Introduction
Aging is an issue that has attracted the interest of various researchers in the past, who have defined it differently. Da Costa et al. (2016) described aging as breaking down a self-organized system, causing a reduced ability to adjust to the environment. Lemoine (2020) considered aging a progressive accumulation of changes associated with increased vulnerability to diseases and death. Older adults are generally defined as individuals who have attained 65 years or more. Gerontologists initially explained that aging results from one gene or a deterioration in the body’s immune system. However, their current findings reveal that several processes combine and interact on multiple levels and contribute to this process (da Costa et al., 2016). Thus, the current definition indicates that the different body systems experience diverse aging factors that result in the overall degeneration in older adults’ health.
Aging is not a disease but is regarded as a risk factor for various severe and chronic diseases. The aging process accelerates due to some specific disorders, which tend to decline the body functionality and impair quality of life. However, it is possible to delay rapid aging, as revealed by recent studies conducted by Correa-de-Araujo et al. (2020) and da Costa et al. (2016). These researchers published various practices that people can implement to reduce their rate of aging.
Aging and Related Factors
The main aim of healthy aging is to lengthen life and, most specifically, extend active years of living. Regrettably, long-term illnesses continue to be directly associated with advancement in age, and to some extent, have become a regular part of aging. However, studies continue to demonstrate that the increased prevalence of several persistent disorders among the younger generation does not correlate with aging but relies heavily on lifestyle and health promotion behaviors. Leading causes of mortality vary depending on age, sex, and ethnicities. According to Berger et al. (2016), older people die mainly from stroke or cerebrovascular diseases. Cancer kills both males and females, followed by heart diseases, accounting for nearly a million deaths (Balakumar et al., 2016). Still, several other diseases affect the elderly that result from earlier health-related behaviors.
Economically advanced countries have the proportion of individuals older than 65 years increasing rapidly, accounting for 15% of the population. The rise in the number of elderly in society results in social and economic pressures associated with caring for them (Amarya et al., 2015). However, several people aged 65 years and above live healthy lives and do not depend on others for assistance. Consequently, the use of chronological assessment of the aged in terms of their medical conditions or economic health limits any particular study in this specific area of interest (Amarya et al., 2015). Thus, it is essential to find alternative ways to understand the elderly and the different factors affecting their health.
The number of older people also continues to rise across the United States. The current global median age was estimated to increase from 26.6 years in 2000 to 37.3 years in 2050 and 45.6 years in 2100, as noted by Amarya et al. (2015). Jin et al. (2015) agree with this trend, citing an increase in global life expectancy that has been on the rise for the past decades reaching a worldwide average of 70 years in 2014. According to Jin et al. (2015), developed countries showed higher years of healthy living, reaching an average age of 80 years. The higher life expectancy in developed nations directly results from advanced medical attention, a rise in living standards, proper sanitation, and reduced child mortality rates (Amarya, 2015).
Experts differ on the factors that contribute to an increase in life expectancy in the 21st century. According to some, the trend may not necessarily result in lower mortality rates. The researchers propose that the expected age of living may decline due to the newly emerging global threats related to changing behavioral factors, ambiguous advances in biomedicine, and climate change (Sharrer, 2019). However, according to Warraich et al. (2017), the current medical technologies have made it easier to attend to patients with cancer and cardiovascular disease (CVD), which are the leading causes of death among people aged 65 years and older.
Life expectancy has continued to rise, with women generally living longer than men. Researchers have made advances to understand the various biological mechanisms that account for higher life expectancy but have not identified a specific factor to explain the disparities (Kanasi et al., 2016; Carmona & Michan, 2016). There are several biological variations among females and males that can account for how long one lives. Studies have shown that the differences in genetic and physiological factors like progressive X chromosome inactivation skewing have mainly contributed to these discrepancies (Galupa & Heard, 2018). Other factors include telomere attrition, mitochondrial inheritance, hormonal and cellular response to stress, immune function, and metabolic substrate handling (Ventura et al., 2017). Researchers have not yet found ways to close the gap resulting from these factors to address the differences in life expectancy in the two sexes.
