Consumers Need Evidence Based Information – Not Myths & Misconceptions
Myths and misconceptions about food and diet can cause confusion which is not confined to one food or one food group. Resorting to ‘self diagnosis’ based on hearsay, quoted personal opinions or the views of some alternative practitioners, rather than qualified medical or professional nutritional advice, can result in the unnecessary removal of certain foods from the diet which are sources of important nutrients.
The latest edition of the DN Forum publication for health professionals explores six common myths about milk and dairy; and promotes the provision of accurate, evidence-based information, providing a summary of the relevant scientific literature in each case.
Cow’s Milk Allergy & Lactose Intolerance
These two terms are often used synonymously or interchanged, although they are quite different and distinct conditions.
Cow’s Milk Allergy is an abnormal immunological response to a food – in this case cow’s milk – which is most prevalent in early childhood but prognosis is good with significant remission rates reported. For example, one study demonstrated that 80% of children outgrow their milk hypersensitivity by three years of age, which has two implications for families.
Firstly, milk is a key source of nutrients, especially for young children. So accurate diagnosis by a paediatrician, allergist or other suitably qualified medical professional is important because taking dairy out of the diet of a young child unnecessarily, is not desirable. Secondly, where a diagnosis is confirmed, re-introduction of dairy through ‘food challenges’ may be considered – these should always be conducted under medical supervision and advice.
Lactose intolerance is non-allergic and does not involve the immune system. It stems from varying levels of deficiency of the enzyme ‘lactase’, leading to the reduced ability to digest lactose, the primary sugar naturally present in cow’s milk. Lactose intolerance arises when the lactose that is not absorbed in the intestine results in gastrointestinal symptoms. There are tests which can assist with diagnosis, which should be made by medical professionals suitably qualified to deal with food hypersensitivities.
There is a misconception that lactose intolerant sufferers should avoid all dairy foods – but in fact that tends not to be the case. An Opinion from the European Food Safety Authority (EFSA) issued last year says that the vast majority of people with lactose maldigestion can tolerate up to 12g of lactose as a single test dose with no or minor symptoms; and that higher doses may be tolerated if distributed throughout the day. The Opinion also acknowledges the variation in individual tolerances.
The lactose content of most cheeses is considerably lower than milk. Cheddar cheese contains only 0.1g of lactose per 100 gram serving. The lactose content of whole milk is 4.5g / 100 g, with a relatively similar content for semi skimmed and skimmed milk. ESFA also issued a positive opinion regarding the relationship between live yogurt cultures in yogurt and improved lactose digestion in individuals with lactose maldigestion.
Therefore when a person is professionally tested and diagnosed with lactose malabsorption/ intolerance, it is important from a dietetic perspective to determine the level of dairy foods that can be tolerated without discomfort. Professional advice, including the spacing of dairy intake throughout the day whilst recognising the lower lactose content of many cheeses and the possible increased tolerance of some yogurts, may help to manage lactose intolerance whilst ensuring that nutritional adequacy is not compromised.