The DASH diet calls for two to three servings each day of low-fat or non-fat dairy products. However, some people cannot tolerate lactose (a sugar found in dairy products). Lactose intolerance can cause people to experience stomach cramps, bloating, nausea and/or diarrhea after consuming dairy products. These symptoms occur because their bodies do not produce enough of the enzyme lactase, which breaks down lactose.

Patients who are lactose intolerant can stay true to the DASH diet by using specialty products. Lactose-free or reduced-lactose milk is sold in the dairy case of most supermarkets. In addition, lactase enzymes can be purchased in liquid or pill form. The liquid can be added directly to dairy products to neutralize the lactose contained in them. Pills can be taken in capsule or chewable tablet form immediately before consuming the dairy product. Any of these methods can enable a lactose intolerant person to stay on the DASH diet.