The differences do not only occur between men and women; it also occurs among twins. Studies have tried to explore how physically identical twins tend to become distinguishable as they age. The scholars did this by comparing the effects of external factors on the genetic composition of the bodies of people who look alike at the same age. According to Skinner et al. (2017), identical twins exhibit discrepancies in signs associated with their aging due to their differences in personal choices and lifestyles. One of the most noted exogenous factors that the researchers attributed to the aging population was smoking behaviors and sun exposure. The study also noted that possible lifestyle factors that led to these differences include stress, diet choice, physical exercise, the burden of disease, use of alcoholic drinks, and medication (Skinner et al., 2017). According to Shlisky (2017), eliminating some significant risk factors for chronic diseases such as smoking, lack of exercise, and low diet may reduce CVD, stroke, and diabetes mellitus by 80%. Hence, the former studies overrated the influence of the genetic constitution on aging as more recent research confirmed the impact of other factors.
The aging process does not solely result from chronological age. Instead, the determining factor relies heavily on the duration that events that harm the body and cells occur. In contrast, it arises from several mechanisms that tend to work together. Researchers have a fundamental comprehension of the wide variety of factors that initiate various processes that lead to growing old (McDaniel et al., 2018). The critical way cells are damaged is by not receiving the nutrients required for functioning, repair, or reproduction. Each cell in the human body needs a reserve of oxygen, vitamins, minerals, amino acids, and sugar; and also requires that waste products such as carbon dioxide be eliminated. Eating a well-balanced diet is the only part of providing nutrients to cells. The food has to be digested, absorbed into the bloodstream, and routed to the appropriate cells (MacFarlane, 2018).
The role of diet is an essential and modifiable risk factor in deterring disease. Research has increasing evidence linking nutrition and health, specifically in older people (Govindaraju et al., 2018). The United States Department of Agriculture recently called for researchers to study and provide evidence for meals and their associated health benefits. Dietary recommendations such as the Mediterranean diet are associated with the reduced risk of cardiovascular diseases, hypertension, and chronic kidney diseases (Govindaraju et al., 2018). Eating more vegetables, fruits, whole grains, legumes, seafood, and lower consumption of sweetened foods, refined grains, and processed meat has been proposed to benefit health (Govindaraju et al., 2018). Considering the recommended dietary allowances (RDAs) that target people aged 65 and older, one must understand the numerous essential factors related to aging with nutrition.
The investigation of nutritional status indicated that older people showed a low-to-moderate prevalence of acute nutrition deficiencies but an increased risk of malnutrition and subclinical inadequacies (Watson et al., 2018). The observations’ significance is critical, particularly by recognizing that the state of one’s nutritional intake affects the rate of age-related functional decline in several organ systems. Proper eating remains an essential element of progressive body composition changes related to aging, for instance, bone loss and loss of lean body mass. There is no dispute among researchers that the chronic diseases affecting adults relate to their diet (de Souza Fernandes et al., 2017).
According to Leslie and Hankey (2015), maintaining a good nutritional status leads to improved health and well-being, including reducing chances for contracting diseases and improving functional independence. New evidence proposed by Carr and Lykkesfeldt (2020) second this suggestion and indicates changes in nutritional requirements linked with aging.
Unfortunately, not many older adults meet the RDA requirements. According to Beasley et al. (2016), only 50% of men and 33% of women amongst older adults meet the RDA for protein. Protein intake is one of the most critical recommendations on the nutrition of older adults. Moderately high protein intake is required to maintain nitrogen balance and offset age-related reduced energy intake, decrease in protein synthetic efficiency, and insufficient insulin action. Even so, the National Health and Nutrition Examination Survey (NHANES) notes that six percent of men aged above 71 and four to six percent of women aged above fifty do not meet the recommended protein intake levels (Tessier & Chevalier, 2018). Evidence from a study by Houston et al. (2008) indicates that men and women aged 70-79 years and exhibiting high protein intake tended to lose a low amount of lean muscle mass within three years period of the study. Such an outcome is desirable for the reason that the loss of lean muscle mass correlates with the proportion of fat mass, and the latter is the risk of metabolic imbalances and chronic conditions. Maintenance of muscle mass in seniors is a preventative health step that healthcare professionals should adopt.
