Bayesian Investor Blog

I got interested in trying ashwagandha due to The End of Alzheimer’s. That book also caused me to wonder whether I should optimize my thyroid hormone levels. And one of the many features of ashwagandha is that it improves thyroid levels, at least in hypothyroid people – I found conflicting reports about what it does to hyperthyroid people.

I had plenty of evidence that my thyroid levels were lower than optimal, e.g. TSH levels measured at 2.58 in 2012, 4.69 in 2013, and 4.09 this fall [1]. And since starting alternate day calorie restriction, I saw increasing hypothyroid symptoms: on calorie restriction days my feet felt much colder around bedtime, my pulse probably slowed a bit, my body burned fewer calories, and I got vague impressions of having less energy. Presumably my body was lowering my thyroid levels to keep my weight from dropping.

I researched the standard treatments for hypothyroidism, but was discouraged by the extent of disagreement among doctors about the wisdom of treating hypothyroidism when it’s as mild as mine was. It seems like mainstream medical opinion says the risks slightly outweigh the rewards, and a sizable minority of doctors, relying on more subjective evidence, say the rewards are large, and don’t say much about the risks. Plus, the evidence for optimal thyroid levels protecting against Alzheimer’s seems to come mainly from correlations that are seen only in women.

Also, the standard treatments for hypothyroidism require a prescription (probably for somewhat good reasons), which may have deterred me by more than a rational amount.

So I decided to procrastinate any attempt to optimize my thyroid hormones, and since I planned to try ashwagandha and DHEA for other reasons, I hoped to get some evidence from the small increases to thyroid hormones that I expected from those two supplements.

I decided to try ashwagandha first, due mainly to the large number of problems it may improve – anxiety, inflammation, stress, telomeres, cholesterol, etc.

2.

I looked at the advice about when to take it, and decided that the massive disagreement on the subject meant that I couldn’t do much better than guess. So I took a standard dose [2] after dinner.

The next morning I measured my pulse, as an incidental byproduct of measuring my HRV, at 98. My pulse had typically been in the low 70s [3], and the highest I’d previously measured was 95 back in 2012. But I was expecting ashwagandha to be barely distinguishable from a placebo, and initially dismissed the measurement as a fluke.

I took a second dose that evening. The next day I went on an ordinary hike (alone, mainly for exercise). About a quarter of a mile up the first hill, I noticed that I wasn’t slowing down and breathing hard. When I hike in a group, I’m normally the slowest person to go up a hill, even when I’m faster than the group on other terrain. I have a habit of pushing myself to go uphill at the fastest pace I think I can sustain, and I pay enough attention to have a good idea what that pace is. I was accidentally pushing myself about 10% harder than I could usually sustain, and yet my breathing and the feel of my muscles told me that I had more energy than usual to spare. I increased my pace, and ended up doing the overall hike 5 or 10% faster than expected. Also, I stopped feeling any hints of the mild muscle pains that I usually felt when hiking over the past 10 or 12 years. I know enough about my hiking patterns to classify these changes as large compared to my normal variations.

That told me that ashwagandha had a surprisingly strong effect on me, and that the thyroid effects were much larger than any other effects. Ashwagandha reportedly lowers heart rates, whereas increased thyroid hormones raise heart rates, so there’s something atypical about my reaction.

3.

I became more cautious about how frequently I took ashwagandha, delaying the dose which I had planned for that evening until noon the next day. My pulse declined back to 81 shortly before taking that third dose.

The evening after that third dose, it took me something like two hours longer than normal to fall asleep, because my pulse was rapid and because I felt too warm (my bedroom was probably around 65 degrees). Also, by around that time my weight had dropped about 3 pounds in 4 days, even though I was eating more (10 to 20% more calories?). I felt an increased desire to eat meat.

That told me that I’d reached clearly hyperthyroid levels. So I cut back to taking 30% to 60% of the standard dose, approximately every other day. I measured my pulse at 97 three days after taking the last of the full doses, but after that it dropped to around 80.

My HRV fluctuated a bit more than normal when my pulse was high, without any clear correlation between the two, and has now stabilized at slightly higher levels. The HRV levels might be influenced more by the work that I was doing than anything ashwagandha-related.

I expect that if I’d come close to harm from thyrotoxicosis, I’d have seen large drops in my HRV. But thinking about the rapid pulse and feeling unusually warm has made me nervous about how much I overshot the optimal thyroid levels. Some reports say that ashwagandha reduces thyroid hormones in hyperthyroid people, but there’s at least one report of minor harm from ashwagandha-induced thyrotoxicosis.

