Kidney stone sufferers are often advised to increase their intake of fluids. While water is the ideal liquid, two studies show that the choice of other beverages may also be wise.

The first was a prospective study of 45,289 men with no history of kidney stones. After adjusting for age, dietary calcium, animal protein intake, diuretic use, geographic region, profession and total fluid intake, researchers found that each 8 ounces of beer lowered the risk of developing a kidney stone by 21 per cent, and each 8 ounce cup of decaffeinated or regular coffee reduced it by 10 per cent. Furthermore, each glass of wine reduced the risk of stones by 39 per cent. But the same amount of apple or grapefruit juice raised the risk by around 35 per cent (Am J Epidemiol, 1996; 143: 240-7).

Very similar but even more dramatic results were found in a study of the association between kidney stones in women and fluid intake (Ann Intern Med, 1998; 128: 534-40). Dr Gary Curhan, who oversaw both pieces of research, commented,”Alcohol suppresses a hormone that keeps the body from urinating, allowing for more frequent, more dilute urine.” Caffeine has a similar effect, but Dr Curhan and his team were unable to explain why apple and grapefruit juices seem to increase the risk of stone formation.

Grapefruit juice, for instance, increases the chance of stones forming by 44 per cent. A daily dose of eight oz (240 ml) of wine, however, reduces the risk by 59 per cent decaffeinated coffee and tea by 9 per cent. Caffeinated coffee was slightly better, lowering the risk by 10 per cent.

The results were based on a study of 81,093 women aged between 40 and 65 who had no history of kidney stones (Annals of Internal Medicine, 1998; 128: 534-40).

A:Nutritional expert Dr Stephen Davies recommends that a first port of call for any stone former is to have your blood calcium levels measured to see if they are elevated. If so (as it is in about 15 per cent of stone formers), you may have an abnormality of the parathyroid glands (which control calcium metabolism), which might require treatment for surgery.

But if not, and if other numerous blood and urine investigations are normal, showing no underlying kidney disease, our American panelist and nutritional expert Dr Melvyn Werbach, says there are a number of foods that people prone to kidney stones should avoid. Chief among these is animal protein, which increases calcium and oxalate loss and also the excretion of uric acid, and fat in general, which is consumed in greater quantities by people who get kidney stones.

You should also limit sugar in your diet, which also promotes loss of those factors linked to the formation of stones, as well as caffeine. Although the oxalate in your diet makes only a modest increase in the oxalate in your urine, Dr Werbach advises people whose urinary oxalate is high to limit high oxalate foods, which include beans, cocoa, instant coffee, parsley, rhubarb, spinach and tea.

Other foods relatively high in oxalates include carrots, celery, chocolate, cucumber, grapefruit, kale, peanuts, pepper and sweet potatoes.

In Healing through Nutrition (HarperCollins, NY, 1993), Dr Werbach suggests that you eat more fibre (which stone formers tend to lack. Several studies show that added fibre can reduce the excretion of calcium in the diet, he says, by up to 40 per cent (Urol Res, 1984; 12: 58). He also recommends that you consider embarking on a vegetarian diet. Make sure you have enough fluids (two quarts a day), unless you have a problem with water retention. Steer clear of sugar, salt, alcohol and caffeine.

Dr Werbach has also discovered that stone formers tend to be deficient in a number of nutrients. Chief among these can be minor deficiencies in vitamin B6, which is needed to break down the oxalic acid in the body. When oxalic acid accumulates, it is more likely to form calcium oxalate. Studies have shown, he says, that stone formers with proven excess oxalic acid in the urine do respond to vitamin B6 supplements, even those without a demonstrable deficiency. Dr Werbach recommends 40 mg as a daily dosage.

Because vitamin C can break down to oxalate, medicine has blamed stone formation on supplementing with high doses of ascorbic acid. Two studies (one in guinea pigs) provide contradictory evidence about this. Kidney disease patients given doses of 500 mg or more of vitamin C showed a statistically significant increase in urinary oxalate (J Urology, May 1992). However, two sets of animal experiments with guinea pigs found that even high doses of vitamin C did not induce stones in healthy animals, but only those with hypercalciuria (Scan Microsc, September 1993). But Dr Werbach says that most other evidence shows that urinary oxalate only increases on megadoses of 6 gms or more a day. If for some reason you have to take that size daily dose, he recommends that you take it with B6, which will tend to reduce the increase in urinary oxalate.

