Introduction
Nutritional needs change from birth to adulthood to serve the
requirements of growth, development, health, and reproduction.
As senescence sets in, a further change in nutrition is
required to counteract aging processes and
associated co- morbidities. This is a huge challenge because
current research is insufficient to quantify nutritional needs
across the whole spectrum of aging, which differs from
person to person.
Malnutrition is common in the elderly. The causes range from
poor access to food due to poverty, neglect, or
isolation; inability to eat due to disease, loss
of dentition or altered taste sensation. Often there is
a lack of nutritional information among health
professionals and the public.
Good nutrition can contribute to improving and preventing
major co-morbidities in the older person, such as immune
dysfunction; macrovascular disease; insulin resistance
syndrome; renal impairment; arthritis; osteopenia and
fractures; neoplastic disease; cognitive impairment; mood
disturbances and depression as also visual impairment.
Nutritional requirements of the elderly vary depending on
their clinical status:
1. Healthy older person for health promotion and
disease prevention.
2. Frailty
3. Acute illnesses
4. Chronic illnesses
5. Life-threatening illnesses in an intensive care setting
Healthy older person for health promotion and disease
prevention
Why do otherwise healthy older persons have special
nutritional needs?
The aging process is associated with over-all loss of
lean body mass and an increase in fat stores. Some of the
organ system specific age-related changes include those in the
musculoskeletal system which undergoes
osteoporosis, sarcopenia, joint degeneration;
atherosclerotic changes occur in the vascular system;
decline in immunity; neuronal synapse loss, are some of the
age-related changes. Malignant disease and infections
occur with increased frequency as compared to younger persons.
Some of these changes can be slowed down by targeted
improvement in nutrient intake and avoidance of alcohol,
smoking and toxin exposure.
With aging, exercise levels decline and hence energy
expenditure is reduced. The excess of energy intake over
expenditure often results in obesity.
This requires the intake of low caloric intake without
compromising on essential nutrients. These foods are
classifies as “nutrient dense foods”. Such foods have more
nutrients per calories.
Other factors which contribute to poor food intake in the
elderly should be looked for and corrected. Taste sensation
decreases and so there is a tendency for the older
person to add more salt and sugar. Since this is likely
to be detrimental, it is advisable to make food more
palatable, using more of fresh herbs and spices, and
enhancing food appearance. Dry mouth and poor
dentition, must be addressed.
Challenges in introducing changes for the older
Indian person
Given that eating habits and food preparation are
culturally and geographically determined and are largely based
on tradition, making major changes is at best challenging, at
most, fairly impossible. Despite this, the weight of
scientific studies in nutrition demands that efforts should be
made to convince the whole family and community to adopt some
changes, so that over a generation, the whole population will
benefit. Recommendations based on International studies
may be in direct contradiction to long held traditional
beliefs; vegetarianism, veganism, Ayurvedic teachings, along
with cost and availability of food will play their parts
in determining the adherence to suggested guidelines.
Macronutrients (Proteins/fats/carbohydrates)
1) Protein: A protein intake of
0.9gms/kg helps to slow down the decline in lean body
mass. This can be challenging in vegetarians and vegans,
because of lower content of protein in plant based diets, as
well as the absence of first class proteins in most vegetarian
food sources. This can be overcome by eating a variety of
vegetables and legumes, and pulses, so that absence of a
specific amino acid in one food is compensated for by a
substitute. Though Soya is a good source of plant
protein, it is not native to India and is difficult (but
not impossible), to make it a mainstream food. It is
worthwhile to encourage the use of soya products such as
flour, nuggets and tofu.
Milk and curds are ubiquitous in every Indian household
and intake of at least 200 ml to 300 ml per day should be
encouraged. The high cost, and lack of refrigeration
facilities may make this a big task among the poorer section
of people. Dairy is a good source for protein, Vitamin
B12, and calcium.
