Dangerous Oils: What Not to Use in Your Everyday Cooking

Why you need to avoid certain cooking oils

Certain cooking oils should be avoided because when repeatedly heated or used at high temperatures, they form harmful compounds like free radicals, aldehydes, and polycyclic aromatic hydrocarbons (PAHs). These substances are linked to several health problems, including oxidative stress, DNA damage, and increased risk of cancers, such as those affecting the lungs, colon, breast, and prostate.

The reason is not the oil itself, but rather what happens chemically during intense or repeated heating. When oils are heated, especially beyond their smoke point, reactive oxygen species and lipid oxidation products are created, which can damage tissues at the cellular level and may result in inflammation, compromised organ function, and higher cholesterol and glucose levels. Research also indicates that the fumes released from overheated oils are hazardous when inhaled, adding another layer of risk, particularly in indoor environments.

The Times of India lists cooking oils carrying potentially harmful substances

A recent report by The Times of India has raised serious concerns about the safety of everyday cooking oils used in Indian kitchens. The article highlights how several cooking oils may contain potentially harmful substances that pose health risks when consumed regularly. This revelation urges consumers to be more cautious and informed about the oils they choose for daily cooking.

Soybean Oil

Soybean oil is popular in many kitchens because it’s affordable and easy to use, but there are some serious health concerns to keep in mind. Most soybean oil comes from genetically modified soybeans and packs a lot of omega-6 fatty acids. While your body does need omega-6, too much can cause inflammation, especially since it’s so common in modern diets.

This oil also tends to break down when heated, which leads to the formation of harmful chemicals. The way soybean oil is made doesn’t help either, it’s often extracted using high heat and chemicals like hexane, raising even more questions about how healthy it really is.

Studies point out that eating a lot of soybean oil can lead to weight gain, higher blood sugar, and problems with insulin, which play a role in obesity and diabetes. In some cases, it can even cause more weight gain than a high-sugar diet. There are also concerns about its impact on gut health and increased inflammation throughout the body. So, despite its convenience, it’s wise to limit soybean oil in your cooking whenever possible.

Corn Oil

Corn oil is commonly found in many kitchens, but it comes with several health warnings. Experts say that consuming high amounts of corn oil—rich in omega-6 fatty acids but almost entirely lacking omega-3s—can promote inflammation in the body. Chronic inflammation is a known factor behind heart disease, obesity, diabetes, and even cancer.

Most corn oil on the market is extracted using chemical solvents like hexane and then goes through bleaching and deodorizing processes. These steps not only reduce the nutritional value of the oil but can also introduce potentially harmful chemicals. According to research from the Schulich School of Medicine & Dentistry, corn oil and safflower oil (both high in linoleic acid, a type of omega-6) do not show clear benefits for heart health in recent studies.

In summary, although corn oil is easy to find and use, it’s best to limit its consumption—especially if you aren’t balancing it with enough omega-3s from other foods—to protect your health.

Cottonseed Oil

Cottonseed oil is a highly debated cooking oil, in part because it comes from a plant that’s not typically grown for food and is often treated with pesticides. One of its main concerns is the natural presence of gossypol, a toxin that, if not removed during processing, can harm the reproductive system and liver, causing issues such as infertility, reduced sperm count, pregnancy problems, and liver damage when consumed in large amounts.

Refined cottonseed oil undergoes extensive processing to remove most of the gossypol, making it generally safe for consumption. However, unrefined or improperly treated cottonseed oil can carry health risks, as gossypol has been linked to toxicity in both animals and humans, with symptoms ranging from weight loss and poor appetite to severe reproductive and liver effects.

Additionally, cottonseed oil is high in polyunsaturated fats but also contains a notable amount of saturated fat, which may negatively impact cholesterol and heart health. While processing removes much of the gossypol, concerns remain about pesticide residues and the loss of beneficial nutrients during refining.

There are few benefits compared to other healthier oils, such as olive or avocado oil, and experts often recommend limiting or avoiding cottonseed oil because of its processing methods and potential residues.

Regular Refined Sunflower Oil

Regular refined sunflower oil is high in omega-6 fatty acids, which, when consumed in excess and especially without enough omega-3s, can drive inflammation in the body. This type of inflammation is a contributing factor to conditions like heart disease, diabetes, and certain cancers. While high-oleic sunflower oil (richer in monounsaturated fats) is more stable and considered healthier for cooking, many commonly available refined sunflower oils contain large amounts of polyunsaturated fats that oxidize easily at high temperatures.

