I suffered from chronic diarrhea for years which I attributed to Crohn's disease. This seemed obvious since diarrhea is a very common symptom of Crohn's, but its onset had been several years after I was diagnosed and prior to that I had tended more towards the opposite problem (constipation). I was thus always suspicious that the root cause lay elsewhere. After much experimenting I found that if I ran my dishwasher through an extra rinse cycle the diarrhea went away.

I tried many different detergents but never found one which didn't cause problems, so I've just continued to run an extra cycle. My GI doctor didn't really believe me when I told him. I wonder how many people are having their IBS/IBD symptoms exasperated by detergent residue left on their dishes.

Ironically, the summary isn't as good as the "Key Messages" section at the bottom:

> * Professional dishwasher rinse aid causes cellular cytotoxicity and directly impaired barrier integrity of gut epithelial cells by damaging TJ and AJ expressions in daily exposed concentrations. > * The underlying mechanisms of epithelial barrier disruption in response to rinse aid were cell death in 1:10,000 dilutions and epithelial barrier opening in 1:40,000 dilutions. > * The alcohol ethoxylates, an ingredient of the rinse aid that remains on washed dishware, caused the gut epithelial inflammation and barrier damage.

It appears to be the rinse aid when used in professional dishwashers utilized in restaurants, etc, due to high concentration of the rinse aid contaminating the "clean" dishes.

Rinse aid is completely unneeded if you properly maintain and use your dishwasher.

I never use any, and my dishes are completely spotless. 30 years old dishwasher, super hard water.

Specifically, you should:

- always fill the salt of the dishwasher's water softener once it's empty. It cannot soften the water if it doesn't get cleaned by the salt. If the water is not softened you will get spots. EDIT: Apparently US folks often have dishwashers which don't soften the water. Ugh. In Europe I haven't even heard that such a thing exists! :|

- configure the dishwasher to your water hardness.

- do NOT use detergent which is advertised as "you won't need salt". This is garbage for lazy people. It cannot properly replace the water softener. Think about it for a moment: The detergent is meant to fully dissolve during washing so you won't have it on your dishes after the final water cycle. The only way it could affect the softness of the water in the final cycle is if it did NOT fully dissolve in time. So there are two factors to be optimized which contradict - stay long enough to soften the water, but not long enough to leave remainders on the dishes. It will never work properly.

- This is not related to rinse aid, but you should know it: Clean the sieve regularly, at least every week. It will get ultra nasty with gunk if you don't. If you have no time for cleaning it, buy a second one, switch them once one is dirty and put it among the dishes so the dishwasher washes it like a dish.

The news around this, this thread, and similar on Reddit seem to be assuming a jump that isn't supported in this paper.

  "The residue remaining after the rinse cycle varies between 1:250 to 1:667 for the dishwasher detergent and 1:2,000 to 1:10,000 dilutions for the rinse aid."
This is actually an uncited claim in the paper, and the paper authors did not test it.

  "In the present study, we hypothesized that if the detergent and rinse aid residues are not completely removed, once dry, they may remain on the surface of the dishware."
But then they go on to only test what would happen to gut lining cells if most dishes most of the time had residue on them in such concentrations as they assume would be present, transfer to the food, and make it past the stomach.

This line of research really should have started with something like,

  "we swabbed 50 recently washed and dried dishes from 25 different restaurants using different dish-washing machines. Here is the average concentration of detergent and rinse aid residue on the dry dishes".
I get that's not the study they wanted to do, of course; who wants to spend hours and days swabbing dry dishes when you have a decent reason to play with new biotech?

But that means the only thing this paper actually looked at is: IF there is residue on the dry dishes, and IF that remains in the assumed concentrations by the time you eat off of it, and IF all of that residue ends up attached to your food, and IF all those chemicals make it past your stomach, let's see what that might do to your gut lining.

Not a bad idea for a study, but definitely not what people on the internet are taking this to be.

The news articles are promoting that unsupported claim to an assumed fact that there is chemical residue on all the dishes people are eating from and that this is destroying people's gut lining. Most of the headlines around this are something to the effect of: "Commercial Dishwashers Destroy Protective Layer in Gut".

Which is pure sensationalism, the paper authors never claim this and this idea is not supported by present evidence.

This isn’t a great way to test this.

It’s a good way to begin exploring it.

>Enterocytic liquid-liquid interfaces were established on permeable supports

This is like a fake very fragile layer of cells cultured on a membrane. It’s good for preliminary data but it needs follow up data in vivo.

