Effectiveness of Written Dietary Advice for Improving Blood Lipids in Primary Care Adults-A Pragmatic Randomized Controlled Trial (MYDICLIN)

Lifestyle management is the first line of treatment for moderately elevated blood lipids in healthy individuals. We investigated the effectiveness of providing food-based written advice for lowering low-density lipoprotein (LDL) cholesterol (intervention) or triglycerides (control) in a pragmatic randomized controlled trial with two parallel arms from 2018-2019 at a rural primary health care center. We sent feedback letters after 3 weeks and 6 months. Out of the 113 adult primary care patients randomized, 112 completed the study. There were no differences between the intervention and control groups for changes in LDL cholesterol after 3 weeks (mean +/- standard deviation -0.21 +/- 0.38 vs. -0.11 +/- 0.34 mmol/L, p = 0.45) or 6 months (-0.05 +/- 0.47 vs. 0.02 +/- 0.41 mmol/L, p = 0.70) (primary outcome). Following the advice to consume plant sterols and turmeric was associated with a reduction in LDL cholesterol after 3 weeks. Following the advice to consume less carbohydrates was associated with reduced triglycerides. In the intervention arm, 14 individuals (25%) reduced their LDL cholesterol by >= 10% after three weeks. Their reduction was attenuated but maintained after six months (-7.1 +/- 9.2% or -0.31 +/- 0.38 mmol/L, p = 0.01 compared with baseline). They differed only in higher adherence to the advice regarding turmeric. In conclusion, this undemanding intervention had little effect on blood lipids for most individuals.