“The Tailored Diet Study”: The effect of tailored dietary modification on lipid levels in FH participants

Abstract

Rationale: Risk factors for cardiovascular disease (CVD) are both modifiable and non-modifiable. Modifiable risk factors associated with CVD poor diet quality, physical inactivity and tobacco consumption. Individuals with familial hypercholesterolemia (FH) have inherited genetic disorders affecting low-density lipoprotein receptors. These individuals are predisposed to a greater risk of CVD due to increased low-density lipoprotein cholesterol (LDL-C) levels. Dietary modifications remain an important part of CVD risk reduction in FH.

Methods: This study was a pre and post intervention design that ran over eight weeks. We recruited FH participants through GP practices in Dunedin and Southland. Dietary assessment for each participant was carried out using a prompted 24-hour recall and a semi-quantitative FFQ. The FFQ was used to create a simulated 7-day diet record for each participant. This was done at baseline and repeated at the end of the study. Nutrient analyses of diets were done using Kai-culator©. Blood lipids were compared pre and post intervention. The blood lipid measurements were taken for total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), LDL-C, triglycerides (TAG), and TC:HDL ratio. Spearman’s correlations and paired t-tests were carried out to determining changes in nutrient intakes and their associations with lipid changes.

Results: No significant differences were found between pre and post mean levels of TC, HDL-C, LDL-C, TAG or TC:HDL-C. There were significant reductions in intakes of biscuits (p=0.002), eggs and egg dishes (p=0.027), bread based dishes (p=0.012) and processed meat (p=0.008). There were also significant increases in intakes of fish and seafood (p=0.003), nuts (p=0.002),fruit (p=0.012), and vegetables (p=0.016) and table spread (p=0.048). This related to a significant reduction in intakes of saturated fatty acids (p<0.001), cholesterol (p=0.003) and an increase in monounsaturated (p=0.01) and polyunsaturated fatty acids (p=0.035). Qualitative feedback indicated that the majority of participants found the study to be helpful in increasing their understanding of heart healthy eating habits, and in changing their dietary practices.

Conclusions: This short term intervention showed that tailored dietary advice was effective in changing nutrient and food group intakes towards a more optimal diet. This study was limited due to the small sample size (n=25) and short study duration.