2) Carbohydrates: The modern Indian diet is high
in carbohydrates, such as rice and wheat, which contribute
more than 60% of the total calorie intake; a reduction to
under 50% would be beneficial. These refined foods are widely
consumed but have been criticized for a high glycemic
index, insufficient protein content, and being low in
fibre. In contrast, common, easily available,
inexpensive older cereals such as millet (ragi),
bajra (pearl millet), barley, oats and sorghum are
better in all the above indices, and should be promoted. Whole
grains of the above cereals are superior because of
higher fibre, protein, vitamin, phytochemical and mineral
content. This will have beneficial effects in prevention
and management of diabetes, hypertension and
dyslipidemia.
3) Fats: Lower fat consumption is advocated for
prevention and management of diabetes and hypertension. High
fat consumption has been blamed for carcinoma colon, pancreas,
and prostate. The atherogenic potential of animal fats
and trans fats is well described. Fatty meats such as
beef, mutton and pork should be avoided, and lean meats such
as fish and chicken are encouraged. Bakery products,
hydrogenated fats, butter and ghee, as well as reuse of
oil used in deep frying (which are high in trans fats)
should be avoided.
Ghee consists of saturated fats and trans
fats, but it occupies a special place in Indian culture
and diet as per the teachings of Ayurveda. In the preparation
of ghee from butter, lactose and milk proteins are removed.
Omega 3 and omega 9 fatty acids, Vitamin A and E contribute
it’s healing properties. It is not clear if it is less
atherogenic than butter. If taken in moderation (1 tbsp) with
reduction in other fats, it is unlikely to be detrimental.
Coconut oil and palm oil are also widely used and native
to India. They contain 90% and 50% of saturated
fats respectively, and have been shown to elevate LDL
cholesterol and are therefore considered to be atherogenic.
However, there is evidence to suggest that the high content
of medium chain triglycerides, and many
micronutrients, may make these oils less atherogenic. More
research is required to substantiate these ideas. Olive oil,
and canola oil contain mono-unsaturated and polyunsaturated
fats with a high 3:6 omega fatty acid ratio and are
considered to be favourable in maintaining a good lipid
profile, and an important factor in longevity in Italian
centenarians. However, these oils are not native to India and
expensive. A general recommendation is that fats should
provide 30 to 35% of total daily calories.
Micro-nutrients in diet
This refers to items which are present in very small
quantities but have a great impact on health. These are also
referred to as “functional foods”. Phyto-chemicals, vitamins,
minerals and trace elements are included in this
class.
a) Phytochemicals: These consist of caretenoids,
flavenoids, Polyphenols, curcumin and catechis. These
substances are also known as functional foods with no
direct nutritive effect, but are able to alter gut microbiota,
acting as pre biotics and exerting beneficial effects.
These effects are anti-oxidants, anti-carcinogenic,
immune enhancement, and anti-inflammatory. Fruits, vegetables,
berries, herbs and spices and herbal teas appear to be
rich in these.
b) Vitamins: All water soluble vitamins, as
well as Vit A, K and E are to be found in green leafy
vegetables, fruits; Vit B12 which is almost exclusively
found in animal & dairy products frequently needs
supplementation in the vegetarian older person as gastric
atrophy decreases absorption of even the small amounts
present in dairy foods. Vitamin D is mainly found in dairy
products and oily fish, but the most abundant source,
sunlight, is often neglected in modern living arrangements,
hence Vit D supplementation is needed in all post-menopausal
women, and some older men.
c) Minerals: Calcium, iron, zinc, and magnesium
are some of the important minerals required for
health. Foods high in these minerals should be promoted. Older
persons are likely to require higher amounts of these. A list
of foods with a high content is shown below..
Calcium: This is required for adequate bone
health. Milk and milk products, calcium-enriched soy products,
salmon with bones, almonds, pulses, broccoli. The recommended
elemental calcium intake is 1500mgs. Since it may be difficult
to achieve this from foods alone, a 500 mgs calcium
supplement, along with Vit D 800 units per day is advised.
