I also believe one should start L-dopa when one's symptoms require it. But I also fear that L-dopa may have serious drawbacks. So, my personal perspective is that I'll only start taking L-dopa when my symptoms will start to seriously impact my daily life (which luckily for me is not the case yet).
In the meantime, I'm trying my best to find the root cause of PD for me (I suspect the root cause is not the same for everybody), delay progression and manage my PD in other possible ways. I know this may sound like wishful thinking and it may not do any good at all (after all, there's no scientifically proven way to do this), but I'm surely going to try.
In a nutshell, my approach is as follows:
1. Find out anything that's wrong and correct it. I went back to my lab reports from medical check-ups I had done over the years and other more recent analyses (I've done tons more since dx some 2 years ago). When I find results "out-of-norm", I try to find doctors that help me correct each one of them. I also spend a fair amount of time on the internet trying to understand what they really mean and see if they might have a link with PD. In some cases, there seems to be a link. My top ones so far are Vitamin D, Iodine, Cortisol, and inflammation. I'm low on the first three and have signs of inflammation. I have found reasonable evidence that suggests links of all these four with PD. I still haven't figured out what to do about Cortisol (Cortisol meds have plenty of negative side effects, so not keen on starting to take them before I'm really sure of what I'm doing), but am taking supplements for the other 3 just in case fixing them has an impact on PD (and anyway, correcting my out-of-norm situation can't be bad).
2. Beef-up on neuroprotective stuff. Some studies suggest that Vit C, Vit E, and CoQ10 are neuro-protective and delay PD progression (though others suggest they don't). As they don't seem to have much drawbacks and just in case they do work I’m also taking supplements of them. My nutricionist also claims that pomegranate is a strong neuro-protective – so I’m taking some highly concentrated version of that stuff too just in case.
3. Exercise helps. This is the only one thing that seems to be scientifically proven to help delay progression (at least in animals) and I find it works well for me.
4. Healthier food might help. I’m not sure what’s the exact link with food and PD, but somehow I feel that my digestive system plays a role in this (I've seen some research that links the digestive system with PD), so I’m generally trying to eat a bit more healthily than before.
5. Reduced stress helps too. It seems clear that stress accelerates PD, so reducing stress must be good. This, however, is a lot easier said than done to me.
6. Meds other than L-dopa. I'm taking Azilect (Rasagiline) and Tyrosine. Azilect is claimed to help delay progression by the equivalent of 2 years (though one of my neurologist is not convinced it helps at all). Tyrosine helps fight fatigue and it's actually the key ingredient that our brains use to make L-dopa naturally. Some people argue that one shouldn't take Azilect together with Tyrosine because of the risk of hypertensive crises (possibly leading to a heart attack). I have low blood pressure and am taking both as I believe the doses I'm taking are still ok and I like the benefits... but obviously given the risk of hypertensive crises, I'm not recommending this to anyone.
7. Check-out genetics and other possible root causes. I tested for the known genetic causes of PD (using "www.23andme.com/pd
" - they are 100% free of charge for PwP). In my case, they didn't detect any known genetic correlation with PD. I also have a few other hypotheses about possible root-cases of my PD, but they are difficult to be sure about and may vary a lot from person to person (h. Pylori infection in the past, etc).
Hope this gives you a couple of ideas and good luck with whatever approach you decide to take.