He's got to be nuts! A man has smashed his way into the Guinness Book of World Records - by breaking over 200 walnuts with his head within 60 seconds. Navin Kumar nutted his way to the bizarre record by breaking 217 walnuts using just his skull. The 22-year-old was officially recognised as a world record holder yesterday. Navin said he was inspired to undertake the crackers challenge after watching a previous record-holder on YouTube. Navin, who lives in Andhra Pradesh in India, said the first time he tried to crack a walnut on his bonce he was left with a headache which lasted a week.