Culinary and herbal resources as nutritional supplements against malnutrition-associated immunity deficiency: the vegetarian review

Malnutrition may be due to undernutrition and/or overnutrition and is responsible for morbidity and mortality. Fulfilling nutrition requirements of all human age groups is necessary for maintenance of health and quality of life. Nutritional supplements, or daily diet, must include a sufficient amount of macronutrient (carbohydrate, protein, and fat), micronutrients (vitamins and minerals), and nonessential dietary components such as fiber. There is a bidirectional relationship that exists between nutrition, infection, and immunity; children are dying due to malnutrition that weakens their immunity and makes them more susceptible to pathogen attack. Culinary and herbal resources containing macro- and micronutrients are required to achieve nutritional deficiencies. In this review, we have documented different culinary herbs that have been used as prime herbal nutritional source and these herbs might be helpful in malnutrition and boosting immunity. The review contains the description of nutritional levels and their distribution to different age group people. This review gives insight to herbal products that boost immunity to fight against infections by restoring micronutrients.


Background
Malnutrition has become a leading public health problem globally, more in southern Asian and African countries [1]. The prime cause of malnutrition in developing countries is prevalence of bacterial and parasitic diseases [2]. It has been estimated that 300,000 deaths occur annually due to malnutrition and is indirectly related to half of all deaths in young children [3,4]. Malnutrition, more specifically to protein-energy, and micronutrient deficiencies, are major health burdens in developing countries. It is one of the most important risk factor for illness and death worldwide.
Malnutrition exists in all countries, irrespective of the economic status of the country, where people are lacking nutritious diet [5]. According to Global Nutrition Report 2018, India is a shelter of 46.6 million stunted children as the world's third highest country having malnourished children. The mortality in below 5-year-old children in India is mostly due to undernutrition [6]. India is faced with serious problems of malnutrition that affect socioeconomic progress. One-third of the children are malnourished [7].
Deficiencies of protein, carbohydrates, fat, and micronutrients such as iodine, iron, vitamin A, and zinc are nutritional deficiencies [8]. Poverty is the major cause of malnutrition in developing countries. Severity of malnutrition depends on several factors: education level, sanitation, economy, political situation, climate, food production, cultural eating traditions, prevalence of infectious diseases, nutrition awareness programs, and quality of health services [9,10]. Improper breastfeeding of infants and children leads to malnutrition. The first 6 months of life is crucial for proper nutrition [11]. Breastfeeding provides immunity to the infant and protects against infection due to presence antibodies and lymphocytes (T and B), numerous cytokines, and growth factors to stimulate an infant's immune system [12,13].
Malnutrition occurs due to improper diet and infection that results to energy and nutrient losses through anorexia, vomiting, and diarrhea. Microbial attack causes contamination of the gut that impairs digestion and nutrient uptake and results in sepsis from bacterial translocation to the intestine [14]. The indicative measures of malnutrition are frailty, impairment of organ functions, cognitive impairment, poor performance, stress and depression, etc. [15]. It can be characterized as physical and mental exhaustion, low basal metabolic rate (BMR), small height (wasting), and rigid skin. India has the highest number of malnourished children in comparison to other developing countries and high rate of mortality due to malnutrition each year [16]. One other cause of malnutrition in developing countries is more consumption of Western diet by the people that is also responsible for the deficient nutrition level in their bodies [17].
Deficiency of nutrition in diets requires proper understanding of processes and determinants that are influencing diets. Thus, there is a need for a large intervention including nutrient-rich food, coverage of immunization, supplements distribution, primary care to children, proper checkup of geriatric patients, and proper sanitation in community which are necessary across different sectors. There may be a rational approach to investigate the dietary supplement effects including all nutrients present in the current government recommended dietary allowance. The solution to malnutrition and other forms of hunger needs to be focused on ensuring the sufficient supply of nutritious and high-quality food.

Status of child nutrition
The United Nations International Children's Emergency Fund (UNICEF) has defined nutrition status among children and investigated roles of food care-health determinants, i.e., quantities of food available at a national level and varieties of food, women's education and equality of gender, and access to safe drinking water and sanitation. One-third of the women in India are malnourished during pregnancy and give birth to malnourished babies [18]. In 2017, the death of malnourished children below 5 years old was accounting for 68.2% in India. A projection for global malnutrition 2030 target was set according to the study of National Nutrition Mission (NNM) conducted in different states of India in 2017. The malnourished data in this study indicated 21.4% low birthweight, 15.7% child wasting, 39.3% child stunting, 59.7% anemia, 32.7% child underweight, and 11.5% child overweight [19].
The influence of income and quality of governance in countries affects nutritional levels. The conceptual framework indicates (Fig. 1) causes of child malnutrition and death [20]; this framework is a hierarchical relationship between immediate, underlying, and basic determinants of child nutritional status. Factors such as dietary intake and health status are immediate determinants that manifest themselves at the level of the individual child. Inadequate dietary intake may lead to enhanced susceptibility to pathogens; disease caused reduced appetite and inhibition of absorption of nutrients present in food [21]. Underlying determinants manifest themselves at household food security (having enough food for living an active healthy life), care for mother and children (care for women that affects children's nutritional wellbeing is care and support during pregnancy and lactation), and home environment and services (children's exposure to pathogens and the use of preventative and curative health care). Basic determinants manifest political, economic, social, environmental, and cultural context in which children's nutritional status is determined [22].

