Research highlight: Does dietary counseling work?

Studies have linked childhood lifestyle factors to the development of cardiovascular diseases in later life. In order to reduce the global burden of atherosclerosis, a number of preventative dietary regimes have been proposed to inhibit the establishment of cardiovascular risk factors in childhood. It has been previously reported that decreasing saturated fat intake in dietary intervention can lead to lowered low-density lipoprotein cholesterol (LDL-C), along with improved insulin sensitivity, lower blood pressure and reduced risk for metabolic syndromes. 

In the STRIP study, a unique longitudinal randomized trial investigation into the effects of dietary interventions, participants were assessed from infancy until 20 years of age. A randomly assigned intervention group received repeated dietary counseling aimed at replacing the proportion of saturated fat with unsaturated fat, without reducing total fat intake. The intervention group had prominent differences in dietary intake of fatty acid quality (unsaturated to saturated fatty acid ratio of 2:1), maintained from childhood to end of adolescence – albeit with diminishing differences over the years.

Participant serum blood samples were collected for assessment at ages 9, 11, 13, 15, 17 and 19. Nightingale’s metabolomics platform was used to analyze 60 lipid and metabolite measures, including: lipid concentrations of 14 lipoprotein subclasses, fatty acids, ketone bodies, amino acids and gluconeogenesis-related metabolites. When compared to a control group (only receiving routine state-provided health education), intervention resulted in increased levels of circulating omega-3 and omega-6 fatty acids, and reduced concentrations of circulating intermediate-density lipoproteins (IDL) and low-density lipoproteins (LDL). The observed changes in fatty acid levels are potentially predictive of lower risk for CVD, as higher relative concentrations of omega 3 and 6 are predict lower CVD risk, whereas higher MUFA predict higher CVD risk (Würtz, 2015: Circulation). 

Intervention children had a greater ratio of unsaturated to saturated fat in their diet, however the proportion of serum monounsaturated fatty acid to fatty acids was found to be lower when compared to the control group. Few non-lipid effects were observed to be associated with intervention, with the exception of an increased concertation of glutamine (potentially predictive of lower risk for type 2 diabetes).            

Gender differences within the intervention group were observed, as reported earlier for routine risk markers/LDL-C levels in the STRIP trial, with boys displaying a more pronounced lowering of triglycerides and triglyceride-rich lipoprotein subclasses, along with smaller very low-density lipoprotein (VLDL) particle size. Total cholesterol, non-HDL-C, and LDL-C were reduced in both sexes, corresponding to lower type 2 diabetes and cardiovascular disease risk. As this study was a long running randomized trial, it avoids a lot of the bias from previous observational studies on dietary effects. These findings indicate that dietary interventions reducing saturated fat intake may lead to favorable metabolic outcomes (e.g. in terms of known and novel blood biomarkers for CVD and type 2 diabetes disease risk), through childhood to adolescence. 

The Special Turku Coronary Risk Factor Intervention Project (STRIP) study is an example of Nightingale's NMR metabolomics platform being applied in dietary research. Our blood analysis service can be utilized to investigate the effects of dietary interventions, using metabolic profiling to identify circulating biomarkers. In this randomized trial on dietary substitution, our platform was used to quantify metabolic measures (including detailed lipid and lipoprotein particle profiles), for 554 participants at 6 time points. Nightingale's platform has been successfully used in a wide range of research applications and has featured in over 220 peer-reviewed studies.

Extra reading:

Discover further research into dietary effects here and access the full paper here.