Sufferers of lactose intolerance - something which affects around 5 per cent if the UK, Irish, North European and American population - lack lactase (the enzyme which breaks down lactose), and can experience bloating, abdominal pains and diarrhoea, as a result of excessive lactose consumption.
Research has established that lactose intolerance sufferers often confuse their condition with a food allergy (an altogether more serious disorder, which activates the immune system) and furthermore, most sufferers self-diagnose - using information based on unfounded preconceptions.
"Around 45 per cent (27 million) of the UK population claim to be lactose intolerant, when in fact only 2 per cent (1.2 million) have actually been clinically diagnosed," commented Michele Stephens, communications manager for the UK Dairy Council.
But even the clinical methods used to diagnose lactose intolerance can prove problematic. One such diagnostic test - the hydrogen breath test - identifies abnormally high levels of hydrogen in the breath after potential sufferers are given a set dosage of lactose to ingest.
This dosage (usually dissolved in water and taken on an empty stomach), however, contains a level of lactose equivalent to that contained in one litre of milk - a high level for even regular dairy consumers, claim some physicians.
According to Stephens, one of the main problems facing dairy producers is convincing sufferers that they can still consume dairy products in moderation, regardless of their condition.
"Being lactose intolerant does not necessarily mean you have to cut out dairy from the diet completely. As is the case with nearly all foods, moderate consumption is the key to a balanced diet," she added.
Hard cheese varieties, for instance Swiss cheese, contain less than a quarter of the lactose content of fresh milk (around 5g per 100g), while fermented milk products contain virtually none (some live cultures in yoghurts can actually help break down the lactose in the digestive tract).
Dr. Robert Heaney, chairman of the Osteoporosis Research Center at Creighton University, Nebraska, told DairyReporter.com: "Virtually no-one needs to be lactose intolerant."
"Many humans lack the necessary enzymes needed to break down certain food groups, which is why adverse reactions sometimes occur," he added.
In 1998 a team of US researchers, led by Dr. Dennis Savaiano, Professor of Foods and Nutrition at Purdue University, Indiana, successfully reversed the condition of lactose intolerance in some patients by asking them to ingest increasing quantities of lactose in their diets.
After a few weeks, Dr. Savaiano found that the digestive system started to create the necessary bacteria needed to break down lactose in the digestive tract - regardless of the patient's ethnic background (African Americans, Hispanics, Native Americans, and Oriental Americans lose lactase during childhood and consequently experience much higher levels of lactose intolerance).
"There are many homely ways of building up tolerance, such as consuming milk with a meal or drinking flavoured milk. Of course, if the exposure stops then the bacteria go away and the condition may resume," Dr. Heaney cautioned.
But while milk consumption in the US has more than halved in the past sixty years, Dr. Heaney was quick to dismiss the suggestion that this decline stemmed from increasing public awareness of lactose intolerance.
"I suspect that the rise in carbonated, soft drink consumption is the single biggest culprit for lowered milk sales," he concluded.