More than 62% of people living in West Somerset will be over the age of 50 by 2029, according to research carried out for the BBC.
The area already has the highest concentration of over-50s in the UK - 52.8% compared with the national average of 34.5%.
It is expected to stay ranked highest over the next 20 years.
The research, by Experian, looks at how areas of England will be affected by an increasing ageing population.
Marcus Kravis, chairman of Minehead and District Chamber of Commerce and Trade, said local businesses were beginning to reflect the older community.
He said that people wanting to work longer meant younger people were moving away to find jobs.
Mr Kravis said: "Market forces will cater for the customers that are out there.
"I always joke about the growth of garden centres, but that's just one example. You only have to go into the local coffee shops and look at the age of the people there. The Costas aren't full of teenagers."
He said: "Everyone's going to have to be flexible. If people want to work longer, they may not want to work 40 hours a week they might just want a part-time job which means you'll end up with more part-time workers.
"This is very useful for supermarkets... but if you've got three or four part-time staff working in a supermarket then maybe they're keeping full-time equivalents out of a job and unemployment could grow."
Dr John Higgie, a GP in Minehead, said he was a strong supporter of plans to build a replacement community hospital for the town as the care it would be able to provide would be better for the older generation.
He said: "It's 26 miles from our local general district hospital and we have an ageing population here where 28% of our patients are over 65 and the sheer journey is a problem for them.
"Many older people have got problems that don't need the facilities of a big hospital and we can care for them perfectly adequately in a local community hospital.
"This saves them the travel, but it also means their relatives can visit more easily, they're looked after by people they know and it's much less of a wrench than moving to the main hospital in Taunton."