I found the follwing fact about lactose intolerance (LI) in "Milk is not for everybody", by Steve Carper, 1995. 1) Lactose is a disaccharide (sugar) found in most mammals' milks. Its digestion produces 2 simple sugars: lactose + water --> glucose + galactose 2) LI refers to symptoms like bloating, gas, diarrhea after ingestion of lactose. It is caused by insufficient secretion of lactase. Diarrhea is caused by the fact that indigested lactose draws the body's water in the intestine by diffusion; gas is produced by colon bacteria which are fed by undigested lactose. 3) Among adults, about 75% of Black Americans, 25% of White Americans and 100% of Japanese are LI. Few Scandinavians are LI. The production of lactose usually decreases with age. 4) It is very difficult to know if you are LI. The only reliable way is to test for it, by drinking 50 grams of lactose in solution (in water), on empty stomach, and watch symptoms. That quantity corresponds to about 1 litre of milk, which is unrealistic. Moreover, 1 litre of milk would be better tolerated because the other compounds slow down the transit. 5) Most (>75%) of LI can still digest 1 glass of milk, even on empty stomach. And even lactose malabsorbers don't necessarily have symptoms because the intestinal flora adapts. When strains of bacteria which digest lactose and don't produce gas develop, you don't experience symptoms. 6) If you drink milk after having been on a lactose-free diet for some time, you are likely to experience bad symptoms, NOT because you produce less enzymes, but because the intestinal flora has changed. However, 1 or 2 weeks are usually enough for the flora to readapt. 7) Some factors can improve lactose digestion: *drink small quantities; most people can tolerate 1 glass. *slowing down the transit, to allow enough time to the enzymes: drink whole milk, after meals. *temperature: human lactase works best at the body's temperature, i.e. 37 degree C (98.6 F). Thus, warm milk is better digested than refrigerator-cold milk. 8) Even with all these precautions, a small percentage of the population still have LI symptoms. 9) Lactose is not the only problem in milk. A small percentage of the population is intolerant to milk protein (usually casein). What happens is that a tiny quantity of undigested proteins enter the blood stream. Normally, the immune system eliminate them silently, but allergics have an exaggerated immunological response. 10) Milk (in moderation, and with precautions) can however benefit to most SADers because they would otherwise be calcium deficient. Except milk, the most important source of calcium is green vegetables (but gnawing fish bones can work too). Of course, getting the correct amount of calcium is not sufficient to assimilate it, you also need vitamin D, correct ratio Ca/P... And for women, hormonal factors and exercising are important too. Best wishes, Jean-Louis [log in to unmask]