Children who eat plenty of dairy foods such as milk and cheese can expect to live longer, a study suggests.

一项研究建议，经常使用牛奶、奶酪等乳制品的儿童可以更长寿。

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Milk is a good source of calcium

Some 4,374 UK children from a 1930s study were traced 65 years later by researchers in Bristol and Queensland.

They found those who had had high dairy and calcium intakes² as children had been protected against stroke and other causes of death, journal Heart reports.

Despite dairy containing artery⁴（动脉，干道） furring fat and cholesterol⁵（胆固醇）, high consumption did not raise the heart disease risk.

The findings appear to back the practice of giving extra milk to schoolchildren.

Protective

The study looked at family diets and found higher intakes of both calcium and dairy, predominantly（优越地，卓越地） from milk, cut mortality by a quarter.

A higher daily intake³ of calcium, of at least 400mg as found in just over half a pint⁶ of milk, cut the chance of dying from stroke by as much as 60%.

These beneficial effects were seen at estimated intake levels similar to those currently recommended by experts.

Three servings of dairy foods - for example, a 200ml glass of milk, a pot of yogurt（酸奶酪） and a small piece of cheese - will provide all the calcium most people need each day.

Other factors may play a part - though researchers say they took into account that children with the highest dairy intakes came from wealthier families and ate better diets overall - but there is evidence that high calcium intake is good for blood pressure.

Balance

Prolonged（持续很久的） high blood pressure increases the risk of stroke.

Dairy consumption may also influence heart and circulation health through a hormone⁷ called insulin（胰岛素）-like growth factor 1 (IGF-1), say the study authors from the UK's University of Bristol and Australia's Queensland Institute of Medical Research.

In adults, high circulating levels of IGF-1 are linked with reduced cases of heart failure and heart disease deaths.

Joanne Murphy of The Stroke Association said: "This is an interesting study, but we need to take a further look to really assess the benefits of milk in reducing the chances of dying from stroke.

"In the meantime, we advise parents to opt⁸ for a diet rich in fruit and vegetables and low in saturated⁹（饱和的，渗透的） fat and salt for the overall health of their children."

June Davison, cardiac（心脏的） nurse for the British Heart Foundation said: "It is important to include dairy as part of a balanced diet from the early years.

"However, older children and adults should consume low-fat dairy products such as semi-skimmed, 1% or skimmed milk and low-fat yogurts, which will help keep saturated fat intake low to help protect the heart."

Studies investigating a link between cancer and dairy products have not given clear results. Some research shows an increase in the risk of developing cancer, and some shows a decrease.