Influence of fruit, meal distribution and dental health on cardio-metabolic risk

Sammanfattning: Background   Fruit is often recommended as a snack between meals and a main component of the cardioprotective Mediterranean diet. The sugar content might be of concern since it theoretically could lead to hepatic fat accumulation and affect dental status negatively. Dental status is associated with cardiovascular disease, but subjective dental health’s association has barely been studied. The aim of this thesis was to study dietary recommendations, as in fruit consumption and meal frequency, and their effect on cardio-metabolic risk factors and dental status. Another aim was to study dissatisfaction with teeth as a marker of cardiovascular risk in type 2 diabetes.  Methods   Paper I-II studied the effect of extra fruit or nuts as a snack between meals on hepatic fat content and dental status. A study population of 30 young, healthy, normal-weight participants were recruited and randomized to each intervention by 1:1 allotment. The amount of hepatic fat content (HFC) was quantified by MRI-examination. Dental status was investigated by the same licensed dentist. In both cases were examinators blinded to the allotted intervention. Other parameters were markers cardiometabolic risk, inflammatory markers, and vitamin levels. Paper III is a randomized cross-over study with the primary outcome of post-prandial energy expenditure after varying meal frequency and fat- /carbohydrate content in fourteen study participants. In parallel the hormones ghrelin and GLP-1 were measured as secondary outcomes. There were 4 types of test meals served with either a single large drink of 750 kcal or divided into five smaller drinks (150 kcal) with the same total energy content in a series every 30 minutes for 2.5 hours. Macronutrient content was varied by low- or high carbohydrate content (54.9 E%/20.0 E%). Protein content was similar (9.9 E%). The remainder of energy was from fat. Paper IV explored the association between dissatisfaction with teeth and major adverse cardiovascular events (MACEs) defined as hospitalization or death due to myocardial infarction or stroke in a population of 601 available cases with type 2 diabetes in primary care. The Cox regression was adjusted for age, sex, inflammation, BMI, duration of diabetes, HbA1c, total cholesterol, office systolic blood pressure, prior MACE, currently smoking, marital status, being born in Sweden, self-reported stress, and self-reported happiness. Paper V investigated the association of self-reported frequency of consumed bananas, apples/pears, and oranges/citrus fruit with office- and home blood pressure in a study population of 2 283 available participants. Adjustments were made for the covariates sex, age, BMI, smoking, alcohol consumption, salt consumption, educational level, physical activity, HbA1c, total cholesterol and S-creatinine levels in a multivariable linear regression. Subgroup analysis by sex was also performed.  Results  In paper I there was no change in HFC in either group. There was a decrease in number of deep gingival pockets in the fruit group with a statistically significant different change compared to the nut group as sign of a potentially improved dental status. In paper III post-prandial energy expenditure was higher after one large drink compared to the series of smaller drinks and the drinks with high-carbohydrate content. GLP-1 levels were higher after the large drink, while similar with varying fat-/carbohydrate content. Ghrelin did not differ at any test occasion at group level. Paper IV revealed an increased risk of MACE when dissatisfied with teeth independent of sex, age, and inflammation. When also adjusting for cardiovascular risk factors and socio-psychological factors the increased risk was attenuated. Paper V showed an independent association between lower systolic- and diastolic home blood pressures for apples/pears and oranges/citrus fruits in total study population. Diastolic home blood pressure was independently associated with all types of fruit consumption in women only.   Conclusions  Fruit as snack in addition to habitual diet in quantities greater than the minimum recommended amount did not increased HFC. Periodontal status was improved in the fruit group with a statistically significant change compared to the nut group. The acute effects of a large meal compared to a series of smaller and high-carbohydrate content resulted in a higher post-prandial energy expenditure. Dissatisfaction with teeth could help determine cardiovascular risk associated with a range of biological and social factors. Fruit consumption was independently associated with lower home blood pressure, predominately diastolic blood pressure in women. There is an undeniable opportunity for future collaboration between health care and dental health care to further expand the knowledge and increase the evidence behind dietary recommendations promoting general- and dental health.