Does dietary folate intake modify effect of alcohol consumption on breast cancer risk? Prospective cohort study
BMJ 2005; 331 doi: https://doi.org/10.1136/bmj.38551.446470.06 (Published 06 October 2005) Cite this as: BMJ 2005;331:807All rapid responses
Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles or when it is brought to our attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not including references and author details. We will no longer post responses that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
Dear Editor,
It may be suitable to consider the questionaries in this article as
an instrument to measure alcohol consumption and folate consumption.[1]
However there are always assumptions/inferences that need to be made from
what had been measured to what the exposure level really was. In this
case, the subjects’ answers regarding their alcohol and food intake were
used to estimate their alcohol and folate intake amount over a period of
time. Therefore, it would be necessary to infer both the average level of
alcohol intake and folate intake at a time, and the period that the intake
level referred to (at least the length of the period) from the answers on
the questionaries. Based on this assumption, a relationship between the
dose of alcohol intake and folate intake can be further investigated;
otherwise, the relationship being investigated is only about the
relationship between the answers on the questionaries and the incidence of
breast cancer. Similarly in another study on stress and breast cancer,[2]
there was at least an assumption needed to make: the answers given by the
subjects, reflected / strongly associated with the stress level of the
subjects over a period of time (at least length of the time).
Giving clear statements on the assumptions/inference on measurements,
it would be much easier to evaluate the measurement method of a study
based on the information provided in the study, and it would be easier to
further construct a study to test the validity of that particular method.
Reference
1. Baglietto, L., et al., Does dietary folate intake modify effect of
alcohol consumption on breast cancer risk? Prospective cohort study. Bmj,
2005.
2. Nielsen, N.R., et al., Self reported stress and risk of breast
cancer: prospective cohort study. Bmj, 2005. 331(7516): p. 548.
Competing interests:
None declared
Competing interests: No competing interests
Dear Editor,
1) When the exposure of alcohol and folate were measured,[1] the
exposure periods of the two substances would be needed to evaluate the
total doses of exposure.
2) People who have a high folate intake (>400 micrograms/ per day)
are more likely to take care of their health: they are likely to have
higher physical activity level, consume a balance diet, consume “better”
alcohol, pay more attention to or even overestimate their risk
factors—they may overestimate the amount of alcohol that they have drunk.
People who have high alcohol consumption (>40g/day) and low folate
consumption may have more problems with their health, therefore they may
visit their GPs more frequently, and high alcohol intake may draw the GPs’
attention to their potential breast cancer risk. This might increase the
“risk” of these people to be early diagnosed.
A further comparison of baseline characters between these two small
groups (people who consume >40g alcoholic drinks, and consume either
less than 200micrograms or more than 400 micrograms) may be appropriate.
Reference:
1. Baglietto, L., et al., Does dietary folate intake modify effect of
alcohol consumption on breast cancer risk? Prospective cohort study. Bmj,
2005.
Competing interests:
None declared
Competing interests: No competing interests
Does Family History influence the results?
Dear Editor,
As a female doctor who enjoys a glass of red wine with her dinner I
read with interest the article by Baglietto et al, (1), regarding dietry
folate intake and whether it modifies the effect on breast cancer from
alcohol.
At baseline a structured interview was used to obtain information
about potential risk factors including age, sex (?), country of birth,
education, reproductive history and alcohol consumption. Similarly, other
potential confounders were examined including eduction, Body Mass Index,
age at menarche, Hormone Replacement Therapy, parity and use of
multivitamins.
I was surprised that missing from this list was family history of
breast cancer in first degree relatives, smoking and use of oral
contraceptive pill. I wondered if this information was collected and if so
did it affect the results?
Reference
1. Baglietto, L., et al., Does dietary folate intake modify effect of
alcohol consumption on breast cancer risk? Prospective cohort study. Bmj,
2005.
Competing interests:
None declared
Competing interests: No competing interests