Herbs and spices at a relatively high culinary dosage improves 24-hour ambulatory blood pressure in adults at risk of cardiometabolic diseases: a randomized, crossover, controlled-feeding study

BACKGROUND: Intake of a single meal containing herbs and spices attenuates postprandial lipemia, hyperglycemia, and oxidative stress, and improves endothelial function. There has been limited investigation of the effect of longer-term intake of mixed herbs and spices on risk factors for cardiometabolic diseases. OBJECTIVES: The objective was to assess the effect of an average American diet containing herbs and spices at 0.5 (low-spice diet; LSD), 3.3 (moderate-spice diet; MSD), and 6.6 (high-spice diet; HSD) g · d(−1) · 2100 kcal(−1) on lipids and lipoproteins as well as other risk factors for cardiometabolic diseases in at-risk adults. METHODS: A 3-period, randomized, crossover, controlled-feeding study with 71 participants was conducted at the Pennsylvania State University. Each diet was consumed for 4 wk with a minimum 2-wk washout period. Outcomes were assessed at baseline and the end of each diet period. RESULTS: No between-diet effects were observed for LDL cholesterol, the primary outcome. Between-diet differences were observed for mean 24-h systolic (P = 0.02) and diastolic (P = 0.005) ambulatory blood pressure. The HSD lowered mean 24-h systolic blood pressure compared with the MSD (−1.9 mm Hg; 95% CI: −3.6, −0.2 mm Hg; P = 0.02); the difference between the HSD and LSD was not statistically significant (−1.6 mm Hg; 95% CI: −3.3, 0.04 mm Hg; P = 0.058). The HSD lowered mean 24-h diastolic blood pressure compared with the LSD (−1.5 mm Hg; 95% CI: −2.5, −0.4 mm Hg; P = 0.003). No differences were detected between the LSD and MSD. No between-diet effects were observed for clinic-measured blood pressure, markers of glycemia, or vascular function. CONCLUSIONS: In the context of a suboptimal US-style diet, addition of a relatively high culinary dosage of mixed herbs and spices (6.6 g · d(−1) · 2100 kcal(−1)) tended to improve 24-h blood pressure after 4 wk, compared with lower dosages (0.5 and 3.3 g · d(−1) · 2100 kcal(−1)), in adults at elevated risk of cardiometabolic diseases. This trial was registered at clinicaltrials.gov as NCT03064932.