A 58-year-old man with no known cardiovascular disease attends his GP. Three separate blood pressure readings over several weeks are around 152/96 mmHg. He is a non-smoker with total cholesterol 6.2 mmol/L and HDL cholesterol 0.9 mmol/L. His calculated 5-year absolute cardiovascular risk using the Australian CVD Risk Calculator is 18%. Which management strategy is most appropriate?