The footballer is sponsoring his brother Stewart to become a "dryathlete" for the whole of January in support of the Cancer Research UK Dryathlon campaign.
The charity is close to the brothers' hearts as their sister Fiona died aged just 21 in May 2008 after being diagnosed with skin cancer.
Those taking part in the Dryathlon challenge are either sponsored to give up alcohol for a month in the new year, or donate the money they would have spent on drink to the charity.
Celtic skipper Brown, 28, said: "Giving up alcohol for a month is a great test of willpower and discipline and the Dryathletes will need the support of a team of friends and family to spur them on with encouragement and sponsorship.
"I'm urging everyone to limber up and sign up now for Cancer Research UK's Dryathlon. Everyone is affected by cancer in some way and sadly our family is no exception.
"That's why Cancer Research UK is very close to my family's heart. Funding the charity's scientists in their endeavours to bring forward the day when all cancers are cured is a worthwhile goal indeed."
This is the second time Stewart, from Cowdenbeath in Fife, has taken on a challenge to raise money for Cancer Research UK.
In August, the 25-year-old ScotRail worker climbed Ben Nevis in bare feet and raised £1,000 in memory of his sister.
He said: "Fiona's death devastated our family. It was really hard. And the sad thing is, cancer affects so many of us. That's why I think it's so important to raise as much money as we can to try and beat cancer sooner.
"I think the Dryathlon is a great idea for a challenge and I hope as many people as possible sign up. Giving up beer for a month won't be easy but I think the sense of satisfaction come February will be fantastic."
More than a third (36%) of Scots, plan to cut down on alcohol this Christmas after regretting some of their drunken behaviour from last year's festive party season, according to research conducted by OnePoll on behalf of Cancer Research UK Dryathlon in November 2013.
Those who want to take part in the Dryathlon can register as individuals or set up a team and get their friends, family and colleagues involved.
Anyone who cannot last the month without a drink can pay the "tipple tax", which allows the Dryathlete to donate a £20 penalty to compensate for falling off the wagon.
Cancer Research UK launched Dryathlon for the first time last year and said it was delighted by its success after more than 33,500 people signed up across the UK and helped raise £4 million.
The charity's spokeswoman Linda Summerhayes said: "Christmas is the time when most of us would admit our willpower is at its weakest.
"As the party season kicks off across Scotland it seems that people are trying hard not to get caught in the same food and drink-fuelled traps they did last year.
"I am sure having Scott and Stewart championing the Dryathlon will go a long way to encouraging other folk in Scotland to bin the booze after Hogmanay. By signing up now, Dryathletes can look forward to a January of clear heads to raise money for the fight against cancer."