As for calcium, studies have shown that even high daily supplements of calcium up to 2 gm a day don’t increase urinary calcium so long as your vitamin D levels are normal. One study found no relation between stone formation in premenopausal women and taking supplements of calcium citrate.

In fact, restricting calcium doesn’t usually cut down the calcium levels in your urine, since it has to do, in many stone formers, with the overproduction of vitamin D. Paradoxically, urinary oxalate increases if dietary calcium is reduced (Br J of Urol, 1982; 54 (6): 590-3).

This may be of interest to women who take high doses of calcium to prevent osteoporosis (although they do better looking to improve magnesium levels see WDDTY vol 4 no 11). If you are taking calcium supplements, Dr Werbach recommends that you take it as calcium, citrate, gluconate or lactate, which decrease the amount of calcium excreted.

Speaking of magnesium, Dr Werbach says that low magnesium may be a cause of kidney stones; magnesium in the urine tends to combine with oxalate to form magnesium oxalate, a harmless form of it. He suggests at least 300 mg per day with foods. He also recommends potassium rich foods and generous portions of potassium citrate (a natural source is cranberry juice).

One study has linked stones to the free radicals in the Western diet. Animal studies have shown that fish oils could prevent the formation of stones without side effects (J Urol, July 1991).

It’s also important to check your body’s level of cadmium, high levels of which can contribute to stone formation. If it is high, you can lower it through zinc supplementation and a low-protein diet.

A:I’m sure they interest many people, as it is an increasingly common problem, particularly among men.

Kidney stones are, in 90 per cent of cases, calcium and oxalate, a salt derived from oxalic acid, which binds calcium together. Medicine believes that they are caused by a flaw in the intestines, leading to increased absorption of calcium. Another cause is hypercalciuria (too much calcium in the urea) caused by excess resorption of bone (tearing down of old bone). Otherwise, the problem may stem from the kidney itself in its ability to reabsorb calcium.

In the other 10 per cent of cases, the stone is made up of amino acids cystine, xanthine, a protein byproduct, uric acid a consequence of hyperuricemia (high levels of uric acid in the blood) or gout, a form of arthritis where crystals of uric acid salts cluster near joints causing periodic inflammation.

Anyone who has passed a kidney stone knows that the pain, which rushes from abdomen to groin, can be excruciating, accompanied by blood in the urine.

Increasingly, medicine has discovered that a number of prescribed drugs may be a major cause of stone formation. Stones have now been linked to carbonic anhydrase inhibitors (acetazolamide or methazolamide), used to treat glaucoma (J of Urology, May 1991); to furosemide in infants, used for congenital heart failure (J of Pediatrics, July 1994); some antiepileptic drugs (J Assoc Phys India, November 1993); triameterene for hypertension (J of Urology, December 1990); trisilicate containing antacids, used for gastric discomfort and heartburn (Scand J of Urology & Nephr, 1993;27(2): 267-9); ceftriaxone, to prevent the body from rejecting transplants (Nephro, Dialysis, Transpl, 1990; 5(11): 974-6) and even thiazide diuretics, combined with restriction of calcium in patients with high blood pressure (Acta Urolog Belg, June 1994).

Numerous studies have made the connection between kidney stones and use of sulphasalazine, particularly in AIDS patients given long-term use of drugs like Septrin as just-in-case measures against pneumocystis carinii pneumonia (J of Urology, June 1994). Laxative abuse can also bring on kidney stones.

In the past decade, a high-tech invention with the unwieldy name of “extracorporeal shockwave lithotripsy” (ESWL) has revolutionized the medical management of kidney stones. In ESWL, the lithotriptor creates shockwaves, which, guided by x-rays, are aimed at the stone, causing it to disintegrate. By use of sound, the lithotripter is theoretically able to distinguish between the body’s own tissues and those of kidney stones.

