Breastfeeding can reduce the risk of a heart attack or stroke later in life and could prevent hundreds of thousands of deaths each year, researchers said on Friday.

Babies who are breastfed have fewer childhood infections and allergies and are less prone to obesity. British scientists have now shown that breastfeeding and slow growth in the first weeks and months of life has a protective effect against cardiovascular disease.

“Diets that promote more rapid growth put babies at risk many years later in terms of raising their blood pressure, raising their cholesterol and increasing their tendency to diabetes and obesity-the four main risk factors for stroke and heart attack,” said Professor Alan Lucas of the Institute of Child Health in London.

“Our evidence suggests that the reason why breast-fed babies do better is because they grow more slowly in the early weeks.”

Lucas said the effects of breastfeeding on blood pressure and cholesterol later in life are greater than anything adults can do to control the risk factors for cardiovascular disease, other than taking drugs.

“My provisional estimate suggests that hundreds of thousands of deaths in the western world could be prevented by breastfeeding,” he said in an interview. “Obviously more could be prevented if the uptake in breastfeeding was even higher.”

An estimated 17 million people die of cardiovascular disease, particularly heart attack and strokes, each year, according to the World Health Organisation.

Lucas and his colleagues compared the health of 216 teenagers who as babies had either been breastfed or given different nutritional baby formulas. They reported their findings in The Lancet medical journal.

The teenagers who had been breastfed had a 14-percent lower ratio of bad to good cholesterol and lower concentrations of a protein that is a marker for cardiovascular disease risk.

The researchers also found that, regardless of the child’s weight at birth, the faster the infants grew in the early weeks and months of life, the greater was their later risk of heart disease and stroke.

The effect was the same for both boys and girls.

“The more human milk you have in the newborn period, the lower your cholesterol level is, the lower your blood pressure is 16 years later,” Lucas said.

He suspects there is a hormonal trigger very early in life that influences infant growth and sets the system for cardiovascular risk later in life.

SOURCE: The Lancet, May 15, 2004.