Effects of aging on nutritional level
The maintenance of healthy life for all age groups depends on diet and nutrition. Obtaining proper nutrition has significant effects for wellbeing, decreasing and delaying risk of diseases, maintaining functional independence, and continuing independent living [23]. Aging leads to physiological and pathological changes in the body that makes it difficult to meet the nutritional requirements for the body (Table 1). Cumulative effects of all these changes lead to malnutrition of elderly people. Aging, combined with arthritis, depression, stroke, respiratory disease, renal diseases, and dementia, creates loss of appetite, inability to swallow properly, alteration in food intake, and unbalanced nutrient in the body [24,25]. Older persons are more prone to malnutrition that causes energy loss, poor wound healing, and vulnerability to infections increasing the risk factor of morbidity and mortality [26,27].

Malnutrition and infection
Malnutrition and infection operate synergistically (Fig. 2). Infection interferes with substrate utilization, reduces nutrient absorption, and promotes tissue breakdown. Weight loss is an indication of malnutrition [28]. Signs for nutritional deficiency in children are stunting.

Immune dysfunction as a cause and consequence of malnutrition
Malnutrition leads to suppression of immune and inflammatory systems with weakened responses to infection or injury. Severe acute malnutrition management that fails to consider these complex metabolic and physiological changes results in severe, or fatal, complications [14]. Poor diet, lack of exercise, environmental toxicity, and age progression causes variable effects on the human immune system (Fig. 3). It has been reported that long-term usage of herbal nutrients, or nutraceuticals, may reverse these immune-affecting variables [29].

Culinary herbs
Culinary herbs and spices (dried) include any part of plant (root, leaves, bark, berry, seed, stigma, or flower) that are frequently used while cooking to enhance the aroma or flavor of foods [30]. These herbs contain several nutritional contents along with their flavoring property [31]. They also have been used for several medicinal purposes to diseases including cardiovascular, neurodegenerative, diabetes, cancer, and many more [32]. The use of herbs and spices as functional food extends their importance beyond basic nutrition. Herbs and spices are generally used in the concentration of 0.5-10% in food preparation [33]. Peppermint leaves are most widely used in herbal teas. It is a folk medicine used for dyspepsia, enteritis, gastritis, and intestinal colic. The total phenolic content (TPC) of peppermint leaves is 19-23% along with present of Ca, Mg, Mn, Fe, Zn, Cu, I, Cr, and Se [34]. Several culinary herbs containing rich nutrients are Melissa officinalis (Lemon balm leaves), Hyssopus officinalis (Hyssop leaves), Agastache foeniculum (Anise hyssop), Capsicum annuum (Red pepper), Juniperus communis (Juniper berries), etc. Table 2 shows the list of culinary herbs and spices used in cooking that are rich in nutritional contents.
Other active constituents of mentha leaves are methofuran, neomenthol, isomenthone, isorhoifolin, leutolin-7-O-glucoside, and 1,8-cineole. It possesses antioxidant, antimicrobial, insecticidal, and anti-inflammatory activities [66]. Thymus vulgaris possess active constituents       Vitamin E Acts as antioxidant, helps in formation of blood cells, lungs, muscles and nerve tissue, it also boosts immunity Nuts, spinach, whole grains, olive oil, sunflower oil, coconut, maize, palm, soybean, wheatgerm [71] Vitamin K Helps in clotting of blood Kiwifruit, avocado, broccoli, green grapes, and lettuce [72] Water-soluble vitamins Vitamin C Acts as antioxidant, maintains healthy bones, teeth and gums, helps in wound healing and cold Herbal teas and tinctures from rose hips, pine needles, and tree barks [73] Vitamin B 1 Helps in conversion of food into energy, useful in neurologic functions Whole grain cereals (e.g., brown rice and bran), nuts, dried beans, peas, and soybeans [74] Vitamin B 3 Helps in conversion of food into energy, useful in brain functions Peanuts, coffee, beans, barley, wheat, rice, potato, soybean, maize [75] Vitamin B 6 Helpful in production of essential proteins and convert protein in to energy Legumes, nuts, bananas, potatoes [76] Vitamin B 12 Helps in production of cells genetic material, aids in formation of red blood cells (RBCs), brain functions, and synthesis of amino acids, helps in metabolism of biomolecules Boletus sp., Macrolepiota procera, Pleurotusos treatus, Morchella conica, Craterellus cornucopioides, Cantharellus cibarius, Lentinul aedodes, Hericium erinaceus [77] Folic acid Helps in production of cells genetic material, first trimester of pregnancy, helps in formation of RBCs, protects body from heart diseases Leafy vegetables, legumes, citrus fruits [76] Pantothenic acid Helps in synthesis of cholesterol, acetylcholine steroids and fatty acids whole grain cereals, broccoli [76] Minerals Calcium Helps in strengthening bones and teeth, nerve conduction, functionality of muscle and glands Orange juice, spinach, soybean, carrots, potato [78] Iron Helps in production of energy production, carrying oxygen to tissues Cereals, pulses, legumes, fruits, and St John's wort (flowers and leaves), sage (leaves), chamomile (flowers), mint (leaves) and nettle (leaves) [79,80] Magnesium Helps in nerve conduction and muscle function, formation of bone, prevention of premenstrual syndrome St John's wort (flowers and leaves), sage (leaves), chamomile (flowers), mint (leaves) and nettle (leaves) [80] Phosphorous Strengthening strong bones and teeth, formation of cells genetic material, production and storage of energy Margarine oil, corn oil, peanut oil, beans, lentils, rice, maize flour, cornflakes [81] Trace elements Chromium Helps in conversion of fats and carbohydrate into energy along with insulin Aniseed, basil, cinnamon, garlic, laurel, mint, mustard, nutmeg, onion, oregano, parsley, paprika, pepper, pepper, saffron, thyme, vanilla [82] Cobalt Helps in production of vitamin B 12 legumes, spinach, cabbage, lettuce, beet greens, and figs. [83] Copper Helps in formation of hemoglobin and production of collagen, maintains heart functions, helps in energy production and iron absorption from body such as cavacrol and thymol [67]. The pharmacological activities of Thymus vulgaris include antioxidant, anti-inflammatory, immunostimulatory, and antimicrobial properties. It is also effective against different types of cancer cells such as glioblastoma, glioma, breast, leukemia, mastocytoma, hepatocellular, osteosarcoma, cervical, laryngeal, gastric, and neuroblastoma cells. Other activities of T. vulgaris include antihypertensive, antiatherosclerosis, antidiabetic, hepatoprotective, antianxiety, antiepilepsy, antiasthmatic, and antiobesity [68]. Origanum majorana contains p-cymene, terpinen-4-ol, sabinene, αterpineol, and trans-sabinene hydrate. However, thymol and carvacrol is found most prominently. It has reported antioxidant, antianxiety, anticonvulsant, antidiabetic, antigout, anti-mutagenic, antiulcer, antibacterial, antifungal, antiprotozoal, insecticidal, and antiovicidal activities.

