People who had low birth weights and those breastfed for short periods may be more likely to develop chronic inflammation linked to heart disease in adults, a study said Wednesday.
Researchers in the United States found a "significant" association in almost 7,000 people between birth weight or duration of breastfeeding and higher levels of C-reactive protein (CRP), an indicator of inflammation, in blood samples of young adults.
The protein is produced by the liver and levels increase when a person suffers from inflammation.
"Each pound of additional birth weight predicted a CRP concentration that was five per cent lower," said a statement from Northwestern University, whose experts took part in the study published in the journal Proceedings of the Royal Society B.
"Three to 12 months of breastfeeding predicted CRP levels that were 20 to 30 per cent lower compared with individuals who were not breastfed."
The study found that breastfeeding had "the same or greater effect" as medicines on reducing CRP levels in young adults.
Chronic inflammation had long been linked to cardiovascular disease, but the causes of the little-understood condition remain unclear.
The U.S. study was done among 24- to 32-year-olds from different race groups and educational backgrounds, and included comparisons between siblings so as to rule out the confounding influence that growing up in vastly different socioeconomic environments could have on the results.
"The results suggest that breastfeeding may reduce a major risk factor for heart disease well into adulthood," said Alan Guttmacher, director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development.
The World Health Organisation describes breastfeeding as "one of the most effective ways" to ensure child health and survival.
It recommends exclusive breastfeeding up to the age of six months, but says this advice is put into practice for less than 40 per cent of infants globally.