RSS feedReducing your risk of developing kidney stones
Once you have developed kidney stones, it is very important to reduce your risk of them recurring again.
This is because if you develop a stone once, your chances of developing stones again are greater than the average lifetime risk. Recurrence rates are 20 per cent at five years, 35 per cent at 10 years and 70 per cent at 20 years. Therefore, if you are at risk of developing stones, you need be particularly aware of the food and drink you consume.
Metabolic investigation to understand your stone type
We carry out a full metabolic investigation to assess your stone type. This is because different types of stones will be triggered by specific foods. There are four main types of stone: calcium, struvite, uric acid, and cystine. Calcium stones normally are the result of an inability to absorb calcium, struvite are due to kidney infections and an excess of magnesium, and uric acid stones form when there is a high acid content within the urine.
Stone type and food groups
Calcium stones are the most common type. If you develop a calcium stone it is likely to be the result of a high level of oxalates in your diet. Oxalates prevent the body from absorbing calcium and consequently, the excess calcium can remain in your kidney to form a stone. Foods that contain oxalates include beetroot, nuts, asparagus, rhubarb, chocolate and berries.
If you have developed a uric acid stone, you should reduce the amount of meat and fish you eat. This is because when protein based foods like meat break down, they produce uric acid. Struvite stones result from infections in the kidney. Preventing struvite stones depends on reducing the risk of infections rather than diet.
Cystine stones are far less common and are caused by a rare genetic disorder that causes cystine, an amino acid, to leak into the kidney and form crystals. Cystine stones are more difficult to prevent because they are normally caused by inherited disease.
Drinking water
For all types of kidney stone, it is important to drink plenty of water. The general advice is that you should aim to drink between 1.5 and two litres of water a day. But it depends on what you are doing each day and the weather conditions – if you take part in high intensity sport, or if you have a physical job, you need to drink more. You should also drink more in hot weather. Equally, drinks like tea and coffee which contain caffeine counter-act the positive effects of water and should only be drunk in moderation.
Balanced meals and individual plan
Overall, we should guard against a simple idea of ‘good’ and ‘bad’ foods. In every meal, you eat a range of food, some of which will have an inhibitive effect on stone formation, for example, fruit and vegetables, while others, such as red meat, carry a risk for stones. So overall, the range of ‘good’ and ‘bad’ food counterbalances each other. Beware of snacks outside of meal times, such as salted nuts, which have a ‘bad’ effect but no positive counterbalance.
Equally, some people are able to eat large amounts of food containing oxalates, or consume a high protein, meat based diet, without developing stones, while others consume a smaller proportion yet are more prone to developing stones. The key is to understand your own individual risk factors and take specific steps to reduce that risk. You should ensure you are seen by a urologist specialising in the treatment of kidney stones, a full metabolic investigation of your stones is undertaken and from this, you are given your own future stones prevention plan.
Related links
▸ News: Mr Simon Choong describes kidney stone risks in the Daily Mail
▸ Read a kidney stone patient's personal account of treatment
