Danger of pregnancy diets

 

Women who diet during pregnancy are cutting years off the lives of their unborn children, scientists warned yesterday.

Fad diets and poor eating habits among mothers-to-be deprive the foetus of essential nutrients - making the child more vulnerable to obesity and premature death.

And bottle-feeding in the first months of life can make the child's outlook even worse, said researchers.

Experiments on mice suggest the human lifespan could be cut by up to a third - the equivalent of dying at 50 rather than 75.

Scientists at the University of Cambridge studied how diet, before and after birth, affected life expectancy.

They found a poor diet in pregnancy leads to poor foetal growth and "programmes" the baby's metabolism for life.

Its metabolism is geared to surviving on reduced amounts of food.

So when food becomes plentiful after birth, the child is prone to obesity - raising the risk of heart disease, diabetes and other illnesses.

Mice experiments

The most long-lived mice were those which developed well in the womb but were then given only moderate nutrition in their first months.

They were virtually immune to the obesity-inducing effects of a junk food diet after weaning, Dr Ozanne found.

She added: "We have shown that minor manipulation of maternal diet can increase life expectancy in mice by more than 50 per cent, a discovery that calls for attention to this aspect of growth and nutrition in humans.

"There is, after all, a significant difference between living to be 50 years old and reaching the age of 75."

Critical organs such as the kidneys may also be damaged in cases where mice are not given the necessary nutrition in the womb, she said.

Her study, with co-author Nicholas Hales, is published in the journal Nature.

In a second round of experiments, half of the baby mice from each litter were weaned at 21 days on a high-calorie, high-sugar diet, similar to a diet that contributes to obesity in humans. The rest were fed a standard diet.

Mice with poor maternal nutrition in the womb and weaned on the unhealthy diet survived only a year, or about half as long as other mice in the study.

The high-calorie diet did not have a noticeable effect on the lifespan of well-fed mice weaned on a restricted diet after birth, researchers reported.

Commenting on the study, Kent Thornburg, a foetal physiologist at Oregon University, said: "Growth during prenatal life has a very powerful impact on longevity."

Balanced diet

Mothers-to-be should eat a mix of foods each day including starches such as potatoes, bread, pasta or pulses; proteins such as fish and meat; fresh fruit and vegetables; calcium from milk and cheese.

They should ensure they eat at least two different kinds of fruit and two different vegetables daily.

Folic acid reduces the risk of spina bifida and is particularly important for women trying to become pregnant and during pregnancy. It is found in green, leafy vegetables.

Oil-rich fish such as mackerel and sardines contain an omega 3 fatty acid that is important for the baby's brain.

A pint and a half of milk a day will provide the calcium needed during the baby's development.

In their study, researchers collected research looking at the time frame just before pregnancy and up to three months. These collected studies represented about 63,000 women of reproductive age and included information about dietary habits collected through questionnaires.

Overall, researchers concluded that compared to those who consumed low amounts of fruits, those who ate high amounts of fruit in the pre-conception and early pregnancy stages had a 61% reduced risk of miscarriage. The risk was reduced by 42% for vegetable intake. Conversely, a diet high in processed foods appeared to double the miscarriage risk. The team also looked for evidence of whether specific diet plans, such as the Mediterranean diet, were linked to reduced miscarriage link. While the team could not find such a link, the team did find evidence that general, overall healthy eating (e.g., plenty of foods with antioxidants, few foods known to cause inflammation) may reduce the risk.

The team suggests that more prospective research is needed to better examine the link between specific diets or foods and the risk of miscarriage.