i think he's making a "pascals wager" type bet on life extension technology. where if he lives long enough to hit a timeframe where they do discover some magical life extension, then he is "saved". therefore, you take every action that puts you towards that goal. if you do hit the magic tech window, then you can have infinite pizza and whatever afterwards.
i do get the rationale behind his decision but my goodness, it's overkill. you could probably achieve 95% of the same "anti-aging" effect he's going for by regular exercise, decent food and good sleep alone. the pill consumption, black sludge and all that; he's asking for a heart attack.
is the extra 5% improvement left on the table really worth up to 75 years of... collecting stool samples and standing in infrared light boxes?