Omega-3 fatty acids and fiber are critical in the maintenance of health during aging. Dietary fiber is especially important in managing intestinal health and protecting against heart disease and related metabolic complexities. Fatty acids are beneficial to all age groups as they lower inflammation, the leading cause of cancer, arthritis, rheumatoid, and heart disease. Foods rich in omega fatty acids also slow down the progress of macular degeneration (AMD), which affects vision (Tessier & Chevalier, 2018). Because most older adults do not consume an adequate amount of these macronutrients, they should be encouraged to consume fish such as sardines, tuna, salmon, nuts, and seeds such as flaxseed and walnuts. In the health care setting, adequate amounts of foods rich in omega-3 fatty acids or supplements should be recommended. These would protect against numerous health conditions, enhance the health of older adults, and improve quality of life.
Micronutrients are also essential in the preservation of health in older adults. A primary concern is Vitamin D. Older adults are at higher risk of Vitamin D deficiency owing to its limited sources in the diet, reduced exposure to sunlight, and diminished capacity to synthesize this vitamin in the skin (Tessier & Chevalier, 2018). Additionally, the kidneys of the elderly have a decreased ability to convert vitamin D into an active form. Recent evidence indicates that Vitamin D can protect against chronic illnesses as multiple sclerosis, type 2 diabetes, rheumatoid arthritis, and cancer (Tessier & Chevalier, 2018). Therefore, older adults should consume foods rich in vitamin D, including cereals, milk, yogurt, and juices, and get safe levels of sun exposure to improve their vitamin D status and reduce their risk of falls and contracting chronic diseases (Watson et al., 2018).
With age, the chewing muscles’ weakness develops, the activity of the salivary glands decreases, and the mucous membrane atrophies due to the increase in dental problems. The elderly often refused to eat solid foods (for example, vegetables and nuts), dry (bread), sticky (honey), and difficult to chew food (meat). This leads to a decrease in consumed protein, vitamins A, C, B6, B1, B2, calcium, and iron (Laguna et al., 2017). The need for such minerals as calcium, magnesium, potassium, iron, and vitamins A, D, E, B12 in old age remains quite high. According to Corcoran et al. (2019), 57.5% of the adult population has a vitamin D deficiency, 12-25% have reduced levels of B vitamins in the blood serum, and 5.3–10.8% have reduced levels of vitamins A and E. Often, a deficiency of vitamins is combined with a deficiency of minerals (calcium, magnesium, iron, iodine, and others) (Corcoran et al., 2019). Adequate intake of folic acid, vitamins B6 and B12 with food have a beneficial effect on DNA methylation processes, preventing the development of age-associated diseases (Steluti et al., 2020). These vitamins are essential for forming S-adenosylthionine, which is the source of methyl groups for DNA methyltransferase (Steluti et al., 2020).
Lack of iron in the diet contributes to the development of iron deficiency anemia with age. Iron deficiency anemia is the second most common in middle-aged and older people in the United States (Halawi et al., 2017). The reasons for iron deficiency in persons over 60 years old may be insufficient intake of it with food of animal origin, especially with veganism, Lacto-vegetarianism. Along with this, they may have impaired absorption of iron from the intestine (dysbiosis, malabsorption syndrome, hypoacid conditions, resection of the stomach or intestines), a deficiency of substances that improve its absorption in the gastrointestinal tract (copper, manganese, vitamins D, C, group B, amino acids, fructose, organic acids), and the presence of substances that hinder absorption (table salt, food preservatives, tannin, calcium salts, phenytoin, and others) (Halawi, 2017).
Deficiencies in essential nutrients can also lead to neurological damage. The most important are metabolic disorders of B vitamins, especially B12, vitamin E, and folic acid (Moore et al., 2018). These vitamins are involved as coenzymes in a variety of redox reactions. This explains the fact that they are critically important in the energy supply of the tissues of the peripheral and central nervous systems (Vauzour et al., 2017). Of particular importance in terms of the occurrence of cognitive impairment is the deficiency of vitamin B12, folic acid, as well as an increase in homocysteine levels (Moore et al., 2018). Vitamin B12 is found mainly in animal products – meat, milk, eggs. In this regard, a strict vegetarian diet can lead to its deficiency, especially in the absence of its external introduction into the body. Accordingly, the transition of older adults from their usual diet to vegetarianism, veganism or a raw food diet is not physiologically justified due to the lack of vitamins, minerals, and essential amino acids in these diets (Campbell-McBride, 2018). A significant proportion of patients with folic acid deficiency are alcoholics who also have a deficiency of other vitamins and have nutritional disorders (Olga Valentza et al., 2019). Often the cause of this condition in the elderly is an insufficiently balanced diet or malabsorption.
