HUMAN LONGEVITY 67 



Lacking this the best that can be done is to discuss some of the 

 environmental factors that have been thought to be, or in fact 

 are, importantly concerned in the achievement of longevity. 

 Only those will be chosen for discussion about which there 

 exists definite scientific evidence, pertinent to the point at 

 issue. 



Of all such factors the use of alcoholic beverages has probably 

 been most discussed. The problem of the effect of such usage 

 upon longevity has excited violent and unreasoning prejudice 

 on the part of large numbers of people. They contend that 

 alcohol always and everywhere shortens the lives of its users. 

 There is much evidence, experimental, statistical, and actuarial 

 that this is not a universally valid generalization. This evidence 

 does not make the slightest impression upon those who believe, 

 that is to say have faithy that the generalization is valid. So an 

 imfasse results. So far as I am aware there has been constructed 

 only once a set of life tables for classes of persons homogenous 

 in respect of their habits relative to alcoholic indulgence, and 

 based upon critically adequate and pertinent data collected at 

 first hand. Those life tables lead to the general conclusion 

 graphically depicted in Figure 11. 



That conclusion is that moderate drinking is not significantly 

 associated with any alteration of life duration, either for better 

 or worse, when compared with total abstention from alcohol, 

 while heavy drinking is definitely associated with a serious 

 diminution in the length of life. 



These results have been accepted by some, and rejected by 

 other equally sincere, equally honest, and intelligent groups of 

 people, who however differ widely in their emotions and senti- 

 ments regarding the use of alcohol by man as a beverage. Noth- 

 ing further can be done about the case. Presumably each one 

 of the present audience is already a component of one or the 

 other of these two groups. 



Let us turn next to the use of tobacco and longevity. This 

 usage is probably, along with that of alcohol, one of the most 

 widespread amongst humanity relative to substances or materials 



