Fruits for boosting immunity

The immune system helps protect the body against different pathogens causing chronic illness and infectious disease. Proper and well balanced nutritious diet and keeping the body well hydrated are vital. Nature’s blessings as fresh and pure fruits vegetables, grains, and pulses, dairy products rich in vitamins, minerals, dietary fibre, protein and antioxidants are the main source to ensure body strength. Additionally avoiding fat intake, lowering intake of saturated fats, and produced trans fats, limiting sugars and salt intake, drinking enough water, and balance calories boost the innate immunity in a human .¹

The body’s immune response may be altered due to the deficiency of any single nutrient. Animal studies have reported that deficiencies in micronutrients such as vitamins A, B6, C, D, and E and minerals such as zinc, selenium, iron, copper, folic acid, and can alter immune responses which help the immune system by protecting the healthy cells, supports the growth and activity of immune cells, and produces antibodies. Studies infer that people who are poorly nourished are more prone to infections ². Fresh fruits and vegetables are loaded with most of the essential macro and micronutrients and daily consumption can also meet the recommended daily amount for adults, children and elders which are essential to maintain the body’s natural innate immunity. One of the best ways to be healthy and keep immunity strong is by selecting fruits that contain the vitamins and minerals required and may be helpful in this Coronavirus pandemic situation. 

Amla is obtained from the plant Emblica Officinalis and is a rich source of vitamin C and other active phytoconstituents such as gallic acid, ellagic acid, quercetin, chebulinic acid, chebulagic acid, emblicanin A, emblicanin B, punigluconin, pedunculagin, citric acid, ellagotannin, trigallayl glucose, pectin, etc, improves immunity, boosts metabolism and longevity, exhibits healing properties Amla also contains vitamins, such as B1, B2, B6, B12, vitamin A and minerals such as potassium, Calcium, Copper, Iron, Magnesium, Manganese, Phosphorus and Zinc. Vitamin C helps to boost immunity. Studies by Kapoor et al revealed that amla consumption may increase plasma antioxidant potential and decrease oxidative stress, which can help promote oxidative homeostasis. Also, studies have proved that daily consumption of Amla enhanced immunity by increasing the white blood cell count and protect the body against different pathogens causing allergies, infections and toxins. ^3,4,5

Mangoes are the fruits obtained from Mangifera indica that contain more than 20 different vitamins and minerals. It largely contains vitamin C, vitamin A, vitamin B6 and B12, folic acid and minerals like copper, iron, magnesium and calcium. Vitamins A, D, C, B6, zinc and iron help in maintaining the overall fuction of the mucosal cells which provide innate immunity to the body ^6,7.

Oranges are fruits obtained from Citrus sinensis and are a rich source of vitamin C, flavonoids and phenolic compounds folic acid, vitamin B (thiamine), potassium, phosphorus, calcium, iron, magnesium, sodium and sulphur which provide balanced nutrition for a healthy human body. Vitamin C helps in the iron absorption, acts as an antioxidant and thus minimize cell damage, enhances collagen formation which leads to wound healing, the antioxidant property removes excess free radicals which causes cancer and also various tissue damages and finally boosts the natural immunity. Calcium helps to maintain the strength of the bones, organs and muscles. Folic acid helps in DNA formation, which is important for pregnant women and helps to prevent birth defects. Potassium helps to lower blood pressure and citric acid and citrates prevent stones formation in the kidney ^{8, 9}

Papaya is the fruit of the plant Carica papaya and contains Dietary fibre, calcium, magnesium, potassium, zinc, vitamin C, folate, vitamin A, b, vitamin E, vitamin K, helps maintain blood sugar levels and keeps cholesterol in check. The fruit excellent immunity booster, reduce oxidative stress in older adults and boost immunity. Vitamin C, vitamin K, carotenoids and Lycopene are excellent antioxidants, which neutralize free radicals and decreases oxidative stress Papain found in papaya reduces pain, inflammation, and swelling. It has also been used to improve digestion and to treat infections, diarrhoea, and allergies ¹⁰. 

Berries may include strawberries, raspberries, blueberries, and cranberries containing antioxidants called flavonoids, limiting the damage to the body cells and improving immune function, vitamin C, potassium, and vitamin A, which are already associated with strong immunity. Containing strong antioxidants and vitamins, elderberry can keep inflammation at bay and reduce stress levels ¹¹. 

