Swiss cheese contains almost no lactose. A typical 40-gram serving (about 1.5 ounces) has roughly 0.04 grams of lactose, making it one of the lowest-lactose dairy products available. For comparison, a cup of milk contains 9 to 14 grams.
Why Swiss Cheese Is So Low in Lactose
Two things strip lactose out of Swiss cheese. First, during production, most of the lactose drains away with the whey, the liquid separated from the curds. Second, as the cheese ages, bacteria consume whatever lactose remains and convert it into lactic acid. Swiss cheese typically ages for several months or longer, which gives those bacteria plenty of time to do their work. By the time the cheese reaches your plate, the lactose content is essentially negligible.
This is a general rule across hard and aged cheeses: the longer the aging, the lower the lactose. Swiss-style varieties tend to be aged long enough that lactose drops to undetectable levels in laboratory testing.
How Swiss Compares to Other Cheeses and Dairy
Swiss cheese sits at the very bottom of the lactose scale among common dairy products. Here’s how it stacks up per typical serving:
- Whole milk (1 cup): 9 to 14 grams of lactose
- Mozzarella (1 ounce): 0.08 to 0.9 grams
- Sharp cheddar (1 ounce): 0.4 to 0.6 grams
- Swiss cheese (1.5 ounces): approximately 0.04 grams
That puts Swiss cheese at roughly one-tenth the lactose of sharp cheddar and a tiny fraction of what you’d get from a glass of milk. Even mozzarella, which most people with lactose intolerance handle fine, contains significantly more.
Emmental, Gruyère, and Jarlsberg
“Swiss cheese” in the United States usually refers to a mild, hole-filled cheese modeled after Emmental. But several related Swiss-style cheeses share the same near-zero lactose profile. Laboratory analysis of multiple samples found that Emmental (in block, sliced, and grated forms), Gruyère, and Jarlsberg all contained undetectable quantities of lactose, falling below the threshold that lab equipment could reliably measure.
The key variable is aging time, not the specific variety. A young, lightly aged cheese will retain more lactose than one that has matured for months or years. Traditional Gruyère is typically aged five months or longer, and Jarlsberg for at least three months. All three consistently test as functionally lactose-free.
Is Swiss Cheese Safe With Lactose Intolerance?
For most people with lactose intolerance, Swiss cheese is a non-issue. Research from the National Institute of Diabetes and Digestive and Kidney Diseases suggests that many lactose-intolerant individuals can handle up to 12 grams of lactose in a sitting without symptoms or with only mild discomfort. Swiss cheese delivers a fraction of a single gram per serving, so you’d need to eat an unrealistic quantity before approaching that threshold.
Swiss cheese is also classified as low-FODMAP, making it suitable for people managing irritable bowel syndrome. A standard 40-gram serving is generally well tolerated. If you’re following a strict elimination diet, Swiss cheese is one of the safest dairy options to keep on your plate.
Tips for Choosing the Lowest-Lactose Option
If you want to minimize lactose as much as possible, look for Swiss cheese that has been aged longer. Imported Emmental and Gruyère with specific aging designations (such as “reserve” or “aged”) will have had more time for bacterial cultures to consume residual lactose. Domestic Swiss cheese sold in pre-sliced packages is still very low in lactose, but artisan or traditionally produced versions aged six months or more are your best bet.
Processed cheese products labeled “Swiss” may contain added milk solids or whey ingredients that reintroduce lactose. Check the ingredient list if you’re particularly sensitive. A block or wedge of natural Swiss cheese, with a short ingredient list of milk, cultures, salt, and enzymes, will consistently be the lowest-lactose choice.