Although cow’s milk gets a bad press amongst some nutritionists, it is an important source of nutrients and energy. In particular, milk contains factors that are anti-obesogenic, possibly fatty acids such as conjugated linoleic acid (CLA) and calcium. This explains the inverse association between full fat dairy produce and body weight. If milk is an anti-obesogenic food, the benefits from that alone suggest that it is a healthy food and should be part of a healthy high quality diet. However, only a small proportion of the World’s population are able to tolerate milk because most people lose the ability to digest the milk sugar lactose into adulthood. Generally people of European descent tend to be able to digest lactose, whilst the rest of the World’s population do not. Consuming lactose without the ability to produce the enzyme lactase results in the lactose passing to the colon where it is fermented by gut bacteria to form hydrogen gas, and this causes most of the symptoms of lactose intolerance, including flatulence, bloating and gut cramps.
The obvious solution to lactose intolerance is to avoid milk and milk containing products, and this is the solution followed by most lactose intolerant individuals. However a number of milk products have been created that claim to circumvent the requirement to digest lactose and are therefore suggested to be suitable for lactose intolerant individuals. For example, the lactose in milk can be predigested using galactosidase enzymes to form hydrolysed low lactose milk. Alternatively, sweet acidophilus milk that contains cultures of the bacteria Lactobacillus acidophilus may be beneficial. Lactobacillus acidophilus cultures are used to produce yoghurt and may be the reason that yoghurt can be consumed by those with lactose intolerance. The bacteria contain beta-galactosidase enzymes and these may be able to digest some of the lactose contained within the milk. A number of studies have assessed the efficacy of these product with respect to taste and the symptoms they induce in subjects.
For example, in one study1, lactose intolerant and lactose tolerant individuals were fed a number of milk products and their symptoms and taste preferences noted. Milk products were consumed for nine weeks and included skim milk, lactose hydrolysed milk, sweet acidophilus milk and skim milk with added glucose (to make it taste like sweet acidophilus milk). Each subject consumed 4 litres of each product per week over the 9 week period, before switching to an alternative milk type. Neither the subjects nor the researchers were aware of the types of milk being consumed. The researchers then assessed the degree of symptoms experienced by the individuals based on pain, bloating, nausea, flatus, emesis and bowel frequency. The results showed that in the lactose intolerant individuals, the lactose hydrolysed milk produced significantly fewer symptoms of lactose intolerance compared to the non-hydrolysed milk, but did not reduce those symptoms to the levels of the lactose tolerant subjects.
Dr Robert Barrington’s Nutritional Recommendation: Therefore lactose hydrolysed milk may be an effective strategy to alleviate some of the symptoms of lactose intolerance in some individuals. However, both the control group (those with lactose tolerance) and the lactose intolerant individuals reported a decreased taste acceptability with the hydrolysed milk product. Interestingly the sweet acidophilus milk was not associated with a alleviation of the symptoms of lactose intolerance, suggesting that the presence of the Lactobacillus acidophilus bacteria, with their inherent beta-galactosidase activity, are not wholly responsible for the reduced degree of symptoms associated with yoghurt consumption in lactose intolerant individuals. In fact other studies have shown that the galactosidase activity of yoghurt is likely not responsible for its improved tolerance in lactose intolerant individuals (here). Consuming either yogurt or low lactose milk is recommended to those with lactose intolerance who desire a milk product. Starting with small amounts and slowly increasing the intake over a period of time is recommended.
RdB
