Dear Reader ,
May I start off this letter by asking you this simple question: How old are you? But before you answer, to yourself, let me remind you that there are three broad aspects to the question. The first is your chronological age. It measures how old you are in terms of calendar years. The second is known as your biological age; and this is measured in terms of your previous life styles and their effects on the cellular processes which have occurred in your body. The third is the psychological age which examines how old you feel you are.
The first aspect is the one most often referred to, and yet it is the most unreliable of the three. For instance, among your friends and acquaintances you may have come across someone who at 50 years old is nearly as healthy and fit as one who is 25; or another, 50 years old, who looks 10 or even 20 years older.
Biological age shows you how much time has affected your organs and tissues in comparison with those of your chronological age groups. Biological age in itself varies considerably between persons. Even in the same person it is not uniform. Every tissue and every organ ages at its own pace and on its time table. For instance, a middle aged long-distance runner may have leg muscles, heart and lungs of someone half his age, but his knees and kidneys may be ageing rapidly due to excessive stress. His hearing and eye sight may be ageing in their unique ways. Biological ageing is therefore very complex. The uniqueness and complexity of biological ageing increase as years pass by. At 20 years old when muscle development, body reflexes, sexual drive and physical strength are reaching their peak; all bodies appear to look alike to a physiologist. All the organs and tissues look firm and are of the same colour. Hardly any individual differences are discernible. However, with time this will change. At 70 years no two bodies are remotely alike. Your body becomes unique, unlike anyone else’s in the world. The age-related changes will reflect, not only all that you have done, but also what you have felt and thought. As a measuring tool, biological age has its limits. It moves so much slowly that its fatal effects can hardly be compared with those of faster-acting diseases. Most critical organs in the body, according to Dr Chopra, can function as well at 30% of their peak capacity. So, if our bodies are losing 1% of their functioning power per year, it is calculated that after the age of 30 years it will take 70 years or a chronological age of 100 years before ageing by itself will threaten the particular organ with impending breakdown. However, social and psychological influences are at work. Our life styles subject us to various conditions, and the differences in how we age show up much earlier in our lives.
Biological age is known to be changeable. Balanced nutrition, regular physical exercise, all can reverse most of the typical effects of biological ageing. These effects include decreased muscle mass, high blood pressure, and excess body fat and improper blood sugar value. Elderly people who agree to improve their life styles can increase their life expectancy by about 10 years. Our bodies become older or younger based on how we treat them.
Psychological age is the most mysterious of the three. Yet it is claimed by psychologists to be the most promising for halting, or even reversing, the ageing process. It is considered to be the most flexible and is very unique to each individual. By the way you react or interpret the events of your life you can literally select your psychological age, your chronological and biological ages notwithstanding.
Having explained the various ways of interpreting how old we are, I will examine briefly the role of nutrition and other factors on the ageing process.
In many developed countries increasing attention is being paid to the problems of ageing, because of the increase in the total number and proportion of people living beyond the age of retirement. Various factors have contributed to this increase; among them are the improvements in medical facilities, advances in environmental hygiene and good nutrition. The result of all these is that an increasing number of persons is living longer and healthier than did their counterparts who lived in the 1800’s and earlier in the last century. This extension of life span has also exposed various complications associated with ageing, reminding one of the warning given by Plato: “Beware of old age, for it does not come alone”.
Research into the nutritional needs of the elderly is complicated by the sheer diversity among the aged in terms of genetic differences complicated by varying degrees of emotional and physical traumas, stresses and poor nutritional states that they had gone through from childhood to adolescence and full maturity. There are wide variations among the elderly in their ability to eat food, digest it and absorb the nutrients. Despite these problems, scientists have been able to study the ways in which nutrition can affect the ageing process and also how the physiological changes associated with ageing influence the requirement and utilisation of dietary nutrients.