Zinc: This element is essential for bowel health, and
is abundant in lean red meat, liver, eggs,
seafood, pork, nuts (e.g. cashews), pulses, whole grains,
wheat germ, brewers yeast.
Magnesium: This is required for many enzymes and
co-factors involved in muscle and nerve function and is
contained in whole grains, seafood, soybeans, nuts, banana,
avocado, pulses, salmon/tuna, meat, yoghurt, seeds.
Vitamin B6: is essential for neuronal health ,
blood elements. Common in foods, e.g. meats, liver, egg yolk,
whole-grain cereals, pulses, yeast
Vitamin B12: present in meat, milk, and deficient
in plant foods. Vegans must take supplements.
Folate: is required for folate-mediated one-carbon
metabolism, in DNA synthesis, and other aspects of cellular
metabolism. Fresh leafy green vegetables, broccoli, oranges,
avocado, yeast, liver, pulses, whole grain cereals, nuts are
high in folate.
Vitamin D: is required for calcium absorption,
and mineralization of bone and for muscle
strength. Vit D also has been shown to be important as
an anti-inflammatory agent in cardiovascular disease, chronic
infections, and as an anti-carcinogenic agent. Vitamin D is
not so abundant in food sources, but sardines,
salmon, cod-liver oil, egg yolks, butter, cheese contain it.
Additionally, skin exposure to ultraviolet light
in sun rays, is the most abundant source of Vit D. Usual
supplemental dose is 800 to 1000 units of vit D /day.
How can the above information be used to suggest a
food-based, culturally sensitive diet plan to the aging
Indian population?
The main nutritional factors to be considered in formulating
food-based dietary guidelines for healthy ageing include:
1) Food variety should be increased. This means
that over several days, foods belonging to a wide variety of
cereals (especially whole grain), dairy produce, fruits,
vegetables, lean meat, nuts, spices, oils, unsweetened
beverages, etc. should be consumed.
2) Nutrient dense foods are those foods which have high
concentration of nutrients with low calorie content. Foods
such as nuts, fruits and vegetables, whole grains,
low-fat or fat-free milk products, seafood, lean meats, eggs,
peas, beans, and nuts.
3) Carbohydrate sources must be changed to high fibre
varieties as suggested above. Chappatis, idlis, dosas, for
example, can be made from high fibre containing cereals.
4) Salt: should be restricted to 4 to 5 gms per day as most
older people have hypertension and related diseases for
which salt restriction is advisable. To enhance taste in
a low salt food, addition of spices, specially herbs such as
mint and coriander are useful. Generally, a no-extra-added
salt approach is sufficient, with avoidance of preserved,
processed foods such as pickles, pappadoms etc.
5) Water: Due to decline in thirst mechanism as aging occurs,
older persons must be encouraged to drink at least 1.5 to 2.0
litres of water (8 glasses of 250 ml tumbler) and liquids per
day. Liquid intake is preferably restricted to morning and
afternoons so that nocturia, if present is not exacerbated.
Excess water intake should be discouraged. Some indigenous
systems of medicine advocate large water consumption which can
exacerbate SIADH (syndrome of inappropriate ADH secretion),
and should be avoided.
6) Supplements: Healthy older persons do not normally require
vitamin supplements except for calcium, Vit B12 & D.
However, protein supplements may be required if high protein
diet is not achieved with food sources in a vegetarian or
vegan.
7) Obesity: Many elderly are obese, but have poor lean body
mass, and are deficient in vitamins and micro-nutrients. The
person should be encouraged to take low caloric
(nutrient-dense) foods such as fruits and vegetables, and
desist from bakery foods, sweets, and processed foods.
It is not advisable to insist on maintenance of a strict
body/mass index because of fear of exacerbating
loss of lean body mass. A loss of 5% of current weight can be
set as the target goal. Aerobic exercise programs which
are possible, given that osteo-arthritis, chronic lung and
heart disease may preclude these, are advised.
