Human genetic clowning is against the law, but it could be done. Agriculture today is many times more productive than even 50 years ago, as per acre harvest have doubled and tripled, primarily do to altering the genetics.
They don't allow the worms to breed until they're older. This means that only those worms with long living genes get to breed. After a number of generations you have worms with long living genes since over time you're weeded out the short living ones. It'd take centuries in humans.
The Russians could keep a responsive dog head alive on artificial organs 50 years ago. It's completely possible now. That would just cause a population problem.
How much scientific data did we get from them though? How much medical data did we get from unit 731? Do you know the things they did to people there? The Japanese were some twisted people as well at the time.
Yuck... Could You Fight Off Worms? Depends On Your Gut Microbes April 7, 2018 • Nearly 25 percent of people are infected with worms. New research suggests that gut microbes may be able to help in waging war against the parasites.
Increasing Human lifespans has been occurring for centuries albeit not through genetic manipulation. Technology has only very recently increased to the point we are looking into doing this. https://www.nature.com/scitable/topicpage/genetic-control-of-aging-and-life-span-847