A Fort Worth woman turned 104 this week, and she credits a very special doctor for her good health and longevity: Dr Pepper.

Elizabeth Sullivan fell in love with the 23-flavored soft drink 40 years ago, when she was in her 60s.

'People try to give me coffee for breakfast. Well I'd rather have a Dr Pepper,' she said. 'I started drinking them about 40 years ago. Three a day. Every doctor that sees me says they'll kill you, but they die and I don't, so there must be a mistake somewhere.'

Scroll down for video

Elizabeth Sullivan turned 104 this week, and on Wednesday the CEO of Dr Pepper Snapple Group, Larry Young, surprised her with a very Dr Pepper-filled day

Sullivan has been drinking Dr Pepper for 40 years, since she was in her 60s. She drinks about three cans a day

Larry Young, the CEO of Dr Pepper Snapple Group, gave Sullivan a big surprise for her birthday on Wednesday: a cake designed to look like the carbonated drink's can, a gift basket and plenty of bottles of the pop to drink, according to CBS Dallas Fort Worth.

As she reveled in excitement from the day, Sullivan reflected on her age.

'Well at 103 I didn't think I'd make it, but I'm still perking along,' she told CBS. 'When you live to be 104 and can still talk to nice people, you deserve some Dr Pepper, but I never expected this.'

The Dr Pepper Snapple company came to Sullivan's house and surprised her with a Dr Pepper-can-shaped birthday cake that read 'Happy 104th Birthday Elizabeth'

Sullivan was also given a gift basket, which included a T-shirt, bottles of the carbonated soft drink and a myriad of other goodies

Sullivan taught math at Paschal High School in Fort Worth for 15 years, where she tutored football players for free.

She said that the secret to living a long life - aside from Dr Pepper - is to 'just keep living'.

'Man I'm feeling good. I'm glad I'm still here. I'm glad I'm not in a rest home. Glad I can still read books and watch TV and have people come by and say hello,' she said.