Heating sunflower oil above its smoke point causes it to break down and produce toxic aldehydes and free radicals—compounds linked to increased risks of chronic illness, including inflammation, cancer, and heart disease.

Additionally, the refining process, which involves bleaching, deodorizing, and extraction with chemical solvents like hexane, can destroy beneficial nutrients and antioxidants naturally present in sunflower seeds. Some researchers also note that the routine use of refined oils is linked to higher rates of obesity and chronic diseases.

When considering sunflower oil for cooking, high-oleic, cold-pressed versions are a safer option, but it’s best to avoid overheating any oil to prevent the formation of harmful by-products.

Vegetable Oil

Despite the name, vegetable oil is not as healthy as it may sound. Most commercial vegetable oils are highly processed blends, often containing soybean, corn, cottonseed, or canola oil. The refining process introduces high amounts of trans fats and removes beneficial nutrients. When these oils are heated, especially for frying or repeated use, they break down and form toxic byproducts such as aldehydes and free radicals. These compounds are associated with cancer, inflammation, and DNA damage.

According to findings from the National Library of Medicine, repeatedly heating and consuming vegetable oil can elevate blood pressure and cholesterol, promote vascular inflammation, and induce changes in blood vessels that increase the risk of atherosclerosis. This strongly suggests that frequent use of processed vegetable oils can undermine heart health and increase the risk of chronic diseases.

What are the harmful effects of cooking oil?

Certain cooking oils, especially those that are refined, repeatedly heated, or used beyond their smoke point, can pose significant health risks. When oils are overheated, their chemical structure changes, leading to the creation of harmful substances like trans fats, free radicals, toxic aldehydes, and polycyclic aromatic hydrocarbons (PAHs). These compounds are linked to serious health problems, including:

Heart Disease and Stroke: Repeatedly using and overheating oils increases trans fats, which raise LDL (Bad) cholesterol, lower HDL (Good) cholesterol, and can harden the arteries, leading to high blood pressure, cardiovascular disease, and stroke.

Cancer: Overheating oils, especially beyond their smoke point, produces carcinogens like PAHs and harmful triglycerides, substantially raising cancer risk. The inhalation of fumes from overheated oils can also increase the risk of lung and respiratory cancers.

Inflammation and DNA Damage: Aldehydes and free radicals generated during overheating and repeated use of oil cause inflammation and cellular damage, both of which play roles in diseases like diabetes and cancer.

Respiratory Issues: Breathing in toxic fumes from overheated oil irritates the respiratory tract and over time can pose risks to lung health.

Increased Blood Pressure and Atherosclerosis: Frequent intake of oils that have been repeatedly heated can elevate blood pressure and total cholesterol, increasing the risk of vascular inflammation and atherosclerosis.

Loss of Nutritional Value: Heating beyond the smoke point destroys beneficial nutrients present in oils, including flavours, and adds bitterness.

To minimize these risks:

• Use oils suitable for your chosen cooking method and avoid overheating or reusing oils multiple times.
• Prefer cold-pressed or stable oils for high-heat cooking, and avoid ultra-processed or repeatedly heated oils.

Stop Reheating Oils

Reheating cooking oil multiple times causes serious health hazards. Each time oil is heated and cooled, it breaks down further, producing toxic compounds like aldehydes, acrolein, free radicals, and trans fats, all of which have been linked to an increased risk of cancer, cardiovascular disease, inflammation, and neurodegenerative disorders.

This process also depletes beneficial fatty acids and destroys natural antioxidants, dramatically lowering the nutritional value of the oil. Over time, reheated oil can become rancid, taste unpleasant, and release more harmful fumes that can irritate the digestive and respiratory system.

Medical experts and health authorities warn that repeatedly heated oil not only increases LDL (bad) cholesterol and promotes arterial plaque buildup but can also accelerate the development of chronic diseases, including diabetes and obesity. The Indian Council of Medical Research specifically cautions against reusing vegetable oils for frying due to the formation of harmful substances such as trans fats, acrylamide, and other toxins, which contribute to inflammation, vascular problems, and even liver damage.

For better health, it’s recommended to:

• Discard oil after frying rather than reusing it.
• Choose oils with high smoke points for cooking.
• Avoid consuming foods (especially fried) prepared with repeatedly used oil.

What’s the Solution?