Urologists all over the world rushed in to embrace lithotripsy (it is now recommended for three-quarters of all stone problems) without subjecting it to proper clinical trials because it seemed, on the face of it, an improvement over surgery, the conventional method of handling stones. Initial reports didn’t demonstrate any short or long-term damage to the kidney and its surrounding tissues.

Or so medicine originally thought. A number of the studies that are only now being done cast a few shadows over these rosy assumptions. It now seems evident that lithotripsy definitely causes damage to the kidney in a good percentage of cases. Most patients experience internal bleeding, ranging from tiny hemorrhage to major bleeding requiring transfusion.

This bleeding also seems to change the dynamics of the blood in the kidney, causing kidney hypertension, in up to 8 per cent of patients (Robert H Heptinstall, Pathology of the Kidney, 1992: 1592). Other studies show irreversible kidney failure (Nephron,1 1993; 63 (2):242-3). One study of 17 patients showed that 5 had a 22 per cent reduction in the kidney filtration rate (J of Endourology, 1994; 8 (1): 15-9). In another French study of 45 patients who’d undergone ESWL, 15 per cent had blood in the urine, 11 per cent pain in the lower back, and 4 per cent bleeding inside the kidney.

Two years later, a computed tomography (CT) scan performed on 20 of the patients showed that 40 per cent had a recurrence of stones and a quarter had scarring, and 1 of the 43 had developed hypertension (Nephrologie, 1993; 14 (6): 305-7).

Other studies confirm that lithotripsy can raise blood pressure (J of Urol, December 1993) and heartbeat (Pol Arch Med Wewnet, May 1993). Rarely, it can even rupture the kidney (Br J of Urol, December 1991). The extent of damage appears dependent upon the dose of shock waves used. In one study, nearly a fifth of patients had sustained damage (Jap J of Clin Radiology, September 1990)

Of 105 patients with CT studies done after ESWL, 31 per cent had kidney edema (water retention) or bleeding in or outside the kidney. Three of the 23 patients who’d been followed after three years had chronic kidney changes, and 10 had new stones (Rof Fort Geb Ront Neuen Bild Verfahr, February 1993).

ESWL can also cause septic shock (Act Urol Japonica, December 1993), and the bacteria within the stones, released upon fragmentation, cause inflammation (Acta Urolog Japon, September 1992).

Aside from the damage to the kidney, there are suggestions that lithotripsy can cause hearing loss, although these suggestions may be unfounded (Br J of Urology, 1994, 73(2): 129-35). Nevetheless, there is evidence that shock waves can structually damage both sperm and the testes. Studies on human semen and rat testes showed that after five weeks, the treated rat testes appeared to have atrophied, with an absence of sperm cells. In the human cells, sperm movement and the percentage of viable sperm decreased, while abnormal sperm correspondingly increased (Urol Internation, 1993, 51 (3): 152-7). Hemorrhage has also been noted in the scrotum (J of Urology, August 1993).

These problems are not only caused by the fragmentation of the stones but also cavitation (bubbling), which can cause physical damage and generate free radicals. One study in rats found that vitamin E, which acts as a free radical “scavenger”, could offer “moderate” protection from their release (Ultrasonics, July 1994). Rarely, it also seems to cause the generation of antibodies to the kidney’s own tissue (Urolog Intern, 1994; 52 (2): 106-8).

For more complicated stone problems, percutaneous nephrolithotomy (a surgical technique), is the procedure of choice. However, this technique is associated with a 29 per cent reduction in kidney function (J of Endourology, 1994; 8 (1): 15-9) and also scarring (J of Endourology, Dec 1993).

Urologists have found that giving patients certain drugs before the procedure may minimize ESWL damage. Studies have shown that calcium antagonist nifedipine may limit kidney tubular dysfunction, and angina drug verapamil also protect patients (European Urology, 1994; 25 (2): 99-104; J of Urology, July 1993).

Besides shock waves, a number of drugs have been used to dissolve stones or prevent the formation of new ones. Glycosamionglycan pentosan polysulphate and chlorhexidine have been used to successfully break down stones, although in the case of the former, half the patients in one study had new stones re-form (World J of Urology, 1994, 12 (1): 52-4). Medicine has even tried non-steroidal anti-inflammatory drug diclofenac sodium (Urolog Internation, 1992, 48 (4): 404-8).