Various factors affect nutrient intake by the elderly. Among these are loss of teeth and the weakening support of the jaw bone, due probably to dietary vitamin D deficiency and low calcium: phosphorus ratio, resulting in chewing difficulties. The next is neuromuscular in-coordination that makes handling of cutlery embarrassingly difficult and forces the elderly to make considerable dietary changes which more often than not result in reduced nutritional value of the diet. The other factors are physiological and involve diminished sense of taste and smell due, probably, to zinc deficiency. In addition, feeding habits, cultivated during childhood and adolescence, affect food choice in middle and old age. These food preferences are difficult to break, especially if they are associated with pleasant memories.
Economic constraints that dictate the type of food products some elderly subjects purchase influence their nutrient intake. For the well-to-do there is no problem; but for the less well-off the tendency is to budget in favour of low-cost foods which will satisfy their hunger and energy needs. In other words, they purchase cereal-based products instead of the more expensive items such as meat, fruit and fresh vegetables which are better sources of protein, vitamins and minerals. The other factors are basically psychological and include loneliness, anxiety and depression.
Utilisation of dietary nutrients in the elderly is affected by such factors as the insidious decreases in physiological processes during ageing, such as diminishing rate of nerve transmissions, the decline in the ability of the heart to pump blood and the reduction in lung capacity. During ageing changes take place in the function of the digestive tract. The secretion of digestive juices and enzymes declines. Food lubrication during chewing becomes difficult because of the reduction in saliva output. The secretion of acid in the stomach is diminished or terminated altogether. This decreased gastric acidity retards the absorption of calcium, iron and vitamin B12. The rate of passage of food along the digestive tract slows down. In the upper part of the digestive tract this reduction allows more time for absorption of nutrients. But, at the lower end, it produces constipation and could cause infections. Other factors which affect nutrient utilisation in the elderly are the decreases in kidney function, leading to diminished capacity of the kidneys to selectively excrete unwanted substances from the body; reduced absorption of nutrients; and changes in the production of hormones, which are the regulators of physiological processes in the body. All these factors conspire to produce many disorders related to nutrition, including diabetes, underfeeding, osteoporosis, neurological malfunction due to certain vitamin deficiencies, and anaemia. In addition, use of certain drugs depresses appetite or damages the absorptive wall of the small intestine, thereby reducing nutrient utilisation.
There are standards sets for nutrient needs of the elderly. According to the Expert Consultation of the Food and Agriculture Organisation/World Health Organisation/United Nations University of 1985, healthy elderly people have a mean daily protein requirement of 0.6 to 0.75 g/kg body weight, values equal to, and even more, than those for young adults. The argument is that protein utilisation in the elderly is less efficient than in the young.
How does society help to improve the nutritional state of the elderly? Concern about the low nutritional state among the elderly, brought about by social, economic or emotional conditions, has resulted in responsible community and private groups providing residential houses, meals-on-wheels and food delivery services for them. For the elderly who live at home alone, regular visits by nursing staffs, home assistants and relatives are commendable. It is known that people with low appetite, caused by loneliness or depression, do enjoy eating out in the company of relatives and friends. Companionship and caring go a long way to improving the dietary intake as well as the quality of life of the elderly.
On your patience for having read this letter so far, I congratulate you. However, I guess you may be wondering what all these have got to do with you, especially if you are in your early twenties or up to your mid-forties, and consider yourself young. But you don’t have to wonder, because the preparation for a ripe, dignified and active old age begins from childhood and through into adolescence and adulthood. As the famous paediatrician Dr N.W. Shock once aptly said, “The best preparation for healthy old age begins in the office of the paediatrician”. So, any bit of relevant information is welcome to enable us lead a healthy life in preparation for an active and enjoyable old age. Age and Nutrition website is well geared to providing the information at princely annual cost to you of only £5.00.
Age and Nutrition features articles on various aspects of human ageing, and the role of nutritional, physiological, psychological, life-style and social factors in influencing its outcome. From time to time, the website carries abstracts and discussions of papers published in scientific journals, materials which normally are not readily available to the general public. All articles published in the website are well-researched and are recommended for use as reference material.
Dr Bartholomew A Ochia