A pill made from the leaves of the olive tree could be a powerful weapon in the fight against heart disease, scientists have said. According to research, the olive pill is as effective as some prescription medicines at reducing high blood pressure. And it also appears to lower levels of harmful blood fats, called triglycerides, known to raise the risk of heart attacks and strokes. In a study, patients who took the olive leaf pill for eight weeks saw a significant decline in blood pressure readings and triglyceride levels. If further studies confirm the powerful effects of olive leaf tablets, they could be used to help patients who struggle to take blood pressure drugs because of their side-effects. Biggest killer Heart disease is Britain\'s biggest killer. High blood pressure is thought to be responsible for 50 per cent of all heart attacks and strokes. In recent years, studies have shown olive oil can protect the heart by reducing the build-up of fatty deposits inside the coronary arteries. Olives have also been credited with helping to lower the risk of breast cancer, ulcerative colitis and even depression. And it seems the trees\' thin, flat leaves may also be able to ward off illness, as they have high levels of compounds called polyphenols. These plant chemicals have been shown to help slash the risk of major diseases by helping to protect against the harmful effects of free radicals. Researchers at the University of Indonesia, in Jakarta, investigated olive leaf extract by recruiting 180 patients with high blood pressure ­ and splitting them into two groups. Volunteers One received olive leaf pills for eight weeks. The rest were given an anti-hypertension drug, captopril, which can cause dizziness. According to the research published in the journal Phytomedicine, systolic blood pressure, the higher reading, ­ dropped an average of 11.5 points in the olive leaf group and 13.7 in the captopril patients. Diastolic blood pressure, the lower reading, ­fell 4.8 points in the olive leaf volunteers and 6.4 points in those on the prescription medicine.