Mineral salts have also been used to break up or prevent stones. Sodium bicarbonate sometimes works, although in one study, some patients only partially responded to therapy, necessitating surgery as a last minute salvage operation (Urolog Internation, 1992; 48 (1): 81-6). Sodium lactate solution has been used without apparent side effects, according to one Russian study (Vrachebnoe Delo, June 1992). Potassium citrate given with a large quantities of water has been shown to break up and stop future formation of stones in nearly three-quarters of patients (Biomed and Pharmaco, 1993 (47 (1): 25-8), although it is not as effective as potassium magnesium citrate combination (J of Bone & Mineral Res, March 1992). And of course with this approach, you’ve got to take these salts for the rest of your life.

But all these procedures do not address the reasons the body is making stones in the first place. In fact, many, including ESWL, may even increase the rate of new stone formation (Hepinstall).

* See a good medical herbalist who will be able to supervise a kidney cleanse. If you have any sizeable stones, you will need the help of a professional; they can be quite painful when they come out if they are not broken up properly. One woman uses parsley and cornsilk tea to flush out her kidneys from time to time, and a friend of hers – who was due to have kidney stones removed – went to a good reflexologist and passed the stones without an operation over the next few days. You may also find support from Berberis vulgaris, a herbal kidney tonic.

* In a recent study, one third of 773 individuals involved in a road accident as a driver, bicycle rider or pedestrian experienced some level of anxiety, depression, fear of travel or post traumatic stress disorder (PTSD) 3 to 12 months later and, in most cases, persisted. After one year, about half the group had phobic travel anxiety, nearly 60 per cent had general anxiety, and half were diagnosed with PTSD (Am J Psychiatry, 2001; 158: 1231-8).

* New research in nearly 1300 men suggests that, during a severe asthma attack, men are less likely than women to notice the symptoms of the attack. The reason for this is unclear, but it may be that men perceive less discomfort because of greater lung size and muscle strength, or because they generally develop asthma at an earlier age than women. Men also tend to only seek medical attention when symptoms are too severe to ignore, the researchers noted (Ann Emerg Med, 2001; 38: 123-8).

* What’s lurking in that paddling pool? Physicians in Canada have found the first outbreak of a new type of Pseudomonas infection called ‘hot foot syndrome’. This discovery was made when 40 children, aged 2 to 15, developed intense pain in the soles of their feet within 40 hours of using the same wading pool. A hot, red swelling began after a few hours, along with pain so severe that the children were unable to stand up. Three children were given oral cephalexin (an antibiotic) while the others were treated with cold compresses, analgesics and foot elevation. In all cases, the condition resolved within 14 days, although it recurred in three children after they revisited the same pool (N Engl J Med, 2001; 345: 335-8).

Ultrasound has largely replaced urography – radiography of the urinary tract using an opaque visualising medium – for assessing urinary tract infections (UTIs) in women and children. It’s also cheaper and quicker.

But men don’t have UTIs as much as they have kidney and urinary tract stones so, for them, urography is still the technique of choice.

However, a urology and radiology department team at Stevenage’s Lister Hospital concludes that, given the hazards associated with the ionising radiation found with urography, ultrasound and X-rays should be used first when investigating men with a known UTI (BMJ, 2002; 324: 454-6).

“Because the majority of stones contain calcium and because hypercalciuria (too much calcium) has been associated with the formation of stones, calcium restriction has been routinely recommended for patients who have kidney stones. However, we are unaware of any data that demonstrate that restriction of calcium intake reduces the recurrence of kidney stones,” say the researchers.

The calcium rich foods offering the best protection against kidney stones are skim or low fat milk, and cottage or ricotta cheese. Calcium supplements were not found to have the same effect. “Nondairy sources of calcium such as oranges and broccoli also appeared to be protective,” says the researchers. They found that a high intake of animal protein was “directly associated” with the risk of kidney stones.

When a stone is too big to pass naturally, it can cause chronic urinary tract and kidney infections, such as pyelonephritis. Kidney stones can act as a focus for organisms to live, and organisms provide the focus around which stones can grow, so the problem of infection can become self perpetuating.

