Grapefruit and Exercise or Flu Vaccine and Anti-biotics?

I had an interesting life experience a couple of years ago when for the second year in a row I had pneumonia in the winter time.  My doctor, a large, jovial Russian-born guy who I like and respect took time with me to talk through my lifestyle.  First of all, he is a big fan of mouth wash.  So, naturally, he suggested I use mouthwash more frequently since it would kill germs acquired from students sneezing in class or my sons at home.  I'm not a big fan of mouth wash, so that one never really took off.  

What did catch my attention was his point that getting regular exercise, at least 30 minutes pushing myself, per day would really boost my well-being.  In addition, I asked him if I should take some supplements or vitamins?  No, he indicated.  The supplements are unlikely to help and could actually tax the body and cause harm.  At the time, I did not think much of his point, but more recently, I see that several studies suggest supplements do not help with longterm disease nor do they help with short-term flu (which typically is the beginning of pneumonia for me).

So, over the past couple of years I have stepped up my efforts at going to the gym and eating well.  In particular, I mentioned to him that I like grapefruit.  He indicated to me to eat as much as I like, because grapefruit has special properties that may help.  Hmmm.  A magic fruit?  I see there is some research suggesting it promotes drug uptake of some cancer drugs.  It is also claimed in a number of homeopathic and casual online sources that grapefruit does indeed cure the flu and colds!  So, I have been eating grapefruit and exercising regularly through the winter this past two years, and guess what?  No flu nor colds!  Hopefully, this success will continue.  In any case, I thought I would share the experience, because in the past I had been getting the flu vaccine and got the flu and colds which led to pneumonia.