Previous research may have overestimated the beneficial effects of breast feeding on blood pressure in later life, says a report in this week's British Medical Journal.

Christopher Owen and colleagues reviewed 24 studies to determine whether breast feeding in infancy was associated with lower blood pressure at different ages compared with bottle feeding formula milk.

Studies that reported noticeable and statistically significant differences in blood pressure between feeding groups were mostly small, raising the possibility of publication bias.

Larger studies showed little difference, suggesting that any effect of breast feeding on blood pressure is, at most, modest and of limited clinical or public health importance, say the authors.

However, the report did stress that breast feeding should be encouraged on the basis of other short and long term benefits, including improved neural and psychological development, potential protection against obesity and allergic disease, and lower blood cholesterol levels in later life.

Recently there have been a host of other studies claiming a variety of benefits from breast feeding, including enhanced brain development, however another British Medical Journal study recently refute claims that breast feeding can help to normalise weight levels laster on in life.