Posted July 15, 2010
DIET high in meat could put girls at greater risk of breast cancer and heart disease by bringing on early puberty.
A study of 3,000 girls found those with higher intakes of meat and protein were more likely to have started their periods by the time they were 12 and a half.
Girls who start puberty early are believed to be at higher risk of a number of diseases – including breast cancer, ovarian cancer and heart disease.
The study, carried out at the University of Brighton, found 49 per cent of girls eating more than 12 portions of meat a week at the age of seven had started their periods by 12 and a half.
This compares with just 35 per cent of girls who ate fewer than four portions a week. And three-year-olds who ate more than eight portions of meat a week were also more likely to have early periods.
A portion is defined as the normal amount of meat a child would eat in a full meal. A portion is therefore smaller for a three- yearold child than for a seven-year-old one.
A small meat-based snack such as a ham sandwich would only be half a portion, but a Sunday roast would include a full portion.
However, study author Dr Imogen Rogers, a senior lecturer at the university’s school of pharmacy, warned against parents cutting meat out of their daughters’ diets entirely.
She said: ‘Meat is a good source of many important nutrients including iron and zinc and there is no reason why girls should adopt a vegetarian diet or that meat in moderation cannot form a valuable part of a balanced diet for children.’ Zinc and iron were both needed in high quantities during pregnancy, she said, which suggests a diet rich in meat could prepare the body for pregnancy.
She added that the findings needed repeating in other populations before firm recommendations on diet can be made.
But she said: ‘These results add to the evidence that it is healthiest to avoid diets containing very high amounts of meat.’ The research, funded by the World Cancer Research Fund, was published in the journal Public Health Nutrition.
The average age at which girls start puberty fell dramatically over the 20th century, perhaps reflecting easier access to meat. The average is 12, although this is now levelling off. Early periods could be linked with breast cancer, possibly because they mean women are exposed to higher levels of oestrogen over their lifetime.
Dr Ken Ong, paediatric endocrinologist at the Medical Research Council, said that the link with meat consumption was ‘plausible’.
‘This was not related to larger body size, but rather could be due to a more direct effect of dietary protein on the body’s hormone levels,’ he said.