The Race for Life is a major event on the fundraising calendar
Cancer Research UK is more likely to receive money from legacies than any other charity in the UK, research by the Cass Business School has found.
The Royal National Lifeboat Institution (RNLI) and the RSPCA were next on the list of the most likely recipients.
Six of the top 20 charities to which people left money through their Wills were health-related, collecting a combined total of £315m in 20 months.
Donations made through Wills average £1.9bn a year, the study found.
This accounted for 34% of the total fundraising income of the 10 charities that benefitted most.
Animals and children
Apart from medical charities, animal charities were the next most popular, also accounting for six of the top 20 spots on the list of legacy beneficiaries. Combined, they received more than £200m during the same 20-month period between April 2007 and December 2008.
Next were children's charities, which received nearly £57m in the same period, the report said.
"This new legacy data is a fascinating insight into people's concerns from the past as well as for the future, and it also sheds light on which charities future generations might support," said Professor Cathy Pharoah at Cass.
"Concern about the impact of major diseases such as cancer will ensure continuing support for well-established health charities, but new contenders - such as environmental charities - will surface as climate change is featured more heavily on the news agenda and people become more aware of such issues."
Stephen George, chairman of Remember A Charity, which represents 140 charities, said: "Without them [legacies] many charities' services would suffer, others would simply not exist."
Charities benefit from other fundraising efforts, such as Cancer Research UK's sponsored jog event called Race for Life.