022, Zero Acre Oil is a promising sustainable cooking oil. It is produced from sugarcane (a perennial crop) grown in South America, where it is irrigated from only rainfall. According to the company, this crop uses 99% less water than olive oil and 87% less land than canola oil.

After being harvested, the raw sugar is fermented, where all the sugar is naturally broken down and converted into oil– the same process that converts sugar into alcohol to make beer or wine. The resulting oil is then the oil is expeller-pressed, purified and tested for freshness and quality.

This oil has a very healthy profile, containing an impressive 90-94% monounsaturated fat, and less than 4% polyunsaturated (including less than 3% omega-6 linoleic acid) and saturated fat. It also contains significant levels of antioxidants. The oil has a high smoke point and a neutral flavor and can be used in place of any other liquid oil.

According to the company, their oil is vegan, keto, kosher, Whole30 Approved, gluten-free, soy-free, nut-free, allergen-free, pesticide-free, Glyphosate Residue Free certified, non-GMO, and deforestation-free. It is packaged in a recyclable aluminum bottle that protects the oil from light.

Many in the food industry have become fans of Zero Acre oil, from fast food chain Shake Shack to chefs at Michelin-starred restaurants. At this point the oil is only available from their website, and is a pricey at $26.99 for a 16oz bottle.

Algae Cooking Club

The Algae Cooking Club utilizes microalgae, which is comprised of single-cell organisms, to create their cooking oil. The algae is fermented and fed sugar, which it converts into oil. When the algae has grown to 80% oil by weight, it is then expeller pressed. There is no need to continually harvest algae; the fermentation process is similar to that of beer or wine, and the company compares it to having a sourdough starter, once you have it you can keep gorwing and using it. Algae Cooking Club report that their process creates about half of the carbon emissions as olive oil, uses a fraction of the water, and has a much higher yield per hectare.

The algae oil contains 93% monounsaturated fats and low concentration of omega-6. It has a neutral, “slightly buttery” flavor and a high smoke point. It is packaged in an aluminum bottle.

Unfortunately, I can’t find any information as to where the sugar that feeds the algae is sourced.

Read more about this company as profiled in Forbes and Food & Wine.

Other oils

Some oils have a low smoke point and should be reserved for salad dressings and other uses, not for cooking. These include flaxseed oil, hempseed oil, and walnut oil.

Best sustainable cooking oil choices

I am not a chef or nutritionist, but based on what I have learned, these are the sustainable cooking oils I have determined are the best choices for me. I feel these versatile choices are healthy and sustainable.

Best oil for high heat cooking: Cold-pressed grapeseed oil

Best oil for moderate heat: EVOO

Best oil for salad dressing: EVOO

Best budget oil: Organic canola oil

Best oil for baking: Organic canola oil

Best oil for deep frying: Organic canola oil

Cooking Spray

Cans of cooking spray are convenient, but completely unnecessary and even unhealthy. Why?

First of all, most cooking sprays contain more ingredients than simply cooking oil. Ever feel like cooking spray has a chemical taste? Here’s why.

Soy lethicin, which is a product extracted from soybeans. It is an emulsifier, used to prevent oil and water from separating, and to keep materials from sticking to each other.

Dimethyl silicone is a synthetic oil derived from silicone. In cooking spray, it is used as an anti-foaming ingredient that ensures fats and oils do do not foam and/or spatter during cooking.

Propellants, which are pressurized gas that is used to dispense the oil from the can when the pressure is released. Commonly used gases in propellants include butane and propane. Flammable? Yes. Healthy? Well…

Cooking oil in spray form is also much more expensive than buying it in a bottle. Below are examples of the cost differences in several types of oils. I randomly chose Kroger as a national brand example.

Besides the additives and the cost, buying cooking spray creates more packaging waste. While a metal cooking spray bottle can and should be recycled once completely emptied, purchasing a larger bottle of liquid oil to use for cooking as well as spraying makes one less bottle. Buy an non-aerosolized oil sprayer or mister such as a stainless steel Misto sprayer or this glass Puzmug sprayer that I have and love. Fill with your cooking oil of choice and you have an cooking spray free of additives, housed in a reusable vessel. Even simpler is to pour some oil directly into your pan or onto on a paper towel to grease your pan.

Cooking Fats

Solid fats are in a solid state because they contain a high amount of saturated fats. Natural plant oils such as coconut and palm oil are semi-solid or solid at room temperature, whereas dairy-based fats become solid through churning. To transform liquid vegetable or seed oils into solid fats, they undergo a process called hydrogenation, where hydrogen is added to liquid oil, altering its chemical structure from liquid to solid. This extends the shelf life of the oil, as unsaturated fatty acids are more susceptible to becoming rancid. It also enhances taste and texture. However, this process generates trans fats, known to have detrimental health effects, especially raising blood cholesterol.

Small amounts of trans fats occur naturally in meat and dairy products. Partially hydrogenated oils were the main dietary source of artificial trans fats until the FDA determined that they were not Generally Recognized as Safe (GRAS) and mandated their removal from processed foods by 2018. Regardless of whether trans fats are present, hydrogenated oils should be avoided, and consumption of saturated fats minimized.

