Day 033 - 10 Oct 94 - Page 27
1 called natural killer cells. Natural killer cells are so
2 named because they are natural killers of cancer cells.
3 They do not need to be primed. One does not need an
4 inoculation. These cells do not need prior experience
5 with cancer. They can simply knock them out. Natural
6 killer cells' function is impaired when, if you will, they
7 have to swim in an oil slick, if I can put it that way.
8
9 With regard to vegetarians, there has been an ongoing
10 study of vegetarians at the German Cancer Research Centre
11 in Heidelberg. Vegetarians have been compared with
12 individuals who are not vegetarians but are working at the
13 Cancer Research Centre. Their cancer death rates have
14 been tracked and, not surprisingly, vegetarians have
15 considerably lower cancer death rates. For women, they
16 have about 25 per cent less cancer death rates over an 11
17 year period; for men it is about 50 per cent reduced.
18
19 Q. Over an 11 year period, did you say?
20 A. Yes. But when one actually looks at their immune
21 systems one finds that the natural killer cell, what is
22 called "natural killer cell activity", which means the
23 natural killer cell's capacity to knock out a standardised
24 sample of cancer cells is double that compared to
25 non-vegetarian controls. It is not known whether that is
26 because the vegetarians have double the number of natural
27 killer cells or if the ones they have are simply that much
28 more ferocious against cancer.
29
30 What is quite clear, well established, well accepted, is
31 that a diet that is high in fat can impair indices of
32 defences against cancer. This is believed to be yet
33 another mechanism by which a high fat diet may make cancer
34 more likely.
35
36 I should say, perhaps, that cancer cells arise in the body
37 from time to time. It is not as if every cancer cell that
38 arises in the body immediately progresses and becomes
39 cancer. Without one's immune defences one would have
40 cancers that would otherwise be recognised by the white
41 blood cells and removed.
42
43 Q. Just one question about that -- it may seem an obvious
44 question -- why do many of the reports you refer to, not
45 all of them but some of them, refer to vegetarians as a
46 control sample or as an area of study?
47 A. Vegetarians are a very useful population to study and
48 have been for many, many years because they consume diets
49 that are low in fat, that are either low in animal fat or
50 devoid of animal fat; they are typically high in fibre.
51 Studies that examine vegetarians will elaborate details on
52 each of these factors and allow their dissection in the
53 course of research.
54
55 Q. In other words, the important thing is not whether they
56 are vegetarians or not, but what the actual fat and fibre
57 content in their diet is? Is that what you are saying?
58 A. In most cases, yes, that is correct. There have been
59 some cases where researchers were particularly interested
60 in vegetarians themselves but, yes; for example, the
