DEAR DR. BLONZ: I know that if you are predisposed to kidney stones, consuming foods high in oxalates is not a good idea. But I also read that oxalates will accumulate in the body. And they are described as tiny, sharp and glasslike. Doesn't sound like something I want in my body. So, even for people who are not prone to kidney stones, is it a good idea to avoid foods high in oxalates like spinach, beets, almonds, etc.? -- B.S., Albany, California

DEAR B.S.: Kidney stones, also referred to as calculi, are painful and nothing to be trifled with, a sentiment that anyone who's had firsthand experience would echo. Family (genetic) history, lifestyle and environmental factors play a role. Adjustments can be made to diet and lifestyle to prevent situations where stones are likely to form and grow large enough to cause misery. But before becoming unduly concerned, the primary goal is to learn whether you are at risk. Asking your family practitioner is key, and a visit to a nephrologist (kidney doctor) may also be warranted. Pathology tests, including urinalysis, can help determine your level of risk.

It is appropriate that you raised the issue of oxalates. Stones form for several reasons, including infection, but about 70% of kidney stones are composed of insoluble calcium salts, usually calcium oxalate. People most likely to suffer from this type are those who have above-normal levels of oxalates in their urine (again, a reason to get those tests).

Does it make sense to limit your intake of the compounds that make up the stones? Several foods are high in oxalates, including spinach, cabbage, chard, beet and rhubarb leaves, cocoa, tea and bamboo shoots. Reducing dietary oxalates is a reasonable strategy, but it won't always solve the problem, and you could be unnecessarily giving up many healthy foods if it turns out that kidney stones are not a huge issue for you. Most of the oxalate inside our body doesn't come from foods; it comes as a result of many metabolic processes.

Research has also found that restricting calcium can increase the risk of developing stones. When you take in adequate amounts of calcium, the calcium can bind with oxalates in food to form calcium oxalate stones in your intestines, which pass from your body. Recent studies have shown that foods high in calcium, including dairy, can help prevent calcium stones. When calcium intake is restricted, almost all the oxalate is absorbed into your bloodstream and passes out through your urine, which could increase the risk of stone formation.

An important lifestyle change to prevent stones is to drink more liquids, with water being the best choice. Even mild chronic dehydration can increase the likelihood of kidney stone formation. Stones are also more common in hot climates and during the summer months, ostensibly because we tend to perspire more and pass more concentrated urine.

Depending on the type of stones that form, dietary adjustments and increased hydration can limit their formation. Some medications can help; another reason to keep your health professional involved.

For a more in-depth consideration, see b.link/3nn8k6, and for kidney stone self-care, see b.link/vstfudp.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: In a recent column about digestion and gas, I felt you should have mentioned probiotics. I have friends who swear a daily probiotic has changed their lives. I take one also and have had good results. I enjoy your column very much. Thank you. -- S.R., Contra Costa, California

DEAR S.R.: Thank you for your comment, which raises an important topic. Most have heard of the term "microbiome," which refers to the community of microbes that live in our large intestine; it is also referred to as the intestinal flora. Despite their reputation for contributing to ill health, not all bugs are bad. Microbes, which for our discussion will include bacteria, viruses, fungi and archaea, play an important role in helping maintain the ecology in the digestive system. Clinical studies reflect their impacts on our overall health.

However, there are also ones that are not so friendly. Think of the microbiome like the Wild West without a sheriff, where survival is the name of the game. All the players seek to multiply, but it is in the interest of good health that we eat and behave in a way that keeps our microbial allies ahead of the game.

Probiotics are the friendly bacteria; a probiotic food or supplement contains these bacteria. Several probiotic strains can survive in your intestines. A related term, "prebiotic," which is addressed in greater detail below, refers to a food that facilitates the growth and survival of probiotics by providing the nourishment they require.

