Day 017 - 25 Jul 94 - Page 37
1 going to take part in studies. It is often very difficult
to, for example, in case control studies get people in the
2 lower socioeconomic groups because of their reluctance to
participate, so you do tend to get bias.
3
Of course, the reason that there is a higher risk in the
4 higher socioeconomic groups is because they are women who
are subjecting themselves the risk factors we discussed
5 already, such as low numbers of members of family, in
other words, not having very many children, often having
6 the first child at a late age, so, you know, it is a
measure of the fact that these are women who are subject
7 to increased risk factors anyway. That is why the
incidence is higher.
8
Q. I will finish it off: "These data are not consistent with
9 the hypothesis that high dietary fat intake increases
breast cancer risk. Indeed, they suggest a possible
10 protective effect of high fat intake, but this result may
be influenced by methodologic problems with the dietary
11 assessment. These results certainly indicate the need for
further exploration".
12 A. Which is a very reasonable conclusion.
13 Q. Are we still on a voyage of exploration?
A. I think we are. In all honesty, I think that we have
14 not overcome a lot of the problems which have existed in a
number of these studies and which continue to be
15 problems. And we do definitely need to conduct further
studies. Whether they will actually be able to overcome a
16 number of these problems of dietary recall and measurement
of fat, measurement of other components of calorie in the
17 diet, is open to question. But we certainly need to
conduct further studies; we do not have the answers yet.
18
Q. I want to look briefly at two more up-to-date studies; one
19 again by Dr. Kinlen who came back to the sort of subjects
he was discussing in 1987 in 1991, which is at tab 7 of
20 your file. This is published in the British Medical
Bulletin Volume 47, No. 2. It is published by the British
21 Council. The article is headed Diet and Breast Cancer.
It is again by the same Dr. Kinlen, in the box: "The
22 issue of diet", do you have it?
A. Yes.
23
Q. "The issue of diet as a cause of breast cancer has been
24 dominated by fat. Some have judged this convincing enough
to warrant dietary recommendations aimed at prevention.
25 Others find the evidence so far rather weak.
26 this hypothesis arose because fat appeared to cause
mammary tumours in rodents and because in women, mortality
27 from the disease in different countries strongly
correlates with the corresponding per caput fat
28 consumption as crudely measured in food balance tables.
These correlations concern animal, and not vegetable, fat
29 and are stronger for postmenopausal than premenopausal
breast cancer. Other early observations that seemed
30 relevant are the increase in breast cancer among the
Japanese in the USA, a group whose intake of fat has also
