Health Benefits of Nuts and Dried Fruits

Cesarettin Alasalvar, Jordi Salas-Salvado, Emilio Ros, Joan Sabate, Cesarettin Alasalvar, Jordi Salas-Salvado, Emilio Ros, Joan Sabate

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9781138042841
• eBook ISBN: 9781351700528
• Topic: Medicine
• Subtopic: Nutrition, Dietics & Bariatrics

Nuts and dried fruits are part of our daily diet. They are consumed whole or as ingredients of many food products such as muffins, cereals, chocolates, energy bars, breads, and cookies, among others. Health Benefits of Nuts and Dried Fruits provides a comprehensive overview of the literature on the health benefits of nuts and dried fruits. The book summarizes the current state of knowledge in key research areas and provides ideas for future scientific research and product development.

Nuts, a term that comprises tree nuts and peanuts, are highly nutritious, containing health-promoting macronutrients, micronutrients, vitamins, and bioactive phytochemicals; they are one of the edible foods with the highest content in antioxidants. The consumption of nuts is recognized for its health-promoting properties, which ranges from a consistent cholesterol-lowering effect in clinical trials to a robust association with reduced risk of cardiovascular disease and all-cause mortality in prospective studies. In spite of the high energy content of nuts, there is no evidence that their frequent consumption promotes obesity, and they may even help control it.

Dried fruits, which serve as important healthful snacks worldwide, are nutritionally equivalent to fresh fruits while providing all of their bioactive components in concentrated form. While the evidence level concerning the health effects of dried fruits lags behind that on nuts, it suggests that individuals who consume dried fruits regularly have a lower risk of cardiovascular disease, obesity, and other non-communicable diseases.

Main features of the book concerning nuts and dried fruits:

• Provides detailed information on health effects

• Highlights current regulation and health claims

• Provides updated dietary recommendations

• Describes nutrient absorption and metabolism

• Discusses mechanisms implicated in the health effects

Although this book is intended primarily as a reference, by comprehensively reviewing the current state of knowledge it can guide future research on the topic. Among others, food scientists, biochemists, nutritionists, health professionals, decision makers, and regulatory agencies can draw much benefit from its contents. Hopefully, it will help in public health strategies to promote healthy aging and improve population wellbeing.

Chapter 1

Health Benefits of Nuts and Dried Fruits

An Overview

Cesarettin Alasalvar, Jordi-Salas Salvadó, Emilio Ros, and Joan Sabaté

1.1 Introduction

1.2 Health Benefits of Nuts

1.3 Health Benefits of Dried Fruits

1.4 Conclusion

References

1.1 Introduction

Nuts and dried fruits have been part of the human diet since prehistoric times [1, 2]. They are key food categories in most plant-based diets, such as vegetarian diets [3], the Mediterranean diet, and other healthy regional diets [4].

According to the botanical definition, a nut is simply a dried fruit with one seed (rarely two) in which the ovary walls are very hard (stony or woody) at maturity, and the seed is unattached or free within the ovary wall. However, the word nut is commonly used to refer to any large, oily kernel in a shell that can be eaten as food. The most commonly consumed nuts are almonds, Brazil nuts, cashews, hazelnuts, macadamias, peanuts, pecans, pine nuts, pistachios, and walnuts. Peanuts are botanically legumes but, because of their similar nutrient composition and their proven cardiovascular health benefits, they are considered as nuts by both nutritionists and consumers.

Fresh fruits are processed by various techniques to become dried fruits in order to extend their shelf life. Therefore, dried fruits are a concentrated form of fresh fruits with lower moisture content. Fruits can be dried whole, in halves, or in slices. In this form, they are easy to store and distribute, are available throughout the year, and are a healthier alternative to salty or sugary snacks. Apples, apricots, currants, dates, figs, peaches, pears, prunes, and raisins are referred to as traditional dried fruits, although other fruits such as blueberries, cranberries, and strawberries have also been included in this food category.

Nuts and dried fruits are nutrient-rich foods and constitute an excellent means to deliver health-promoting bioactive compounds. As such, they serve as important healthful snack items, besides being part of many traditional and new recipes of gastronomy worldwide. Frequent consumption of nuts and/or dried fruits is highly recommended to obtain the full benefit of the nutrients, bioactives, and antioxidants that they contain, together with their desirable flavor. The macronutrients, micronutrients, and other health-promoting bioactive compounds contained in nuts and dried fruits may synergistically interact to modulate the risk of cardiometabolic and other non-communicable diseases through various mechanisms.

