Keep the Java, Bag the Little Fishies

People with gout (a painful form of arthritis in which uric acid crystals form in the joints) are often advised to limit their consumption of, among other things, caffeine-containing beverages.

Why?

Well, note the similar 2-ring formations in the objects below:


Now, if I told you that gout was a result of having lots of uric acid in your blood, and if I told you that uric acid is a product of the breakdown of something called purine, you might guess that caffeine could be a problem since it is so structurally similar to purine. In fact, some literature states that caffeine breaks down into uric acid in the body too.

I can understand the initial logic behind attempting to reduce the level of uric acid in the blood by reducing the amount of uric-acid-producing foods, in this case caffeine. I just can't find good evidence to support that logic. What I can find evidence for is:

1. Most (85-90%) of the uric acid in our blood comes not from the purines we eat, but from the purines that are manufactured or already reside in our body.


2. Even among foods we eat, caffeine-containing beverages are relatively low in purine, compared to, say, organ meats (intestine, kidney, heart, brains) and little fishies (anchovies, herring, sardines).


3. Caffeine acts as a diuretic, encouraging loss of uric acid through urine. (I read that caffeine "impairs kidney function which is needed to get uric acid out of the body", yet no mechanism was described. I tend to place statements like that, along with others, e.g. "It cleanses the body.", under the heading of Bogus, until I'm convinced otherwise.)


4. Caffeine may interfere with uric acid tests, producing inaccurately high serum levels.

There's even a Japanese study from 1999 that found coffee-drinking actually reduced uric acid concentrations.¹ And the American Academy of Family Physicians lists coffee under the "No Limitation" column on a table of foods to avoid following a gout attack.

So why are we limiting these undeniably enjoyable, uplifting, and certainly in the case of tea, antioxidant-rich beverages to people who endure an intimate relationship with their pain thresholds?

I'm not sure why this advice is perpetuated. If there was anything I'd steer a gout patient away from, it would be beer.

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¹Kiyohara C, et al., Inverse association between coffee drinking and serum uric acid concentrations in middle-aged Japanese males. British Journal of Nutrition, 1999, 82(2), p. 125-130.