Part 1: Swallow This - Oil

This is part 1 in a blog series looking at one of my favourite books ‘Swallow This’ by Joanna Blythman. I’m a massive fan of her work, as an award-winning food investigative journalist, having read three of her seven books and most of her articles for the guardian. Joanna is one of my respected and go to sources for info especially on the subject of industrial food processing.

Part 1 of this series is looking at the subject of oil, an area which still has a few health conscious people confused.

So quick history recap, around the 1950’s the arch enemy and scapegoat in the food industry was the named and shamed saturated fat. Blamed for obesity, heart disease, and stroke. The script went as follows, ‘Hard Fats = bad fats and Liquid Oils = good fats.’ However, some people where left scratching their heads as to how ‘mother nature had created such deviant fats to shorten the life expectancy of the human race, and how could natural fats like butter, ghee, dripping, suet, lard, chicken, goose, palm and coconut fat that had sustained populations for centuries, suddenly be so bad for us.’

Anyway, the food industries and manufacturers bought into it and ‘switched to oils rich in polyunsaturates like corn, soy, safflower, sunflower and oilseed rape’, which did them a favour and still does, as they are much cheaper than saturated fats. However, there was a downside to the switch, in that, ‘saturated fats, which are stable at room temperature, keep reasonably well, and are fairly tolerant of being heated, whereas polyunsaturated oils are highly susceptible to deterioration. Light and heat have a devastating impact on their more sensitive chemical structure.’  As one oil company executive explains: “If you heat it up, then you degrade it and create much more reactive substances than monounsaturated {the predominant fat in olive oil and many meats} or saturated fat.

‘In an attempt to make polyunsaturated-rich oils more stable, oil suppliers adopted a technique known as hydrogenation, which had been developed for hardening soaps. Liquid oils were heated and combined with hydrogen atoms using a nickel catalyst. These oils, referred to as partially hydrogenated, act as a preservative, giving products a longer shelf life. These partially hydrogenated vegetable oils and fats became the mainstay of the processed food industry, for everything from margarine, salad dressings, and sauces to pre-cooked chips, chicken nuggets, crisps and fish fingers.’
Even local chip shops were making the switch, often advertising in the windows that they now fry in vegetable oils, instead of beef dripping.

It was the 1990’s when it emerged that hydrogenation caused the deadly trans fats. These really did cause heart disease, stroke, type 2 diabetes. The food industry went into denial and hoped the issue would blow over, it didn’t, and it was ‘2002, when the US government acknowledged for the first time that there was no safe level of trans fats, and that people should eat as little of it as possible.

By 2006, it was mandatory to list trans fats on US food labels. In the UK, the FSA (Food Standards Agency) took no such action, justifying its inaction on the basis that manufacturers were voluntarily removing trans fats from their products.’ It’s funny because, us lot, here in England short-sightedly think that it’s the American’s that have the dodgy and sneaky food products and agencies – but as you will see from my blog series, that often isn’t the case.

Trans fats still though linger on in products such as crackers, biscuits, cakes, frozen pies and pizzas, microwave popcorn, coffee creamers, ready to use frostings etc.
So, with hydrogenated oils now joining the banned list with sat fats, what do the manufacturers do?... They still use polyunsaturated oils, but now choose unhardened, non-hydrogenated ones. As one oil executive says ‘The biggest issue in frying today is the incorrect use of polyunsaturated oil for deep fat frying. It’s pretty cheap. The downside is-and people don’t realise it, is that it goes off faster (than unsaturated fat).'
When polyunsaturated oil degrades it develops a distinctive taste and aroma that oil experts refer to as ‘fishy’. If you have ever reheated deep-fried factory foods that description might evoke some memories.

The next problem is that they build up as gunk, or the technical term, is polymerisation. This leaves ‘a sticky, varnish like deposit on everything around – walls, work surfaces, utensils, workers’ hair and clothing.’

A further problem is aldehydes, the reactive breakdown products from polyunsaturated fats, recently been thought to be responsible for several diseases, such as cancer, Alzheimer’s and Parkinson’s. We can ingest aldehydes either directly from the degraded oils by inhalation or by eating foods fried at high temperatures.

So what next, well oil suppliers trying to stay out of trouble are now marketing a new batch of polyunsaturated oils – that are meant to be healthier than their previous types. These new ones are ‘high in oleic fatty acids, also known as omega-9s (the dominant fat in olive oil) and lower in linolenic acid. The latter has the bad habit of decomposing during deep frying into acrolein, a pungent, possible carcinogenic aldehyde compound that irritates the eyes and respiratory tract.’

So surely a cooking oil that mimics or is olive oil, is the answer?! Sadly not. The oleic oil in olive oil is perfect when drizzled on a salad, but behaves completely differently when heated up or deep fat fried. ‘To be specific, it produces oxidised monomeric triglycerides – that are absorbed in the human stomach and intestinal tract. These have been linked to cardiovascular disease and type 2 diabetes.
Any oil, however virgin and healthy at the outset, will come a cropper with overheating, and this is true whether you are frying in a domestic kitchen, a takeaway, or in a factory. The longer the oil is in use, the greater the presence of the undesirable breakdown products. On a factory scale, oils are used intensively over and over again, typically for anything from 7 to 12 days.