Frailty
Frailty syndrome is a perplexing phenomenon in an aging
person. It is defined as a condition which leads to a loss of
reserve function due to decline in many physiological systems,
resulting in unintended weight loss, loss of energy, slow
walking speed, low physical activity, and decreased grip
strength. The pathogenesis of frailty is under active
research and currently chronic inflammation, poor nutrition
and genetic predisposition are thought to be causative
factors. Physical exercise is advocated for prevention and
treatment. Studies in nutrition have suggested, but not
proved, that a high protein intake of 1 to 1.2 gms/kg
body weight, may be beneficial. To this end, protein
supplementation with proprietary formulae should be tried,
after ensuring that dentition, swallowing and other factors
are not contributing to inadequate food intake.
Supplementation of micronutrients in nutrient dense foods
should be adhered to. Physical exercise has been shown to
prevent and ameliorate frailty, and the help of a
physiotherapist is essential. No medications have been shown
to be useful.
Acute and chronic illnesses
Poor nutrition is instrumental in susceptibility to, and
delayed recovery after an illness. Infection-induced
catabolism leads to further decrease in serum albumin.
Medications, especially antibiotics, can interfere with taste,
cause gastro-intestinal symptoms and further worsen food
intake.
All elderly who are admitted to hospital, must be assessed by
a dietitian and advised to increase protein intake in natural
food, or if illness precludes this, oral protein
supplementation should be prescribed and continued for
several months after discharge. Micro-nutrients intake as
vitamin supplements and nutrient-dense foods are also
necessary. Since intake of regular meals can be difficult due
to nausea, vomiting, weakness and delirium, meal pattern has
to be changed to ensure adequate nutrition. This is done by
making a meal plan consisting of semi-solid or
liquid diet at frequent intervals of 2 to 3 hours, and
incorporating protein supplements. The latter can produce
diarrhoea due to high solute load and osmolality. The
help of an expert dietician is paramount.
Chronic co-morbidities such as diabetes, hypertension, renal,
cardiac and respiratory disease impose their own dietary
restrictions. Here again the help of an expert dietician
familiar with the elderly is required.
Conclusion
Aging healthy persons require dietary modifications to
compensate for the natural aging changes in different organ
systems, as well as to alleviate the degenerative changes
due to co-morbidities. These modifications involve all
macro-nutrients. Micro-nutrients intake needs to be enhanced.
To achieve these changes without increasing caloric intake,
nutrient dense foods, and a wide variety of foods should be
consumed. The challenges faced by vegetarians, vegans, and the
normal Indian plant-based diet are highlighted.
The special aging syndrome of frailty, and acute and chronic
illnesses require special care to provide adequate nutrition
for which dietician advice is paramount.
Suggested reading
1. Dixit AA, Azar KM, Gardner CD, Palaniappan LP.
Incorporation of whole, ancient grains into a modern Asian
Indian diet to reduce the burden of chronic disease. Nutr Rev.
2011;69(8):479–488.
2. Nutrition, Physical activity and quality of life Keep
Fit for Life . Meeting the nutritional needs of
older persons. WHO & Tufts University School of
Nutrition & Policy.
https://apps.who.int/iris/bitstream/handle/10665/42515/9241562102_annexes.pdf?sequence=2&isAllowed=y
3. Adam Drewnowski, William J. Evans: Nutrition, Physical
Activity, and Quality of Life in Older Adults: The Journals of
Gerontology: Series A, Volume 56, Issue suppl_2, 1 October
2001, Pages 89–94.
4. Chen X, Mao G, Leng SX. Frailty syndrome: an overview. Clin
Interv Aging. 2014 Mar 19;9:433-41.
5. https://www.nhp.gov.in/healthlyliving/elderly-health
6. Leslie W, Hankey C. Aging, Nutritional Status and Health.
Healthcare (Basel). 2015 Jul 30;3(3):648-58.