4 ms·

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 rins

by alpos 4y ago

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.

matthewdgreen 4y ago
I can smell detergent scent on my dishes after a wash and rinse, even if I don’t use rinse aid. Maybe my dishwasher’s rinse cycle isn’t very good: but if so I imagine that I’m not alone. I agree with what you’re saying here in terms of the raw findings, but I wonder if as a society we’re approaching this question wrong. Specifically: if I proved that dishwasher detergents contained a toxic chemical (say: arsenic), shouldn’t dishwasher detergent makers now bear the burden of proof for demonstrating that it doesn’t remain on dishes? And isn’t it reasonable for people to treat this as major, worrying news just based on the precautionary principle?
- e40 4y ago
  To add to this. When I take dishes out of my dishwasher and rinse them manually, sometimes they feel slippery until I rinse the residue off them. I always wondered what that was. I think the detergent I use with my Miele (also made by them) includes a finishing agent, not sure. I will check and perhaps try something else for a while.
- theGnuMe 4y ago
  Modern dishwashers use way less water, so you are likely using too much detergent. You can probably cut the amount in half. I actually run an extra sanitize cycle which is like an extra rinse I believe to help remove the extra residue. Older dishwashers in general use a lot more water which helps. Sometimes I run the tough cycle since it uses more water as well. I use the pods most often but I've found that cascade platinum leaves more noticeable residue then quantum but I may actually switch to something else entirely. The problem is if I use anything besides these two my dishes don't get as clean. The pods are also difficult to chop in half. I think the manufacturers need to create a low dose high efficiency detergent. There's probably a formula and I bet cascade platinum and the quantum are optimized for an older generation of washers that use more water.
- alpos 4y ago
  I agree, caution still seems justified, whenever we find toxic effects of materials we might contact daily it's worth considering whether the risk that this is a real and present threat is worth the benefits of having those things around. Similar story with Teflon, plastic packaging and utensils, clothing detergents, surface cleaners, micro-beads in face products, cosmetics, talcum powder, deodorant, etc. For this specific case, I'd still rather see the evidence that most dishwashers, when used according to manufacturer operating instructions (or even when used as most people operate them in practice) actually do leave enough dangerous chemical residue on the dishware to be a risk and that significant amounts of this stuff transfers to food before I'd say it's a claim the manufacturers have a burden of defending. Similar claims could be made about ceramics and glazing for instance, and the ceramics would harm us if ingested, but there's no evidence that ceramics from plates transfer to foods as we eat, even if we cut food on the plate with a knife. Of course, ceramics don't tend to dissolve readily in water either so we can presume detergents and rinse aids have some higher chance of transferring to food if present. Of course the reality is, if enough people take the sensationalist headlines seriously, the manufacturers will have to defend it anyway; but this effect is what makes organization leaders assume most people are too stupid to hear the truth about nearly anything and the root cause of things like bad nutritional advice recycling over and over again. Many people are still afraid of stuff like MSG, even though it occurs naturally in many foods and has been proven safe over and over again. The root cause of that scare was a science article in the New England Journal of Medicine back in 1968 which was sensationalized by the New York Times. Bad memes like "Chinese Restaurant Syndrome" are prevalent enough throughout the history of scientific literature to merit an equal portion of caution before reacting to any single paper with too little skepticism or too much drive to change our lifestyles or behaviors.

by alpos 4y ago

matthewdgreen 4y ago

I can smell detergent scent on my dishes after a wash and rinse, even if I don’t use rinse aid. Maybe my dishwasher’s rinse cycle isn’t very good: but if so I imagine that I’m not alone. I agree with what you’re saying here in terms of the raw findings, but I wonder if as a society we’re approaching this question wrong. Specifically: if I proved that dishwasher detergents contained a toxic chemical (say: arsenic), shouldn’t dishwasher detergent makers now bear the burden of proof for demonstrating that it doesn’t remain on dishes? And isn’t it reasonable for people to treat this as major, worrying news just based on the precautionary principle?

e40 4y ago
To add to this. When I take dishes out of my dishwasher and rinse them manually, sometimes they feel slippery until I rinse the residue off them. I always wondered what that was. I think the detergent I use with my Miele (also made by them) includes a finishing agent, not sure. I will check and perhaps try something else for a while.
theGnuMe 4y ago
Modern dishwashers use way less water, so you are likely using too much detergent. You can probably cut the amount in half. I actually run an extra sanitize cycle which is like an extra rinse I believe to help remove the extra residue. Older dishwashers in general use a lot more water which helps. Sometimes I run the tough cycle since it uses more water as well. I use the pods most often but I've found that cascade platinum leaves more noticeable residue then quantum but I may actually switch to something else entirely. The problem is if I use anything besides these two my dishes don't get as clean. The pods are also difficult to chop in half. I think the manufacturers need to create a low dose high efficiency detergent. There's probably a formula and I bet cascade platinum and the quantum are optimized for an older generation of washers that use more water.
alpos 4y ago
I agree, caution still seems justified, whenever we find toxic effects of materials we might contact daily it's worth considering whether the risk that this is a real and present threat is worth the benefits of having those things around. Similar story with Teflon, plastic packaging and utensils, clothing detergents, surface cleaners, micro-beads in face products, cosmetics, talcum powder, deodorant, etc. For this specific case, I'd still rather see the evidence that most dishwashers, when used according to manufacturer operating instructions (or even when used as most people operate them in practice) actually do leave enough dangerous chemical residue on the dishware to be a risk and that significant amounts of this stuff transfers to food before I'd say it's a claim the manufacturers have a burden of defending. Similar claims could be made about ceramics and glazing for instance, and the ceramics would harm us if ingested, but there's no evidence that ceramics from plates transfer to foods as we eat, even if we cut food on the plate with a knife. Of course, ceramics don't tend to dissolve readily in water either so we can presume detergents and rinse aids have some higher chance of transferring to food if present. Of course the reality is, if enough people take the sensationalist headlines seriously, the manufacturers will have to defend it anyway; but this effect is what makes organization leaders assume most people are too stupid to hear the truth about nearly anything and the root cause of things like bad nutritional advice recycling over and over again. Many people are still afraid of stuff like MSG, even though it occurs naturally in many foods and has been proven safe over and over again. The root cause of that scare was a science article in the New England Journal of Medicine back in 1968 which was sensationalized by the New York Times. Bad memes like "Chinese Restaurant Syndrome" are prevalent enough throughout the history of scientific literature to merit an equal portion of caution before reacting to any single paper with too little skepticism or too much drive to change our lifestyles or behaviors.