jane m. rees, ms, rd lecturer, public health & pediatrics maternal child health program...
TRANSCRIPT
Jane M. Rees, MS, RD
Lecturer, Public Health & Pediatrics
Maternal Child Health Program
University of Washington
Seattle, WA. U.S.A.
Supported by
Food of the modern world:
Does it affect the age of puberty?
From the Cover of Time Magazine, (Oct. 30, 2000)
“Early Puberty
Why Girls are Growing Up Faster”
“Is it hormones?
Is it fat?
Is it something in the water?
How parents and kids are coping”
“The Making of an 8-Year-Old Woman”
“How do we understand early puberty?
……through the prism of our time.”
From an article in the New York Times Magazine (Dec. 24, 2000)
From the New York Times
Article: “Two Endocrinology Groups Raise Doubt on Earlier Onset of Girls’ Puberty” (March 3, 2001)
Letter to the editor: “Early Puberty in Girls” (February 24, 2001)
New clinical study
% Stage 2 or more 7.00 - 7.99 years
African-American European-American
Breast buds 15.4% 5.0%
Pubic hair 17.7% 2.8%
Herman - Giddens et al: Pediatrics 1997
Initial signs of puberty (female)
African-American European-American
Previous 8 years 8 years
New 6 years 7 years
Kaplowitz et al: Pediatrics 1999
Recent history of menarche
1800 17.0 years
2000 12.5 years
Tanner, J: Harvard U. Press, 1978
Adair & Gordon-Larsen: A. J. Pub. Hlth., 2001
Studies show
Body Weight - Menarche
Heavy - Early
Light - Later
Population based study: % overweight
Menarche 11 a 11-13 a 14 a
European American 36.4% 22.4% 22.3%
African American 57.5% 36.4% 37.5%
Adair & Gordon-Larsen: A. J. Pub. Hlth. 2001
• Foods
• Pollutants
• Phytoestrogens
• Social
?
Time Line
200,000,000 y
100,000 y
65,000,000 y Today
10,000 y
Agriculture
Angiosperm & First Mammals
130 y
Infant Formula
Extinction of Dinosaurs
Homo Sapiens
Mammals flourished
Directional selection - corn
Source: http://entmuseum9.ucr.edu/ent010jm/Evol.html
Storage/Supply
Energy
Reproduction
0
50
100
150
200
250
8 10 12 14 16 18 20
YEARS (y)
FR
EQ
. (#
)
MenarcheConception
Frequency distribution of menarcheal age and age at conception of a sample of African-
American adolescents (n=574)
Rees JM, 2001 (unpublished)
Fatness
Accessibility
Treats
A Book Reference
Title: The Botany of Desire: A plant’s view of the world
by Michael Pollen
Publisher: Random House Books, 2001
Exchange of energy linked in brain
From: Worthington, BS, Vermeersch, J, and Williams, SR: Nutrition pregnancy and lactation. St Louis, CV Mosby, 1977. p 139.
Feeding not linked to mother
Intake not linked to output
Rich food & Excercise
Size
Advanced puberty
Masculine puberty
Has it changed?
Equivalent distance line
1 Km
5 m
325 m Today
50 cm
Agriculture
Angiosperm & First Mammals
5 mm
Infant Formula
Extinction of Dinosaurs
Homo Sapiens
Mammals flourished
Will clarify the influence of modern foods on the age of menarche
Future research
Change in foods has been dramatic
The evidence