The number of would-be students applying to university has dropped for just the third time in 15 years.
Figures show that around 30,000 fewer people had applied to start degree courses this autumn by January 15 - the main deadline for submitting applications.
A breakdown reveals that, in the wake of Brexit, the number of EU students planning to study at a UK university has dropped by around 7%.
There has also been a 5% decrease in UK applicants, while the number of potential international students, from countries outside the EU, remains similar to last year, Ucas figures show.
Overall, 564,190 people have applied to UK universities and colleges, down 5% (29,530 students) compared to the same point in 2016.
It is the third fall in applicant numbers since 2002, and the biggest since 2012 - the year that tuition fees in England were trebled to £9,000. The other drop was in 2006, when fees were raised to £3,000.
The fall has been caused by a number of factors, Ucas suggested, including drops in EU student applicants and in potential nursing students, a fall in older people - those aged 19 and over - applying for degree courses, and a slowing of application rates from 18-year-olds.
Across the UK, the numbers applying to go into higher education have fallen by 6% in England, 5% in Northern Ireland, 2% in Scotland and 7% in Wales.
Among EU students, there have been 42,070 applicants, compared to 45,220 at the same point last year.
According to a Ucas analysis, EU applicant numbers would have been expected to go up by around 3,000 this year, based on previous trends. They have actually dropped by around 3,000.
The Brexit vote initially caused uncertainty over whether or not EU students applying to start courses at English institutions in September 2017 would be eligible for loans and grants in the future.
Ministers announced on October 11 - four days before the early application deadline - that these students will be able to access funding for the duration of their degree. This arrangement will be honoured even if the UK leaves the EU during this time.
Ucas chief Mary Curnock Cook said: "Despite the overall decrease, it is encouraging that the number of 18 year old applicants remains high, and that application rates for disadvantaged groups continue to rise.
"However, we are seeing large falls for older applicants, partly because of strong young recruitment in recent years depleting the pool of potential mature applicants, and probably also reflecting increased employment, the higher minimum wage, and more apprenticeship opportunities.
"About half the fall in nursing applicants is mirroring the fall in non-nursing applicants from older age groups."
Dame Julia Goodfellow, president of Universities UK, said: "There seem to be a number of factors behind this decline in applicant figures. This includes the possible impact of the Brexit vote on EU applicants and changes to the way degrees in nursing, midwifery and some other allied health professions in England are funded.
"While the drop is not catastrophic, particularly given last year's record high, there is a need to address some issues urgently."
Universities Minister Jo Johnson said: "More young people than ever are choosing to go to university with record application rates for 18 year olds this year as well as those from disadvantaged backgrounds.
"The reforms we are bringing in through the Higher Education and Research Bill will mean people choosing to go to university in the future will benefit from more choice and universities will have a duty to do more to promote equal opportunities."
Professor John Latham, Vice-Chancellor of Coventry University, which has over 2,000 EU students, said: "The figures bring the perception of how welcoming the UK is as a study destination into sharp focus, regardless of whether they prove Brexit is having a chilling effect on demand.
"In Poland for example, the numbers of young people choosing to study in the UK have grown by almost 150% over the last five years, so the sector will not want to see a check on such growth.
"The falls from UK and EU students suggest that universities may need to go more global, more quickly, but each is now going to have to look at its model, I am sure some will reduce in size and scale while others may increase their share."