Red meat consumption speeds and fatty fish consumption stalls puberty in girls, new findings suggest.

A new study reveals that girls who have high red meat consumption are significantly more likely to start their periods five months earlier than those who don't. In contrast, girls who have high fatty fish consumption get their periods significantly later than those who don't.

Researchers at the University of Michigan evaluated six years of data from 456 girls participating in the Bogota School Children Cohort in Colombia. The girls were between the ages of 5 and 12 years old and none of them had started their period at the beginning of the study.

Study results revealed that red meat consumption ranged from less than four times a week to twice a day, and girls who ate the most red meat had their first menstrual cycle at a median age of 12 years and 3 months. However, those who ate less red meat had their first period at 12 years and 8 months.

The study also revealed that girls who ate fatty fish like salmon, mackerel and sardines at least once a week experienced their first menstrual cycle significantly later than those who ate it once a month. Researchers found that girls who ate fatty fish most frequently had their first menstrual cycle at 12 years and 6 months.

Researchers said the findings are important because early puberty in girls has been linked to breast cancer, type 2 diabetes, heart disease and obesity.

"It is an important difference because it is associated with the risk of disease later in life," said study author Erica Jansen, a doctoral candidate in the University of Michigan School of Public Health. "It is significant because few dietary factors are known to affect the timing of puberty. This finding may also contribute to explain why red meat intake early in life is related to increased risk of breast cancer later in life."

"We cannot conclude that there is necessarily a causal role of red meat on onset of puberty from this study. However, there is a mounting body of evidence suggesting that excessive intake of red meat at different stages of life is related to a number of adverse health outcomes, especially to getting some types of cancer," added senior author Dr. Eduardo Villamor, professor of epidemiology at the University of Michigan School of Public Health. "Although animal protein intake during childhood is important for growth and development, some sources of animal protein may be healthier than others."

The latest findings were published in the Journal of Nutrition.