Healthcare systems play a significant role in integrating nutrition care for older adults in primary, acute, subacute, chronic care, and home settings. Nutrition screening and dietary assessment are essential in the primary care regimen for the prevention and diagnosis of multiple conditions in older adults. Examples of these include CVD, diabetes, unprovoked weight loss, and cancer. In the acute care setting, the Joint Commission calls for the completion of nutrition screening within twenty-four hours of hospitalization (Shlisky et al., 2017). The screening process helps identify risk factors, including unintentional weight loss, low BMI, inadequate dietary intake, changes in the ability to swallow, or the presence of pressure ulcers. Recognizing that a client is at nutritional risk helps trigger nutrition consultation with a registered dietitian nutritionist (RDN).
The proposal should also address current environmental and lifestyle dynamics, which have called for more complicated dietary recommendations for the elderly. How different family life patterns have changed have resulted in less support among the aged, while at the same time, making them face various challenges related to taste and smell. Moreover, the older adults continue to experience anorexia, mobility difficulties, dental and chewing problems, and access to high-quality fresh meals (Thakur, Banerjee & Nikumb, 2013). The challenges mentioned above are significant concerns since older people need increased nutrient-dense foods to meet their changing needs for more nutrients and reduced energy requirements.
A barrier to nutritional well-being among older adults is the lack of knowledge of their dietary needs. Most older adults are unaware of what foods are nutritious or which ones to purchase to stay healthy. The study by Vasconcelos et al. (2020) also shows that caregivers have limited knowledge of nutrition despite being educated. Focusing on educating caregivers on the nutritional needs of older adults and recognizing clinical manifestations of malnutrition can help maintain the nutritional status and standard life quality of the elder adult. It is critical to design community-based interventions that can help older individuals achieve their need for nutrients. Such approaches should help the elderly understand the elements required to improve the quality of their meals and help them determine the right amount of food they need to consume. Even though there are some similarities between younger and older people’s nutrient recommendations, specific factors dominate nutrition among the elderly. According to Bloom et al. (2018), there were inadequate diets among 65 or older individuals who live alone in four European nations. The study also revealed that a deficient meal did not relate to a lack of resources among the elderly. The chronological age had little effect on food quality among older members of society (Bloom et al., 2018). Insufficient data on the age-related impact on eating habits reveal consistency in the differences between biological and chronological periods. Furthermore, it prompts the need to understand how age-related factors play a critical role and are essential in determining food and quality of diet, thus informing interventions that can support older people.
Conclusion
Aging suggests changes in nutritional requirements and, thus, the proper criteria for RDA selection. It leads to the necessity of adjusting nutritional requirements to meet the age-associated body’s physiological changes. At the same time, a properly selected RDA design is intended to a maximal reduction of risks to diseases, especially chronic ones associated with aging and imbalanced nutrition. Healthy aging is intrinsically linked to the adoption of proper nutritional practices suggested by an adequate RDA selection. Maintaining a good nutritional status leads to improved health and well-being, including reducing chances for contracting diseases and improving functional independence.
Ensuring an optimal intake of nutrients is essential for maintaining a healthy weight and reducing the risk of developing chronic diseases such as hypertension, diabetes, and heart disease (Shlisky et al., 2017). Many older adults do not show desirable nutrition practices with their typical diet not meeting the recommended intakes for water, vitamin D, B12, and calcium (Watson et al., 2018). It is essential to evaluate liquid intake when considering nutrient intake since an optimal hydration level is required for optimal nutrient absorption (Molnár & Pal, 2020).
Meeting individual energy and nutrient needs helps to maintain energy levels (USDA, 2020). The primary source of energy, carbohydrates, should preferably be provided by fruits, vegetables, low-fat dairy, and whole grains. Most foods naturally contain fats, including dairy products, meats, poultry, seafood, eggs, seeds, nuts, and avocados. Fat-intake is recommended through oils rather than hard saturated fats (Steinfeldt et al., 2020). An adequate fiber intake should be an essential part of a healthy diet, especially for older people, to prevent and address intestinal problems, including constipation, and assist to lower cholesterol and blood sugar levels. The most important restriction recommended is to avoid saturated fats and trans fats (de Oliviera et al., 2017).
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