This page, about a low purine diet study, was last reviewed or updated on 12 March 2014.
Here's a study that will encourage anyone who seeks a natural remedy for gout.
In this study, (full details at the end of this article) the participants did NOT have gout, but they were at a risk for it because they had high uric acid levels (8.5 mg/dL or more, males; 7.5 mg/dL or more, females), hypertension, and they were overweight or obese.
The researchers hoped to discover whether a low purine diet, a low purine diet plus Allopurinol or Allopurinol alone, would be effective in reducing uric acid levels. Study participants were therefore divided into three groups and placed on one of these three gout treatment courses. The study lasted 36 weeks, and a total of 55 patients completed it.
THE LOW PURINE DIET STUDY RULES
High purine foods were defined as those containing 100 mg – 1,000 mg of purines per 100 grams of food. (There's a link to a purines table below).
The diet was high in carbohydrates, and calorie amounts on average, varied between 1,670 and 1,854 daily across all groups during the first twelve weeks. (Calories, carbohydrates, protein and fat amounts after 12 weeks were not reported).
One end result of the study was that the participants did not lose weight. Had they done so, uric acid (UA) levels could have fallen further. However, the main objective of the study was to observe UA changes as a result of purine restriction alone, not to lose weight.
Foods high in oxalates were also restricted. These foods can be a risk of kidney stones made from oxalates. Liquids (unspecified in the study report) were encouraged, a de rigueur part of gout treatment. In this case 2.5 – 3.5 litres (liters) daily. That is 93 fl.ozs – 127 fl. ozs, or about 12 – 16 glasses daily, which is at the high end of the usual daily recommendations for water only.
Allopurinol dosage Those participants who took Allopurinol received at first 150 mg daily. After six weeks, if their uric acid levels remained high, the dosage was increased to 300 mg daily. 150 mg – 300 mg daily is a fairly typical dosage of Allopurinol for people with gout and no other medical problems.
medications Most participants took anti-hypertensive
medications during the study. Remember they did suffer hypertension
(high blood pressure). Actually most took thiazide diuretics for
hypertension. These have a reputation for raising UA levels but the
researchers said that in this study these anti-hypertensive drugs did
not affect outcomes, probably because they were taken in low dosages.
THE LOW PURINE DIET STUDY RESULTS
Results were expressed as averages, and with standard deviations also shown.
After six weeks all three groups reduced uric acid levels. After 12 weeks, in Group 1 (low purine diet only) and Group 2 (low purine diet plus Allopurinol) participants' UA levels rose slightly; but those in Group 3 (only Allopurinol) enjoyed an additional fall.
However, after 36 weeks the picture changed. In Group 1 (diet only) uric acid levels fell;
in Group 2, (diet plus Allopurinol) they rose for the second time, and
in Group 3 (Allopurinol only) there was a rise above the levels achieved
after 6 and 12 weeks!
And after 36 weeks, the winner was? If the whole period of the study is considered, all groups enjoyed a fall in UA levels, but in which group did it fall the most? It was in Group 1, those on the low purine diet. By, on average, –2.09 mg/dL (excluding measurements of standard deviations which the researchers must have felt did not affect the overall story).This was a fall of 24% from initial levels.
In Group 2 (diet plus Allopurinol) the UA fall over the whole period was –1.23 mg/dL (–13% from starting levels). The balance of men to women in Groups 1 and 3 was about the same (1 man: 2 women). In Group 2, because group participants were chosen at random, it was reversed (2 men: 1 woman). This may have affected the Group 2 outcomes.
In Group 3 (Allopurinol only) the 36 weeks fall was –1.20 mg/dL (–13.25%).
In the 24 weeks after the monitoring at 12 weeks, UA levels rose in the diet plus Allopurinol and Allopurinol only groups. In the first 6 weeks, Allopurinol plus the diet, worked best across all three groups.
It may be inaccurate to draw firm convictions from one low purine diet study. Gout treatment is a matter of probabilities not certainties. And in this low purine diet study, patients did NOT have gout, merely hyperuricemia, hypertension and they were overweight or obese. But here are a few ideas worth remembering, considering and comparing.
Allopurinol on its own (with no other additional treatment except drinking lots of water) may work best in the first 6 – 12 weeks, as it did here. If it doesn't work after 12 weeks it may never work. Allopurinol dosages were increased after 6 weeks among patients for whom Allopurinol was not working, but this seems to have had no effect after 36 weeks.
On the other hand, Allopurinol has performed better than in this study, in other trials.
The benefits of a low purine gout diet grow over time. You may need to try it (if it's the sole treatment plus water drinking) for 5-6 months.
Trying a low purine diet plus Allopurinol (a fairly common treatment)
worked the best, among these three Groups, during the first six weeks.
But the 12 and 36 week measurements recorded increases (the 12 week one a
tiny one) in UA levels. Again, Allopurinol dosages were increased after
6 weeks among patients in this group for whom Allopurinol was not
working, but this also seems to have had no effect after 36 weeks. So
after 12 weeks it may never work. However, as in all groups, the 36 week
figure was down from initial levels.
The researchers' conclusion was that a low purine diet for gout should be tried first. It also has the advantage of being a cheap gout cure.
Related pages you might enjoy
you wish to read, or download, this low purine diet study, which took
place in Brazil in 2001 – it's called "Diet and Medication in the
Treatment of Hyperuricemia in Hypertensive Patients" – click on this
link. It's five pages, Adobe PDF format.
This study also looked at markers of insulin resistance. Insulin resistance is another cause of gout. This low purine diet had no effect on insulin resistance markers.
Visit our first of two pages about the Mediterranean diet for gout - it lowered uric acid in three studies.
Want to read the menu and recipe ingredients for five courses of low/medium purine dishes which are also restricted carbohydrate?