Thread by @fperrywilson

A million tweets echoing the headline "#sucralose is toxic to your DNA" but, like, has anyone read the actual study this is based on? Let's dig in. (thread/)

This is the study that the articles are based on, appearing in the Journal of Toxicology and Environmental Health.
tandfonline.com/doi/full/10.10…

The culprit agent in the article is actually sucralose-6-acetate, not sucralose. The authors note that lab testing has shown that there is "up to 0.67%" of sucralose-6-acetate in commercially available sucralose. I can't verify this. Their citation doesn't lead anywhere.

For what it's worth, Splenda says they have no sucralose-6-acetate in their branded product:
newsweek.com/artificial-swe…

Do we metabolize sucralose into sucralose-6-acetate? Maybe. Sucralose is not absorbed, but stuff can happen in the gut (maybe due to gut bacteria) as shown in this rat study by many of the same authors as the study we're talking about. tandfonline.com/doi/figure/10.…

One of those metabolites is sucralose-6-acetate. Authors state they see up to 10% of administered sucralose dose come out as sucralose-6-acetate in rat feces.

Those rats were given hefty doses, fwiw. Also rats aren't people. But let's get to the important bit. How do they know that sucralose-6-acetate damages DNA?

They used TK6 cells - a cell line of cancerous lymphocytes, and exposed them to various concentrations of sucralose-6-acetate. The readout was a variety of biomarkers of DNA damage, integrated through an algorithm of some kind.

They found evidence of DNA damage when sucralose-6-acetate levels exceeded 500 ug/ml. Is that high? This study dosed people at 10mg/kg/day and shows these levels of sucralose (not s-6-acetate) in the blood.
sciencedirect.com/science/articl…

10mg/kg sucralose is a pretty big dose, btw. A packet of splenda has 12 mg of sucralose - so... think 60 packets a day. There is some absorption into blood, with levels getting above 500. But that is sucralose itself, NOT the metabolite.

In short, I don't believe blood levels of sucralose-6-acetate, with normal consumption, would come close to the DNA damage threshold noted in the article.

Also - DNA damage does not always equal mutation. They tested the mutagenic potential of sucralose-6-acetate on bacteria and found no signal. To quote the article:

The authors do some interesting work looking at sucralose-6-acetate on gut cells (which is more important, imo, since that's where sucralose lives). Again we see some signal of "leak" at high dose, but no real dose response.

Taken together, I would interpret this paper as we should interpret many toxicity studies. MANY things are toxic, in certain dosages, in certain cells, in certain ways. That doesn't necessarily mean they have any real-world risk.

And yet, the authors stated in a press release "I would strongly advise against use of sucralose as a sweetener".

Also this interesting quote "The amount of sucralose-6-acetate in a single daily sucralose-sweetened drink far exceeds the threshold of toxicological concern for genotoxicity of 0.15 μg/person/day recommended by regulatory agencies such as the European Food Safety Authority".

I was curious about that. The 0.15 ug/person/day thing is NOT specific to sucralose. It's the level the European Food Safety authority sets as its limit for any substance that is genotoxic. (Some agencies have no acceptable level of genotoxicity).

So I want to be clear that the authors are saying s-6-acetate is genotoxic and therefore SHOULD be subject to this limit, not that it IS subject to this limit (yet). They also show this table demonstrating how common beverages might be well above this limit:

But the way they calculate that is multiplying the sucralose content by 0.67%, the highest concentration of S-6-Acetate in the study I can not find. (Again, splenda says they have 0 s-6-acatete in their product). This feels a bit alarmist to me.

To be clear, artificial sweeteners are far from a panacea. They may have substantial metabolic risks and we're probably all better off reducing our intake of anything sweet (artificial or not) but that's another story.

What this hubbub is real about is our obsession with what I call "one simple thing" medicine. This repeated idea that if we just change one easy thing - cut this out of our lives, add this into our lives - we will meaningfully change our health. It's not true.

Changing your risk of cancer, or IBS, or depression, or anxiety, or death, or dementia, or anything is not easy. It's never going to be "take a vitamin". It's - change your diet dramatically. Lose weight. Exercise way more. And of course stop smoking.

We are attracted to "sucralose damages your DNA" because it is easy to cut out sucralose. We can feel like we are doing something good for ourselves. But it's a shell game. There will always be studies saying something is toxic because life is toxic.

Your DNA is being damaged all the time. From food, smoke, pollution, cosmic rays, radiation and so on. Thankfully, we have ways to repair that. So, yeah, stop the sucralose if you want but please also do the harder work too. If there is a secret to health, that's it.

If you want to learn how not to fall for the hype cycle of modern medical science reporting, you can check out my new book. (Sorry for the log-rolling).
amazon.com/How-Medicine-W…