(PhysOrg.com) -- Increased amounts of meat in children's diets may be part of the reason why girls go through puberty at a much younger age than they did 100 years ago, new research using the Children of the 90s cohort shows.
With evidence suggesting that girls who start their periods early are at higher risk of developing cancer and heart disease, scientists involved in the study said their results added to evidence that it was healthier to avoid high-meat diets.
The research, led by Dr Imogen Rogers from the University of Brighton, involved a study of 3,000 girls taking part in the University of Bristol's Children of the 90s study.
Dr Rogers, working together with colleagues at the University of Bristol including Professor Andy Ness, looked at the girls' dietary intake at the ages of three and seven years and how likely they were to have started their periods by the time they attended a research clinic aged around 12½ years.
They found that girls who had a higher intake of meat and protein at three and seven were more likely to have started their periods by 12½ years old than girls who ate less meat and protein.
Their report 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 age 12 ½, compared to only 35 per cent of those who ate less than four portions of meat a week.
Dr Rogers, a senior lecturer at the University of Brighton's School of Pharmacy and Biomolecular Sciences, said there was evidence that girls who start their periods early were at higher risk of a number of diseases including breast cancer, ovarian cancer and heart disease. This work suggests that a girl's diet in early childhood may affect her risk of suffering from these diseases as an adult.
Dr Rogers 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.”
She said the findings needed repeating in other populations before firm recommendations on diet can be made but she added: “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, has just been published in the journal Public Health Nutrition.