The increasing popularity of plant-based milk alternatives like almond milk has raised questions for many, especially those concerned about kidney health. Kidney stones are a common issue, often leading people to scrutinize their dietary choices, bringing almond milk into focus regarding its potential impact on stone formation.
Almond Milk and Oxalate Content
Oxalates are naturally occurring compounds in various plant foods, a primary concern for kidney stone formation, especially for calcium oxalate stones, which constitute about 80% of all kidney stones. When too much oxalate is present in the urine, it can bind with calcium to form crystals that aggregate into stones.
While almonds are high in oxalates, the oxalate content in almond milk is generally much lower than in whole almonds due to processing and dilution. Commercial almond milk typically contains between 0.08 to 0.44 milligrams of oxalate per 100 milliliters. However, other research suggests a broader range for almond milk, from 5.6 mg to 68 mg per 100 ml, with homemade versions potentially having the highest content.
Almond milk is often cited as having a higher oxalate concentration compared to some other plant-based milks like oat, rice, and macadamia milk, which have more favorable parameters regarding kidney stone risk. Coconut milk and flax milk, for instance, have almost undetectable oxalate levels. While almond milk does contain oxalates, the amount can vary significantly by brand and processing, and it is typically lower than in whole almonds.
Calcium and Phosphorus in Almond Milk
Calcium plays a complex role in kidney stone formation; adequate dietary calcium can help prevent calcium oxalate stones. When calcium from food binds to oxalates in the digestive tract, it prevents oxalate absorption into the bloodstream and reaching the kidneys. A diet low in calcium can paradoxically increase stone risk because more oxalate is absorbed and excreted in the urine.
Fortified almond milk often contains added calcium to rival levels found in dairy milk. A cup of commercial almond milk can provide around 482 mg of calcium, which is substantial, especially compared to skim milk’s 316 mg. However, the body’s absorption of this added calcium from plant-based milks might not be as efficient as from naturally occurring sources like cow’s milk. Many fortified almond milks aim to match or exceed dairy milk’s calcium content.
Regarding phosphorus, almond milk generally contains lower levels than cow’s milk, typically around 73 mg per cup, unless phosphate additives are included. While phosphorus is a component of some kidney stones (calcium phosphate stones), for most individuals, the natural phosphorus levels in almond milk are not a primary concern for stone formation. However, it is important for individuals with advanced kidney disease to monitor phosphorus intake, and they should check product labels for added phosphate ingredients.
Making Dietary Decisions for Kidney Stone Prevention
For many individuals, almond milk is not a significant risk factor for kidney stone formation, particularly if consumed as part of a balanced diet with adequate hydration. The primary concern for stone formers relates to its oxalate content, which can be higher than some other plant-based milks. However, the amount is considerably less than in whole almonds, and factors like fortification and processing can influence its composition.
General dietary recommendations for preventing kidney stones emphasize ample fluid intake, aiming for 2-3 quarts of liquid daily to ensure sufficient urine production. Maintaining a moderate and consistent intake of dietary calcium, ideally 1000-1200 mg per day from food and beverages, is also important, as this helps bind oxalates in the gut. While limiting extremely high-oxalate foods like spinach or rhubarb may be advised for some, a varied diet with adequate calcium intake is often more beneficial than strict oxalate restriction. Always consult a healthcare provider or registered dietitian for personalized dietary advice.