Pomegranate juice, strawberries, walnuts and almonds help to combat the effects of ageing, new research suggests. Oncologists in Switzerland have discovered that a natural compound called Urolithin A reverses decline in blood regeneration and keeps the immune system functioning healthily. Urolithin A is produced bny the transformation of ellagic acids and ellagitannins in the gut flora. The richest source of ellagatannins is pomegranate juice – already thought effective against prostate cancer cells – but it is also found in other fruits, including nuts.