Caveats off the top of my head-

1. Your real gut is massively more robust than Caco-2 cells grown as a monolayer on a support. You’ve got blood supply, lympathic system, villi and connective tissue, layer upon layer of cells covered in mucus- just a completely different ballgame.

2. Rinse aid would first go through your stomach, exposed to acid, be absorbed maybe, have pancreatic secretions added to it, have food with it and all the lipids, very long list.

3. What’s the concentration of rinse aid you actually absorb from your dishes? 1:20,000 doesn’t seem like enough dilution to me but maybe they address that.

Nevertheless I won’t use rinse aid again. :) It’s not necessary for my dishes and it isn’t even worth the cost.

My son has eczema and food allergies and I did a lot of research on actions we could take to help prevent the so called "atopic march" to hay fever and asthma. There's a lot of woo-woo stuff out there that I think can be safely ignored, but I did find what I consider strong evidence that families that hand wash their dishes have significantly lower incidence of some allergic symptoms. I thought it sounded weird and I didn't know what the mechanism could be but the evidence looked so strong that we stopped using our dishwasher. I guess this is one potential mechanism.

Gas stoves and ovens are the other thing we stopped using, with good justification I think.

decreased transepithelial electrical resistance

If you look it up, gut epithelial barrier basically means the mucosal lining.

Mucus is mostly water, some salt and some biopolymers.

Mucus can vary slightly depending on what part of the body produces it, but typically it is made up of 98 percent water, 1 percent salt and 1 percent biopolymers—very long molecules that interact with one another and give mucus that gel-like quality.

If you add chemicals to what is essentially saline solution, it shouldn't be shocking that the solution changes. The decreased electrical resistance is likely some kind of salt derangement from what I gather.

And the biopolymers in mucus are apparently called mucins and -- quick and dirty -- these seem to be glycoproteins, as is true of many immune related things in the human body.

EPA has an article talking about a specific type of ethoxylate (NPE) in the context of impacts to aquatic life which has some interesting info in it [1].

Does some one know if alcohol ethoxylates are a type of nonylphenol ethoxylates? Some brief searching implies these may be separate things.

From the article:

> Q2. How are NP/NPEs used?

> NPs/NPEs, which are produced in large volumes, are used for industrial processes and in consumer laundry detergents, personal hygiene, automotive, latex paints, and lawn care products.

> Q6. What are the potential risks to people?

> NP has been detected in human breast milk, blood, and urine and is associated with reproductive and developmental effects in rodents.

> Q7. Is there an easy way for consumers to avoid using products with NP/NPEs?

> Consumers can avoid products with NP/NPEs by looking for products with EPA’s Safer Choice Label on the shelves of major retailers. …


We sought to investigate the effects of professional and household dishwashers

Interestingly, detergent residue from professional dishwashers demonstrated the remnant of a significant amount of cytotoxic and epithelial barrier–damaging rinse aid remaining on washed and ready-to-use dishware.

Is the reader to draw the conclusion that significant levels of rinse-aid are not found in dishes cleaned by home dishwashers?

A professional dishwasher completes 1 or 2 wash and rinse cycles using 3.5 L of water per cycle.

That's about 1/4 the water usage of a home dishwasher. Does an increased amount of water in home dishwashers result in negligible levels of rinse-aid?

I have been having bigger bowel troubles ever since I started working in Google five years ago. They went away during the pandemic, but this week I'm sick with some kind of infection in my abdomen again.

I never had that before starting in Google, and I always was able to pretty much eat what I want.

Now I don't think it's the food, which is great (and I have been experimenting to see if I could narrow it down). But this article makes me think it might be the cutlery and plates! Or maybe the glasses and cups?

Any other Googlers here with similar issues?

It seems to me that a lazy person who reads or hears about this article and who worries about potential harm from dishwasher detergents is likely to run the cycle a second time with only water.

A rough calculation would seem to indicate that a complete rinse-only cycle would reduce residue levels to well into the safety zone but at the cost of double the water and possibly double the power (if hot water were used).

If this became a widespread concern and people acted this way then it wouldn't bode well for water conservation efforts.

I remember washing clothes at my aunts for some holiday, and started sneezing crazily sometime afterward. 12 year old cousins kid said “oh, you’re allergic to Tide”

derp. If it was toxic on my clothes, I wondered what I was eating.

People think I’m crazy to not have a dishwasher or microwave.

