Since Britain voted to leave the European Union more than a year ago, Europeans have mockingly said that the decision will result in an isolated, lonely island nation.

But Britain, in fact, already has a serious problem with loneliness, research has found. More than 9 million people in the country often or always feel lonely, according to a 2017 report published by the Jo Cox Commission on Loneliness.

The issue prompted Prime Minister Theresa May on Wednesday to appoint a minister for loneliness.

"For far too many people, loneliness is the sad reality of modern life," May said. "I want to confront this challenge for our society and for all of us to take action to address the loneliness endured by the elderly, by carers, by those who have lost loved ones — people who have no one to talk to or share their thoughts and experiences with."

Mark Robinson, the chief officer of Age UK, a charity working with older people, warned that the problem could kill. "It's proven to be worse for health than smoking 15 cigarettes a day, but it can be overcome," he said.

The prime minister announced that Tracey Crouch, the undersecretary for sport and civil society in the culture ministry, would lead a governmentwide group to build on Cox's legacy and establish policies on the issue.

In parallel, the Office for National Statistics would help to establish a method of measuring loneliness, and a fund would be set up to help the government and charities to develop a wider strategy to identify opportunities to tackle the problem.