A recent UK study of 216 teenagers, published in the Lancet, found that breastfeeding in infancy is likely to reduce the risk of atherosclerosis and cardiovascular disease in later life.
The research by the UK Institute of Child Health found that breast feeding also helped to reduce ratios of low-density to high-density lipoprotein cholesterol protein which has been linked to clogged arteries.
The findings suggest human breast milk could help protect against atherosclerosis.
Atherosclerosis is a disease characterized by the hardening of arteries caused by the deposition of fatty material in the arterial wall.
The resident cells interpret this as an intrusion, "call for help", and inflammation results. Immune cells called monocytes circulating in the blood enter the artery wall, turn into macrophages and ingest the fat which is in the form of LDL particles (Low density lipoprotein), thereby turning into large "foam cells". The inflammation also causes a fibrous cap to be formed between the fatty deposits and the artery lining (the intima). These capped fatty deposits (called atheromas) narrow the blood vessel. This can lead to narrowing (stenosis) of the artery. The atheromas are fragile. When they rupture, the tissues of the artery wall are exposed to the blood which clots. A partial blockage can then form which be quickly converted into a complete obstruction, resulting in a heart attack or stroke, depending on which artery is obstructed.
The research looked at a group of teenagers who had already been studied as premature babies. They had been randomly assigned to be fed with either breast milk, standard formula milk or preterm formula.
The teenagers were re-examined when they were aged 13 to 16. Blood samples were collected and ratios of "bad" LDL cholesterol to "good" HDL cholesterol were studied
Results indicated that those who had been given breast milk during infancy had a significantly lower ratio of bad to good cholesterol than those given formula milk.
The researchers also examined concentrations of c-reactive protein (CRP). Higher concentrations are associated with the development of atherosclerosis.
Teenagers who had been breast-fed had lower concentrations of CRP than those who had been given formula.
Factors such as birth weight, teenage weight and social class did not differ between breast and bottle-fed groups.
The research team suggest that this could be because breast-fed babies grow more slowly than those who are bottle-fed.