In VST Industries thread, I did cover about Cigarette being cockroaches among the listed companies. US and UK sector wise data in CSFB Global Wealth study only show Cigarette being a major sector which continiue to exist in 20th century. Having said that, lot of changes have happen. My wish is ITC can maintain its cashflow around 5-10 years from Cigarette and after that Other FMCG sector shall become sufficiently large to provide for future growth territory. This is my wish and market environment is not obliged to fulfill my wishlist 
There can not be clear cut answer to such question when there are mutilple moving parts. However, being addictive business, ITC cashflow from cigarettes, are least volatile in my opinion. How long that situation can persist, I do not know. One has to look at once risk profile and decide for allocation after developing conviction in investment idea.
Discl: Among my top 5 holding and with small addition last month, my view may be biased. Not a SEBI registered advisor, Not Recommeding investment in the company, Please do your own due diligence before investing.
Link for Cigarette Industry Market cap globally over 20th century