How does diet affect heart health in type 1 diabetes?

The aim of this study was to investigate the association between markers of heart health and diet quality in patients with type 1 diabetes. The main finding of the study was that diets that included whole grains, whole fruits, added sugar and poly-unsaturated fats may affect heart health.

Patients with type 1 diabetes (T1D) have a higher risk of heart disease. There are certain substances in the blood that we can measure that tell us how healthy the blood vessels and heart are. We call these cardiovascular (CV) biomarkers. These biomarkers include total cholesterol, LDL cholesterol (bad cholesterol), HDL cholesterol (good cholesterol), triglycerides (fat), HbA1c (average blood sugar level over past 3 months) and other markers of inflammation. Blood pressure is also a CV biomarker. It is unknown how different types of foods affect these biomarkers in type 1 diabetes.

This study included 136 patients with type 1 diabetes and their families who were followed for 18-months. Patients were assigned to an intervention group (66 patients) or the control group (70 patients). The intervention group received nutrition advice with the aim of increasing whole foods (whole fruits, whole vegetables, whole grains, nuts, legume, and seeds) in their diet. The control group did not receive any nutrition advice. Patients completed detailed records of their diet.

Overall diet quality was not associated with changes in CV biomarkers. The greater the whole grain intake, the lower the total cholesterol, LDL and HDL cholesterol. The higher the saturated fat and added sugar, the higher the triglycerides and HDL cholesterol. Lower diastolic blood pressure (the bottom number of the BP reading) was associated with a higher whole grain, fruit, and poly-unsaturated fat intake. Dark green vegetables, beans, seafood, nuts, and seeds had no effect on the biomarkers.

The authors concluded that a greater intake of whole grains, whole fruits, and lower added sugar and poly-unsaturated fats are associated with better CV biomarkers patients with T1D.

Additional studies are required to confirm if intake of greater whole grains, lower added sugar and poly-unsaturated fats may favorably influence CV biomarkers in this population.