In the early 1900s, Elie Metchnikoff, a Russian biologist working at the Pasteur Institute in Paris, proposed that health and longevity were linked to the type of bacteria living in the intestines. In his 1908 book "The Prolongation of Life," Metchnikoff attributed the health and long lives of Balkan tribes to the bacteria used to make the yogurt that was a staple of their diet. Milk products have proven to be popular probiotic foods because they are easily cultured to grow these bacteria. The common culturing strains are s. thermophilus and l. bulgaricus.

In addition to yogurt, milk products such as kefir, low-fat acidophilus milk and buttermilk contain these bacteria and can also have added l. acidophilus or bifidus (bifidobacteria) -- friendly bacteria equipped to establish themselves as long-term residents in the large intestines. Always check the label to see what is in products you are considering. Other foods containing friendly bacteria include sauerkraut (fermented cabbage), kimchee, miso soup, tempeh and natto. The friendly bacteria are also available as a dietary supplement. For more on probiotic foods, see b.link/breafb7. For a probiotic pro and con, see b.link/ph7772f.

Prebiotics, an associated topic, are foods with elements that can bypass normal digestion. When arriving in the large intestine, they can serve as nourishment for the microbiome. Foods such as legumes, peanuts, garlic, onions, leeks, Jerusalem artichokes, wheat, barley, asparagus, rye, chicory and berries contain constituent substances that feed the intestinal flora. There are also substances known as fructooligosaccharides (FOS) and inulin, which have a special ability to reach the large intestine intact. (You may see these as ingredients in supplements.) Be sure to discuss any intestinal health issues with your physician and express your interest in opting for a probiotic with the best organisms in the best dosage for issues you face.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I respect your expertise and skepticism, but feel the need to vent about your rejection of all that's alternative, much in the same way that medical doctors do. I hear about many successes involving alternative medical treatments, where the doctor says, "I don't know what you are doing, but keep doing it." Current medical education has fallen short in addressing alternative medicine. -- S.F., St. Paul, Minnesota

DEAR S.F.: I am not against all things new and will not reject something simply because it is "alternative." At the same time, I am not in lockstep with all things mainstream. Ours should be a system that tests, verifies and efficiently integrates new treatments. Research takes funding and time, however, and people understandably clamor for any new product as soon as they hear it might help in their situation. Evidence is not always within easy reach.

Given your question, how would you expect a medical doctor to react if a patient relates that some nontraditional therapy has "worked" for them? There is a danger, especially with social media, when people broadcast their experience with a product or treatment as being something that will work for all, but there is no clinical evidence to support the claim.

Don't lose sight of the fact that a properly nourished and cared-for body is designed to fix what it can, but it can take time. Say you are trying a series of products to find one that helps. Was the one you were using at the time things improved really the one that worked? Or was it your body's innate capacity for healing finally getting the upper hand? That is why testimonials are unreliable.

Objective clinical testing, that would ideally include the use of placebos, is needed to provide a controlled examination of whether and under what circumstances something can be effective. Be skeptical if the origin of their claims involves a product being sold by those having a financial interest in its success.

There is no question that alternative medicine has its allure. To an individual dissatisfied with the medical establishment, or to one frightened by disease, discomfort and pain, the temptation to try something that promises benefits can be irresistible.

There may be situations where it helps, but in others, it can lead to frustration compounded by a waste of one's time and money. Time is key here. With certain health conditions, delaying the initiation of proven, even if only marginally effective, medical therapy can result in tragedy, allowing for the progression of a treatable condition into something much more serious.

Those who profit from alternative treatments should shoulder the burden of substantiation before being able to make claims of success, and they should do so with research providing competent and reliable scientific evidence. At the same time, there is a definite responsibility that falls upon scientists, educators and health professionals to be objective and open-minded.

There is nothing wrong with being new and different; many of the treatments that are currently in the mainstream were once considered revolutionary. Being reflexively dismissive of alternative approaches is not the way, but where health is concerned, the concept of "let the buyer beware" takes on special importance.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.