Recently someone with TS wrote me to say that he had discovered a trigger for tics and a potential treatment that might apply to others. I applaud his careful observations and willingness to share. But how can we move this observation forward? After all, numerous potential cures to TS have been proposed, ranging from antibiotics to herbal products to dental orthotics to group therapy. So I believe my response to this person may be useful to others. I’ve removed all personally identifiable information.
Here’s the letter:
I have done extensive testing for environmental & dietary triggers over 20 years on myself including every mineral, vitamin, food type, anything you can think of under relatively strict scientific testing conditions. The number 1 trigger of severe tics is WHEY PROTEIN. I have tested all types of whey protein, natural, no sweeteners etc…. it is clearly the protein itself which causes a massive increase in tics, which continue until I stop taking the whey protein. I have repeated this testing with whey protein dozens of times and without fail, and no other environmental factors or lifestyle changes, it causes a severe increase in tics every single time. If I eat a mainly vegetarian diet, my tics are massively reduced.
Below is my response.
Thank you for writing. This is definitely a lead worth following up on! However, there are 2 questions that have to be settled before your experience will influence medical care generally. (1) The mind is powerful, and as you know, anxiety or concern can worsen tics transiently. So the first question is, could any of the effects you see be influenced by your knowing when you eat whey? (2) Does whey affect only a few people with TS, or most of them?
Here is a plan that would help settle these questions:
- Choose a good comparator, like say soy protein.
- Get a dietitian or compounding pharmacist to make up batches of stuff that you can’t tell apart, one with whey and one with soy. They can do this by adding flavors or turning it into fake burgers or whatever. Check to make sure you can’t tell them apart better than chance guessing.
- Have the dietitian or pharmacist dispense 1-2 weeks’ worth of protein at a time without telling you whether each batch is whey or soy. They keep a secret record of the order.
- Have a no-added-protein interval between batches of protein, long enough that you would expect any benefit or worsening to disappear before starting the next batch.
- Keep track in some standard way of the severity of tics during each week. Ideally, something like 5-minute video sessions, one a week, that could be all viewed together by someone unaware of the order of the videos. Or, a self-rated tic severity rating scale (there are a couple that have been widely used).
- Repeat the above for, say, 10 batches of protein—some number high enough that the results are unlikely to occur by chance.
- “Lock” all the severity scores (i.e. make sure they’re right, and dono’t change them later). Then the pharmacist or dietitian reveals the code.
- Do a statistical test to see whether the difference in tic severity scores between whey and soy is significantly more than one might see just by chance.
The steps above are what we call an “N-of-1” trial. They can help settle question number 1 above, and convince others that you were right all along (or else liberate you to eat cheddar and ice cream! 🙂
To address question number 2, we’d have to repeat this process in a group of, oh, 30 people or more, depending on how big a difference we want to be able to detect. However, for this purpose we can have as few as one or two batches of protein for each person.
Also, it’s fair to point out that the above study, even if successful, would allow other interpretations. For instance, soy protein contains phytoestrogens, which one might hypothesize would actually improve tics, based on some very thin, scattered data about tics and androgens. So maybe a different comparator would be better than soy.
You can see why more studies like this aren’t done—it takes some work and volunteers and money. The Tourette Association of America and the National Institutes of Health, and similar organizations in other countries, do offer money to perform studies like this. However, they’d want to know if there are others who have had the same experience you have. For instance, some people in my family have tics and I have seen no effect of whey protein supplements (or dairy products). Maybe our experience is the unusual one, but it makes me less eager to do the experiment without some initial idea that more than a few people have the results you have with whey. So if you participate in a social media network of people with TS, consider asking others to see if they notice something similar.