Lactose intolerance occurs when the small intestine does not produce enough lactase enzyme to break down lactose, the sugar found in milk. Lactose is a disaccharide consisting of two simpler sugar molecules, glucose and galactose, which must be separated for absorption. Undigested lactose moves to the large intestine, where it interacts with bacteria, causing uncomfortable symptoms like bloating, gas, and abdominal pain. Over-the-counter lactase supplements provide the missing enzyme, allowing individuals to digest dairy products and avoid these issues.
Quantifying Lactase Activity: The FCC Unit
Lactase supplements are measured by their biological activity, not by weight like milligrams. The industry standard for quantifying this activity is the Food Chemicals Codex (FCC) unit. The FCC is an international standard that provides a uniform method for measuring the potency of food ingredients, including enzymes. One FCC Acid Lactase Unit (ALU) is defined by the quantity of enzyme that liberates one micromole of a specific substrate per minute under controlled conditions (pH 4.5 and 37°C). This standard ensures consumers can accurately compare the strength of different supplements, as a higher FCC unit count indicates the ability to break down a greater amount of lactose.
Estimating Lactose Content in Dairy Products
Calculating the necessary enzyme dose begins with determining the amount of lactose being consumed. Lactose content varies significantly across different dairy products due to processing methods. Whole milk, for example, typically contains 12 to 13 grams of lactose per one-cup serving, and soft dairy products like ice cream and low-fat yogurt also contain elevated levels.
In contrast, hard, aged cheeses like Parmesan and Cheddar contain very little lactose, often less than one gram per serving, because the aging process naturally breaks down the milk sugar. Consumers can estimate intake by checking the nutrition facts label on packaged foods. Looking at the “sugars” line is a precise method, as most sugar in plain dairy is lactose. Processed foods, baked goods, and even some meats may also contain “hidden” lactose, making label reading essential.
Calculating Your Dose: Lactase Units per Gram of Lactose
The standard guideline suggests using approximately 1,000 FCC units of lactase for every 5 grams of lactose consumed, translating to about 200 FCC units per gram of lactose. For example, a person consuming a cup of milk with 13 grams of lactose would need roughly 2,600 FCC units to break down the sugar. The required FCC units are calculated by multiplying the estimated grams of lactose in a meal by 200.
Since supplement dosages come in fixed amounts (e.g., 3,000 FCC or 9,000 FCC), individuals should round up to the nearest available strength. People with severe intolerance may need a higher ratio, sometimes closer to 500 FCC units per gram, while those with mild intolerance may tolerate a lower dose.
Optimizing Enzyme Supplementation
Achieving optimal effectiveness from lactase supplements requires proper timing, not just the correct numerical dose. The enzyme must be present in the stomach and small intestine simultaneously with the lactose for digestion to occur. Therefore, the supplement should be taken immediately before or with the first bite or sip of the dairy product.
The duration of the meal also influences the required dosage. The enzyme’s activity in the stomach typically lasts for a limited time, often around 30 to 45 minutes. For larger meals involving continuous dairy consumption, an additional dose may be necessary after the initial period to maintain sufficient enzyme activity. Individuals who require consistently high doses should consult a healthcare professional for proper management.