So the Annonaceous acetogenins are what's called mitochondrial complex I inhibitors. Basically the way they work is they cause a buildup of radical oxides within your mitochondria, which decrease how efficient your mitochondria are at producing energy. In small doses, this is probably a good thing -- you give your mitochondria a good workout, and then eventually some antioxidants clear out the radical oxides and your mitochondria end up stronger than before. But in sufficiently large doses, you will start killing off your mitochondria, and if you kill enough (likely over several decades) it will cause something called Progressive Supranuclear Palsy, which is fatal.

The good news is that there is only one recorded case in history of someone who is suspected to have gotten PSP from eating pawpaws, a grower in New Jersey. The acetoenins in pawpaws have a fairly low bioavalability, so it's probably only a significant risk if you are 1) eating large quantities 2) doing something to increase the bioavailability of the acetogenins, e.g. cooking them with fat or maybe mixing them with alcohol.

If you eat moderate quantities out of hand, then most likely you are just reducing your cancer and diabetes risk, without taking on any increased risk of PSP. And since cancer and diabetes kill hundreds of times more people than PSP, overall eating them out of hand is almost certainly a net positive for your health -- especially when you compare them with the health effects of ice cream or whatever other dessert you'd have otherwise have been eating in their place.

That said, the cultivars that are specifically known to be low in acetogenins are: Sunflower, Wabash, Potomac, Zimmerman, Wells, Mango, Shenandoah.

Of these, the ones that are actually good are Wabash, Shenandoah, Sunflower, and Potomac. So if you just want to grow cultivars low in acetogenins, grow at least two of those four.