A graph plotting numbers dying versus age reveals that, while most die between around 60 and 85 significant numbers make it through into their 90s and beyond. The oldest person to have lived reached 122, and while she may have been somewhat exceptional, scientists reckon that humans have the natural ability to make it to around 110.
The fact of the matter is that very few people die solely of old age. And very few more die as a result of bad luck - diseases for which no cure is possible. Those two causes together amount to only 17% of deaths, leaving 83% down to other causes. The key message from the analysis Brian and others have undertaken is that some 43% of deaths take place earlier than they need to. They are the result of adverse lifestyle factors such as poor diet, smoking, insufficient physical activity, and excessive drinking. Brian's main message was that the harmful effects of all of these factors can be reduced simply by changes in lifestyle.
The fewer of these premature lifestyle related deaths that take place, then the average age of the population at death rises. Brian did however point out that other factors contributed to longevity in a positive way. These include having a good social life and having an optimisitic, positive attitude to living - a reason to live if you like. It was evident from an hour or so in his company that Brian very much practises what he preaches, particularly in his sunny outlook on life. All in all, an uplifting talk.