I’m concerned about the increase in my pulse, since there are correlations which suggest the optimal pulse is around 65, and that when it gets up around 80, that’s associated with substantially less healthy outcomes. But researchers probably can’t get patients to change their resting heart rate on purpose, so they probably won’t get evidence about whether heart rate changes cause health changes. It’s easy to imagine that pulse differences are just symptoms of things like exercise and stress, and don’t have independent causal effects on health.

I’ve seen some hints that my pulse is now dropping more than would be expected from the recent declines in my ashwagandha and thyroid levels, possibly due to beneficial effects of more intense exercise that I’m now able to do.

So now I’m balancing my desire for more energy with my desire for a lower pulse, and adjusting my ashwagandha doses to keep my pulse in the 70s.

I have some concerns that higher thyroid levels may be undoing the long-term benefits of calorie restriction. It certainly felt like calorie restriction worked partly through reducing my thyroid levels. But my blood tests don’t confirm that it reduced my thyroid levels – maybe calorie restriction just caused more day to day fluctuations in my thyroid levels, and I’m paying more attention to the times when my thyroid levels are lowest. And calorie restriction has other effects that seem to be pushing in the same direction as higher thyroid levels push: both have reduced my need for weight-related willpower, and have moved me farther away from the “uncomfortably full” feelings that I commonly had before starting calorie restriction.

4.

There’s some important sense in which I feel younger. My mind seems to be faster, but maybe less focused. I get out of bed faster in the morning, but maybe start to feel a bit more tired near bedtime.

I feel a bit more tense or defensive. This feels a bit different from anxiety, but in ways I can’t articulate. I initially attributed it to my unusual pulse causing some parts of my mind thinking that other parts were reacting to danger. But it isn’t going away as my pulse gets back near normal, so there’s something more going on there.

I feel like I have at least 10% more muscle power (but little change in how tired or sore I feel the day after a strenuous hike).

I remain alert for 2 or 3 hours in social contexts where my alertness would previously have faded significantly after an hour. People seem more willing to start conversations with me. That suggests there’s something different about my body language, but I’m unclear what.

I’m guessing I have at least 5% more mental energy for work/blogging, but that’s not something I’ve observed carefully enough to confidently distinguish it from random. I seem to be writing significantly faster this week, but I’m fairly sure I didn’t write faster during the first few days on ashwagandha, so if there’s any connection, it’s not a simple one.

My weight seems to be stabilizing at about 2 pounds below where it was before starting ashwagandha.

Before starting ashwagandha, I attempted a more restricted than normal calorie restriction day (627 calories, compared to a normal range of 720 to 950 on normal calorie restriction days), in an attempt to work my way gradually to an occasional all-day fast. I felt lousy that night, with some subconscious part of my mind saying that something was wrong. In contrast, I worked my way down to a 506 calorie day this past weekend while feeling as normal as I’d felt in response to 750 calorie days a few months earlier. I presume the ashwagandha had an important effect on that, but I don’t understand it well.

5.

I get the impression that there are large variations in how people respond to thyroid-influencing interventions. That could help explain why the medical community is hesitant to optimize thyroid levels. I can easily imagine that there are plenty of patients who would be careless about observing their symptoms, or focus only on the good symptoms and overlook the evidence of risks. But it seems likely that there’s room for improved measurement strategies (frequent pulse or body temperature tests?) that would reduce the risks of thyroid interventions. That could cause some fairly large improvements in many peoples’ quality of life.

[1] – high TSH implies low T3. T3 is the hormone that matters most, but T3 levels fluctuate more in response to food and other common changes, so TSH has become the standard measure. Yet I get the impression that TSH measurements are still noisier than most things that are measured via blood tests. Here’s speculation that we should distrust TSH results. (There’s a more detailed and very verbose version of that speculation here).

Optimal TSH levels seem to be about 1 to 2, with levels in the 2 to 10 range being mildly hypothyroid but not bad enough to create any consensus about whether it’s worth treating.

I also got an unusually high reverse T3 reading this fall. The most likely explanation seems to be that I did calorie restriction the day before the blood test. This seems to be a good example of why it’s hard to get good measures of thyroid function via blood tests.

[2] – 125 mg, from LEF, with 10% withanolide. Which is potentially confusing, because most vendors use 2.5% withanolide.

[3] – that isn’t quite measuring my resting heart rate, since I exercise briefly right before measuring my HRV. I measure it over 5 minutes of trying to get into a meditative state of mind, and it gets close to my resting rate about halfway through. I estimate that what I measure is about 5 points above my resting rate, and should be fairly consistent about that.