Herbs containing nutrients against malnutrition
Herbal products have been used as a valuable source of natural products for medicinal purposes and maintain the healthy human life since a long ago [30]. The lifestyles of human beings are being changing due to the increasing work, industrial age, longer work schedules, improper diets, low physical activity, and various psychological pressures that led to the incidence of obesity, diabetes, various cancers, and vascular diseases. Noticeably, the advancement in nutrition sciences, the herbal products, and medicinal herbs are gaining extensive attention in the public. People started eating more fruits, vegetables, dietary supplements, culinary herbs, phytotherapeutical substances, and other plant foods. The demand for phytonutrients has enhanced over the past few decades and they are being used by people to fulfill their nutrition [29]. Table 3 shows several herbs and herbal products containing different types of nutrition.

Conclusion
Malnutrition is a state of imbalance in a person's intake of energy and/or nutrition. It is a complex interplay between nutrition and socioeconomic status of the country. It has been seen that proper consumption of vitamins and other nutritious food may protect the body from several infections, maintains immunity, and also protects the body from age-related disorders. In certain cases of nutritional deficiencies especially with vitamin B 12 and vitamin D, it has been assumed that only nonvegetarians have sufficient amount of this vitamin in their body; however, today we came to know that several herbal sources are available for vegetarians through which they can maintain the level of vitamins in their body. Several herbs, microalgae, sea-inhabiting plants, and other photosynthetic organisms are the rich sources of vitamins and nutrients. Thus, it can be used as natural form of nutritious food.  L-carnitine Helps in oxidation of fatty acids, excretion of organic acid and help in oxidative phosphorylation Avocado and asparagus [87] Choline Helps in treatment of fatty liver and disturbed fat metabolism Wheat germ, bacon, dried soybeans, Mustard seed, tomato [88] Vitamin F Helps in development of various membranes and synthesis of prostaglandins, leukotrienes, and fatty acids Flaxseed, hemp oil, soya oil, canola oil, chia seeds, pumpkin seeds, sunflower seeds, leafy vegetables, walnuts, sesame seeds, and avocados [89] Inositol Helps in transportation of amino acid, potassium, and sodium High-bran cereals, fruit, nuts, and beans [90]