Breast Milk May Fight Hypertension

Friday, February 9th 2001, 12:00 am
By: News On 6

LONDON (AP) — Babies fed infant formula grow up to have higher blood pressure than those given breast milk, new research suggests.

The findings, to be published Saturday in The Lancet medical journal, come from the first experimental study of how early nutrition influences blood pressure, a predictor of heart disease risk later in life.

Earlier studies have noted that adults with high blood pressure tended to have been fed formula as babies. But none took account of scores of other factors that raise blood pressure, such as a bad diet in adulthood, stress and lack of exercise.

Experts say the results bolster the theory that an infant's diet influences the risk of several diseases in adulthood. Breast-feeding is also considered better for children's intelligence.

The study by scientists at the Institute of Child Health in London involved pre-term babies, who are sometimes not strong enough to suck or may need a more concentrated formula.

That also eliminated the ethical problem of experimenting with healthy full-term babies whose mothers can easily breast-feed exclusively.

``When you put this together with the two observational studies linking formula to higher blood pressure in full-term babies, there's a strong possibility these results would apply to healthy full-term babies,'' said one of the researchers, Dr. Alan Lucas, a professor of pediatrics at the Institute of Child Health.

Nearly 20 years ago, the researchers randomly divided 216 pre-term babies into three groups: one received donated breast milk, one received infant formula made for pre-term babies and the third received regular infant formula. Each diet, begun within 48 hours of birth, was used as a sole food or as a supplement to mother's milk, depending on what the mother wanted to do.

The infants remained in the study until they weighed enough to go home, usually after one month. The children then returned about 16 years later to have their blood pressure measured. There were two comparisons. One compared breast milk with pre-term formula, and the other compared pre-term formula with full-term formula.

``Just one month of one diet rather than another had a major impact,'' Lucas said. ``We created a situation where the only difference between them was what they were fed in the first month of life.''

The scientists found that the diastolic blood pressure reading — the lower number — was 3.2 points lower in the teens fed breast milk than in those given pre-term formula. The systolic reading — the higher number — was 2.7 points lower. An elevation in either reading is bad.

Within the formula-fed group, babies on the highest proportion of formula to mother's milk ended up with the highest blood pressure.

There was no difference in blood pressure between the groups fed pre-term formula and regular formula, which contain different nutrients.

The results were not related to birth weight, the study said.

``These few millimeters may look small, but it's a large effect,'' Lucas said.

Major American heart disease studies have found that if adults' diastolic blood pressure was lowered just two points, the prevalence of high blood pressure would drop by 17 percent, the risk of heart disease would fall by 6 percent and the risk of stroke and heart attacks would drop by 15 percent, he noted.

``The most likely thing is there's something in breast milk that protects,'' Lucas said.

Identifying the specific differences in the composition of human milk and commercial formula that produced the difference in blood pressure is important for making better infant formula, said Susan Roberts, an expert at Tufts University's Human Nutrition Research Center in Boston, who was not connected with the study.

The study discounted any relation between high blood pressure among teens and sodium and total fat in the infant milk or formula, she noted.