Lactose-free milk may raise blood sugar more quickly than regular milk, warns endocrinologist

Endocrinologist Tsai Ming-chieh highlights that lactose-free milk, often considered a gentle alternative for those with lactose intolerance, can still impact blood glucose levels, emphasizing the importance of checking nutrition labels for those managing diabetes or weight.

Lactose-free milk is often marketed as a gentler choice for people who cannot tolerate ordinary dairy, but it is not the same as sugar-free milk. Endocrinologist Tsai Ming-chieh said he tested a cup for himself and saw his blood glucose rise sharply, underscoring a point that can easily be missed by consumers who are trying to manage weight or blood sugar.

Tsai said on Facebook that many people with lactose intolerance turn to lactose-free fresh milk because standard milk can trigger stomach cramps and frequent trips to the toilet. The appeal is understandable: the product is designed to remove the digestive discomfort caused by lactose, the natural milk sugar that some people cannot break down properly.

But, as Tsai explained, lactose is not removed from the drink. Instead, it is split in advance by an enzyme process into glucose and galactose, which the body can absorb more quickly. That means lactose-free milk may be easier on the gut, but it can still affect blood sugar, and in some cases may do so faster than regular milk.

In Tsai’s test, his blood glucose rose from 93 mg/dL to 176 mg/dL after one cup, a jump of 83 mg/dL in a short time. Health information from HealthCentral, Healthline and other nutrition guides similarly notes that lactose-free milk still contains carbohydrates and should not be assumed to be a low-sugar option. Those sources also point out that unsweetened almond, soy and pea-protein milks generally contain less carbohydrate, while sweetened, flavoured or oat-based drinks can raise glucose more noticeably.

For people with lactose intolerance, lactose-free milk remains a useful option for avoiding digestive symptoms. For those trying to control blood sugar or reduce calorie intake, however, the label alone is not enough. The safer approach is to check the nutrition panel, watch portion size and avoid assuming that “lactose-free” means “sugar-free”.