Butter

Go Green: Minimize butter consumption; buy organic, ethically-produced butter

If you’re not quite ready to kick the butter habit, or for those foods where a butter substitute won’t cut it, make sure you are buying butter from ethical dairy producers. Local is best if available to you, as small farms are much easier to verify animal care practices.

• Straus Family Creamery Organic Butter – This USDA Organic European style butter boasts 85% fat, which makes for good baking. The wraps are paper based rather than plastic. The California-based company employs numerous green practices, including a biodigester that converts methane from manure into biogas that provides power for operations.
• Horizon Organic Butter – Cows are fed a non-GMO, all-organic diet, grazing on pasture at least 120 days per year. The company is a Certified B Corp; products are USDA Organic.
• Maple Hill Creamery Organic Butter – Cows at this New York dairy farm are 100% grassfed year-round. USDA Organic.
• Organic Valley Butter – USDA Organic Non-GMO butter comes from cows who, according to the company, average 50% more time on pasture than USDA Organic standards require. All facilities source energy from 100% renewable energy.

Go Green: Plant-based butter

As previously stated, plant-based butters create significantly less GHG emissions and require less water and land than traditional butter. However, you need to be aware of what plant oils are being used. Many contain palm oil and soy, which have their own serious environmental implications, as detailed in earlier sections. In addition, vegan butter is often highly processed and usually contains additives for texture, color, or flavor.

Since these butter alternatives are plant-based, they contain much less saturated fat than butter, no cholesterol, and are higher in monounsaturated and polyunsaturated fats. But they may be higher in omega 6 and contain less essential nutrients due to their processing. Look for products that are low in highly refined oils and free of artificial preservatives, colorings, and flavors.

I have yet to try any plant-based butter substitutes, so I can’t personally attest to flavor or performance, especially in baking.

• MiYOKO’S Creamery Plant Milk Butter – this highly rated plant butter is made with USDA Organic cashew milk and coconut oil, which of course won’t work for those with allergies. It is free of soy and palm oil. The company is a Certified B Corp.
• Flora Plant Butter – Made with RSPO palm kernel and palm oil, this is a non-GMO, vegan butter that is free from soy and artificial flavors and preservatives.

Margarine

Margarine is composed of either animal or plant-based fats. Most commonly, it is made with vegetable oils, such as soybean, corn, palm, canola, or olive oils. Some, but not all, margarines are vegan–if you desire vegan margarine, look-out for animal-based ingredients such as suet, whey, lactose, buttermilk, and casein. The sustainability of margarine largely depends on the plant oil used and sourcing practices. Again, you don’t necessary need to avoid palm oil altogether if you can find it certified sustainable, but this is a difficult task (I haven’t found any).

In its natural form, margarine is white, but dyed yellow for a more appetizing butter-like appearance, usually with beta carotene, a natural pigment found in plants such as carrots. Most margarines also contain other additives and preservatives.

Traditional margarine’s fat content primarily consists of polyunsaturated and monounsaturated fatty acids, which vary based on the types of oils used in its manufacturing process. Although margarine contains lower levels of saturated fatty acids compared to butter, it lacks the beneficial saturated fats found in butter, such as butyric acid and myristic acid. Margarine only contains a trace of cholesterol from dairy milk solids.

The consistency of margarine is an indicator of its hydrogenated fat content: the firmer it is, the more hydrogenated fat it contains; conversely, softer or more liquid forms of margarine contain less hydrogenated fat. Tub margarines and spreads are partially hydrogenated and tend to incorporate more water or liquid vegetable oil into their composition.

Vegetable oil spreads that resemble margarine can vary significantly in fat content, ranging from 10% to 90%. This variance can have a considerable impact on the outcome of your baking. Some of these spreads, which may not meet the criteria to be labeled as margarine, include phytosterols. These natural compounds found in plants mimic the function of sterols in the human body. Consuming phytosterols in the amounts recommended on product labels has been demonstrated to lower LDL cholesterol levels.

Go Green: Plant-based margarine

See plant-based butter above.

Ghee

Typically made from cow’s milk (and therefore not vegan, as commonly believed), ghee is a type of butter that has been clarified. In this process, butter is heated in order to evaporate water content. Milk solids separate from the liquid and are removed, resulting in less dairy proteins, such as casein, and lactose. Thus, it serves as a potential alternative for individuals who have trouble digesting dairy products. The result is a more concentrated fat with a stronger, nuttier flavor and a darker color.

The nutritional profile of ghee very similar to butter but is slightly higher in calories and saturated fat, therefore should be consumed in moderation. It does contain Vitamin A and is high in omega-3. Both Healthline and the Cleveland Clinic both report that there are no health advantages in ghee versus butter.

Ghee has a higher smoke point than butter so it is best suited for frying, while butter remains the better option for baking.

