Milk is widely believed to threaten heart health because it raises cholesterol levels. Also ecological studies have found a positive relationship between the average per capita milk production in a number of countries and heart disease deaths.
But the new study by researchers from the University of Bristol, the University of Wales and the University of Ulster in the UK challenges these beliefs and will lend support to the increasingly health-related marketing activity done by the European dairy industry.
The researchers used data provided by more than 650 middle-aged men who had been asked to record all food and drink consumption over a seven-day period.
This method is said to offer more reliable information on total food intakes than a food frequency questionnaire, which researchers use to gain an estimate of typical food intake. Many of the studies on milk to date have used food frequency questionnaires.
Following up for stroke and heart disease cases 20 years later, the UK team found that those men who consumed at least 200ml of milk a day were half as likely to experience stroke as those drinking the least milk.
This amount is recommended by the dairy industry as providing a third of an adult's daily calcium requirement.
The scientists report in the Journal of Epidemiology and Community Health (issue 59, pp 502-5) that men who drank the most milk were also at lower risk of ischaemic heart disease.
The findings held true even for those men who had started out drinking full fat milk. At the start of the study, virtually all milk consumption was whole (full fat) milk, but a random sample of the surviving men in 2000, showed that almost all of them had switched to skimmed or semi skimmed milk within the preceding eight years.
The authors write: "The present perception of milk as harmful, in increasing cardiovascular risk, should be challenged, and every effort should be made to restore it to its rightful place in a healthy diet."
There is some evidence in the new study that milk's protective effect on the heart may be down to its role in an overall healthier lifestyle.
For example, the Bristol team found that men who consumed the most milk every day (a pint or more) had a higher energy intake, suggesting that they were more active.
But the researchers say that the findings are also supported by an overview of 10 major studies that assessed milk consumption. It also found an association between milk drinking and lower risk of heart disease and stroke. In addition, milk has been shown to lower blood pressure.
These results will help change public perceptions of milk and lend support to the dairy industry's increasing positioning of milk as a healthy food.
The UK industry, following similiar initiatives in the US, has begun filing evidence to the voluntary health claims body the JHCI in a bid to gain approval for at least two different health claims related to the beverage.
The first, already filed to the JCHI, concerns cheese, which is said to be beneficial to dental health and hygiene when consumed after a meal or sugary snack.
The second, assembled, but yet to be submitted, links the consumption of milk with maintaining bone health and its role in preventing bone disorders like osteoporosis.
Recent figures from TNS suggest that health-related promotional activity, which has most recently targeted specific groups such as teenage girls who may not be getting enough calcium, is helping milk sales in the UK.
Health-orientated dairy products are proving popular across the UK multiples, also bolstered by high advertising spend, while traditional dairy commodities - own-label milk for instance - are failing to maintain such a high-profile retail presence.