Enriched skimmed milk may curb bouts of gout

By Sophie Ramsey

BMJ Group News

What do we know already?

Gout is a fairly common condition, especially among older people. It occurs when tiny crystals of a chemical called urate build up in your joints, causing bouts of bad pain and swelling, often in your big toe.

Doctors often recommend changing your diet to prevent gout flare-ups, as certain foods and drinks can increase urate levels. These include meat, fish, beer, and spirits. On the other hand, low-fat dairy products, such as skimmed milk, may lower these levels. Research also suggests that components of dairy products - called glycomacropeptide (GMP) and G600 milk fat extract - may help limit gout pain and swelling.

Researchers have now done a high-quality study to explore whether skimmed milk enriched with GMP and G600 might lower the chance of flare-ups.

What does the new study say?

The researchers recruited 120 people who’d had at least two gout flare-ups over the last four months. They randomly assigned them to drink a vanilla-flavoured milkshake each day, containing one of the following: lactose powder, skimmed milk powder, or skimmed milk powder with added GMP and G600.

After three months, flare-ups had decreased in all three groups. However, people drinking the enriched skimmed milk had a greater reduction than those in the other two groups. They also had greater improvement in their joint pain and in the amount of uric acid (a form of urate) leaving their body in their urine.

Some people in the study reported side effects, including diarrhoea, nausea, and wind. However, these problems were no more common in the enriched skimmed milk group than in the other groups.

How reliable is the research?

These findings should be quite reliable, as this was a randomised controlled trial (RCT), the best type of study for finding out the effects of a treatment. It was also ‘double blind’, which means that neither the participants nor the researchers knew which treatment each person was getting. This strengthens the study’s findings, by minimising the effect that people’s expectations might have had on the results.

However, bear in mind that this was a fairly small, short-term study, and it looked only at people who had frequent attacks of gout. We need larger and longer-lasting trials to back up these findings and to see whether enriched skimmed milk might also help people who get less frequent attacks.

What does this mean for me?

There are few good treatments to prevent flare-ups of gout, so these findings provide encouraging news. However, the research is still at an early stage and the enriched skimmed-milk powder used in the study isn’t widely available. Even so, you might talk to your doctor about adding more skimmed milk to your diet, as other research suggests this may also help on its own.