This is why oils destined for factory use and fast food need to be as hard as nails to withstand the commercial scale of deep frying. They are known as RBD, short for refined, bleached, and deodorised.
The process is as follows, ‘oil seeds are crushed, and the oil is extracted using solvents, usually hexane. More chemicals are used to remove most (although not all) of the solvents; residues do remain. By this point in the refining process, some gummy stuff will have appeared in the oil, so it needs to be degummed, with the aid of either acids or enzymes.
Hot by this point, the oil doesn’t smell so good and will have darkened in colour, so it then has to be bleached using clay. Then it must be deodorised, which means heating it to a very high temperature at least twice.
When we buy cheap refined vegetable oils for home cooking these are also RBD oils, but at least we don’t add anything further to them.
Next up, to get some longevity out of the RBD oils, manufacturers and fast food outlets add a number of improving agents that extend the ‘fry life’.
‘First on the list are citric acid, gallates, TBHQ (terbutylhydroquinone), which is also used in varnishes and resins, and BHA (butylated hydroxyanisole). The last item is anticipated to be a human carcinogen. It usually comes in a solution of propylene glycol (antifreeze), and is wonderfully user-friendly because it remains colourless even when heated at 194 degrees Celsius for one hour.
Next an antifoaming agent might be added, such as polydimethylsiloxane (a type of silicon) along with an anti-spattering agent, such as lecithin. An emulsifier, such as mono and diglycerides of fatty acids can also go in the blend. And mineral filters such as silica, bentonite and perlite to slow down the build up of tacky, sticky residue.’

So there’s more to cooking oil than you would think, yet none of it appears on the label of your finished fried product like tortilla chips, doughnuts, chips, chicken kiev's etc …..why? Because they count as processing aids, and not additives. And processing aids as horrible and dangerous as they are, don’t have to be labelled!

So whatever your choice of oil, extreme heat and length of time frying, create another well-documented health hazard: acrylamide. ‘This nerve poison causes cancer in animals and is classed by the US Environmental Protection Agency as a “probable carcinogen in humans”. In 2014, the European Food Safety Authority eventually concluded that acrylamide poses a bigger cancer risk to humans – particularly children – than it had previously thought. Crisps and chips have been identified as the biggest source of acrylamide in the British diet.
In 2013, Bradford-based researchers – part of an international team studying the diet of pregnant women and newborns – concluded that women who eat foods high in acrylamide during pregnancy are more likely to produce babies with lower birth weights and smaller head circumferences. British babies had the highest levels of acrylamide of all the five European centres studied, almost twice the level of Danish babies, largely because their mothers share the national fondness for deep fried chips and crisps.’ The wide-spread use of pre-fried oven chips do not escape the acrylamide saga, the key is in the name I just used… ‘pre-fried’ –  consumers often not aware when supposedly buying this healthier alternative. Which also highlights that a large proportion of acrylamide intake comes from industrially prepared food found in supermarkets – not just in your takeaways and fast food outlets.

Saturated fats are still on the naughty list and always will be, as Governments and Agencies regretfully hate putting their hands up and saying they got it wrong! Even though there’s the so called French paradox in which most of the French population eat a diet high in saturated fat, and have a low incidence of cardiovascular disease. Not to mention ‘over 72 academic studies involving more than 600,000 participants funded by the British Heart Foundation, that found that saturated fat consumption was not associated with coronary heart disease.’ The government is still trying to save face and plug cheap low fat alternatives, like margarine. A synthetic marriage of two cheap substances that don’t naturally combine together: Oil, refined and processed out of all recognition, and water. Forced together by emulsifying additives – ‘the resulting slippery sludge then needs to be coloured to be lifted out of a murky greyness, flavoured to help us actually swallow it, fortified with vitamins that it naturally lacks, and spiked with substances to stop it turning rancid.’

One simple experiment that has flooded the internet, is the reaction of ants to butter and margarine, and it’s a very telling experiment in the fact that ants are simple creatures, they seek out real nutritious food, and leave non-food items. When given the choice on a plate or on the floor, ants don’t go near margarine – not one single ant went rogue and decided to sniff out, eat or even go near the margarine!! Instead they swarmed over the butter, because its rich in natural vitamins and is a real, healthy food source.
Not to mention, when heating, saturated fats are incredibly stable and don't undergo the oxidation reaction that polyunsaturated oils do which produce the dangerous and carcinogenic aldehydes. 

Highly recommended purchasing 'Swallow This' by Joanna Blythman. It's so important to know the tricks and processes used on your food, to enhance flavour, look, texture, taste, and to extend shelf life.... Scary stuff!