Day 033 - 10 Oct 94 - Page 32
1 I regard that limit as being quite generous in fat, and
2 that a protective diet might be configured with
3 considerably less fat than that to be safe.
4
5 MR. MORRIS: So the government recommended a figure of 30 per
6 cent; you would say that is a cautious one or not?
7 A. I would say it was set to be higher than I would say
8 is optimal. I might call it a conservative one rather
9 than cautious. To be cautious one would suggest a much
10 lower fat intake perhaps.
11
12 Q. If we move on, you said something on obesity and about
13 other mechanisms. I cannot remember what mechanisms you
14 did describe. Do you remember?
15 A. The mechanisms linking -----
16
17 Q. You said something ----
18 A. - linking fat and breast cancer?
19
20 Q. You said there other mechanisms -- I cannot remember the
21 mechanism you did mention?
22 A. Yes, I did cite a number of mechanisms. With regard
23 to breast cancer, one is that a high fat diet can elevate
24 oestrogen levels, fibre can reduce oestrogen levels, and
25 we talked about fat impairing immune defences against
26 cancer. In addition, obesity is widely agreed, widely
27 accepted, as something that increases the risk of breast
28 cancer.
29
30 That may be mediated by the fact that adipose tissue, fat
31 tissue, increases oestrogen levels in the body because the
32 fat allows the production of oestrogens. So, again that
33 is another mechanism. So, again, when we have talked
34 about all these various links there are many, and it is
35 really quite widely accepted and widely known that a high
36 fat diet encourages obesity, that obesity encourages
37 breast cancer, and therefore a high fat diet without any
38 question is going to encourage the risk of breast cancer;
39 it is going to increase the risk of breast cancer. We
40 presume that at least one mechanism is through its effect
41 on sex hormones. When women lose weight and when they
42 reduce the fat in their diet, you can very quickly change
43 their hormone levels to a smaller amount, a smaller amount
44 in the blood.
45
46 Q. Over the page, on page 10, you very briefly touch on lung
47 cancer rates. Any particular point you want to make on
48 that?
49 A. One has to presume that lung cancer is linked most
50 tightly to cigarette smoking. After all, one is inhaling
51 carcinogens and they hit the lung tissue directly.
52 However, researchers have noted that even when smoking is
53 controlled for vegetarians have less lung cancer. That is
54 simply an association. One presumes that the reason is
55 that whatever exposure one may have to carcinogens,
56 vegetarians have a stronger immunity along some of the
57 lines that we spoke of earlier, and perhaps less of a
58 tendency to actually absorb mutagens into their bodies,
59 which is another presumed mechanism; because mutagens that
60 are inhaled through the lungs travel into the blood stream
