To be able to answer this question I have to extend it:
Can homemade dog food extend their lives compared to other dog foods?
Unfortunately I wasn't able to find any scientific paper that looked at this specific question. But I still feel confident to say:
- Compared to cheap, high grain content food: possibly yes.
- Compared to high-quality food with a low grain and high meat content: probably no.
Manufacturers of dog food have laboratories to make sure their food contains exactly all vitamins, minerals and essential nutrients a dog needs to survive. Cheap dog foods are then filled up with the cheapest ingredients (which are grain, potato or animal fat). However, this food has a high starch content which is known to contribute to obesity and diabetes in dogs. That alone can lower the life expectancy.
High quality dog food is expected to contain more animal product than grain. "Animal product" means more than just lean muscle flesh, it also contains skin (for collagen and fiber), finely crushed bones (for calcium) and inner organs (for vitamins and minerals). Some vegetables should be added (for fiber, vitamins and minerals) and some grains, but no more than 30%. This should be a balanced diet that contains all required nutrients in the right amount to avoid deficits.
In theory, feeding your dog the high-quality dog food appropriate for their age group should extend their life expectancy more than a home-cooked diet that may be lacking in certain vitamins or minerals. My biggest concern is that almost all of the home cook recipes include only turkey or chicken meat. The most logical option for consumers is to buy chicken / turkey breast, but that lacks skin, bone and inner organs (the stuff a wolf or wild dog would consume in nature). I'm no food scientist and cannot say if any of the other ingredients make up for the lack.
If you feed your dog such a diet, I recommend having a blood test done at the annual vet checkups just to make sure there's no deficit in any essential nutrient. I'd also consider switching between different recipes to balance the diet.