A strategy for end of life care in the UK.

Iron intake may affect blood pressure, but further confirmation is needed Nutritional and lifestyle factors are key determinants of blood pressure across populations, and lifestyle modi-fications—including weight reduction if overweight or obese, reduced dietary sodium intake, increased dietary potassium intake, moderation of alcohol consumption, adoption of the DASH (dietary approaches to stop hypertension) diet, and regular aerobic exercise—are effective at reducing blood pressure. 1 In the linked study (doi: 10.1136/bmj.a258), Tzoulaki and colleagues assess the association between iron and red meat intake and blood pressure using data from the international collaborative study of macro-/micronutri-ents and blood pressure (INTERMAP), a large cross sectional study of the nutritional determinants of blood pressure across 17 population samples from Japan, China, the United Kingdom, and the United States. 2 The authors found significant inverse associations between intake of total iron and non-haem iron and systolic blood pressure. Conversely, intake of red meat was significantly associated with increased systolic blood pressure, but the association between intake of haem iron and blood pressure was not significant. Substantial experimental evidence has linked iron overload with accelerated atherosclerosis, and diets deficient in iron have been linked with reduced athero-sclerosis, 3 but whether there is a link between iron and coronary heart disease is still uncertain. Firstly, meta-analyses of the association of biomarkers of iron metabolism—such as ferritin and transferrin saturation— with coronary risk have mostly found no associations. 4 Secondly, a large randomised controlled trial in which phlebotomy was used to reduce iron stores in patients with symptomatic peripheral arterial disease found that iron reduction had no effect on cardiovascular end points, 5 although iron reduction may have been beneficial at younger ages. Thirdly, mutations in the gene encoding the hereditary haemochromatosis protein (HFE) do not seem to be associated with the risk of heart disease, 6 possibly as a result of lower concentrations of low density lipoprotein cholesterol in people with HFE mutations. 7 Lastly, prospective studies have also failed to show a clear association between iron intake and the development of coronary heart disease. 8 Interestingly, the pattern seen in the health professionals' follow-up study was similar to the pattern seen in INTERMAP: an inverse association for total iron and positive association for haem iron in relation to the risk of coronary heart disease. 8 The study by Tzoulaki and colleagues provides new data that underline the complexity of the association between iron and heart disease. …