Effects of Almond Consumption on Innate and Adaptive Immune System

Effects of Almond Consumption on Innate Myeloid and Lymphoid Cells Composition and Activity

Almonds are a rich matrix of different nutrients with demonstrated benefits on immune system. This proposal examines the effect of regular consumption of almonds on innate and adaptive immune system in healthy individuals with overweight regularly consuming a Western-style diet and unhealthy snacks.

In the last months, with the whole world grappling with COVID-19 and because like in many other diseases, the host immune system determines the progress of COVID-19 and the severity, there is a frantic race for finding treatment strategies based on current knowledge until effective vaccine is developed. Therefore, the modulation of inflammatory response and cytokine production using immunonutrition makes more sense than ever.

The almond is a tree nut, rich in fiber, vitamin E, biotin, minerals such as magnesium and phytonutrients, specifically flavonoids, plant sterols, phenolic acids and could have a potential beneficial role in immune system. However, beyond its beneficial role and down-lowering specific circulating cytokines in low-grade chronic inflammatory diseases, the role of almond on both innate and adaptive immune system has not been explored.

The investigators hypothesize that regular consumption of almonds will contribute to strengthening the immune system through the modulation of specific circulating miRNAs.

The primary objective is to evaluate the effect of almond consumption on the maturation of innate lymphoid cells (ILCs).

Secondarily, the insvestigators aims to:

1. Examine the effect of regular consumption of almonds in the context of a Western-style diet on: a) innate immune system through the analysis of other blood cell populations including monocytes and lymphocyte's subsets (T-cells, B-cells). b) adaptive immune system assessed by: b.1) circulating inflammatory markers and b.2) ex-vivo ability for peripheral blood mononuclear cell (PBMC) to produce cytokines.

   c) circulating miRNAs, focusing in immune-related miRNAs.

2. To investigate whether changes in miRNAs mediate the effect of almonds on ILCs activity and the other innate and adaptive immune system indicators analysed.

The expected results would enhance understanding of the role of almonds in immune function, to establish the basis of new research for the promotion of the health benefits of nuts in immune-related diseases and facilitate the use of personalized nutrition to improve human health.

Inclusion Criteria:

• BMI 25.0-34.9 Kg/m2
• Western-style diet
• Unhealthy snacks other than nuts (i.e. potato chips, crackers, corn puffs, pretzels, pastries, cookies, candies) >1 serving/day

Exclusion Criteria:

• Regular smokers (≥ 10 cigarettes/day)
• Diagnoses of type 2 diabetes
• Cardiovascular disease, chronic kidney disease, liver disease, active inflammatory bowel disease, celiac disease, chronic pancreatitis or other disorder potentially causing malabsorption, cancer - active malignant cancer or history of malignancy within the last 5 years, psychiatric disorders
• Use of anti-inflammatory or antioxidants drugs
• Not stable medication in the last 3 months
• Regular alcohol consumption above of the national recommendations or drug abuse
• Frequent consumption of nuts
• Allergy to the intervention products or other severe allergies and food intolerances
• Dietary patterns interfering with the study protocol (e.g. vegetarian, vegan, low carbohydrate dieters, high fat dieters) two months prior inclusion, during the study or plans to initiate during the study
• Daily use of multivitamin or mineral supplements
• Bad dentures, implying difficulty to chew nut
• Pregnancy or lactation, pregnancy within the past 12 month or plans to become pregnant during the study
• Consumption of probiotics or prebiotics in the last 3 months and laxatives