As far as sustainability, ghee can be a good choice with responsibly-sourced dairy, and can easily be made at home with unsalted butter. However, while not having nearly the environmental impact of beef, the dairy cattle industry is also responsible for GHG emissions and deforestation.

• Ancient Organics Ghee – USDA Organic. Milk is sourced from Straus Family Creamery in northern California. The cows are pastured and grass-fed year round. Buy at Amazon / Whole Foods
• Spring Sunrise Organic Grass Fed Ghee – USDA Organic, certified kosher. Cows their Iowa farm have access to pastures and naturally growing coastal grasses at least 10 months per year, more than 19 hours per day. Ghee is produced in a solar-powered kitchen. The company also offers cultured, basil, or brown butter ghee. Buy at Amazon
• Pure Indian Foods Ghee – USDA Organic. Milk is sourced from grassfed cows on small family farms in the Northeast USA, California and New Zealand. The ghee is small-batch processed and has been handmade since 1889 by 5th Generation Ghee Makers. Buy at Amazon

There are dairy-free ghee options available. Just make sure to pay attention to the plant oils used; palm oil is often an ingredient because it is solid at room temperature and doesn’t contain trans fats.

• Nutiva Organic Plant-Based Ghee – USDA organic, non-GMO, certified vegan. Composed of a blend of avocado and coconut oils with turmeric added for color. (CURRENTLY UNAVAILABLE)

Vegetable shortening

Shortening is technically any fat that is solid at room temperature; this includes lard and margarine. Vegetable shortenings are usually made from hydrogenated or partially hydrogenated vegetable oils like soybean, cottonseed, or palm oil. It has a neutral flavor and has a higher melting point than lard or butter. Make sure to choose shortening made with sustainably-sourced oils.

Go Green: Skip the Crisco

If you bake, you more than likely have the iconic blue can in your pantry. But Crisco is comprised of a blend of fully hydrogenated palm oil (which is not RSPO certified) and soybean oil, along with a couple additives.

Instead, ditch the classic blue can and switch to Spectrum Organics Organic All Vegetable Shortening, made with only one ingredient: RSPO certified palm oil. It does not contain hydrogenated oils or trans fats. It is also USDA Organic, non-GMO, Rainforest Alliance certified, and Fair Trade certified. Buy at Amazon / Whole Foods

Animal fats

The ethics and eco-friendliness of animal fats can vary depending on factors including animal welfare and processing. Products from pasture-raised animals that are allowed to roam freely and are fed a natural diet are generally considered more ethical. Additionally, fats like lard and tallow can be seen as eco-friendly since they are a byproduct of meat production, utilizing parts of the animal that might otherwise go to waste.

Unprocessed, non-hydrogenated animal fats may also be considered cleaner as they are more natural than refined oils. They do contain small amounts of naturally-occuring trans fats.

Like all meat products, they are best sourced locally when possible to support nearby farms and ranches. In addition, it is easier to verify animal welfare practices in smaller operations.

Bacon fat

Lard

Lard comes from pork fat that is cooked slowly, or rendered, until the fat is melted. Processed lard is filtered, followed by full hydrogenation to make it shelf-stable without the need for refrigeration. It may also be bleached, deodorized, emulsified, or treated with antioxidants. This comes with potential downsides, such as the inclusion of trans fats and various additives, making it important to scrutinize the packaging labels.

Leaf lard is the highest quality of lard. Supermarket lard is mostly rendered from a mixture of high- and low-quality lards.

Tallow

Like lard, tallow comes from rendered fat found in cow’s, often called suet. It can also come from other animals such as mutton, bison, or venison.

Clean, ethical animal fat brands

• Fatworks – Fats are not processed, smoked, hydrogenated or otherwise altered in anyway. Animals are all pasture-raised and free of antibiotics and hormones.
• Epic Provisions – Beef tallow comes from 100% grass-fed cows, and pork lard is 100% organic. A cornerstone of the company’s values is holistic land management.

Cooking oil disposal

Now that you’ve chosen your sustainable cooking oils and used them to prepare a world class meal, are you wondering what to do with used cooking oil?

You may reuse cooking oil once or twice if you use cheesecloth to strain food particles from it. Place it in an airtight container in a cool, dark place or freeze it.

Disposing of cooking oil properly is an important aspect of using these oils. Do not pour oil down the sink or toilet as it can congeal in pipes, damaging plumbing or causing clogs in your home or even the main sewer line. Grease accumulation is responsible for almost half of sewer backups in the U.S.

Used cooking oil is not biodegradable and should not be added to a compost bin or pile.

Collect oil in a large can or jar under the sink and recycle it, if available in your area. Cooking oil can be converted into biodiesel. Many restaurants recycle their cooking oil, and if your municipality does not provide this service for residential use, you might find a friendly restaurant that will accept your used fat and include it with their oil recycling. If there is an anaerobic food digester nearby, that is another option.

If these options are not possible, put completely cooled oil into a sealed non-recyclable container and throw it in the trash. Do not add hot oil as it may melt containers or attract insects or pests to your trash. You may also add the oil to absorbent materials like sand, flour, or cat litter.