Then what's your explanation for the huge rise in life expectancy and food availability--starting in capitalist Western countries, and then spreading to the rest of the world along with the market economy?

Capitalism is certainly imperfect at distribution of food and medicine. As the saying goes: it's the worst system, aside from every other that has existed. And the margin isn't particularly close.

You date the origin of capitalism to Columbus? Seems pretty arbitrary. Markets date back thousands of years, and recognizably capitalist forms of government emerged in the 18th and 19th century at the earliest. Columbus was sponsored by a king seeking new land, not capitalists seeking new markets.

Alternative systems such as...? I can think of several, but none I'd describe as 'successful'.

It's kind of a red flag (no pun intended) when your preferred system can be destabilized with some money stuffed in the right pockets, isn't it? Most failed systems that were 'undermined by capitalists' mostly involved funding and support, not invasion or anything. Meanwhile, democracy and capitalism emerged in the midst of hostile aristocracy and royalty, and survived decades of attempts by the USSR (and now Russia) to undermine it.

My personal opinion is that those systems were doomed from conception, though I don't deny that the US certainly engaged in speeding their demise.

Anyway, that's all beside the point. Both populations and consumption increased under the Soviets, and any other system you care to name, proportionate to their effectiveness at keeping people fed and healthy.