Watermelon: it contains 92 per cent of water. is perfect keeping the body refreshed and hydrated. It also contains carbohydrates, vitamin A, vitamin B6, vitamin C, potassium, and no fat, cholesterol or sodium. Vitamin A is essential for the eye and skin, protecting the body from all external pollutants and allergens. Also, B6 is essential for protein metabolism, enhancing immunity and improve the functioning of nerves. Vitamin C helps in strengthening immunity by increasing ht white blood cell count and protects the body against different pathogens causing allergies, infections and toxins and aids in the absorption of iron. Potassium helps lower blood pressure and is important for nerve function as well ¹². 

Foods to be avoided include processed and canned foods which include a higher amount of refined carbohydrates including sugar, fats, more salt and other additives. A study conducted in 2017 reported that consuming processed foods containing additives, preservatives, emulsifiers, thickeners, excess, refined oil, excess sugar, artificial sweeteners, could increase chances of several chronic inflammatory or metabolic conditions and affect the cells of the immune system directly or indirectly leading to metabolic dysregulation ¹³. 

Another study conducted in 2014 reported that high intake or overconsumption of salt, refined sugar, saturated fat, and reduced  omega-6-fatty acids could damage the immune system In vitro evidence suggest processed, simple sugars also reduce white blood cell phagocytosis and possibly increase inflammatory cytokine markers in the blood.¹⁴

Processed foods may include chips, wafers, microwaveable meals, etc. Food containing high amounts of refined sugar include cookies, cakes, flavored milk, sugary drinks, sugary breakfast cereals. Overconsumption of sugar in any form may lead to heart diseases and type 2 diabetes. High sugar intake may reduce the body’s immune system to fight against any diseases. reducing the effectiveness of white blood cells and increasing inflammation.¹⁴ Also, foods high in refined carbohydrates include white rice, white bread, white flour should be avoided as it can lead to obesity and related diseases.¹⁴

Studies have shown that high fat-containing foods have harmful effects by enhancing the prostaglandin system as it feeds into the arachidonic and prostaglandin E2 (PGE2) pathways. PGE2 is pro-inflammatory, increasing IL-17 production and macrophage activation among other pathways. Some studies in animal models infer that elements in gluten can stimulate inflammation through TLR4.¹⁵

Thus it becomes evident that intake of seasonal fruits enhance the immunity and ensures a robust immune system while the intake of different processed foods having high quantity of refined carbohydrates, fats, salts and other additives have a detrimental effect on the immunity.

References:

1. http://www.emro.who.int/nutrition/healthy-eating/index.html
2. https://www.hsph.harvard.edu/nutritionsource/nutrition-and-immunity/
3. https://www.clinicaleducation.org/resources/reviews/amla-an-ancient-super-berry-emerges-from-india/
4. https://www.netmeds.com/health-library/post/amla-benefits-uses-for-hair-and-health-conditions-supplements-and-recipes
5. Mahendra Parkash Kapoor 1, K. S., Timm Derek 4, Makoto Ozeki 1, Tsutomu Okubo 1. Clinical evaluation of Emblica Officinalis Gatertn (Amla) in healthy human subjects: Health benefits and safety results from a randomized, double-blind, crossover placebo-controlled study. Contemp Clin Trials Commun 2019, 17:100499., 1-10.
6. https://mynutrition.wsu.edu/nutrition-basics
7. Adrian F. Gombart, A. P., and Silvia Maggini. A Review of Micronutrients and the Immune System–Working in Harmony to Reduce the Risk of Infection, Nutrients 2020, 12,236, 1-41.
8. Olabinjo1, O. O.; , A. S. O.; , O. O. A.; , A. P. O. Analysis of Physical and Chemical Composition of Sweet Orange (Citrus sinensis) Peels. International Journal of Environment, Agriculture and Biotechnology (IJEAB) 2017, 2 (4) 2201-2206.
9. https://www.webmd.com/food-recipes/health-benefits-oranges
10. https://www.healthline.com/nutrition/8-proven-papaya-benefits
11. https://www.india.com/lifestyle/berries-that-can-improve-your-immunity-amidst-coronavirus-pandemic-3986592/
12. https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/the-wonders-of-watermelon
13. Heitor A. Pula Neto, P. A., Lilian S. Gomez, João G. B. Leandro, Patricia Zancan, and Mauro Sola-Penna. Effects of Food Additives on Immune Cells As Contributors to Body Weight Gain and Immune-Mediated Metabolic Dysregulation. Front Immunol. 2017, 8: 1478., 1-11.
14. Myles, I. A. Fast food fever: reviewing the impacts of the Western diet on immunity. Nutr J. 2014, 13: 61.
15. Kalinski, P. Regulation of immune responses by prostaglandin E2. J Immunol 2012, 188(1):, 21-28.