Last year, a new type of bacteria called nanobacteria was discovered in both human and cow blood. Related to the Brucella and Bartonella species, the bacteria is the smallest known strain with a cell wall. Scientists discovered that these novel bacteria can produce, in culture, a structure that precipitates carbonate apatite crystals, similar to those found in the core of many kidney stones.

When the Finnish team that discovered the nanobacteria examined 30 randomly collected kidney stones, it found them thriving in each and every one of the stones. Their results were confirmed when cultured extracts of all 30 stones grew the nanobacteria (Proc Natl Acad Sci, 1998; 95: 8274-9). Bacterial infection has long been associated with kidney stones. However, this study suggests that at least some kidney stones might be caused by infection a conclusion which opens up new possibilities for treatment and prevention.

Eat calcium rich foods, including milk and dairy products, all cheeses (especially Swiss and cheddar), almonds, brewer’s yeast, parsley, corn tortillas, globe artichokes, prunes, pumpkin and sesame seeds, cooked dried beans, cabbage, winter wheat, soya beans, salmon, sardines and green vegetables. Ironically, some of these are also high in oxalates, so choose carefully.

Avoid high oxalate foods, such as beans, cocoa, instant coffee, parsley, rhubarb, tea, spinach, beet tops, carrots, celery, cucumber, grapefruit, kale, peanuts, pepper and sweet potato. Although the influence of these foods on your risk of stone formation is small, especially if your diet is high in calcium, regular “stone formers” should consider limiting or cutting them out altogether.

Drink plenty of fluid. Water is the first and best choice. You should aim to drink at least 8 to 10 glasses a day. This will lower the concentration of stone forming minerals in the urine. Probably due to its high calcium content, harder water has been correlated with a smaller incidence of kidney stones (Urol Res, 1979; 7: 157-60).

Increase dietary fibre. Patients with kidney stones tend to have lower intake of fibre (Br J Urol, 1981; 53: 416-20). Adding fibre to the diet of stone formers has been shown to lower their calcium excretion by as much as 40 per cent (Rev Paul Med, 1989; 107: 19-24; Br Med J, 1980; 281: 426). This may be due to the phytic acid found in whole grain wheat, corn, rye, millet, barley and beans which, by binding to calcium and magnesium, helps remove their excess from the body more efficiently (Lancet, 1980; ii: 1113-4).

Cut out sugar. Sugar must be processed by insulin which, in turn, causes calcium to be excreted into the urine (J Clin Invest, 1975; 55: 845-55). While the effect is most marked in stone formers, sugar consumed by normal individuals has also been found to increase the excretion rates of calcium, oxalate, uric acid and glycosaminoglycans (Nutri Health, 1987; 5: 9-17). To placate your sweet tooth, eat fruit which contains fructose and so doesn’t need insulin for processing.

Try herbal remedies. Cranberry juice or extracts may help to reduce urinary calcium levels (Urol, 1973; 1: 67-70), as might rose hip tea (Planta Med, 1992; 58: 509-12).

The Chinese herb Desmodium styracifolium is thought to inhibit the formation of calcium oxalate stones by increasing urine output and decreasing the excretion of calcium (Br J Urol, 1993; 71: 143-7). Compounds isolated from the rubia, cassia and aloe species bind calcium in the urinary tract and significantly reduce the growth rate of urinary calcium crystals (Pharmacology, 1980; 20: 104-12). Madder root (Rubia tinctoria) and Aloe vera may be used either as a preventative or to reduce the size of the stone during an attack (J John Bastyr Coll Nat Med, 1981; 2: 18-27).

Khella (Ammi visnaga) has long been known as an effective relaxant for the ureter, thus allowing stones to pass more easily (Br J Urol, 1933; 5: 213-24; W Mitchell, Naturopathic Application of Botanical Remedies, Seattle, Washington: W Mitchell, 1983).

The most powerful herbs for dissolving stones are Hydrangea arborescens, gravel root (Eupatorium purpureum), parsley (Petroselinium crispum), Arctostaphylos uva ursi and wild carrot (Daucus carrota).