In a recent study published in the journal nutrition and metabolismResearchers evaluated the effects of a lacto-ovo vegetarian diet (VD) and a Mediterranean diet (MD) on apolipoprotein levels and cardiovascular disease (CVD) risk factors in low-intermediate risk individuals.
CVD is a major cause of global mortality and requires the development of new biomarkers for prevention, early diagnosis, and treatment. Apoproteins, which regulate lipoprotein metabolism, are considered risk markers for CVD. The European Society of Cardiology (ESC) recommends his ApoB as a CVD risk marker. ApoA-I is primarily found in high-density lipoprotein (HDL) lipids and plays a protective role in reverse cholesterol transport. However, data regarding the effects of diet on apolipoproteins are limited.
Study: Effects of lacto-ovo-vegetarian and Mediterranean dietary interventions on apolipoproteins and inflammatory cytokines: Results of the CARDIVEG study. Image credit: Brian A Jackson / Shutterstock
About research
In this study, researchers evaluated the effects of MD and VD diets on circulating apolipoproteins and their association with cardiovascular disease risk estimates, including inflammatory cytokine levels and lipid profiles.
The study included 52 participants (39 women, mean age 49 years) from the randomized crossover clinical trial of the Vegetarian Cardiovascular Prevention (CARDIVEG) Diet. All individuals had a low-moderate CVD risk (<5.0% at 10 years using ESC guidelines) and were selected from the Clinical Nutrition Department of an Italian College Hospital.
Eligible individuals are overweight or obese, have a BMI ≥25 kg/m2, and a cardiovascular disease risk factor ≥1.0: low-density lipoprotein (LDL) >115 mg dL-1; triglyceride level greater than 150 mg dL-1; total cholesterol >190 g/dL;Fasting blood sugar levels range from 110 to 125.0 mg dL-1. Researchers studied people with unstable medical conditions, people taking prescribed medications, women who were pregnant or breastfeeding, people who had consumed poultry, fish, meat or meat products, and people who had participated in a weight loss program in the past six months. Those who did were excluded.
Participants followed their MD (27 participants) and VD (25 participants) diets for 3 months. Both diets consisted of 50% to 55% carbohydrates, 15% to 20% protein, and 25% to 30% total fat (<7.0% saturated fat and <300 milligrams of cholesterol). The team provided participants with a menu plan for the week, a variety of recipes, and accurate data on the foods they should consume and the foods they should avoid.
Primary outcomes were changes in body weight, fat mass, and BMI, and secondary outcomes included changes in circulating CVD risk markers and apolipoprotein levels. The research team obtained medical history, demographics, comorbidities, risk factors, lifestyle, and dietary data at the beginning of the study. They collected blood samples including body composition and BMI data before and after the intervention.
The research team used the Medi-Lite and National Health and Nutrition Examination Survey (NHANES) questionnaires to assess dietary adherence in MD and VD, respectively. They conducted a primary analysis using general linear modeling to assess differences in apolipoprotein levels by gender, age, and CVD risk factors. They used linear regression to examine the association of these changes with lipid profile, inflammatory profile, and dietary components.
result
MD and VD improved lipid profiles and anthropometric variables, decreased total energy, fat, and cholesterol, and increased total carbohydrates. VD lowered protein and increased dietary fiber, whereas MD decreased body weight, fat mass, and BMI. VD also reduces lean body mass. VD reduced LDL by 5.0%, and MD reduced serum triglycerides by 9.0%. Both diets reduced inflammatory parameters, with MD significantly reducing interleukin-10 by 37% and interleukin-17 by 49%, respectively.
Both diets reduced inflammatory parameters, with significantly higher ApoC-I levels (24%) after VD. Both diets reduced ApoA-I (2.7% in VD and 6.1% in MD), ApoC-I (24% in VD and 11% in MD), and ApoD (6.5% in VD and 6.2% in MD) levels. Increased. However, the ApoB/ApoA-I ratio decreased by 1.9% and 7.4% after VD and MD, respectively. Conversely, the team found that ApoB (+0.7% by VD, -1.6% by MD), ApoC-III (-5.6% by VD, +1.8% by MD), and ApoE (+14% by VD and – by MD and 1.6%).
The research team found a negative correlation between apolipoprotein C-III and carbohydrates after MD, and between ApoD levels and saturated fat after VD. In contrast, they found positive correlations between HDL and ApoD after VD and between serum triglycerides, ApoCI, and ApoD after MD. IL-17 was positively correlated with ApoB and ApoC-III after VD. However, they found a significant negative correlation between ApoC-III and carbohydrate percentage after MD, and between ApoD and saturated fat percentage after VD. Serum triglycerides positively correlated with ApoC-I and ApoD levels after MD.
HDL changes were positively correlated with ApoD levels after VD. Results were confirmed by linear regression adjusting for potential confounders such as weight change and treatment sequence. Subgroup analysis showed that both diets had a positive impact on circulating apolipoproteins, especially in women over 50 years of age who had fewer than three of their risk factors for cardiovascular disease.
Study results showed that VD and MD improve cardiovascular disease risk in individuals with low-moderate CVD risk by modulating lipid and inflammatory profiles. MD has an even more positive impact on apolipoprotein levels, especially in women, individuals over 50 years of age, and people with one or two of their CVD risk factors. The study also found differences in the association between apolipoprotein levels and specific nutrients, and an unexpected inverse association between carbohydrate intake and ApoC-III after MD.