Using cooking oils that contain unhealthy fats is not advisable. Highly processed oils can harm your health and tend to be nutrient-deficient. A healthier choice is to select cold-pressed cooking oils. These oils are extracted by mechanically pressing seeds or nuts under minimal heat, without the use of chemicals. As a result, cold-pressed oils better retain their nutritional value and natural properties compared to highly refined alternatives.

You might consider options like Jivo cold-pressed cooking oils, which are sources of healthy fats. Some varieties are fortified with vitamins and are lower in saturated fats than certain other oils, making them a more health-conscious choice.

Jivo’s Cold-Pressed Oils: A Closer Look

Jivo offers a variety of naturally cold-pressed oils that set themselves apart with their pureness, nutritional richness, and thoughtful extraction methods. Below, you’ll find quick insights into some of their core offerings, each with key details and bite-sized pointers for a clear, natural understanding.

1. Jivo Cold-Pressed Canola Oil

Jivo is the largest seller of cold-pressed canola oil in India. This oil is extracted gently by using mechanical cold-pressing method to ensure nutrition retention. It is known for its healthy ingredients, like omega-3 fatty acids and monounsaturated fats, which may help lower blood cholesterol levels if consumed in moderation.

• Low in Saturated Fat: Significantly less saturated “bad” fat than most other cooking oils, making it an excellent option for cardiovascular wellness.
• Rich in Omega-3 & Monounsaturated Fats: Provides a solid boost of heart-healthy fats while helping balance cholesterol levels.
• High Smoke Point: Suitable for all kinds of high-heat cooking, from frying to baking—without compromising on nutrition or taste.
• Natural Antioxidants: Contains vitamin E and other phytochemicals, supporting immune response and cellular repair.

2. Jivo Cold-Pressed Sunflower Oil

Nutrient-rich, Jivo cold-pressed sunflower oil preserves natural properties because it is extracted through mechanical pressing, avoiding chemical processing. Its light, neutral flavour and high content of healthy monounsaturated and polyunsaturated fats make it ideal for all kinds of cooking, from sautéing to salads.

• 100% Natural & Unrefined: Free from additives and retains more micronutrients, thanks to cold pressing.
• High in Vitamin E: Supports skin health and acts as a potent antioxidant.
• Light Texture: Makes dishes lighter and is easy to digest.
• Versatile for Cooking: Works well in sautéing, stir-frying, and salad dressings.

3. Jivo Cold-Pressed Groundnut Oil

Jivo Cold-Pressed Groundnut Oil is extracted through traditional cold-pressing method, ensuring the natural flavour, aroma, and nutrients of groundnuts remain intact. Rich in heart-healthy monounsaturated fats, it may help lower bad cholesterol and support overall health.

• Rich in Healthy Fats: High in monounsaturated fats, which boost heart health and aid nutrient absorption.
• Retention of Nutrients: The cold pressing preserves the benefits of fat-soluble vitamins like A, D, E, and K.
• Perfect for Indian Cooking: Supports high-temperature cooking and traditional flavors.
• Distinct Aroma: Adds a signature touch to a variety of recipes.

4. Jivo Cold-Pressed Soyabean Oil

Jivo Cold-Pressed Soyabean Oil is carefully extracted using a gentle cold-press method, allowing it to maintain its natural goodness and light, neutral flavour. Rich in plant-based nutrients and omega-3 fatty acids, this oil is a versatile companion for your everyday cooking.

• Rich in Omega-3 Fatty Acids: Helps reduce inflammation and supports heart health.
• Supports Blood Circulation: Noted benefits for cardiovascular function.
• Promotes Skin Health: Moisturizing and protective properties.
• High Smoking Point: Suitable for a variety of cooking styles.

5. Jivo Cold-Pressed Extra Virgin Olive Oil

Jivo Cold-Pressed Extra Virgin Olive Oil is produced from carefully selected olives using a gentle cold-press method to ensure maximum purity and nutrient retention. Its golden colour, fresh aroma, and distinctive fruity taste add a vibrant Mediterranean touch to salads, drizzles, dips, and dressings

• Cold-Pressed Extra Virgin: Maximizes flavour and antioxidants, perfect for dressings and finishing dishes.
• Extra Light Olive Oil: Subtle taste, excellent for high-heat cooking and when you want a lighter profile.
• Rich in Polyphenols: Naturally combats cell damage and supports inflammation control.