A woman who just ate a grapefruit each day nearly had to have her leg amputated due to a dangerous blood clot so says a case study, reported in the Lancet .
In November 2008, emergency doctors in Olympia, Washington, treated the 42-year-old woman upon her being admitted with dizziness, shortness of breath and problems with walking.
An ultrasound scan highlighted that she had a large clot which was blocking the veins in her left leg.
She was in immediate danger of losing her left leg to gangrene, however, doctors administered a clot busting drug straight into the blockage which dissolved it safely.
The doctors discovered that she had driven quite far, for about an hour and a half, the day before the incident. She has also taken a daily dose of oestrogen oral contraceptives; a genetic variant, known as the factor V Leiden mutation, linked to blood clot disorders.
All these factors are known to cause deep vein thrombosis (DVT).
However, what may have tipped the balance for the woman in question is her eating a grapefruit each morning due to a weight loss diet started three days earlier. Grapefruit juice blocks the action of an enzyme called CYP3A4, which busts the contraceptive hormone oestrogen.
This in turn boosts the tendency of blood to clot, that is, the level of its coagulability.
Grapefruit juice is broken down extremely slowly, so, this means that it has a cumulative effect when taken daily.
Hence, the patient’s oestrogen levels would have been multiple times more than normal, assisting the formation of the clot. The fact that the patient had been sitting for a while of course has also meant that the blood had not been able to flow properly.