Steve Levitt, co-author of Freakonomics, has done me the great favor of bringing my omega-3 self-experimentation to a wider audience in this post. He thinks my results might be due to my expectations. I posted this comment:
Thanks, Steve, for writing about this. Hereâ€™s why I think the balance improvements Iâ€™ve noticed are unlikely to be due to expectations:
1. I first noticed the effect putting on my shoes the morning after I started taking flaxseed oil. I had been putting on my shoes standing up for two years; until that morning, I had always had trouble. Every morning. (I had expected it to get much easier â€” practice effect â€” but it didnâ€™t.) The sudden improvement was a complete surprise. I had never heard of such an effect. I had hoped that flaxseed oil would improve my sleep.
2. The sudden improvement I saw when I switched from 2 tablespoons/day to 3 tablespoons/day was also a surprise, although I realize this may be harder to believe.
3. When I switched from flaxseed oil and walnut oil to sesame oil, I expected my balance to get worse. It did, but not when I expected. (It took 2 days to see a change; I expected to see it on the first day.)
Which is not to say Iâ€™m sure. If the effects Iâ€™ve seen are repeatable, Iâ€™ll test myself not knowing what oil Iâ€™ve ingested.
And forgot to sign my name. Oops.
My reading of the data (such as this) is that placebo effects sometimes exist but are vastly overrated — like many dangers.
Addendum: Stephen Dubner, Levitt’s co-author, blogged today that
nearly everything weâ€™ve written about, either in the book or our journalism or the blog, has some element of people worrying too much about something