Indeed, and this possibility is called the kidney. Young people with 'healthy' kidneys are able to eat and drink almost anything they want and are much more lik

Indeed, and this possibility is called the kidney. Young people with 'healthy' kidneys are able to eat and drink almost anything they want and are much more likely to have well-regulated blood pressure. However, as we age, our kidneys perform more poorly (a simple explanation as to why older people are more likely to take blood pressure medications than younger people). As our physiology weakens, our diet (and exercise, among other things) become more important to our physiological health. This, in conjunction with the hardening of our arteries due to age and atherosclerosis, means that our diet (particularly our sodium intake) becomes exponentially more important in our older age than our younger age. If this sounds unlikely, understand that the kidney is the direct or indirect target of many medications for blood pressure. Diuretics such as hydrochlorothiazide and loop diuretics such as furosemide act very directly on the kidney. Drugs such as ACE inhibitors (e.g. lisinopril), ARBs (e.g. losaratan), and renin inhibitors (aliskiren) act on the renin-angiotensin-aldosterone system, which directly involves the kidneys in a different manner. (I am a pharmacist).