Preface

Nuts, also referred to as "tree nuts," and peanuts are associated with good health and have always been an important part of the human diet. There has been renewed interest in understanding the reasons why nuts and peanuts, when consumed as part of a healthy diet, are beneficial in the prevention of several chronic diseases such as cancer, cardiovascular diseases, diabetes mellitus, obesity, and high blood pressure. Over the past few decades, extensive research has been undertaken to study the nutritional and phytochemical composition of nuts, their mechanism of action, and the need for dietary guidelines for the consumption of nuts. At the same time, research is also being directed at the issues of fungal contamination of nuts and the associated toxicity and risk to human health. In recognition of the important role that nuts and nut products play in human health and nutrition, several original research and review articles have now been published. This book, *Nuts and Nut Products in Human Health and Nutrition*, contains chapters that address some important aspects of consuming nuts as part of a healthy diet. It is organized into four sections. Chapter 1 in Section 1, by AV Rao and LG Rao, is an introduction to the important role that nuts and nut products play in human health, their composition, including health-friendly lipids and beneficial phytochemicals, and their micronutrient composition. It points out the nature of basic, clinical, and epidemiological research that still needs to be undertaken in the future for a better understanding of the role of nuts, including peanuts, and formulation of dietary guidelines based on such research outcomes. Section 2, "Nutrient and Phytonutrient Composition of Nuts", includes two chapters: Chapter 2, "Nut Phytonutrients for Healthy Gut: Probiotic Potential," by Jinu Medhi and Mohan Chandra Kalita, and Chapter 3, "Nuts as Dietary Source of Fatty Acids and Micro Nutrients in Human Health" by Chiranjiv Pradhan, Nikhila Peter and Namitha Dileep. Together, these two chapters address the reasons why nuts and peanuts are health-friendly components of a good diet. Section 3, "Fungal Contamination of Nuts," contains Chapter 4 "Fungal Contaminants and Mycotoxins in Nuts" by Giulia Mirabile, Patrizia Bella, Antonio Vella, Vincenzo Ferrantelli and Livio Torta, and Chapter 5 "Nutrient Composition and Aflatoxin Contamination of African Sourced Peanuts and Cashew Nuts: Its Implications on Health" by Modupeade C. Adetunji, Stephen A. Akinola, Nancy Nleya and Mwanza Mulunda. Fungal contamination and production of toxic byproducts are important since they can mitigate the beneficial role that nuts play in human health. These two chapters balance out the pros and cons that need to be considered with respect to nuts. Finally, Section 4, "Genetic Improvements Towards Human Health," includes Chapter 6, "Genetic Potential and Possible Improvement of Sesamum indicum L." by Muthulakshmi Chellamuthu, Selvi Subramanian and Manonmani Swaminathan, which looks at the genetic potential for possible improvement of nuts. This chapter uses sesame seeds, though not nuts, to highlight the need for genetic research that needs to be done to improve nutritional quality and the health beneficial properties of nuts.

 Overall, this book provides important information, authored by international authors, to health professionals, researchers, and other scientists that will be very useful in understanding the mechanisms by which nuts provide health benefits, the concern of fungal infestation of nuts with the resultant production of toxic

metabolites and how to prevent such undesirable effects, and formulation of dietary guidelines for the consumption of nuts and nut products. It also provides a guide to future research directions in the important area of human health.

> **Venketeshwer Rao and Leticia Rao** University of Toronto, Canada

**Md Ahiduzzaman and A. K. M. Aminul Islam** Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh

Section 1 Introduction

#### **Chapter 1**

## Introductory Chapter: The Role of Nuts and Nut Products in Human Health and Disease

### *A. Venketeshwer Rao and Leticia Rao*

#### **1. Introduction**

Consumption of nuts dates back to the prehistoric times. Nuts were an important part of the diet of early humans. Since then, humans have shown continued interest in the consumption of nuts and more recently in nut products as well, both for their taste and for their nutritional quality and health benefits. Mediterranean diets that are associated with lower incidence of several chronic diseases in particular, contain significant amounts of nuts [1–3]. Several epidemiological and human intervention studies since then have provided evidence for the association between the consumption of nuts and reduced risk in the incidence of several chronic diseases such as cancer, cardiovascular diseases, diabetes mellitus, obesity and high blood pressure just to name a few [4–6]. These observations encouraged scientific search to investigate the reasons as to why nuts are considered to promote health. This introductory chapter will look into the diversity of nuts that are consumed by humans and their nutritional and phytochemical composition. It will also discuss briefly the scientific evidence supporting the health beneficial properties of nuts. Chapters that follow this introductory one are authored by internationally known researchers and will cover various aspects of tree nuts and peanuts.

Common use of the term nuts is somewhat confusing. Nuts are in reality fruits. A common definition is that 'they are single-seeded fruits that have high oil content'. Wikipedia defines a nut 'as a fruit composed of an inedible hard shell and a seed which is generally edible'. However, in its general usage a wide variety of dried seeds are referred to as tree nuts. In a botanical context, nuts are strictly a particular kind of dry fruit that has a single seed, a hard shell, and a protective husk [2]. In the context of this chapter, a more general term 'Tree nuts and peanuts' will be used, although peanuts are strictly not nuts but are legumes.

