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Research Nut: Almonds

Effect of almond consumption on metabolic risk factors-glucose metabolism, hyperinsulinemia, selected markers of inflammation: a randomized controlled trial in adolescents and young adults.

Madan, J., S. Desai, P. Moitra, S. Salis, S. Agashe, R. Battalwar, A. Mehta, R. Kamble, S. Kalita, A.G. Phatak, S.A. Udipi, R.A. Vaidya,  A.B. Vaidya, 2021. Effect of almond consumption on metabolic risk factors-glucose metabolism, hyperinsulinemia, selected markers of inflammation: a randomized controlled trial in adolescents and young adults. Front. Nutr. 8:668622. https://doi.org/10.3389/fnut.2021.668622

A large percentage of the Indian population has diabetes or is at risk of pre-diabetes. Almond consumption has shown benefits on cardiometabolic risk factors in adults. This study explored the effect of almond consumption on determinants of metabolic dysfunction-blood glucose, lipids, insulin and selected inflammatory markers in adolescents and young adults aged 16-25 years from Mumbai city. This randomized controlled trial was conducted for a period of 90 days on individuals with impaired levels of fasting glucose levels between 100-125 mg/dL (5.6-6.9 mmol/L) and 2-h post-glucose value 140-199 mg/dL (7.8-11.0 mmol/L) and/or fasting insulin (≥15 mIU/ml)/stimulated insulin (≥80 mIU/ml). Of 1,313 individuals screened, 421 met the inclusion criteria, of which 275 consented to participate and 219 completed the trial. The trial was registered with Clinical Trials Registry India (CTRI) CTRI/2018/02/011927. The almonds group (n = 107) consumed 56 g almonds daily, the control group (n = 112) was provided an iso-caloric cereal-pulse based snack. At baseline and endline, blood glucose, insulin, HbA1c, LDL-c, HDL-c, total and ox-cholesterol, triglycerides, hs-CRP, IL-6, TNF-α, adiponectin, leptin were measured and HOMA-IR and FG:FI ratios were calculated. Dietary intakes were assessed. The anthropometric measurements, biochemical markers as well as macronutrient intakes did not differ significantly between the two groups at baseline. Almond consumption significantly decreased HbA1c, total cholesterol and LDL-c. Stimulated insulin decreased post-intervention in both groups, but the decrease was greater in the almonds group. Fasting glucose was reduced post intervention in the controls with no change in the almonds group. FG:FI ratio decreased in the almonds group. TNF-α and IL-6 decreased in the almonds group, while it increased in the control group. Our results showed that almonds reduced HbA1c, LDL-c and total cholesterol levels in just 12 weeks of consumption in these adolescents and young adults who were at risk for developing diabetes. Almonds can be considered as part of food-based strategies for preventing pre-diabetes. Clinical Trial Registration: ClinicalTrials.gov, identifier: CTRI/2018/02/011927.

Almond consumption increased UVB resistance in healthy Asian women.

Li, J. N., S.M. Henning, G. Thames, O. Bari, P.T. Tran, C.H. Tseng, D. Heber, J. Kim, Z. Li, 2021. Almond consumption increased UVB resistance in healthy Asian women. J. Cosmet. Dermatol. 20(9):2975–2980. https://doi.org/10.1111/jocd.13946

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.

Prospective randomized controlled trial on the effects of almonds on facial wrinkles and pigmentation. 

Rybak, I., A.E. Carrington, S. Dhaliwal, A. Hasan, H. Wu, W. Burney, J. Maloh, R.K. Sivamani, 2021. Prospective randomized controlled trial on the effects of almonds on facial wrinkles and pigmentation. Nutrients. 13(3):785. https://doi.org/10.3390/nu13030785

Background: Almonds have long been studied as a rich source of fatty acids, phytochemical polyphenols and antioxidants such as vitamin E. A recent study compared almond supplementations to a calorie-matched intervention for 16 weeks, yielding statistically significant improvement in wrinkle severity in postmenopausal women with Fitzpatrick skin types I and II that received almonds. This study furthers that assessment with a larger population and duration of 24 weeks to assess the influence of almond consumption on wrinkle severity, skin pigmentation and other skin biophysical profiles. Objective: To investigate the effects of almond consumption on photoaging such as wrinkles and pigment intensity as well as facial biophysical parameters such as sebum production, skin hydration and water loss. Design and interventions: A prospective, randomized controlled study assessed postmenopausal women with Fitzpatrick skin types I or II who consumed 20% of their daily energy consumption in either almonds or a calorie-matched snack for 24 weeks. A facial photograph and image analysis system was used to obtain standardized high-resolution photographs and information on wrinkle width and severity at 0, 8, 16 and 24 weeks. Measurements of transepidermal water loss (TEWL), skin pigmentation, skin hydration and sebum production were also completed at each visit. Results: The average wrinkle severity was significantly decreased in the almond intervention group at week 16 and week 24 compared to baseline by 15% and 16%, respectively. Facial pigment intensity was decreased 20% in the almond group at week 16 and this was maintained by week 24. There were no significant differences in skin hydration or TEWL in the almond group compared to the control, although sebum excretion was increased in the control group. Conclusion: The daily consumption of almonds may improve several aspects of photoaging such as facial wrinkles and pigment intensity in postmenopausal women. In conclusion, the daily consumption of almonds may contribute to the improvement of facial wrinkles and reduction of skin pigmentation among postmenopausal women with Fitzpatrick skin types I and II.

Snacking on almonds lowers glycaemia and energy intake compared to a popular high-carbohydrate snack food: an acute randomised crossover study.

Brown, R., L. Ware, A.R. Gray, A. Chisholm, S.L. Tey, 2021. Snacking on almonds lowers glycaemia and energy intake compared to a popular high-carbohydrate snack food: an acute randomised crossover study. Int J Environ Res Public Health. 18(20):10989. https://doi.org/10.3390/ijerph182010989

Consuming nuts may have advantages over other snack foods for health and body-weight regulation. Suggested mechanisms include increased satiety and lower glycaemia. We used an acute randomised crossover trial to assess glycaemic and appetite responses to consuming two isocaloric snacks (providing 10% of participants’ total energy requirements or 1030 kJ (equivalent to 42.5 g almonds), whichever provided greater energy): raw almonds and sweet biscuits among 100 participants with available data (25 males and 75 females) following 106 being randomised. Two hours after consuming a standardised breakfast, participants consumed the snack food. Fingerprick blood samples measuring blood glucose and subjective appetite ratings using visual analogue scales were taken at baseline and at 15 or 30 min intervals after consumption. Two hours after snack consumption, an ad libitum lunch was offered to participants and consumption was recorded. Participants also recorded food intake for the remainder of the day. The mean area under the blood glucose response curve was statistically and practically significantly lower for almonds than biscuits (mean (95% CI) difference: 53 mmol/L.min (45, 61), p < 0.001). Only the composite appetite score at 90 min was higher in the almond treatment compared to the biscuit treatment (45.7 mm vs. 42.4 mm, p = 0.035 without adjustment for multiple comparisons). There was no evidence of differences between the snacks for all other appetite ratings or for energy intake at the ad libitum lunch. However, mean energy intakes following snack consumption were significantly lower, both statistically and in practical terms, for the almond treatment compared to the biscuit (mean (95% CI) diff: 638 kJ (44, 1233), p = 0.035). Replacing popular snacks with almonds may have advantages in terms of glycaemia and energy balance.