Method to Gauge Breast Cancer Risk May Be Flawed
    [07/18/2003; The Lancet (UK; Free Registration Required)]

THURSDAY, July 17 (HealthDayNews) -- A research tool commonly
used to determine links between diet and breast cancer could 
be seriously flawed. 

That's the conclusion of a research letter that appears in the
July 18 issue of The Lancet. 

The method in question is known as the "food-frequency questionnaire,"
or FFQ. Researchers say defects in the basic methodology behind
the questionnaire could mean it fails to reveal the association
between dietary fat and the development of malignant breast tumors.

"We believe that, in the past, finding links between breast cancer
and fat intake has been hampered by imprecise research methods
which appear to have obscured a link between the two," says lead
researcher Dr. Sheila Bingham, deputy director of the Medical
Research Council Dunn Human Nutrition Unit in Cambridge, England.

A food-frequency questionnaire requires patients to rely on their
memory to answer a series of questions designed to reveal their
dietary habits during a specific time period. When combined with
health history and medical data, the dietary information is analyzed
and used to postulate links between what people eat and their
risk of disease. 

An alternate method of dietary calculation is the "food diary."
Here, patients write down everything they eat for a specific
period of time. That information is then used by researchers
to calculate food-disease risk factors. 

The food diary is the better way to go, Bingham's research contends.

"We believe that the comprehensive food diaries that our participants
completed give a more accurate picture of eating habits compared
to other methods," Bingham says. 

The full article can be found at:

http://story.news.yahoo.com/news?tmpl=story&cid=97&ncid=751&e=11&u=/hsn/20030718/hl_hsn/methodtogaugebreastcancerriskmaybeflawed

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 2) Are imprecise methods obscuring a relation between fat and breast
    cancer?
    [07/18/2003; The Lancet (UK; Free Registration Required)]

Pooled analyses of cohort studies show no relation between fat 
intake and breast-cancer risk. However, food-frequency 
questionnaire (FFQ) methods used in these studies are prone to 
measurement error. We assessed diet with an FFQ and a detailed 
7-day food diary in 13,070 women between 1993 and 1997. We compared 
168 breast-cancer cases incident by 2000 with four matched controls. 
Risk of breast cancer was associated with saturated-fat intake 
measured with the food diary (hazard ratio 1.22 [95% CI 1.06-1.40], 
p=0.005, per quintile increase in energy-adjusted fat intake), 
but not with saturated fat measured with the FFQ (1.10 [0.94-1.29], 
p=0.23). Dietary measurement error might explain the absence of 
a significant association between dietary fat and breast-cancer 
risk in cohort studies.

The full article can be found at:

http://www.thelancet.com/journal/vol362/iss9379/abs/llan.362.9379.original_research.26493.1

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