The process of ageing begins even before we are born, according to an international team of researchers. In a study using rats to model pregnancy and fetal development, the researchers also found that providing mothers with antioxidants during pregnancy meant that their offspring aged more slowly in adulthood.

However, the offspring of mothers with lower levels of oxygen in the womb - which, in humans, can be a consequence of smoking during pregnancy or of pregnancy at high altitude - aged more quickly in adulthood.

Our DNA is 'written' onto chromosomes, of which humans carry 23 pairs. The ends of each chromosome are known as telomeres and act in a similar way to the plastic that binds the ends of shoelaces, preventing the chromosomes from fraying. As we age, these telomeres become shorter and shorter, and hence their length can be used as a proxy to measure ageing.

In a study published in The FASEB Journal, scientists report a study that involved measuring the length of telomeres in blood vessels of adult laboratory rats born from mothers who were or were not fed antioxidants during normal or complicated pregnancy.

The most common complication in pregnancy is a reduction in the amount of oxygen that the baby receives - this can be due to a number of causes, including expectant mothers who smoke or who experience preeclampsia. To simulate this complication, the researchers placed a group of pregnant laboratory rats in a room containing 7% less oxygen than normal.

The researchers found that adult rats born from mothers who had less oxygen during pregnancy had shorter telomeres than rats born from uncomplicated pregnancies, and experienced problems with the inner lining of their blood vessels - signs that they had aged more quickly and were predisposed to developing heart disease earlier than normal. However, when pregnant mothers in this group were given antioxidant supplements, this lowered the risk among their offspring of developing heart disease.

Even the offspring born from uncomplicated pregnancies - when the fetus had received appropriate levels of oxygen - benefited from a maternal diet of antioxidants, with longer telomeres than those rats whose mothers did not receive the antioxidant supplements during pregnancy.

ttp://www.cam.ac.uk/research/news/old-before-your-time-study-suggests-that-ageing-begins-in-the-womb