‘Seed oils’ are refined oils used in cooking, including rapeseed oil – better known as canola oil in the US – as well as sunflower, safflower, grapeseed, sesame and peanut. Modern diets include more of them than ever before, as they are widely used in commercial kitchens (think restaurant and takeaway food) and in many of the processed and ultra-processed foods we buy in the supermarket.
Colorectal or bowel cancer is the third most common cause of cancer-related death in the UK, and among young people, rates are rising. From the early 1990s to 2018, the number of adults aged 25 to 49 diagnosed with bowel cancer in the UK increased by 22 per cent, leading a global trend. So it’s understandable that searching for a ‘cause’ is at the forefront of many minds.
Omega-6 fatty acids are also present in large amounts in, you guessed it, seed oils. The results of the study led its lead author, Professor Timothy Yeatman, to state that “a human’s immune system can be extremely powerful and drastically impact the tumour microenvironment, which is great if harnessed correctly for health and wellness, but not if it’s suppressed by inflammatory lipids from processed foods.
However, while what we eat does have a role in the production and growth of every cell in the body, the link established in this particular study is far from a direct one, says Dr Megan Rossi, a dietitian and postdoctoral research fellow at King’s College London.
square LIFESTYLE Couples TherapyMy lazy husband embarrasses me when we stay with my family
Read More
It’s also worth noting that Professor Yeatman pointed to ultra-processed foods (UPFs) – and the seed oils within UPFs specifically – as being a concern, rather than to seed oils alone.
Published in the Journal of Clinical Oncology, research by medics at the University of California Los Angeles showed that a diet low in omega-6 and high in omega-3 fatty acids, combined with fish oil supplements, significantly reduced the growth rate of prostate cancer cells in men with early stages of the disease. After a year, the group of patients on the high omega-3 diet had a 15 per cent decrease in a marker of cancer progression, while the control group – who had no changes to their diet – saw a 24 per cent increase.
“But it’s important to note that this study saw people take out a load of ultra-processed foods from their diets and increase the amount of healthful foods, including omega-3 supplementation. So more has changed than just the omega-6 to omega-3 ratio: the amount of fibre would have changed, the polyphenol [plant chemical] content would have changed, all the things that we know feed the microbiome, which then has a role in reducing inflammation, too.”
The fact is, we actually need omega-6 fatty acids in our diets – they are not something optional that we can completely erase. “The main omega-6 fatty acid is linoleic acid, and that’s an essential fatty acid – our bodies need it for certain metabolic functions,” explains Dr Rossi. “And when we’ve looked at studies supplementing with isolated linoleic acid, it doesn’t seem to have this inflammatory cascade at all.”
But there is an ideal ratio of omega-6 to omega-3, thought to be between 2:1 and 4:1, say the experts. The problem may be that we are now consuming omega-6s far in excess of this, with a typical Western diet seeing intakes of between 15:1 and 17:1.
Processed oat milks, ready meals, biscuits and even crackers and breads may all contain high levels of omega-6 fatty acids that if made from scratch, would contain none at all.
The thing is, unless we scrutinise the label of every processed food we eat, we’d never know.
“Is it just the omega-six to omega-3 ratio? Or is it the way those oils get processed and change during processing? Is it the fact that ultra-processed foods contain so many emulsifiers? Is it that they contain hardly any fibre, when fibre intake has been shown to greatly reduce the risk of bowel cancer? The take home for me is: remove or switch out these ultra-processed foods, which happen to have the seed oils in them, and eat more wholesome foods,” says Dr Rossi.
SO WHAT OILS SHOULD WE USE FOR COOKING OUR FOOD?
Different oils have different qualities, and choosing the right one depends on the intended purpose, says dietitian Nichola Ludlam-Raine, author of How Not To Eat Ultra-Processed. Alongside Dr Rossi, she says extra virgin olive oil – sometimes referred to as EVOO – is the number one oil most of us should choose for cooking and eating. “It’s great for dressings, drizzling, and low to medium-heat cooking, as it’s rich in monounsaturated fats and antioxidants. It’s a versatile oil that’s been well-studied for heart health benefits,” she says.
What you shouldn’t do, urges Dr Rossi, is what many seed oil detractors suggest – swap cooking with seed oils for cooking with animal fats such as butter.
“If you’re going to ditch seed oils for olive oil then I say great, go for it – it can only be beneficial for your health, whereas currently I would consider cooking with seed oils more of a ‘neutral’ health choice. But if you’re going to switch seed oils for drenching everything in butter, I’d be concerned. Consistently the evidence still shows that replacing butter or other saturated fats with seed oils – unsaturated and polyunsaturated fats – is better for reducing inflammation in your body, among other health benefits.”
Read More Details
Finally We wish PressBee provided you with enough information of ( The truth about cancer and cooking oils )
Also on site :