Many people suffer from a condition called endothelial dysfunction, which may be an underlying cause of heart disease. In one study, regular consumption of black teas including orange pekoe varieties was shown to be able to reverse this condition, thus potentially lowering the risk of developing cardiovascular problems. In addition, black tea contains polyphenol and flavonoid compounds, which may reduce overall risk of death from heart disease.
Thanks to its high level of antioxidants, food science scholars believe orange pekoe tea and its fellow black tea varieties may be able to combat or perhaps contribute to the prevention of cancer. Studies of the polyphenols found in tea have shown that a particular compound called TF-2 can actually slow the growth of cancerous cells. Antioxidants also work to thwart damage to cellular DNA so that no mutations are replicated and new cells are healthy when they're formed.