I think it stands to reason that a healthier outdoor lifestyle with better exercise and diet should lead to a better healthier life in Spain assuming any alcohol, food and drug excesses are avoided. But it is unrealistic to say there are no bugs - lately maybe because of wide temperature fluctuations there has been a lot of illness around.
So moving to Spain does not necessarily guarantee instant health and long life but I do not believe it does help especially with mental attitude, warm sun and blue skies are a marvellous tonic.