Almond consumption increased UVB resistance in healthy Asian women.
Background: Almonds are a rich source of phenolic and polyphenolic compounds, which have antioxidant activity. In vitro and in vivo studies have demonstrated that topical application of almond oil and almond skin extract reduces UVB-induced photoaging. Ultraviolet-B (UVB) protection by oral almond consumption has not been previously studied in humans.
Objectives: To investigate whether oral almond consumption can increase resistance to UVB radiation and reduce skin aging in healthy Asian women.
Methods: Thirty-nine female participants (18-45 years) with Fitzpatrick skin type II-IV were randomly assigned to consume either 1.5 oz of almonds or 1.8 oz of pretzels daily for 12 weeks. Minimal erythema dose (MED) was determined using a standardized protocol, which determined the minimal radiation needed to induce erythema on the inner arm following UVB exposure. Facial skin texture was evaluated by two dermatologists using the Clinician's Erythema Assessment scale and Allergan Roughness scale. Facial melanin index, hydration, sebum, and erythema were determined using a cutometer.
Results: The MED was increased in the subjects consuming almonds compared to the control group consuming pretzels. There were no differences noted between the groups consuming almonds versus pretzels in Allergan roughness, melanin, hydration, or sebum on facial skin.
Conclusions: Our findings suggest that daily oral almond consumption may lead to enhanced protection from UV photodamage by increasing the MED.
Effects of daily almond consumption for six months on cognitive measures in healthy middle-aged to older adults: a randomized control trial.
Background: Age-related cognitive decline is a major public health issue. Almonds are rich in nutrients that benefit cognitive function.
Objective: To investigate the impact of almonds on cognition in elderly adults.
Design: In a six-month, single-blinded, randomized-controlled trial, the effects of an almond intervention on cognition in healthy, middle-aged/older adults (50-75 years) was tested. Subjects were assigned to one of three groups: 1.5 oz/d almond (n = 19), 3 oz/d almond (n = 24), or 3.5 oz/d snack (control, matched for macronutrients in 3.0 oz almonds, (n = 17). Serum analyses for tocopherols, oxidative status and inflammation, and cognition were assessed at baseline (M0), three (M3), and six (M6) months.
Results: At M6, serum alpha-tocopherol concentrations increased by 8% from M0 (p < 0.05) in the 3 oz almond group but did not increase in the other groups. Serum markers of inflammation and oxidative stress were not significantly different throughout the study among the groups. There was no difference in change over time in cognitive tests among the groups. However, there was a significant improvement in visuospatial working memory (p = 0.023), visual memory and learning (p = 0.017), and spatial planning and working memory (p < 0.001) in subjects receiving 3 oz/d almonds at M6, while the snack group showed no improvement.
Conclusions: Almonds did not significantly improve cognitive function in cognitively intact middle-aged/older adults over six months. However, a significant improvement at M6 in cognitive measures was observed with 3 oz/d almonds. While these results are encouraging, a study of longer duration in subjects at risk for age-related cognitive decline is warranted.
The Effect of Nut Consumption on Diet Quality, Cardiometabolic and Gastrointestinal Health in Children: A Systematic Review of Randomized Controlled Trials.
Tree nuts and ground nuts are nutrient-rich foods known to improve human health when consumed regularly in the diet. Past observational studies suggest that nuts improve adult and child health; however, limited randomized control trials (RCTs) have assessed the health effects of nuts in children. Using a systematic review approach, we examined the effect of nut intake on health outcomes in children aged 8-18 years. We searched PubMed, Scopus, Web of Science, EMBASE and Cochrane library to identify RCTs of interest. A total of 5783 articles were identified, 4821 were screened by title and abstract and 37 by full text resulting in four articles that met the inclusion criteria for the review. Nut consumption was between 15 and 30 g with durations of between 3 and 16 weeks. Nut consumption was shown to improve children's diet quality (increase children's intake of essential nutrients including fats (monounsaturated and polyunsaturated fats), protein and fiber), there were inconsistent effects on biomarkers of cardiometabolic health (improve lipid profiles, microvascular reactivity and inflammation) and gastrointestinal health (increase in the proportion of beneficial fecal bacteria). Further studies exploring the broad health benefits of nuts in children are needed with consideration given to higher doses and longer intervention periods.
https://doi.org/10.3390/ijerph18020454
Nut consumption and type 2 diabetes risk: a systematic review and meta-analysis of observational studies.
