Ummm, scurvey and other nutritional diseases do respond pretty quickly to vitamin intake unless the person is literally within a day or two of dying.
You are assuming that all scientific research is being done by the big pharmaceutical companies. You forget all the universities with those bright young graduate students just dying for a thesis topic and those professors who would love to gain tenure with a break through article published in
Science or the
Lancet.
Your theory would be a relatively inexpensive one to undertake to test in any university biochem lab that could afford a few hundred lab rats or white mice. Construct a double blind study where one group of mice was fed apricot kernels and the other group a regular diet. When the mice reached maturity, expose them all to some known carcinogen. Compare the survival rates of the mice after a year. Easy instant fame for some kid working on his PhD, never mind his advisor who would take the credit for it all.
It hasn't happened because it doesn't work. Very simple.
My advice: Move to an area as free of environmental pollutants as possible and eat only organic foods. Don't eat fish of any sort. Get a really good water purifier. Never drink water from the tap. Don't join the US military where you will exposed to God knows what chemical and biological weapons. Avoid becoming an uranium miner or living anywhere near mine tailings of ANY sort. Stay away from microwave relay towers and ovens, just in case. Wear only natural fabrics and have bare wood floors in your home or else carpets made of only wool or cotton. Avoid harsh chemical cleaning supplies. Have your home checked for abestos if its an older structure. Build a pond and stock it with salamanders. Check on their well being daily. Amphibian's are the environment's canaries. They're the first to go south if anything nasty is around.
Most people can't manage the above life style, so they turn to things like apricot pits.
Oh, yeah, pick parents and grandparents who never had cancer. Genetic susceptibility is a key factor,
