(6) Gout
Gout is caused by raised levels of urate and is a condition
in which diet is known to play a part. If plasma urate concentration increases
too much, some will precipitate as uric acid crystals. These crystals
may then deposit in the joints, causing pain and inflammation. Uric acid
is the end product of purine metabolism. Purines are a constituent of
DNA and during cell turnover they are released and converted into uric
acid, which is excreted via the kidneys. Dietary purines are also broken
down to uric acid and excreted. However, there is no dietary requirement
for purines as they are synthesised endogenously.
- Diet may contribute to the development of gout, although it is rarely
the only factor. A high dietary purine intake may exacerbate the formation
of uric acid crystals.
- Obesity and hypertension increase the risk of gout (due to reduced
urate clearance).
- Diet no longer plays a large role in the treatment of gout. However,
if the condition is accompanied by obesity or overweight, weight reduction
and a healthy diet may help and may reduce the need for long-term medication.
- Avoidance of large quantities of purine rich food may also be helpful
(see Table).
- Alcohol can increase blood urate concentration and excessive amounts
may bring on an attack of gout.
Purine content of some common foods
|
|
High
|
Low
|
|
Yeast extracts (eg, Marmite), yeast tablets, beer
|
Tea
|
|
Meat, offal
|
Coffee
|
|
Shellfish
|
Cheese
|
|
Sardines
|
Eggs
|
|
Fish roes
|
Milk
|
|
Mycoprotein (eg, meat substitutes, such as Quorn)
|
Cereal
|
|
|
This series of “dietary advice tips” is intended
to be a reminder of the main points to be made by pharmacists when giving
nutritional information to the public. The conditions included in the
series are those where diet is a well recognised risk factor, those in
which diet contributes to the management of the condition, and others
for which patients may welcome sound dietary advice.
Written by Dr Pamela Mason (a pharmacist with a postgraduate qualification
in nutrition)
|