Background: Previous meta-analyses, with some methodological controversies, have assessed the relation between nut consumption and type 2 diabetes (T2D) risk and pointed to contradictory results, making desirable the performance of an updated meta-analysis.Objectives: We aimed to systematically review and meta-analyze all the published studies investigating the relations of total nuts and different types of nuts-i.e., walnuts, peanuts, peanut butter, and total tree nuts-with the prevalence and incidence of T2D.Methods: A systematic search was conducted in the PubMed and Cochrane databases through 12 August, 2020. The inverse variance method with fixed-effect models was used to pool data across studies, expressed as risk ratios (RRs) or ORs and 95% CIs for prospective cohort and cross-sectional studies, respectively. The Cochran Q test and I2 statistics were used to test and quantify heterogeneity, respectively. Dose-response meta-analysis was also conducted.Results: Eight studies (5 prospective and 3 cross-sectional) were included in the quantitative synthesis. Meta-analyses of cross-sectional studies and prospective cohort studies, comparing the highest with the lowest categories, revealed a nonsignificant association between total nut consumption and T2D. Meta-analyses of prospective cohort studies showed an inverse association between peanut butter consumption and T2D incidence (RR: 0.87; 95% CI: 0.77, 0.98; I2 = 50.6%; Pheterogeneity = 0.16), whereas no association was observed between peanuts or tree nuts and T2D. There was no evidence of a linear dose-response or nonlinear dose-response gradient for total nut and peanut consumption in prospective cohort studies. The certainty of the evidence using NutriGrade was very low for all the exposures.Conclusions: Current results do not demonstrate an association of total nut, peanut, or tree nut consumption with T2D. Peanut butter consumption may be inversely associated with this disease.This review protocol was registered at www.crd.york.ac.uk/prospero/ as CRD42020149756.
https://doi.org/10.1093/ajcn/nqaa358
Nut Consumption and Cardiovascular Health Among Iranian Population
During the follow up after 135 months, the researchers identified 751 cases of cardiovascular events. They found that participants who were in the highest quartile of nut consumption had a lower cardiovascular disease risk and all-cause mortality. In conclusion, the consumption of nuts may have an inverse association with the risk of cardiovascular disease among individuals from Iran. The authors suggest more studies should be carried out to analyze individual types of nuts and how they related to cardiovascular disease risk and mortality.
Mohammadifard, N., Ghaderian, N., Sajjadi, F., Hassannejhad, R., Salas-Salvado, J., Sadeghi, M., ... & Sarrafzadegan, N. (2020). Longitudinal association of nut consumption and the risk of cardiovascular events: a prospective cohort study in Eastern Mediterranean Region. Frontiers in Nutrition, 7, 315.
Meta-Analysis of Nut Consumption and Prevention of Type 2 Diabetes
In conclusion, the current results reveal no significant association of total nut consumption with type two diabetes. On the contrary, peanut butter consumption may be inversely associated with the disease. While there is plenty of research that suggests nut consumption does not increase weight and may help those with type 2 diabetes control it, this study does not give a clear-cut answer on the role nut consumption may play in preventing diabetes. Therefore, there should be more long-term clinical trials that review this association.
Becerra-Tomás N, Paz-Graniel I, Hernández-Alonso P, Jenkins DJA, Kendall CWC, Sievenpiper JL, Salas-Salvadó J. Nut consumption and type 2 diabetes risk: a systematic review and meta-analysis of observational studies. Am J Clin Nutr. 2021 Jan 20:nqaa358. doi: 10.1093/ajcn/nqaa358
Consuming Nuts for Your Cognitive Health
At the conclusion of the study, 14.3% of the participants were identified to have a cognitive impairment. It was discovered that those who ate 1-3 servings of nuts per month, 1 serving of nuts a week, and more than 2 servings of nuts a week had a 12% lower risk of cognitive impairment. The authors also discovered that 50.8% of the association between nuts and risk of cognitive impairment was mediated by the consumption of total unsaturated fatty acids. Overall, increasing consumption of nuts in midlife may lead to a lower risk of cognitive impairment later on in life.
Jiang, Y. W., Sheng, L. T., Feng, L., Pan, A., & Koh, W. P. (2020). Consumption of dietary nuts in midlife and risk of cognitive impairment in late-life: the Singapore Chinese Health Study. Age and Ageing.