The biggest diet-related heart-disease signal in a new 27-country model was not processed meat. It was too little whole grain

Whole grains can get lost in a list of dietary advice. A new analysis gives them an unusually prominent place — but not in the way a food study usually does. The researchers did not ask people to eat more oats or brown bread. They used Global Burden of Disease estimates to model the share of heart and metabolic illness linked to seven dietary risks across 27 countries in Western Europe and North America from 1990 to 2023.

For ischaemic heart disease, low whole-grain intake was the largest diet-related contributor in both regions in 2023, accounting for more than 12% of the modelled age-standardised disability-adjusted life-year rate. In the same model, high processed-meat intake accounted for more than 9% of the heart-disease burden in North America and more than 6% in Western Europe. Those are not percentages of all heart disease caused by a sandwich. They are the model’s attributed shares after combining population exposure estimates with the Global Burden of Disease risk framework.

The order changed for type 2 diabetes. High processed-meat intake was the leading dietary risk in the paper’s 2023 estimates, at more than 15% of the attributed burden in both regions. High red-meat intake approached 10%, while sugar-sweetened drinks accounted for more than 12% in North America and more than 8% in Western Europe. The authors report that the diabetes burden attributed to dietary risks rose in North America over the study period while it was stable or fell modestly in Western Europe.

There is a longer view in the paper too. From 1990 to 2023, the estimated diet-related burden of ischaemic heart disease fell by more than 60% in both regions. For stroke, it fell by more than 60% in Western Europe. The authors’ forecast model projects North America to retain a slightly higher diet-related vascular and metabolic mortality rate through 2035, especially for heart disease. Forecasts are extrapolations of past patterns, though; they cannot tell us what a future food policy, price change, treatment or personal diet will do.

The paper also has an important internal caution. Its simple, pooled comparison suggested that a higher socio-demographic index tracked with lower diet-related heart disease, stroke and diabetes burden. Once the analysis accounted for each country and year, those within-country associations were no longer statistically significant and explained very little variation. In other words, the study can describe large regional patterns, but it cannot cleanly assign their cause to prosperity, policy or one food.

The practical takeaway is deliberately less dramatic than the map. Whole grains and processed meat are useful things to notice in an overall eating pattern, but this study does not test a single food swap in a person, prove that one food causes an individual diagnosis, or set a target for everyone. For someone managing diabetes, heart disease, pregnancy, kidney disease or an eating disorder, food changes belong in an individual plan with their healthcare team. For public health, the study is a reminder that the unglamorous basics — grains, drinks, sodium and processed meat — still show up when researchers zoom out to populations.