The researchers, led by Professor Alan Lucas, director of the Medical Research Council's Childhood Nutrition Centre in London, say their latest study provides further evidence in support of the suspected link between breast milk and heart health.

The team conducted a follow-up study among 216 teenagers (aged 13 to 16 years) who were either breast-fed of given formula milk as infants.

The results revealed that those who had been breast-fed had significantly lower levels of C-reactive protein - a substance in the body linked with inflammation and artery disease (atherosclerosis) - than individuals who received formula milk.

Furthermore, adolescents who had been given breast milk in infancy had a healthier ratio of low-density lipoprotein (LDL), or "bad" cholesterol, to high-density lipoprotein (HDL), or "good" cholesterol. This ratio of was an average 14% lower than in the formula-fed group. A higher proportion of human milk intake was associated with lower ratios of LDL to HDL cholesterol.

Writing in the current edition of The Lancet, the researchers say: "The findings of our prospective study suggest that infant nutrition permanently affects the lipoprotein profile later in life, and specifically that breast milk feeding has a beneficial effect.

"Furthermore, we have shown a possible benefit of breast milk compared with formula feeding on later concentration of CRP, a marker of the inflammatory process associated with atherosclerosis and cardiovascular disease."

They conclude: "Our findings suggest that breast milk feeding has a major beneficial effect on long-term cardiovascular health."