Research suggests that fear of debt can play a key role in whether these youngsters decide to undertake a degree.
The study, by researchers at the Centre for Research on Learning and Life Chances (LLAKES), at the UCL Institute of Education, compared the results of two surveys of would-be university students, aged 17 to 21, in England, conducted in 2002 and 2015.
This covers the period when fees were increased twice, first in 2006 from around £1,000 to around £3,000, and then again in 2012 to a maximum of £9,000.
It found that in general, young people were more willing to take on student loan debt in 2015, and see borrowing money for a degree as a good investment, but that around a third of the students surveyed strongly agreed with the statement "I would worry a lot if I ever got into debt".
The study goes on to say that debt aversion has increased among lower-class and middle-class students.
Overall, the numbers of people attending university, including those from poorer backgrounds, has continued to rise, the research says.
Researchers noted that poorer students were less likely to apply to university due to gaining lower results at schools.
But they added that when comparing poorer and richer students with similar GCSE grades, taking into account factors such as gender and school type, a lower proportion of disadvantaged students had applied to go to university (85%) compared to their richest peers (89%) because of debt fears.
The study concluded: "Lower-class students are still far more likely than students from other social classes to be deterred from planning to enter higher education because of fear of debt."
Author Claire Callender said: "The lower proportion of university students from disadvantaged backgrounds cannot be adequately explained simply by pointing to academic achievement at school.
"Student funding and fear of debt play a role.
"University enrolments may be increasing overall but policymakers must focus on ways to level the playing field for poorer students."
Labour has pledged in its election manifesto to scrap university tuition fees, while the Conservatives would continue with a fees and loans system.