Southern District Health Board medical oncologist Dr Christopher Jackson began the break after talking at an alcohol and cancer conference on June 19.
The talk made him ''rethink'' his drinking patterns - a daily glass of wine, or two, with dinner.
''There is nothing like a glass of pinot noir to go with a good cut of lamb,'' Dr Jackson said.
Dry July, a nationwide fundraiser during which participants give booze the boot for a month, was a chance to remember the link between alcohol and cancer.
Abstaining had been difficult, especially when watching the Super Rugby final and during celebratory drinks after his father-in-law won a book prize.
''Everyone else had a glass of champagne and I had a glass of Soda Stream.''
The money he raised for Dry July would pay for patient support services in the South, such as more comfortable chairs in the chemotherapy unit or DVDs for patients to watch.
''They are non-essential [items] but make a huge difference to people when they are here for days, or weeks, at a time, in isolation.''
Dr Jackson had raised the most money in Otago and Southland and was second on the national leaderboard.
Yesterday, his total was $2256 and he wanted to pass the national leader, an Aucklander, who was about $200 ahead.
He was unsure whether on Saturday, when Dry July will be over, he would open a bottle of wine to celebrate.
''I might keep going for a bit longer.''
The links between alcohol consumption and cancer were ''very strong'' and alcohol was a ''grade one carcinogen''.
''If people drink more alcohol, there is more cancer.''
Alcohol consumption had links to several common cancers and the harm it caused ''far outweighed'' any benefit, he said.
''I'm not going to be a teetotaller for the rest of my life - I've got a good Otago pinot noir collection - but it has made me reflect on the fact that drinking every day is probably not a good idea and it's not something I want to be doing long-term.''
People could give to Dr Jackson's effort at nz.dryjuly.com/profile/chrisjackson.
Dry July NZ country manager Scott Savidge said Otago and Southland residents had given more than $25,000 to the more than 200 people doing the challenge.
Otago-Southland was the most generous region in terms of average donations, he said.
