Nutrition and Functional Foods for Healthy Aging

Ronald Ross Watson

• Publisher: Academic Press
• Year: 2017
• ISBN:
  9780128092996
• Topic: Technology & Engineering
• Subtopic: Food Science
• Index: Technology & Engineering

Nutrition and Functional Foods for Healthy Aging aims to equip anyone studying geriatric nutrition or working with aging adults with the latest scientific reviews of critical topics. The major objective of this book is to review, in detail, the health problems of the aged and how normal food, lifestyle, or nutritional and dietary supplements can help treat them.

Nutrient requirements for optimum health and function of aging physiological systems are often quite distinct from those required for young people. The special nutrition problems of the aged are intensively researched and tested, especially as the elderly become a larger percentage of the population. Many chronic diseases and cancers are found with higher frequency in the aged, and it is also widely known that many elderly people use foods and nutrients well above the recommended daily allowance, which can be detrimental to optimal health.

• Explains the evidence supporting nutritional interventions relevant to age-related diseases
• Reviews the macro- and micro-nutrient requirements of aging adults and their variables
• Describes how alcohol, drugs, and caffeine can impact deficiencies, also exploring functional food and dietary supplements that can be used for prevention and treatment

Part I

Overview Health and Aging

Outline

Chapter 1 Impact of Nutrition on Healthy Aging

Chapter 2 Aging and the Recovery of Skin Function and Appearance

Chapter 3 Changes in Nutritional Needs With Aging

Chapter 4 Sugars, Glucocorticoids, and the Hypothalamic Controls of Appetite

Chapter 5 Appetite Regulation in Healthy Aging

Chapter 6 Human Microbiome and Aging

Chapter 7 Fibromyalgia Syndrome: Role of Obesity and Nutrients

Chapter 8 Aging and Gait

Chapter 9 Assessment of Nutritional Status in the Elderly

Chapter 10 Eating Capability Assessments in Elderly Populations

Chapter 1

Impact of Nutrition on Healthy Aging

Prabhakar Vissavajjhala, Sugen Life Sciences, Pvt Ltd, Tirupati, Andhra Pradesh, India

Abstract

Aging is a unidirectional physiological phenomenon, but one can retard its detrimental consequences by healthy nutrition. It is alarming that escalating global trends of diet-induced excess weight and obesity are leading to type 2 diabetic and cardiovascular complications and inflammatory diseases among adults and adolescents. Appropriate nutritional implements and active lifestyles are recommended to help safeguard healthy aging. While many functional food ingredients may have beneficial impacts on human health, the current chapter highlights the specific roles of dietary fiber, prebiotics, and probiotics in conjunction with commensal gastrointestinal and gut microbiota, and the subsequent microbial metabolites such as short-chain fatty acids and their receptors that play critical roles in controlling a variety of molecular events. Such events influence antitumorigenicity, energy metabolism, feeding behavior, T-cell differentiation, inflammation, and immune homeostasis in preventing individuals from becoming susceptible to a variety of diseases that often come with aging. The chapter reviews the recent literature and prospective lines of further research.

Keywords

Dietary fiber; prebiotics; probiotics; gastrointestinal; gut microbiota; short-chain fatty acid; GPR41; GPR43; propionate; butyrate; antitumorigenicity; obesity; immunity; inflammation; type 2 diabetes; energy metabolism; appetite; homeostasis; healthy aging

Introduction

Aging is a continuous, unidirectional phenomenon for any system; in a real sense, it refers to all of the changes that occur during a system’s entire existence. However, biological aging is often perceived as the changes that occur toward senility, or the declining phase of an individual. Growth and development are the terms often used to denote the changes occurring from inception to an organism’s early phases, but these are also part of aging. Metaphorically, if the human body is similar to an automobile, the best performance of the body or vehicle is mostly based on maintenance through timely inputs of appropriate fuel as measured both quantitatively and qualitatively. Besides providing energy, ideally the fuel does not generate or produces only minimal harmful residues or effects and lets the body or vehicle function smoothly over a long period of time with a sense of well-being. Such a scenario for humans may be best termed healthy aging. This serves as the basis not only of healthy growth and development during an individual’s earliest phases but also for a feeling of wellness during senility, where the fuel in question is nothing but nutritious food. In practice, healthy aging for humans depends on eating right, which often also means avoiding the wrong types of foods.

Though inborn genetic defects profoundly affect an individual’s health and wellness, in general they may not be frequent. Obviously, for humans the impact of food for healthy development and survival has been of paramount interest, especially in the wake of recent alarming global trends in the numbers of overweight and obese adults and adolescents. When high caloric intake and inadequate nutrient variety and density coincide with sedentary lifestyles, the results have included diet-induced metabolic syndrome and adverse consequences on health such as insulin resistance, type 2 diabetes, cardiovascular complications, inflammation, inflammatory diseases, and some types of cancer. In addition, such situations often necessitate pharmacological intervention, which add to both social and economic burdens on countries all over the world. How a variety of foods that include diverse nutrients can address issues of metabolic syndrome has been recently reviewed (Vissavajjhala, 2014), but this chapter provides a simplified overview, highlighting the enormity of the impact of dietary fiber (DF), prebiotics, and probiotics specifically in conjunction with gastrointestinal (GI) tract and gut microbiota on humans for healthy development that continues even as individuals age.

