Update on the Best Diet for Gout

Summarized by Robert W. Griffith, MD
May 19, 2004

Introduction

Gout affects about 3½ million men in the USA. It has long been though that purine-rich foods and a high protein intake are risk factors for the condition, and sufferers are advised to avoid meats, seafood, purine-rich vegetables, and animal protein. But this advice is based more on the theory of how excess blood uric acid can occur, rather than actual clinical studies.

In addition to the purine/protein factor, some researchers have implicated dairy products as having an effect on uric acid levels. But here again, clinical studies are lacking. Now there's a report in the New England Journal of Medicine on a large study analyzing the relationship between diet and the occurrence of gout in men.

What was done

Over 50,000 men from health professions (dentists, optometrists, osteopaths, pharmacists, podiatrists, and veterinarians) were enrolled in 1986 in the Health Professionals Follow-up Study. A mailed questionnaire revealed that over 2,500 of them reported a history of gout, and they were removed from the analysis, leaving 47,000 participants.

Food-frequency questionnaires were sent out at baseline, and in 1990 and 1994. Weight, medications, and medical conditions were recorded every two years. If someone reported having gout, they were sent a more detailed questionnaire to make sure that their case met the American College of Rheumatology's criteria for this diagnosis.

The participants were assigned to five equal groups according to the amount of their intake of total meat; these groups were called 'quintiles'. They were then assigned to different quintiles for their consumption of seafood, purine-rich vegetables, dairy products, low-fat dairy products, total protein, and animal protein.

What was found out

There were 730 new cases of gout during the 12 years' follow-up. Most of them were aged 55 to 64.

When total meat consumption was analyzed, the risk of acquiring gout was 1.41 times greater in the top quintile of meat eaters than in the lowest quintile; in other words, eating more meat was a risk factor for gout.

Similarly, men in the top quintile of seafood eaters were 1.51 times as likely as the lowest quintile to develop gout.

In contrast to these results, gout was less common in those taking more dairy products. For those in the highest quintile of dairy intake, the likelihood of getting gout was 0.56 (about half) that of men in the lowest dairy intake quintile. It was similar (0.58) for the low-fat dairy consumption quintiles. Thus men who drank two glasses a day of skim milk, or ate a serving of low-fat yogurt more than twice a week, halved their risk of developing gout.

The amount of high-fat dairy products, purine-rich vegetables, and total protein had no influence on the chances of getting gout. Body mass index (BMI) and alcohol intake didn't affect the findings - except for a stronger association between gout and seafood consumption in men with a BMI below 25 (i.e. those that weren't overweight).

What this means

This large study confirmed what many experts have been proposing for years - that a diet high in meat and seafood increases the likelihood that a susceptible person will develop gout. This view is based on the finding that dietary purines increase serum uric acid levels, at least in the short term. However, a substantial number of people with high uric acid levels don't get gout, so other mechanisms are clearly at work - genetics or alcohol intake, for instance.

The 'protective' effect of dairy products has also been proposed for some time; milk proteins have been shown to increase the excretion or uric acid in the urine, while a 4-week dairy-free diet significantly increases the serum uric acid.

The protein content of foods is not a good replacement for the purine content when making dietary choices. In fact, some high-protein vegetables may have a small protective effect, due to increased urinary uric acid excretion; however, this is not as effective as that of low-dairy products.

The bottom line: to avoid developing gout, especially if the disease runs in your family, try to limit your intake of meat (beef, pork, lamb, and innards, such as liver, kidney, sweetmeats etc) and seafood, while increasing your intake of low-fat dairy produce (skim milk, yogurt). Experts have been saying this for ages, but now it's been proved in a large 12-year study.

(PS: Don't forget there's a condition called 'pseudogout', and that the metabolic syndrome - the insulin resistance syndrome, or Syndrome X - may have similar bodily changes as those seen in gout patients; see the first two links below).

Source

• Purine-rich foods, dairy and protein intake, and the risk of gout in men. HK Choi, K Atkinson, N Engl J Med, 2004, vol. 350, pp. 1093--1103

Related Links
Is it Really Gout?
The Right Diet for Gout Victims?
How to Eat If You Have Gout

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