> our results suggest that alcohol ethoxylates were the main culprit component of the rinse aid responsible for the observed toxicity and damage to the epithelial barrier integrity.
Ok, so what do I use as a rinse aid then? I just dug all over amazon and pretty much everything has akoxylated alcohol or some form of polyoxypropylene laureth. And yes, I've purposely let the rinse aid run out just to see what happens. It wasn't pretty... Anyway to make something more "natural"? Some other ingredients I've seen include citric acid, urea, trisodium phosphate. But not sure if just mixing those together would work out....
A reason behind mysterious endless baby crying is often soap residues left on milk bottles. Always rinse a bottle again before using it.
It’s endocrine awareness day on Hacker News (
Is my reading of the summary correct that it is only (or mainly?) talking about rinse aid and not about the detergent?
Why is anyone surprised by any of this ?

I don't mean to sound like a pleb, but the biggest lesson of the past two centuries is how much people bluff, use the name of 'science, progress, blah blah' to push for their own profits, regardless of actual consequences (bodily or environmentally or ecologically).

I generally stick to old-school goods that are totally natural, cheap and are still massively produced in India. With the 'generic' stuff, half the shit is made from tortured-killed cows (urgh vomits) (admittedly, this is mostly outside India), and all of them are filled with god knows what, and made from god knows what.

If you're India, check out Patanjali's ash and lime dishwasher soap that cost like Rs. 20 per bar. Shout out to FitTuber on Youtube who reviews a lot organic products from India.

wonder how the proliferation of small motors + robots will affect the use of chemicals in applications like this

better robotics tech can reduce chemical use by:

1. spot application of sponge in place of general application of chemicals

2. more targeted application of chemicals (only when + where needed)

3. replacing poison for pest / weed elimination with smart mobile traps (have seen laser POCs for both bugs + weeds)

4. cleaning materials for recycling using targeted friction instead of soap. separating oil and food scraps from drain water. separating human waste from gray water (and selling the nitrates)

even for something innocuous like brushing your teeth, a robot can use advanced sensing to modify the dose of fluoride

feels like lots of 'bits to atoms' projects here for someone who enjoys garbage

I wash dishes by hand with hot water and a Korean abrasive cloth using no soap ... It's quicker and easier than anything else
So what does this mean for all of us who buy coffee at coffee shops every morning? Will this cause serious problems long term since we are consuming residues of their dishwasher chemicals? One potential solution is to always get your coffee to go, but that probably only partly solves the problem.
The real news here is that there is such a thing as a "gut-on-a-chip."
It’s time to place all chemicals in the “unsafe until proven safe” category.
For the one looking for a low-tech alternative to rinse aids: white vinegar does wonders. You can easily get it food grade as it is used to make preserves. Similarly it can be used as a softener for washing clothes. The cherry on top: it's cheap!
Here's an interesting video by Technology Connections on how most dishwasher "pods" are overkill:

I see the bubbles foaming at the edges of my cups when I fill them with water, so I always rinse them before use. I would avoid most dishwasher detergent pods if I could, but I can't sell the idea to my significant other.

I use white vinegar instead of a dedicated rinse aids.
Solid dishwasher powder doesn't seem to usually contain detergents. For one brand:

Sodium Sulfate Sodium Carbonate Water Copolymer Of Acrylic Maleic And Sulphonic Acids Sodium Silicate Sodium Carbonate Peroxide PEG/PPG/Propylheptyl Ether Fragrances Subtilisin Amylase Enzyme Transitional Metal Catalyst Reactive Green 12 Copolymer Of Acrylic Maleic And Sulphonic Acids

Those of you with chronic diarrhea, please look into bile malabsorption. Normally consumed by gut bacteria at the end of your small intestine, it can cause problems when it passes into the lower intestine. Bile sequestration medication, normally used to reduce cholesterol levels, can be used to remediate the symptoms.

IANAD, but it worked for me.

What the hell is rinse aid anyway
I've always felt uncomfortable using these, from the residual smell. I wonder how many subtle toxins we can't smell. I hardly fill the auto-release spot these days for that reason, haven't noticed any down side so far.
I think a lot of people use an excessive amount of dishwasher soap

Also I'm very suspicious when I fill a glass and it comes out foamy, I rinse them again before drinking from it

Vinegar is a perfectly satisfactory rinse aid. The only downside it costs less, and the steam will smell funny if you open the door too soon.
I always rinse my dishes before using them, even if they've been in the dishwasher. Does anyone else do this?
What is the solution? (Don't have the focus to read, understand, and analyze the scientific paper atm.)
How to recognize an alcohol ethoxylate?
huh, I didn't know home and commercial rinse aids were any different?
Wait, people were serious when they said we shouldn't eat Tide Pods?
Oh wait....cue gluten-allergy
maybe dont wash them that often
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