Better Nutritional Status Is Positively Associated with mRNA Expression of SIRT1 in Community-Dwelling Older Adults in the Toledo Study for Healthy Aging.

Background: The expression of certain genes involved in response to oxidative stress is likely related to aging-related outcomes, such as frailty in old age. Given nutrition's substantial impact in aging and age-related diseases, one of its mechanisms might be through influencing gene expression. Objective: This study aimed to investigate the association between nutrition and the expression of 15 genes related to cellular response to stress in older community-dwelling individuals. Methods: A nested case-control study of 350 participants (mean ± SEM age: 76.5 ± 6.9 y, 42.9% men, 22% frail according to Fried's criteria) was selected from the Toledo Study for Healthy Aging. Blood-derived RNA was retro-transcribed into complementary DNA. TaqMan Arrays were used for determining gene expression. The Mini Nutritional Assessment (MNA) and the PREDIMED (PREvención con DIeta MEDiterranea) questionnaire measured nutritional status and adherence to the Mediterranean diet (MD), respectively. Data were reweighed so that inference from linear and logistic regression models applied to the original sampling population. Results: Higher MNA scores were associated with higher expressions of the gene coding for sirtuin-1 (SIRT1), regardless of age, sex, and Charlson comorbidity score (P = 0.04) and even after adjusting for frailty status (P = 0.016) and level of adherence to the MD (P = 0.04). Malnutrition risk and SIRT1 gene expression were inversely associated (P = 0.0045) independently of frailty status (P = 0.0045) and level of adherence to the MD (P = 0.0075). Conclusions: In older individuals, improvement in nutritional status is positively associated with SIRT1 gene expression independently of frailty status or adherence to the MD. These findings may provide potential biomarkers and targets for health interventions among the elderly.

Impact of Melatonin Enrichment during Germination of Legumes on Bioactive Compounds and Antioxidant Activity.

This study assesses the impact of melatonin enriched watering on the germination of lentils (Lens culinaris L.) and kidney beans (Phaseolus vulgaris L.). The melatonin levels in lentil and bean sprouts measured by HPLC-MS/MS were more important than those found in other legumes and sprouts, being higher in lentil (1090 ng/g) than in kidney bean (529 ng/g) sprouts. This alternative germination promoted a significant increase of the development of radicles in comparison with the traditional germination. The decreases in the phenolic load were less accentuated than previously observed (lentil sprouts displayed 394 mg gallic acid equivalents (GAE)/100 g of dry weight (DW)), probably due to the protective effect of melatonin. The antioxidant capacity (oxygen radical absorbing capacity assay) increased in these sprouts, reaching 85 and 56 µmol of Trolox equivalents/g DW in lentils and beans, respectively. Hence, the melatonin-enriched foods exhibited potent free radical scavenger and antioxidant functions that may be used as a nutritional strategy to alleviate and prevent chronic and age-related diseases.

Effect of illumination on the content of melatonin, phenolic compounds, and antioxidant activity during germination of lentils (Lens culinaris L.) and kidney beans (Phaseolus vulgaris L.).

This study reports the effects of two different illumination conditions during germination (12 h light/12 h dark vs 24 h dark) in lentils (Lens culinaris L.) and kidney beans (Phaseolus vulgaris L.) on the content of melatonin and phenolic compounds, as well as the antioxidant activity. Germination led to relative increase in melatonin content and significant antioxidant activity, while the content of phenolic compounds decreased. The highest melatonin content was obtained after 6 days of germination under 24 h dark for both legumes. These germinated legume seeds with improved levels of melatonin might play a protective role against free radicals. Thus, considering the potent antioxidant activity of melatonin, these sprouts can be consumed as direct foods and be offered as preventive food strategies in combating chronic diseases through the diet.