Several prospective studies, clinical trials, and experimental investigations have reported beneficial effects on several outcomes after nut consumption [5]. The benefits of dried fruits, however, have been less explored [6].

This overview chapter summarizes the nutritional significance and health benefits of nuts and dried fruits and also discusses their great potential as salutary foods for a number of diseases afflicting humans.

1.2 Health Benefits of Nuts

Tree nuts are recognized as healthy foods because of their unique nutritional attributes. Tree nuts and peanuts are rich in monounsaturated fatty acids, with the exception of Brazil nuts, heartnuts, pine nuts, and walnuts, which are rich in polyunsaturated fatty acids [7]. They are good sources of dietary fiber [8, 9] and provide macronutrients, micronutrients, fat-soluble bioactives, and phytochemicals [9 –12].

Frequent nut consumption has especially been shown to have beneficial effects on the cardiovascular system. It has been well over two decades since nut consumption was first associated with a reduced risk of coronary heart disease (CHD) in the Adventist Health Study cohort [13] and its lipid-lowering effects shown in a randomized controlled trial [14]. In large epidemiologic studies, the frequency of nut consumption was consistently related to lower rates of CHD and total cardiovascular disease (CVD) incidence and mortality [15]. The frequency of nut consumption was also related to lower rates of sudden death in a large cohort of men, as well as lower rates of peripheral artery disease [16], atrial fibrillation [17], and all-cause and CVD mortality [15, 18].

Nuts may exert a protective effect on CVD through different mechanisms. The most recognized is their lipid-lowering effect, which has consistently been demonstrated in several population groups using different types of nuts, study designs, and comparator diets [19, 20]. However, the magnitude of the reduced risk of CHD associated with nut consumption cannot be explained only by the cholesterol lowering effect.

Thus, nuts may protect against CVD through other potential mechanisms such as improving endothelial function, but no effect on inflammation [21] and oxidation [22], reducing postprandial glycaemia and insulin resistance while substituting other sources of carbohydrates [23], or increasing satiety [24]. Nut consumption has also recently been shown to change gut microbiota composition and metabolism with potential beneficial effects on cardiovascular risk factors [25].

Because nuts are an energy-dense food containing a high amount of fat, a widespread concern regarding their consumption is that it may lead to weight gain and obesity, and consequently increase the risk of type-2 diabetes (T2D) and other comorbidities. In addition, because nuts are frequently consumed salted, it is believed that they could contribute to an increased risk of hypertension. However, there is consistent evidence that frequent nut consumption does not lead to any appreciable weight gain or increase in the risk of abdominal obesity when incorporated into healthy diets [26, 27]. Moreover, the evidence suggests that nut consumption does not increase insulin resistance in the long term and may even increase insulin sensitivity [28], and that it ameliorates endothelial function [21]. In addition, an inverse association was found between the frequency of nut consumption and the prevalence and incidence of metabolic syndrome (MetS) [29]. Finally, some clinical trials evaluated the effect of nuts in individuals with MetS and found that they may have benefited some of the components of the syndrome [29]. However, controversy exists as to the protective effect of nuts against T2D. Nuts may lower the risk of incident T2D in women, but the effect inconclusive in men [15]. Furthermore, limited evidence suggests that nuts might reduce blood pressure [30].

There is also incipient evidence that nut consumption may beneficially impact non-cardiovascular outcomes. Thus, nuts appear to reduce the risk of certain types of cancer [31, 32], delay age-related cognitive decline [33], reduce the risk of depression [34], and improve sperm motility and other parameters of fertility [35].

In summary, a large body of scientific evidence suggests that individuals who regularly consume sizable amounts of nuts (30 or 42.5 g/day, depending on recommendation by European Food Safety Authority [EFSA] ...

Table of contents

• Cover
• Half-Title
• Title
• Copyright
• Contents
• Preface
• Editors
• Contributors
• 1 Health Benefits of Nuts and Dried Fruits: An Overview
• Section I Nuts
• Section II Dried Fruits
• Index