Did grapefruit juice kill Michael Jackson?

[link to www.metro.co.uk]

Michael Jackson's death could have been caused by grapefruit juice – at least that's one of the more bizarre theories circulating on the web.
The singer was, on the advice of a nutritionist, drinking up to 2litres a day of a grapefruit-rich smoothie for three weeks while he rehearsed for his London concerts.

He is also rumoured to have been addicted to the narcotic painkiller pethidine.