Famous for his experimental dishes such as snail porridge and bacon and egg ice cream, Blumenthal said medication initially dulled his culinary imagination.
He was diagnosed after being admitted to hospital in November 2023 and said he was now more involved with the The Fat Duck than for years.
"When I first came out of hospital the medications were so strong I was zombified - I had no energy at all," he said.
"As my medications have been changed and my levels of self-confidence and self-awareness have gone up I realise my imagination and creativity is still there.
"It was at levels that were so extreme before... looking back I can remember during my manic highs I was interrupting myself with ideas."
Bipolar UK estimates more than one million adults in the UK have bipolar disorder, about 30% more than the number of people with dementia.
But it is estimated at least 500,000 people are undiagnosed.
"It's an honour to have Heston onboard as an ambassador," Simon Kitchen, chief executive of Bipolar UK, said.
"We hope that his experience will encourage more people to seek help if they are struggling with their own diagnosis or are in the process of seeking one."