Uric acid in athletes in Stephen Phinney’s early studies.

Stephen Phinney and Jeff Volek theorized that uric acid falls after a period of "keto-adaptation". But is this always true?

Last update and review: December 8, 2020.


A short summary.

A factoid and several comments on serum uric acid.

Theory and “factoids” on serum uric acid in people on low carb diets.

We recently took another look at an important metabolite, serum uric acid. In the “Related” section below, there are links to some of our articles on uric acid.

In this particular article, we publish a “factoid”, a table from one of Stephen Phinney’s early studies on the ketogenic diet. Indeed, Stephen Phinney and Jeff Volek theorized that after an initial increase, serum uric acid drops and this is a sign of a “keto-adaptation”. From another article on this website:

Uric acid levels do not always fall during prolonged starvation. What about ketosis?

Stephen Phinney and Jeff Volek theorized that uric acid falls after a period of “keto-adaptation”. But is this always true?

Phinney and Volek on the website of Virta Health (2):

“In short, the figure below depicts the serum uric acid levels typical for a healthy person fed a moderate protein ketogenic diet for 12 weeks. The acute rise in the first week occurs simultaneously with the increase in blood ketones, but then the slow progressive decline occurs despite stable levels of dietary protein and blood ketones. In other words, the initial rise in blood uric acid appears linked to the onset of nutritional ketosis, but then the body slowly adapts back to normal uric acid clearance despite sustained ketones in the blood.”

Are there any studies that show that there is a consistent drop in serum uric acid after several weeks of a ketogenic diet?

Uric acid levels can be similar after 4 weeks of ketosis and 4 weeks of starvation.

Let us look at one of the early studies by Stephen Phinney (Phinney et al., 1983, (1).

What was the diet in that study? We estimated the average daily intake of protein in that study for an average 75kg participant as 75*1.75 = 131.25 grams. The “eucaloric ketogenic diet (EKD)” in Phinney’s study (1) was, therefore, composed of 131.25 grams a day of protein, 20 grams of carbohydrates, with the rest of the calories coming from fat.

Some the subjects were trained athletes who continued training during the study period.

The table below shows that during the week 4 of the eucaloric ketogenic diet, serum uric acid was still relatively elevated (Source: Phinney et al., 1983, (1)).

Liver and Renal Function Tests, including bilirubin and uric acid. From Phinney, 1983.
Liver and Renal Function Tests, including bilirubin and uric acid. From Phinney, 1983.

The variations in the levels of uric acid in Phinney’s study (1) are similar to the variations observed by Irving et al., 1976 (2), in eleven subjects during a 30-day starvation period (see the figure below).

Serum uric acid and uric acid clearance during starvation. Eleven patients were studied during total therapeutic fasting. The mean values plus or minus the standard error of the mean are shown for the serum uric acid (A), the renal clearance of uric acid and creatinine (B), and the blood values of p-hydroxybutymte and acetoacetate (C). Source: Irving, 1976.
Serum uric acid and uric acid clearance during starvation. Eleven patients were studied during total therapeutic fasting. The mean values plus or minus the standard error of the mean are shown for the serum uric acid (A), the renal clearance of uric acid and creatinine (B), and the blood values of p-hydroxybutymte and acetoacetate (C). Source: Irving, 1976.

Phinney and Volek proposed that the ketoadaption should kick after 10 to 12 weeks on a ketogenic diet.

Phinney and Volek proposed that the ketoadaption should kick after 10 to 12 weeks on a ketogenic diet. So, the levels of serum uric acid actually observed during the week four on a ketogenic diet or during starvation do not contradict the hypothesis by Phinney and Volek (3).

Stephen Phinney and Jeff Volek theorized that uric acid falls after a period of "keto-adaptation". But is this always true?
Stephen Phinney and Jeff Volek theorized that uric acid falls after a period of “keto-adaptation”. But is this always true?

What really happens with serum uric acid in people who follow a low carb diet and should anybody worry about somewhat elevated levels of uric acid?

But what really happens with serum uric acid in people who follow a ketogenic diet? Do they really go through a keto-adaptation after 10 or 12 weeks “on keto”? And most importantly, should anybody worry about somewhat elevated levels of uric acid on a ketogenic or other low carb diet? After all, clinical gout is not present in 85-90% of people with elevated serum uric acid. Bardin and Richette, 2014 (4):

85–90% of hyperuricemic patients do not have clinical features of gout.

Related:

Selected references:

1. Phinney et al., Metabolism, Vol. 32, No. 8 (August), 1983.

2. Irving et al. Metabolism, Vol. 25, No. 5 (May), 1976 551

3. Phinney and Volek. Article on the website of Virta Health.
https://www.virtahealth.com/blog/keto-adapted
Accessed on December 2, 2020.

4. Bardin and Richette. Curr Opin Rheumatol2014, 26:186–191

Leave a Reply