Dairy products

The Food Pyramid says we should eat moderate amounts of dairy products like milk, cheese and yoghurt. On the one hand, dairy products contain saturated "bad fat". Some, like soft cheeses, have it in large amounts.

But on the other hand, dairy is rich in calcium, a mineral essential for strong teeth and bones. And milk is low in fat - in fact, many milks and yoghurts are extremely low.

At Harvard, they've cut the recommended amount back. They claim there is no evidence calcium from dairy foods keeps bones strong. In fact, they say the highest rates of bone fractures are seen in countries with high dairy consumption. They also point to studies suggesting a link between some cancers and high dairy intake.

In the Harvard pyramid, just one or two servings a day are suggested. They say we can get the calcium we need from wholegrains and legumes (soy, beans and the like), and/or from a calcium supplement.

These are startling claims. Most people don't eat enough wholegrains and legumes to satisfy their calcium needs. And it's generally thought that food nutrients should be taken in food, rather than pills, because this gives them a better chance of working properly.

Osteoporosis New Zealand says there are many studies showing dairy products are beneficial for bones and teeth. In a study published this year women with a low milk intake during childhood had double the risk of getting fractures. A Massey University study says milk replenishes the calcium and phosphate lost after consuming sugary drinks.

Several foods (including some biscuits, drinks and cereals) are now fortified with calcium. But often they also contain a lot of sugar. And dairy foods contain other nutrients, including phosphorus, vitamin A and zinc.

In our view, although more research is required, there is a lot of evidence for the value of low-fat (and calcium-enriched) dairy products.