Evolutionary Association, Chapter 7: Emulsifiers
Soap and detergent are emulsifiers. They dissolve fats in water, and that is what makes proper cleaning possible in the first place.
Emulsifiers have “always” been in use. They occur in nature too - and there in food as well - among other things for the very same purpose: joining water and fat/oil.
A nice example is mayonnaise: the oil and water it contains are combined with the help of the lecithin in the egg yolk. Hollandaise would be impossible without an emulsifier (classically, egg yolk again), and mustard is a standard ingredient in a vinaigrette, turning vinegar and oil into a salad dressing - without an emulsifier a vinaigrette would be plain “vinegar and oil”: two clearly distinguishable ingredients in your salad.
Nature also builds emulsifiers that were never meant for cooking, though: the saponins in quinoa and legumes are genuine soaps - when the water foams up as you rinse quinoa, you are watching them at work. The plant makes them for defence, not for whisking dressings, and they treat cell membranes correspondingly roughly. More on that in the overview of antinutrients.
More about Antinutrients - for example Saponins
Superfood or Antinutrient?
Foods praised for their ingredients often bring the antidote along too. How do antinutrients work? Can they be rendered harmless? A selection.
Read more →The Dietary Change
Since the industrial revolution - and especially since the invention of margarine(1) in the late 19th century - isolated and later synthesised emulsifiers came into deliberate use, and they are pretty much what made the mass production of ultra-processed convenience food possible in the first place.
And consumers ask for them - not for the emulsifiers, obviously, but for what they achieve, cheapen or simplify:
Emulsifiers improve the dough volume of baked goods, keep bread soft for longer and stop it going stale so quickly.
They prevent “fat bloom” - some readers will know it as the white coating on chocolate. Not very popular, but at the same time a sign of missing (or “too” little) added emulsifier. Incidentally, emulsifier in chocolate also raises the “melt factor” without the manufacturer having to raise the more expensive cocoa butter content. Bycatch or secondary objective? Lucrative either way.
In ice cream and margarine they provide the texture and prevent ice crystals (those would be frozen droplets of water that have come out of the emulsion), and ready-made sauces would be unsellable, because the ingredients would separate inside the packaging between production and purchase.
So emulsifiers are an important component of industrially produced food - and we can well imagine that a manufacturer would rather handle shelf-stable isolated powders (or however the ingredients arrive) than perishable egg yolk.
What makes them interesting for this series, though, is that something shifted along with them: how much of our food comes out of a factory, and how little out of a kitchen. And that has apparently not been without consequences.
The Phenomenon
In recent years emulsifiers - above all the synthetic ones, such as polysorbate 80 (E433) and carboxymethylcellulose (E466) - have come under increasing scrutiny from microbiome and gut research(2).
The reason is the study of damage to the intestinal lining: some emulsifiers appear to pass through the stomach unharmed and then start dissolving the protective layer (“mucus”). The plausible consequence goes by the name “leaky gut”, which sounds dramatic and is meant to. The undramatic reading would be “permeable gut”.
Which, well: the gut is explicitly permeable. Otherwise there wouldn’t be much happening in the way of nutrient absorption.
What is meant is permeability for everything that ought to stay outside(3). That has a habit of triggering silent systemic inflammation, and from there it is not too far a leap to the not-so-silent kind: the chronic inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis. Emulsifiers have even been linked to type 2 diabetes, metabolic syndrome and obesity.
The Biochemical Association
Let me return to the detergent: there are people who prefer to wear rubber gloves when washing up (quite apart from the fact that dishwashers are surely far more popular still), because detergent attacks the skin on prolonged contact. Food is in contact with the gut for hours, so that as many nutrients as possible can be absorbed. If the emulsifiers it contains cause an unintended permeability of the gut, then other particles (usually larger ones) - bacteria among them - get into the body, where they have no business being.
The rising numbers of inflammatory bowel disease have a plausible explanation in the rising use of emulsifiers - though that is certainly not the only plausible explanation. It is far from my intention to identify them as the clear - the sole - cause.
But surely there are limits
In the EU and elsewhere, food additives are studied rigorously and have to demonstrate that they are harmless. Because of how food law is written, this is often done through animal testing(5).
Limits based on such studies are typically set so that they lie orders of magnitude below any level of concern - so we ought to be safe. And indeed most people do not suffer from Crohn’s disease or ulcerative colitis.
Where the precautionary principle kicks in for me is the use in real life: even when the limits are observed, they apply in isolation, per group of additives. A combination with other substances - natural ones such as anti-nutrients or pollen, artificial ones such as preservatives - is generally not part of the investigation of the isolated additives.
A natural attacker: anti-nutrients
Foods praised for their ingredients often bring the antidote along too. How do antinutrients work? Can they be rendered harmless? A selection.
Read more →Everyone reacts differently to particular combinations - and if one substance can cause other, unwanted substances to be absorbed in greater quantity in the gut, then a substance whose limit is considered safe in isolation (preservatives again, say) may suddenly end up in the body in considerably larger amounts than intended.
The body’s immune system responds to such intruders - by way of systemic (low-grade) inflammation. That inflammation is a lifesaver against acute threats - but when it occurs across a wide area and over a long period (chronically), because the same substances are taken in regularly, I consider that worrying.
Sometimes it does not stop at inflammation. The immune system is trained to leave the body’s own tissue alone - good, but not infallible. If an intruder binds to the body’s own structures, the defences attack the complex and hit the body’s own tissue along with it. Collateral damage.
For some autoimmune diseases the trigger is known and can be removed - coeliac disease is the textbook case: a dietary protein, an autoimmune reaction, and peace as soon as it disappears from the plate. For others, Hashimoto’s or multiple sclerosis, the trigger is not known.
Whether emulsifiers play a part here, I don’t know. Only the first step is plausible: making the barrier more permeable increases the number of opportunities.
Another intruder: pollen
Personally, I have decided: soap goes into the pan for the cleaning - not during the cooking. That means I can’t help myself freely and uncritically in the supermarket - but I regard being able to avoid entire aisles and shelves as a gain in quality of life.
As set out in other articles here, my gut has not filed a complaint since. I take that as “five out of five stars: 🌟🌟🌟🌟🌟”. The highest rating I can get from that organ.
