J David Spence

Lifestyle is far more important than most physicians suppose. Dietary changes in China that have resulted from increased prosperity are probably responsible for a marked rise in coronary risk in the past several decades, accelerating in recent years. Intake of meat and eggs has increased, while intake of fruits, vegetables and whole grains has decreased. Between 2003 and 2013, coronary mortality in China increased 213%, while stroke mortality increased by 26.6%. Besides a high content of cholesterol, meat (particularly red meat) contains carnitine, while egg yolks contain phosphatidylcholine. Both are converted by the intestinal microbiome to trimethylamine, in turn oxidised in the liver to trimethylamine n-oxide (TMAO). TMAO causes atherosclerosis in animal models, and in patients referred for coronary angiography high levels after a test dose of two hard-boiled eggs predicted increased cardiovascular risk. The strongest evidence for dietary prevention of stroke and myocardial infarction is with the Mediterranean diet from Crete, a nearly vegetarian diet that is high in beneficial oils, whole grains, fruits, vegetables and legumes. Persons at risk of stroke should avoid egg yolk, limit intake of red meat and consume a diet similar to the Mediterranean diet. A crucial issue for stroke prevention in China is reduction of sodium intake. Dietary changes, although difficult to implement, represent an important opportunity to prevent stroke and have the potential to reverse the trend of increased cardiovascular risk in China.