Seed oils have become a disputed topic. While some critics, especially on social media, are calling them toxic, others say they are slowly killing you. Many are also of the opinion that they are contributing to the obesity epidemic and driving up rates of chronic diseases like cancer, heart disease and diabetes. Much of the recent criticism actually revolves around the omega-6 fatty acid content of seed oils, and the resultant inflammation. An ingredient that is otherwise staple in home kitchens and restaurants, and something that is considered affordable and easy to cook with, has suddenly become a focal point in public discourse. This leads us to the question – are seed oils really bad for you?
Moderation is key
For the average healthy individual, the risk of consuming seed oils, alongside other fat sources, is minimal, says Bhakti Samant, chief dietician at Kokilaben Dhirubhai Ambani Hospital, Mumbai. “The problem is more linked to how much and in what form they’re consumed rather than their mere presence in the diet,” he adds.
Samant further explains that seed oils like sunflower, soybean, canola, corn, and cottonseed oils are rich in polyunsaturated fatty acids (PUFAs), particularly omega-6 fatty acids. “In moderate amounts, these fats are essential for health, supporting brain function, hormone production, and cell structure,” he says. “However, the concern arises from excessive consumption, especially in diets already high in omega-6 and low in omega-3, which may promote inflammation,” he adds. Over-refining and repeated heating of seed oils can generate trans fats and oxidation by-products that may impact heart health and metabolic function, he says.
Ritika Samaddar, dietician and regional head, south zone, nutrition and dietetics, Max Super Speciality Hospital, New Delhi, breaks this down further. “The body needs omega-6 to omega-3 in the ratio of 5:1 to a maximum of 10:1. But a high intake of omega-6 rich oils can cause inflammation and is not heart friendly,” she adds.“When we talk about fat, the body needs all of them – saturated, poly and mono in the desired ratio of 1:1:1… Consuming too much of seed oils is a concern as it disrupts the ratio,” she adds.
Seed oils can turn out to be harmful, but only for those with already compromised immune systems. According to Samant, people with chronic inflammatory conditions – for example, rheumatoid arthritis or inflammatory bowel disease – may be more sensitive to an omega-6-heavy diet. “Those with cardiovascular risk factors might need to be mindful of oils high in omega-6 and low in omega-3; those with impaired liver function or fatty liver disease may process certain refined oils less efficiently; and finally infants and young children should not have diets dominated by seed oils, as they require a balanced fat profile for development,” he adds. “Heating and processing of poly unsaturated fats leads to change in composition and the production of trans fat, which is unhealthy, causing heart concerns, even cancers, besides disrupting the gut biosis,” explains Samaddar.
The right combination
Given that seed oils are such a common ingredient in so many preferred food items like packaged bakery items, fast foods, processed sauces and salad dressings, and more, it is difficult to
realistically cut them from a diet completely. More importantly, eliminating it from the diet is uncalled for if consumed in moderation by a healthy adult. Samaddar advises: “The right combination is to take some amount of ghee, couple it with the refined oil in moderation (cold pressed, if one can afford) and take nuts and seeds to get the right quality and quantity of fats.” “One could opt for either whole-food sources of healthy fats like nuts, seeds, olive oil, and fatty fish as they are linked to better health. Alternatively, one can use the cold pressed oils and limit ultra-processed food consumption as well, if they have preexisting health conditions and want to largely cut out seed oils from their diet,” says Samaddar.
Samant further suggests that instead of thinking of seed oils as safe or unsafe, one is better off considering how it is processed and how it can be balanced out. “Cold-pressed or expeller-pressed sesame, flaxseed, sunflower, and canola oil used sparingly are good choices for consumption, whereas highly refined and industrially processed seed oils, especially when repeatedly heated, can carry harmful side effects.” She, however, warns: “Cottonseed oil is controversial due to pesticide residues and natural toxins if not properly refined.”
She suggests a few ways in which public awareness can be increased on the use and functions of seed oils:
- Public health campaigns could highlight oil diversity-rotating between different types rather than relying solely on one
- Simple infographics explaining omega-6:omega-3 balance and cooking methods could be shared on social media
- Nutrition labels could indicate omega-6 content, similar to how sugar is listed
What research says
Seed oil consumption has been a hugely debated topic, with an outpouring of discussions on social media, given the rising awareness of ultra-processed foods, and the use of seed oils in them. Some oils have also been dubbed ‘the hateful eight’ by netizens, referring to a list of oils that are considered particularly harmful for health. These include soy oil, sunflower oil, canola oil, grapeseed oil, rice bran oil, corn oil, safflower oil and cottonseed oil.
The new discourses that are emerging now advise that the key lies in moderation in consumption rather than complete elimination of seed oils from diet, as that too may have detrimental effects on health. Experts from the Food Is Medicine Institute of the Tufts University, Massachusetts, US, have reportedly found in their research through controlled trials that all omega-6 fatty acids do not increase inflammation. In fact, “new research shows that omega-6 fatty acids give rise to unique natural molecules, like lipoxins, that have powerful anti-inflammatory effects in the body”, as per the Food Is Medicine Institute.
The World Cancer Research Fund (WCRF) has also published research to this effect, and also holds the opinion that these oils are versatile and budget-friendly. Most have a neutral flavour and a high smoke point, which makes them a safer and more reliable option for everyday cooking.The WCRF article further says that since seed oils are high in unsaturated fat and low in saturated fat, it makes them a healthier alternative to animal fats like butter and ghee.