In general nuts have a similar macronutrient content with an average energy content of 2,900 kJ. However, their micronutrient content including vitamins and mineral may differ to some extent.

**Table 1** provides a list of tree nuts and peanuts that are commonly consumed by humans and their macronutrient nutrient content.

Fatty acid composition of the commonly consumed nuts is shown in **Table 2**.

As shown in **Tables 1** and **2**, nuts in general are high fat, energy dense and fiber rich food products. Their fats are composed mainly of monounsaturated and polyunsaturated fatty acids with very low saturated fats and no cholesterol. They are also good sources of linoleic and alpha linoleic fatty acids [7, 8]. In addition to the heart and health friendly lipid profiles of nuts, they are also good sources of plant sterols and other beneficial phytochemicals with significant antioxidant properties [9]. They are rich in vitamins such as pyridoxine and folate. With respect to minerals, they are

#### *Nuts and Nut Products in Human Health and Nutrition*


*Source: US Department of Agriculture Nutrient Data base at: http://www.nal.usda.gov/fnic/cgi-bin/ nut\_search.pl [7]. Ros E. 2010.Health Benefits of Nut Consumption***.** *Nutrients: 2, 652–682 [8].*

**Table 1.**

*Macronutrient composition of some common nuts and peanuts (per 100 grams).*


*Source: US Department of Agriculture Nutrient Data base at: http://www.nal.usda.gov/fnic/cgi-bin/nut\_search.pl [7]. Ros E. 2010.Health Benefits of Nut Consumption***.** *Nutrients: 2, 652–682 [8].*

#### **Table 2.**

*Fatty acid and plant sterol content of common nuts and peanuts (per 100 grams).*

significant dietary sources of calcium, iron, phosphorus, zinc, copper and selenium. In addition to the lipids, nuts are also a good source of proteins and essential amino acids such as arginine that promote good health [3]. Overall, when consumed on a regular basis they provide significant amount to the daily requirements of nutrients essential to lower the risk of chronic diseases and maintain good health.

In view of the potential positive nutritional characteristics of nuts, they have been studied extensively over the years for their role in preventing several human chronic diseases and maintaining good health [10]. **Table 3** shows some of the

*Introductory Chapter: The Role of Nuts and Nut Products in Human Health and Disease DOI: http://dx.doi.org/10.5772/intechopen.100146*


**Table 3.**

*Examples of health benefits of consuming nuts as part of a healthy diet and life style.*

health benefits, based on research conducted over the years, of consuming nuts as part of a healthy diet and a life style. It should be pointed out that the health benefits shown in the table are only a few examples. However, the research to evaluate the health benefits of consuming nuts continues and new information as to the prevention of diseases, their mechanism of action and recommendation are published regularly.

It should be pointed out that there are a few concerns of consuming nuts and nut products such as bodyweight, allergic reactions for some individuals and the possibility of adverse effects associated with fungal contamination of nuts, have to be kept in mind.

#### **2. Conclusion**

In conclusion it should be pointed out that consuming nuts including peanuts can play a significant role in the prevention and treatment of human diseases and benefiting human health. Following chapters, authored by well-known international researchers will contribute significantly to our understanding of the role of nuts and nut products in human health.

#### **Author details**

A. Venketeshwer Rao\* and Leticia Rao University of Toronto, Toronto, Ontario, Canada

\*Address all correspondence to: rao@utoronto.ca

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

### **References**

[1] Romaguolo, DF and Swlmin, OI. 2017. Mediterranean diet and prevention of chronic diseases. Nutr Today. 52:208-222

[2] Mandalari G and Grassb T (Eds). 2020. Special Issue "Nuts Intake and Human Health" *Nutrients* 12. https://doi. org/10.3390/nu12041180

[3] Mohammadifard N1, Ghaderian N, Hassannejad R et al. 2021. Longitudinal Association of Nut Consumption and the Risk of Cardiovascular Events: A Prospective Cohort Study in the Eastern Mediterranean Region. Front. Nutr., 21 January 2021. https://doi.org/10.3389/ fnut.2020.610467

[4] Nuts and seeds. Better Health Channel. https://www.betterhealth.vic. gov.au/health/healthyliving/Nutsand-seeds

[5] Machado de Souza RG, Schincaglia RM, Pimentel GD, and Mota JF. 2017. Nuts and Human Health Outcomes: A Systematic Review. Nutrients 9(12): 1311.

[6] US Department of Agriculture Nutrient Data base: http://www.nal. usda.gov/fnic/cgi-bin/nut\_search.pl

[7] Ros E. 2010. Health Benefits of Nut Consumption. Nutrients. 2010 Jul; 2: 652-682.

[8] Gull, A., & Nayik, G. A. 2020. Antioxidants in vegetables and nuts: properties and health benefits (1st ed. 2020.). Springer. https://doi.org/10. 1007/978-981-15-7470-2

[9] Consumer health: Nuts and your heart. Mayo Clinic News Network, Distributed by Tribune Content Agency, LLC. 2021.https:// medicalxpress.com/news/2021-03 consumer-health-nuts-heart.htmlMayo Clinic Staff. Nuts and your heart: Eating nuts for heart health

[10] Spritzler F. 2019. 8 Health Benefits of Nuts. https://www.healthline.com/ nutrition/8-benefits-of-nuts

### Section 2
