Aging and Chronic Disease
It is unclear to what degree the cardiometabolic health benefits of plant-based diets are driven by their lack of meat, dairy, and egg (MDE) products versus their relative abundance of fiber- and antioxidant-rich fruits and vegetables. On the one hand, inclusion of more whole, plant-based foods in an omnivorous diet can improve health markers. On the other hand, the replacement of MDE products with highly processed or refined plant-based foods could negatively influence health markers. This study investigated whether any health effects of temporary spiritually-motivated restrictions on MDE products are dependent on the quality of plant-based foods consumed in their stead.
This study focused on a sample of 94 Orthodox Christians with varying degrees of adherence to the Lenten ritual of restricting intake of MDE products for 48 days. Diet was measured using undocumented 7-day food records and food frequency questionnaires. Multiple linear regression models tested 1) the degree to which dietary composition changed in response to reductions in MDE products; 2) associations between MDE reductions and measures of body fat, blood lipids, glucose metabolism, and inflammation; and 3) whether the effects of MDE reductions on health biomarkers were modified by shifts in whole grains, refined grains, legumes, meat alternatives, nuts and seeds, fruits and vegetables, oils, or added sugars.
Greater restriction of MDE products was not strongly associated with increases in fruits or vegetables but was strongly associated with small increases in the consumption of legumes, meat alternatives, nuts and seeds, and discretionary oils. Each serving reduction in MDE products was associated with decreases in total and LDL cholesterol that occurred independently of calorie reductions and were only partly explained by weight loss. Inclusion of non-MDE foods in the regression models attenuated but did not appear to modify the relationship between MDE reductions and cholesterol changes.
This study suggests that reductions in MDE consumption and concurrent increases in plant-based foods can lead to decreases in blood cholesterol. Larger study samples are needed to differentiate the health effects of increased intake of qualitatively different plant-based foods when MDE products are restricted or removed from the diet.