Is your cooking oil choice contributing to chronic inflammation?

It is interesting to see how the popularity of cooking oils has evolved over the years. It is hard to believe that in the 1970s, when vegetable oils were first hydrogenated, how coveted they were.

Today, we know that trans fats produced by hydrogenation are harmful for our health, hence we actively seek to avoid them. Yet what were once considered culinary villains, like ghee and coconut, have made a comeback and their virtues reconsidered. Right now, avocado, grapeseed and moringa oil are in vogue for some consumer groups, but their high cost acts as a deterrent for most shoppers. Hence, picking the right oil for cooking seems to be a dynamic process.

While we consider our choices, concerns around cooking oils, it seems, are here to stay. Excessive consumption of fats and oils and their links to obesity, diabetes and cardiovascular disease is very much a problem that we are all grappling with. As our understanding of chronic diseases grows, there is evidence to show that inflammation lies at the core of many of these ailments. Naturally, this directs our attention to cooking oils. In reality, oil is an omnipresent ingredient in our everyday life through all forms of food preparation.

The fact that chronic inflammation is often the associated with a raft of non-communicable diseases like autoimmune disease, strokes, heart disease, cancers, diabetes, chronic kidney disease, osteoarthritis, osteoporosis and Alzheimer's disease, many of the seed oils we consume extensively are often blamed for exacerbating chronic inflammation. Seed oils like soybean, sunflower and corn have a fatty acid composition which is very high in omega 6 fatty acids, hence considered pro-inflammatory. Such oils, when they form the bulk of the fat we consume in a day, enhance the inflammatory pathways in our body. A study linked a high soy oil diet to increased gut inflammation in mice, while some human studies found no significant correlation.

At present, the relationship between soy oil and inflammation remains complex and context dependent. This is why, in specific health conditions like Inflammatory Bowel Disease (IBD), high consumption of soy oil is not advisable. It is believed to promote the growth of harmful bacteria in the gut and promote inflammation. High omega 6 fatty acids present in seed oils such as soyabean have been linked to the increased risk of obesity, type 2 diabetes and cardiovascular disease. The advice is therefore to minimise the use of such pro-inflammatory oils.

It is also possible to maintain a favourable balance of fatty acids (omega 3 and omega 6) in our everyday diets by using two or more different kinds of oils in a day for food preparation. Adopting a complementary approach by using two-to-three oils helps to achieve an ideal fatty acid ratio. Not only is this beneficial for our health, but it also provides a variety of flavourings for our food. For example, a nutty taste can come from sesame or peanut oil, a fruity one from extra virgin olive oil, and a buttery one from avocado. There could also be times when one wants neutral oil which won't alter the taste of the dish, and here we might consider using grape seed oil or a deodorised palm oil.

Another aspect of fats and oils that is critical to their consumption, but often overlooked, is their smoking point. Many of the methods of cooking involve reaching high temperatures and this is why the smoke point of the oil that we use becomes important. Stable oil is needed for this purpose and many of the seed oils (soy, corn, sunflower, and safflower) are prone to oxidation at high heat. Hence the stability of the oil becomes valuable at high temperature cooking. This is why avocado oil or palm oil could be better suited for this purpose.

As each oil has a different smoke point, being aware of the smoke point of the oil being used is important. On reaching the smoke point, a breakdown of the chemical bonds happens in that particular oil, which can produce off-flavours and generation of harmful compounds. Being mindful of this aspect of cooking oils will lead you to choosing the best suited oil for the temperature and duration of heat needed for the cooking process of a particular dish.

(Neelanjana Singh, Dietitian/Nutritionist, member of Indian Dietetic Association)