Reporter Volume 25, No.27 May 5, 1994

By LOIS BAKER
News Bureau Staff
New research from UB indicates that women who were breast-fed as
infants may experience a measure of protection against breast cancer
later in life. The UB study, involving 1,130 women from two counties
in Western New York, indicated that women who were breast-fed had a 25
percent lower risk for developing breast cancer than women who were
bottle-fed as babies.
	The study appears in the May issue of Epidemiology.
	"There is growing interest in exposures in early life,
including diet, and their relationship to breast cancer risk," said Jo
Freudenheim, UB associate professor of social and preventive medicine
and the study's principal investigator.
	"There has to be some environmental component to explain the
geographical variation in breast cancer rates. Risk factors relating
to exposures in adulthood don't explain all the variation we see. This
finding of a possible protective effect from having been breast-fed
could be significant, and it is certainly worth looking at further."
	Freudenheim cautioned that the findings are preliminary, and
need to be replicated in other populations before any conclusions can
be drawn.
	From 1986-1991, Freudenheim and a team of researchers
collected data on an array of potential risk factors from 528 women
newly diagnosed with breast cancer, and 602 women with no cancer who
were selected randomly from the same population and matched for age.
The women were between the ages of 40 and 85 at the time of the study.
	After controlling for age, education, age at menarche, age at
first pregnancy, number of months they nursed their own children,
number of pregnancies, family history of breast cancer, history of
benign breast disease, body-mass index and height, the researchers
found that one aspect of early nutrition--whether a woman had been
breast-fedQwas associated with a decrease in risk.
	Breast-feeding differs from bottle-feeding in several ways,
any or all of which could influence breast cancer risk, Freudenheim
stated.
	n Caloric intakeQStudies with animals have shown that early
calorie restriction may be related to decreased breast-cancer risk.
When the women in the study were infants, the milk and formula fed to
babies were sometimes higher in calories than breast milk, and
bottle-fed babies often received larger quantities than breast-fed
babies, with infants frequently being encouraged to finish a bottle.
	n Exposure to important nutrients--Animal studies and
ecological data suggest protein intake may be positively related to
breast cancer. Undiluted cow's milk has a higher concentration of
protein than breast milk.
	n Exposure to other biological factors--Breast milk contains
relatively high concentrations of potentially important biologically
active substances not found in cow's milk.
	n Exposure to colostrumQProduced by the mother during the
first few days of lactation, colostrum is high in immune factors and
other substances that may have a long-term impact. 	Freudenheim
said the study findings are important because they add credence to the
theory that exposure to factors early in life may increase cancer
risk, while pointing to a possible link between a specific exposure
and breast cancer risk.
	Other members of the research team, were James R. Marshall,
Saxon Graham, Rosemary Laughlin, John Vena, Elisa Bandera, Takuma
Nemoto and Mya Swanson, from UB; and Paoli Muti from UB and the
National Cancer Institute, Milan, Italy.