Let's Talk About Milk

Milk
Is it a near perfect food or a dietary demon? Let's put the spotlight on some common claims you'll hear about our daily dairy.

CLAIM: "Milk is an essential part of a healthy diet"
Evidence:
Australia's National Health and Medicinal Research Council says milk is one of the most complete foods. As well as calcium, it contains carbohydrate, protein, phosphorous, potassium, riboflavin, vitamins A and B12, magnesium and zinc. The further good news: milk delivers these nutrients in an absorbable and relatively low-calorie form.


Research shows that drinking milk may lower the risk of high blood pressure and colon cancer. Three serves of milk in a diet low in fat and salt but high in fruit and vegetables can also reduce the risk factors for coronary heart disease, such as elevated cholesterol.


Calcium from dairy, as opposed to calcium supplied from a supplement or fortified food, has a much greater effect on weight- and body fat-loss. Dairy food are low GI (glycemic index) and there's good evidence cheese can help protect teeth against decay.


Still, you can get too much of a good thing. Milk is designed to sustain and grow young mammals; some of the nutrients that are essential for infants, such as saturated fat, are not so important to adults.

CLAIM: "Lots of people are allergic to milk"
Evidence:
It's true that milk is implicated in one in five allergies and one in four severe food allergy reactions. Among children under 12 months, around one in 50 are allergic to milk, which can result in symptoms ranging from anaphylaxis and eczema to colic and reflux.

That said, there's a lot of confusion in our minds. A true milk allergy involves an immediate immunological response, and even the tiniest amounts - for example, the milk powder used to make many potato chips - will set it off. Many of the common reactions that people attribute to milk allergy - tummy aches, rashes and runny noses - are not allergies but due to a food intolerance.


The good news: children with milk allergy tend to outgrow it by school age and it's extremely rare to develop it as an adult. If you suspect you have an allergy, the only way to be sure is through a skin test or a blood test done by a doctor. You cannot diagnose yourself, and if you try, you risk malnutrition or misdiagnosis.

CLAIM: "Human can't digest cow's milk properly"
Evidence:
It's a fact that drinking milk can lead to tummy troubles in some people. It's called lactose intolerance. Around six percent of Caucasians have the condition and that percentage skyrockets to above 50% in people from Asia, the Middle East, Africa and the Mediterranean. In some Asian countries, the prevalence is almost 100%.


It occurs when people don't produce enough lactase, an enzyme that digests lactose in milk. Without lactase, lactose ferments in the gut, leading to a range of problems such as cramping, bloating and nausea. Those symptoms are also typical of irritable bowel syndrome (IBS), a condition that is becoming more and more common. Quite often, people who are diagnose with IBS find relieve from the symptoms when they eliminate dairy from their diets.

Lactose intolerance is quite different from other types of food intolerance. However, people may mistakenly believe that they are 'allergic' to milk, when in fact they have another food intolerance. People lop out whole food groups, but they might be knocking out preservatives and flavour enhancers, and these may be actually causing the intolerance.

Even if you are lactose intolerant, you don't need to completely avoid milk. Symptoms occur only if you consume more than 12.5 grams of lactose at once - that's about one glass of milk. It's OK to spread your milk intake over the day in small amounts of tea and coffee..

CLAIM: "It's linked to disease"
Evidence:
A growing body of research quoted particularly by the vegetarian and alternative medicine communities links milk consumption with serious health problems. Indeed, White Lies, a report published by the Vegetarian and Vegan Foundation in the UK, asserts that compelling evidence links cow's milk to allergies, arthritis, coronary heart disease, Crohn's disease, diabetes, dementia, kidney disease, autoimmune diseases and obesity. Other researchers have looked and milk and cancers, especially breast, prostrate, ovarian and colorectal cancers. One controversial study claims dairy consumption affects biological pathways associated with carcinogenesis.


To counter popular alarm, last year the New South Wales Cancer Council in Australia declared that the health benefits of consuming three serves a day of milk far outweigh any certain risk. And the council points out that milk actually protects against some types of cancer.


Milk also gets the blame from some for exacerbating asthma, eczema and hay fever. Its role here is also being investigated by a range of researchers. Meanwhile, the National Asthma Council in Australia says there's currently no research proof that reducing or eliminating dairy will reduce asthma symptoms, and it confirms milk does not generate more mucus in the airways.

For 20 years scientists have been exploring if there's a relationship between milk and type 1 diabetes - the theory being that the proteins in cow's milk, particularly casein, can fool the body into attacking its own insulin-producing cells. It's worthy of further research. However it's too early to be making public health recommendations.


The other big area of debate is autism and ADHD. People with these conditions don't appear to produce the enzyme that digests gluten and casein. Fragments of these proteins cross the gut wall and mimic morphine - it's called the 'opiod effect' and results in some of the symptoms autistic children display such as repetitive behaviour and social withdrawal. However, Dairy Australia says there's insufficient evidence to support the use of dairy-free diet as an effective intervention for persons with autism.

CLAIM: "Milk builds bones"
Evidence:
Without a doubt, calcium is an essential mineral for our bone and teeth as well as the functioning of our nerves, muscles and heart. We need it all through our lives, but most of us don't consume nearly enough.

The calcium in milk is high in bioavailability - that means of the 300mg of calcium in a glass of milk, about 90mg is absorbed. To absorb the same amount from broccoli you'd need to eat two and one quarter cups. So if milk provides us with lots of calcium, and calcium builds strong bones, shouldn't it follow that drinking lots of milk will help our bones?

Surprisingly, several large studies have found a high intake of diary doesn't necessarily cut the incidence of osteoporosis. Cornell University found that the effects of eating plant- versus animal-based foods drinking too much milk was worse for bones than too little. And the Harvard Nurses Study, which followed 75,000 women for 12 years, has suggested an increased intake of calcium from dairy food is actually associated with a higher risk of fracture.

It's a controversial area, but one theory is that a high intake of animal protein may cause calcium loss from bones even as most health institutions still support milk as an important source of calcium.

CLAIM: "Milk helps kids"
Evidence:
It's certainly hard for children to get all the calcium they need from no-dairy sources. Things like nuts and fortified orange juices can pack on the calories and lack the other nutrients found in milk.

In studies, children who consume little or no milk have poorer bone mineral density and a fracture risk more than two-and-a-half times higher than average. One study showed children on milk-free diets had a markedly lower intake of energy, fat, protein, calcium, riboflavin and niacin compared to milk drinkers.

However, the best thing for young babies is breast milk and it is recommended babies are kept on breast milk or formula until at least 12-18 months. Cow's milk differs from human milk in its protein, calcium, phosphorous, iron and essential fatty acid content. The high protein, sodium, potassium, phosphorous and chloride content of cow's milk puts pressure on the kidneys. Feeding it to infants has been linked in some studies with milk allergy, type 1 diabetes and cot death.


Babies fed a lot of cow's milk in their second six months of life often end up with iron deficiency. This may be due to minor irritation of the bowel lining or because babies who drink too much milk are less likely to eat enough meat and vegetables.

The Conclusion:
The evidence that cow's milk causes disease is not convincing, but one thing is clear: milk is an important part of regular diet. Experts stress it's vital to get professional advice before you self-diagnose any condition that prompts you to give up dairy.

How to get enough calcium without drinking milk:
* Try a calcium-fortified soy milk, though if you suffer from a true food allergy to milk you may also be allergic to soy
* If you can't tolerate soy milk, try a fortified rice or oat milk.
* Calcium from supplements isn't as bioavailable, but can provide an alternative.
* Eat more canned fish bones, green leafy vegetables, nuts, seeds or beans.