Day 269 - 25 Jun 96 - Page 11
1 only contribute to 35% of the risk the figures are 31,750
2 and 15,875 respectively. These figures pertain to those of
3 the 1,905,000 who eat once a week at McDonald's before they
4 reach retirement age and are only intended as a guide to
5 assess the contribution to the sum total of an individual's
6 saturated fat load."
7
8 MR. JUSTICE BELL: Just pause a moment, because I think I need a
9 bit of explanation of the mathematics there. Can you just
10 take me through it, Professor Crawford, the one in three
11 men will have a heart attack or stroke, as you say, before
12 they reach the age of retirement?
13 A. That is in the lower socio-economic groups.
14
15 Q. Right. And then to get an idea of the contribution to risk
16 one can use the factorial calculation of the proportions
17 which gives at 70% a risk?
18 A. Yes.
19
20 Q. Of risk?
21 A. One in seven days exposure.
22
23 Q. Well, how do you do that?
24 A. Well, if you sort of -- I mean, this is only a --
25 Willett did something very similar with regard to the
26 question of the contribution that trans-isomers might
27 make to --
28
29 Q. Forget that for a moment. I want to understand what you
30 have done in this paragraph.
31 A. If you take the figure of 1,900,00 and divide it
32 by seven --
33
34 Q. Just pause a moment. Yes?
35 A. And that gives you sort of the impact of the
36 contribution of the particular diet of one day in a seven
37 day week.
38
39 Q. Yes?
40 A. You can then take 70% of that as your risk factor.
41
42 Q. Why do you take 70%?
43 A. Because that is the prediction from the Ancel Keys data
44 from the country to country relationships between diet and
45 mortality from heart disease.
46
47 Q. Yes?
48 A. So if you then take one-third of that.
49
50 Q. One-third coming from?
51 A. From the one in three risk.
52
53 Q. Yes. That is the one in three men?
54 A. Yes.
55
56 Q. Who will have a heart attack?
57 A. Yes. You then end up with that figure of 63,500.
58 Now, if you are of the view, for argument's sake it is
59 quite useful to discount the perception that is quoted of
60 70% and say let us argue that it is not 70%, let us argue
