Day 035 - 12 Oct 94 - Page 45
1
2 Q. No, I agree; it probably is not.
3 A. Because, well, when one looks at studies and one looks
4 at the power of dietary recommendations, one is looking at
5 the effect overall of fibre, fat and deficiencies in
6 vitamins and minerals or their supplementation. The
7 degree to which those factors collectively might influence
8 the risk of breast cancer has been described in various
9 terms, but it is quite large, certainly much more than
10 threefold, because that is the type of difference that one
11 sees in international variations.
12
13 Q. Again, I am afraid, a slight red herring: Can I take it
14 from something you have said earlier, Dr. Barnard, that
15 you would accept at least the possibility that a diet
16 which is high in fat but also high in the right kind of
17 fibre may be perfectly satisfactory from the point of view
18 of being protective against the risks of colon cancer?
19 A. No, that is not what I suggested. I would say that
20 fibre is protective. However, that is not to say that it
21 can totally undo the effects of a high-fat diet.
22
23 Q. May we read on with -- we will come back to that question
24 later -- Dr. Willett?
25 A. Please.
26
27 Q. "Other data suggest that having a large number of children
28 also independently reduces the risk. The protective
29 effect of early first full-term pregnancy may be due to a
30 permanent differentiation of mammary stem cells, resulting
31 in a reduced lifetime risk of breast cancer." Do you
32 accept that as what I call a respectable hypothesis?
33 A. I do not see it as being offered as a hypothesis
34 necessarily; it is offered as a suggestion and a
35 possibility and in that sense it is respectable, yes.
36
37 Q. "Many studies show an association between early age at
38 menarche and increased risk of breast cancer; typically
39 early menarche confers about a 1.5-2 fold increase in risk
40 compared with late menarche." One notices there the 1.5
41 to twofold increase. To what extent, in your view,
42 Dr. Barnard, is early menarche a function of diet and diet
43 alone?
44 A. To what extent?
45
46 Q. Yes.
47 A. Well, dietary factors do influence the age of menarche
48 and the degree in change, the total change in the number,
49 simply the number of years between the high end of
50 menarche and the low end of menarche, if we look
51 internationally and across all different diets, is about
52 four and a half years. One would presume that the maximal
53 affect that a diet could have on the age of menarche, say,
54 from the highest fat/lowest fibre diet to the reverse
55 might be about a five year difference in the age of
56 menarche.
57
58 Q. "Early menopause provides protection, removal of both
59 ovaries before the age of 35 reduces the risk of disease
60 by about 0.6 compared with natural menopause. These
