(P19-056-23) Low-Carbohydrate Diets and Risk of Coronary Heart Disease in U.S. Men and Women

Objectives: The current study aimed to evaluate the associations between low-carb diet scores and the risk of Coronary Heart Disease (CHD).

Methods: A prospective cohort study was conducted in 39,231 men in the Health Professionals Follow-Up Study, 73,429 women in the Nurses’ Health Study (NHS), and 90,881 women in NHSII, who were free of T2D, CHD, and cancer at baseline and were followed for up to >30 years. Five LCD scores based on sources of protein, fat, and carbohydrate differentiated by their qualities were derived every four years based on dietary assessments by a validated food frequency questionnaire. Associations between the cumulative averages of these scores and the risk of CHD were examined using Cox proportional hazards regression models.

Results: During 5,273,667 person-years of follow-up, 5,715 CHD cases were documented. After adjustments for baseline body mass index (BMI) and other time-varying covariates, a plant-based LCD score that emphasizes vegetable protein and fat intake was associated with 11% lower CHD risk (HR comparing extreme quintiles: 0.89 [0.82-0.97; P-trend < 0.05]), and a healthy LCD score that further de-emphasizes refined carbohydrate intake was associated with 21% lower CHD risk (HR comparing extreme quintiles: 0.79 [0.72-0.85; P-trend < 0.05]). In contrast, an unhealthy LCD score further de-emphasizing high quality carbohydrate (i.e. whole grain intake) was associated with 21% higher CHD risk (HR comparing extreme quintiles: 1.21 [1.11-1.32; P-trend < 0.05]). Null associations of animal-based LCD score and overall LCD score with CHD risk were observed.

Conclusions: We found out that long-term adherence to LCDs that emphasize plant-based protein and fat as well as high quality carbohydrate were significantly associated with lower risk of developing CHD, whereas an opposite association was found for LCD that further de-emphasize high quality carbohydrate. Our findings underline that LCDs were not beneficial for the primary prevention of CHD unless they emphasize the quality of the macronutrient compositions.

Funding Sources: National Institutes of Health grants: UM1 CA186107, P01 CA87969, R01 CA49449, R01 HL034594, U01 HL145386, R01 HL088521, U01 CA176726, R01 CA67262, U01 CA167552, R01 HL035464, R01 HL060712, DK126698, DK120870, and DK119268R01 DK120870, and T32 HL 098048.