From the article that Yuri cited:
"Summary:
• Drink 2 quarts of water a day. Consider mineral water as part of this fluid consumption.
• Consume moderate animal protein, seafood and alcohol.
• Increase fruit and vegetable consumption.
• Do not consume drinks sweetened with fructose. Unsweetened orange juice is encouraged.
• Do not drink cranberry juice.
• Take magnesium (citrate) 200mg 1-3 times daily with food.
• Maintain urine pH from 6.2 to 6.5. Test urine pH at 10 a.m. 2 p.m. and bedtime. Adjust food, mineral water,
water and mineral supplements accordingly."
I've been doing some research. Here is a summary of my findings (I can supply references if anyone is curious where I got any of this info):
Factors associated with increased incidence of kidney stones:
Low water intake
High omega 6 intake and low omega 3 intake
High arachidonic/linoleic acid ratio
High intake of poorly-absorbed calcium, such as from cheap calcium supplements and dairy products
Hypercalcuria (high urinary calcium levels)—possibly in part due to the high-dairy intake of many
Urinary magnesium/calcium ratio lower than 0.7
Hyperoxaluria (high urinary oxalate levels)
Diet high in animal protein, poorly-absorbed calcium (dairy products, some calcium-enriched processed foods), oxalate (colas, chocolate, legumes like peanuts and soybeans, nuts, beets, coffee, cola, rhubarb, spinach, black tea, phytate-rich whole grains—especially wheat bran, beer, ale), and purines (poultry, seafood, organ meats, red wine, stouts)
High intake of vitamin C supplements
Urine with a pH below 6.0 in combination with high urinary uric acid or above 7.2 in combination with high urinary phosphate
Ketogenic diet—dairy products, oils (e.g. canola, olive, and MCTs like coconut), meats (bacon, beef, etc.), seafood, eggs, peanut butter, keto yogurt, some limited fruits (like apples) and sugar-free desserts like Jello and keto custard (
http://www.jhu.edu/jhumag/495web/fat.html,
http://en.wikipedia.org/wiki/Ketogenic_diet)—other risk factors from this diet include dehydration (which could account for part of the kidney stone risk) and gall stones
Low urinary citrate
Factors associated with low incidence of kidney stones:
High water intake, especially mineral water containing magnesium
Low omega 6 intake and high omega 3 intake
Low arachidonic/linoleic acid ratio
Urinary magnesium/calcium ratio higher than 0.7
Oral magnesium supplementation
Low intake of animal protein, poorly-absorbed calcium, and oxalate
Urine pH between 6.0 or 6.2 and 6.5
High urinary citrate
Based on this, I’m thinking of keeping my intake of water (mostly mineral water containing magnesium), magnesium, and omega 3 fats relatively high while keeping omega 6 fats low and continuing to avoid dairy products, grains, legumes, red wine and beers/ales/stouts.
I'm guessing that the traditional Inuits had urinary pH's below 6.0, whereas they reportedly had low rates of kidney stones, so I don't think it's absolutely necessary to get it within the 6.2 to 6.5 level, though that may be a benefit.
Note about the ketogenic diet: it includes dairy products, which is a risk factor for calcium oxalate/phosphate stones and there was also above-average dehydration among the 5% of dieters who developed kidney stones.