Dietary Fiber

DF or roughage is defined as the “undigested plant material that animals/humans may ingest.” Chemically, DF consists of nonstarch polysaccharides such as arabinoxylans, cellulose, and hemicellulose and many other plant components such as resistant starch (RS), resistant dextrins, inulin, lignin, chitins, pectins, β-glucans, and oligosaccharides. Based on its physical properties, DF has both water-soluble and water-insoluble components (Slavin, 2013).

While all plant foods contain some DF, some are richer in specific ones. Soluble fiber is found in varying quantities in all plant foods, including oatmeal, rye, chia, barley, nuts, beans, lentils, some fruits (including figs, avocado, plums, prunes, berries, ripe bananas, the skin of apples, quinces, and pears), certain vegetables such as broccoli and Jerusalem artichokes, root tubers and root vegetables such as sweet potatoes and onions, psyllium seed husks, and flax seeds. Sources of insoluble fiber include whole grain foods, including whole wheat, corn bran, and brown rice; legumes such as beans and peas, nuts, and seeds; potato skins; lignans; vegetables such as cauliflower, zucchini, celery, carrots, and cucumbers; and some fruits, including avocado, unripe bananas, the skins of some fruits such as kiwis, grapes, and tomatoes (Spiller, 2001).

GI and Gut Microbiota

A plethora of microbial populations develop in humans, the distribution of which include the skin, the oral and nasal cavities, and the urogenital, respiratory, and GI tracts. They are colonized by an enormous variety of bacteria, archaea, fungi, and viruses that form a community collectively known as the human microbiome or microbiota. Among them, the key player in host health, and working in conjunction with DF, is the commensal GI or gut microbial population, which comprises more than 1000 different species contributing more than 3.3 million microbial genes to the human GI tract. In fact, the human acquisition of certain vitamins such as B and K and antibiotics is only possible because commensal bacteria are present in the digestive tract.

Mechanisms of Health Benefits

Though human food may contain a variety of carbohydrates and polysaccharides in the form of plant material (cell walls and storage polymers), animal connective tissue, food additives, and microbial and fungal products, the digestion of carbohydrates in humans is confined only to starch, lactose, and sucrose (El Kaoutari et al., 2013) because of indigenous limitations. Human gut microbiota compensate for the lack of necessary enzymatic entities in the host genetic makeup to act on DF components and generate microbial metabolites that result in health benefits for the host. While soluble components of DF are readily fermented by microbiota in the colon and result in gases and physiologically active by-products, most of the insoluble components of DF are metabolically inert (e.g., lignin), may be fermented (e.g., RS), or are incompletely fermented (e.g., cellulose) in the large intestine. Due to their physical presence and ability to absorb water, insoluble DF increases fecal mass (called bulking), eases defecation, and minimizes constipation. Bulking also aids in diluting toxins, reducing intracolonic pressure, shortening fecal transit time, and increasing defecation frequency.

Short-chain fatty acids (SCFAs) contain fewer than six carbons: in general, formate (C1), acetate (C2), propionate (C3), butyrate (C4), and valerate (C5) are produced as microbial metabolites in the colon, playing critical roles both locally (GI level) and systemically, influencing host health and immunity. These will be highlighted in later sections.

Diversity of Gut Microbiota

The complexities and variability of adult gut microbial populations have become increasingly evident in recent years and led to the establishment of the Human Microbiome Project (HMP) (http://www.hmpdacc.org/). Owing to the burgeoning technological advances in genomic DNA sequencing, the emergence of metagenomics—the study of collective genomes of the members of microbial community in the human gut—has vastly increased human awareness of gut microbiota. The study involves cloning and analyzing the genomes without culturing the organisms in the community, offering the opportunity to describe the diverse microbial inhabitants, many of which cannot be cultured (Ursell et al., 2012).

Humans may have 10¹⁴ microbes—i.e., 10 times more than the eukaryotic cells in the human body—existing as commensal colonies and often playing critical roles in human health and disease (Koboziev et al., 2014). The intricate microbiome includes mostly bacteria, which live with commensal (not harmful) or symbiotic (mutually beneficial) or dysbiotic (potentially harmful or pathogenic) characteristics in relation to the host. Hence, imbalances of gut microbiota may lead to a number of pathologies such as obesity, types 1 and 2 diabetes, inflammatory bowel disease, colorectal cancer, and chronic inflammation (inflammaging) and immunosenescence in the elderly (Brown et al., 2012).

The mammalian microbiota are highly variable with several dominant bacterial phyla: Firmicutes (e.g., Lactobacillus, Clostridium), Bacteroidetes (some commensals such as Bacteroides ovatus and some pathogenics such as Bacteriodes fragilis and ...