Effect of infancy-onset dietary intervention on salivary cholesterol of children: a randomized controlled trial

Bone turnover markers in serum but not in saliva correlate with bone mineral density

Saliva was proposed as a diagnostic tool for systemic diseases. Here we determined the correlation of bone turnover markers in saliva, bone turnover markers in serum and bone mineral density in postmenopausal osteoporotic and healthy women. Forty postmenopausal osteoporotic and 40 age-matched healthy non-osteoporotic females were recruited for this case–control study. Serum and stimulated saliva levels of osteocalcin, N-terminal propeptide of type I collagen, bone-specific alkaline phosphatase and cross-linked-C-telopeptide of type I collagen were determined. Bone mineral density of the lumbar spine, proximal femur, and total hip were obtained. We show that osteocalcin and cross-linked-C-telopeptide of type I collagen (CTX) reached detectable levels in saliva while N-terminal propeptide of type I collagen and alkaline phosphatase were close or below the detection limit. Serum levels of bone turnover markers were significantly higher than saliva levels. Correlation analysis revealed a strong correlation of serum osteocalcin and, to a lesser extent, also serum CTX values with bone mineral density in lumbar spine, femoral neck, or total hip, respectively. There was, however, no significant correlation of bone mineral density with the respective bone turnover markers in saliva. There was a trend that saliva osteocalcin correlates with femoral neck (p = 0.16) or total hip (p = 0.06). There was also no association between serum and saliva bone turnover markers. This study reveals that saliva cannot replace the withdrawal of serum to evaluate bone metabolism.

Salivary Composition Is Associated with Liking and Usual Nutrient Intake

Salivary flow and composition have an impact on flavor perception. However, very few studies have explored the relationship between saliva, individual liking and usual dietary intake. The aim of our study was to evaluate the association of salivary flow and composition with both a liking for fat, saltiness and sweetness and the usual nutrient intake in an adult French population. Liking for fat, saltiness, and sweetness were inferred from liking scores obtained during hedonic tests on 32 food products among 282 French adults participating in the Nutrinet-Santé Study. Before assessing liking, resting saliva was collected. Standard biochemical analyses were performed to assess specific component concentrations and enzymatic activities. Dietary data were collected using three web-based 24h records. Relationships between salivary flow and composition, sensory liking and nutrient intake were assessed using linear regression. Total antioxidant capacity was positively associated with simple carbohydrate intake (β = 31.3, 95% CI = 1.58; 60.99) and inversely related to complex carbohydrate consumption (β = -52.4, 95% CI = -87.51; -19.71). Amylolysis was positively associated with both total (β = 0.20, 95% CI = 0.01; 0.38) and simple carbohydrate intake (β = 0.21, 95% CI = 0.01; 0.39). Salivary flow was positively associated with liking for fat (β = 0.14, 95% CI = 0.03; 0.25). Proteolysis was positively associated with liking for saltiness and for fat (β = 0.31, 95% CI = 0.02; 0.59; β = 0.28, 95% CI = 0.01; 0.56, respectively). Amylolysis was inversely associated with liking for sweetness (β = -10.13, 95% CI = -19.51; -0.75). Carbonic anhydrase 6 was inversely associated with liking for saltiness (β = -46.77, 95% CI = -86.24; -7.30). Saliva does not substantially vary according to a usual diet, except for carbohydrate intake, whereas the specific association between salivary flow/composition and sensory liking suggests the influence of saliva characteristics in food acceptance.

The effect of dietary intervention on paraffin-stimulated saliva and dental health of children participating in a randomized controlled trial

OBJECTIVES

The aim was to study the impact of dietary intervention on the properties of paraffin-stimulated saliva, and on dental caries.

STUDY DESIGN

At 7 months of age 1062 infants (540 intervention; 522 controls) started in the prospective, randomized Special Turku Intervention Project (STRIP) aimed at restricting the child's saturated fat and cholesterol intake to prevent atherosclerosis of adult age (www.clinicaltrials.gov NCT 00223600). At 3 years of age, every fifth child was invited to an oral sub-study, and 148 (78 boys) children attended. At 6, 9, 12 and 16 years of age 135, 127, 114 and 88 children were restudied, respectively. Dietary intakes of carbohydrates, protein, saturated fat, calcium, phosphate, and fibre were regularly recorded using 4-day food records. Height and weight were regularly monitored. Paraffin-stimulated saliva samples were collected at 6, 9, 12 and 16 years of age, and analyzed for flow rate, buffer capacity, calcium, phosphate and proteins. Dental health was recorded and expressed as d3mft/D3MFT, and as time of caries onset.

RESULTS

Dietary intakes of calcium, phosphate and fibre, and salivary flow rate increased with time in both groups (p<0.001, GLM for repeated measures). Fibre intake and salivary flow rate were higher in the intervention than in the control group (p=0.042 and p=0.0394, respectively, GLM for repeated measures). There were no correlations between dietary intakes and salivary concentrations of calcium or phosphate. Children who did not have caries experience (d3mft/D3MFT=0) during the entire follow-up had higher salivary calcium than those who had caries already at 3 years of age. The association between salivary calcium and caries onset was significant up to 12 years of age. Toothbrushing frequency was statistically significantly associated with caries-onset at ages 6 (gamma statistic 0.457, p=0.046) and 12 years (gamma statistic 0.473, p=0.019).

CONCLUSIONS

The current long-term dietary intervention increased children's paraffin-stimulated salivary flow rate. The concentration of salivary calcium was directly correlated to dental health. Higher salivary flow rate in the intervention group is believed to be due to higher fibre intake in the intervention group.