The health secretary, Andrew Lansley, has been forced into a major U-turn on funding for public health campaigns, after evidence emerged that the spending freeze had cost lives.

An extra £15m has now been set aside for promoting the government's anti-smoking website and £14m will be made available for a campaign promoting healthy living.

The decision has come in response to a damning Department of Health (DoH) report on the consequences of the government's decision to "all but cease" publicly-funded advertising last year.

The DoH found that the number of people ringing the drug abuse support helpline, Frank, had fallen by 22%, that visits to the Smokefree website had fallen by 50% and that the number of people joining the government's lifestyle website was down by two-thirds.

Most worryingly, the report said, there was evidence that "the cessation of marketing activity [had] resulted in declining quit attempts, and subsequent loss of life from smoking-related illness".

It added: "Following the coalition government's freeze on non-essential marketing expenditure, all social marketing programmes were reduced and expenditure on advertising all but ceased.

"We have now had the opportunity to learn from the freeze and to assess where the loss of mass communications had a negative impact... We now recommend that some advertising, and other forms of mass communication such as sponsorship, paid media partnerships and PR, be resumed."

The revelation follows savage criticism of the DoH decision last year to axe the £1.5m awareness campaign for flu vaccinations. Figures released this month showed there had been a rise in deaths from 474 in 2009/10 to 535 in 2010/11 and that a disproportionate number had been among the young.

Lansley justified the freeze on marketing spending last year as a departure from the "lecturing" attitude, which he said characterised some previous government's interventions.

But shadow health secretary John Healey said Lansley needed to publicly apologise for his mistakes: "Mass publicity must play a part in good public health. This report shows that Andrew Lansley made the wrong judgment in axing anti-smoking promotions, just like he did on the flu-jab adverts last autumn.

"The health secretary needs to tell people that he's learnt the lessons and won't make the same mistake again."

Key evidence for the loss of life caused by the government's policy was provided in a submission to the all-party parliamentary group on smoking and health by Professor Robert West, director of Tobacco Studies at Cancer Research UK.

West told the group: "Evidence shows that total spending on government mass media campaigns in a given quarter is associated with smoking cessation activity in that quarter. If, as seems likely, this association is causal, the recent suspension of mass media campaigns will lead to significant loss of life, and with every month that passes without further activity the death toll will grow."

West told the Observer that the most recent figures on giving up smoking confirmed his fears: "For smoking, most of the population are in a state of motivational tension, they are a bit dissonant about it and what the marketing does is tip them over the edge into activity. So if you stop doing that they carry on being dissonant.

"We looked at a number of objectives – markers of cessation activity, attendance at clinics, hits on the website and the quit line – and the correlation is very striking. The association between marketing activity and spend was very strong.

"It [lack of marketing] will have cost lives. For every year that someone over the age of 35 carries on smoking they lose three months of life expectancy. So if you just lose a year of significant activity you have already lost lives. That is the inescapable logic of it."

Research by the DoH suggests smokers' motivation to quit is in decline, with the number of people saying they do not want to quit at all at 30%, its highest level since tracking began in 2007. Over recent years, there has also been a year-on-year decline in people trying to stop smoking, from 43.5% in 2007 to 35.8% in 2010.

On top of the spending on anti-smoking and the healthier living campaign, Change4Life, a further £4m will be spent on marketing targeted at young people, and £11m on advertising issues related to older people.

Professor Geof Rayner, an adviser to the Change4Life programme, said he was delighted: "I am pleased the civil service has put this in front of the politicians and that the politicians have seen some sense. They should be pragmatic, not ideological, about public health."

However, the total spending is still less than half the £93m spent by the Labour government in 2009/2010.

A DoH spokesman denied the decision to start spending again was a U-turn but claimed that the freeze had been an opportunity to test the efficacy of previous spending.

"Our campaigns have a high impact," he added. "A study found that two-thirds of the public think advertising is vital to the success of government campaigns."