With the advent of the COVID-19 pandemic, the interest relating immunity boosting food has spiked up. While adding immunity boosting food to the diet would certainly help you have a healthier immunity and helps prevention of many diseases, diet is just one pillar among immunity boosters. Dr. Subash Mendis, former Head of Food Safety Unit, Colombo states that adequate sleep, proper rest, managing stress levels and daily exercise contribute to increasing immunity and causing resistance for various diseases. “If one of the pillars; adequate sleep, proper rest, managing stress levels, daily exercise and immunity boosting diet, is not followed then it could cause immunity levels to drop. So all must be followed to have a healthy immunity levels in the body,” said Dr. Mendis. He also underscored that it was important to have a healthy blood and gut microbiome as these microorganisms contribute to maintaining immunity by preventing colonisation by pathogenic microorganisms.

Immunity Boosting Diet
“Firstly  it is important to have adequate hydration,” said Dr. Mendis. He stated that young children and older people were more prone to get dehydrated. “Young children are very active and they ignore thirst, therefore it is important that young children are trained to drink water. In older people, they don’t get thirsty, so it is important for them to have a routine to stay hydrated,” he elaborated. He shared that when the people  are dehydrated, it affects their immune levels. People can stay hydrated by drinking water, coconut water, king coconut water, fresh milk and tea. He further stated that king coconut water has electrolytes which are also beneficial for increasing immunity. Regarding fruit juices, Dr. Mendis stated that home made fruit juice directly squeezed from the fruit using all components of the fruit was healthy as otherwise, fibre rich and micro nutrients of the fruit were often lost in fruit juices. He warned against using sugar in fruit juices as fruits naturally consist of sugar in the form of fructose. 

Dr. Mendis also advised to lower sugar intake. “A high sugar diet can lead to increased inflammation in the body and that causes insulin resistance. It also forms a favourable environment for harmful microorganisms,” he said. Insulin resistance could lead to excess weight gain and obesity which is a causative factor for many diseases. He also stated that Sri Lankans consume much sugar on a daily basis. “Frizzy drinks, flavoured milk, flavoured tea, malt based drinks, ketchup, salad dressings and breakfast cereals- all contain high amounts of sugar,” he warned. While stating that yogurt provided probiotics which are beneficial for maintaining a healthy gut microbiome, he recommended the consuming of low sugar yogurt rather than consume ones low in low fat.

• Vitamins A, B, C, D and E were also found to be immunity boosters. Dr. Mendis advised that taking them through diet via natural means was more beneficial than taking them in the form of supplements and mentioned a few sources.
• Vitamin A- animal liver, coloured fruits and vegetables (carrot, pumpkin, orange, tomato) and green leaves 
• Vitamin B- Green leafy vegetables, meat, fish, chicken, lentils, nutritional yeast
• Vitamin C- Citrus fruits (lime, lemon, orange, grapefruit)
• Vitamin D- egg yolk, mackerel fish, cod liver oil, mushroom, sardine. Vitamin D is also available in the sunlight (10am- 2pm)
• Vitamin E- Nuts (walnuts, almonds, peanuts, cashew nuts), peanut butter (homemade,  without extra sugar)

He also emphasised on the importance of adding immunity boosting micronutrients in the diet and provided some sources:

• Zinc- Seafood (oysters, cuttlefish  prawns), red meat, lentils and pulses (chickpeas, green gram, dhal), sesame seeds, pumpkin seeds, nuts (cashew nuts, peanuts), milk, cheddar cheese, egg
• Selenium- Nuts, multiseed bread
• Magnesium- Lentils, green leafy vegetables

“Even the spices we use in our cooking help in boosting immunity. Spices like garlic, ginger and turmeric have been medically proven to boost immunity while other spices and green tea are also believed to boost immunity,” he shared. 
Dr. Mendis also insisted on consuming healthy fats in the diet such as omega- 6 and omega- 3 fats. However, he noted that in the recent past people have started consuming more of omega- 6 fats than required which has lead to many disease conditions. 

• Omega- 3 fats- Coconut oil, olive oil, fatty fish (tuna, salmon, sardine), eggs, omega- 3 fish oils
• Omega- 6 fats-Vegetable oil, palm oil, canola oil, sunflower oil, margarine

Immunity destroyers
“High sugar levels in the diet along with higher amounts of Omega- 6 can cause detrimental effects on one’s immunity,” he shared. He added that alcohol and smoking also contributed to  reducing immunity levels. 

While immune rich food is necessary to be included into our diet, diet is just one pillar of immunity. “It is very crucial to combine all the pillars to have increased immunity levels,” reiterated Dr. Mendis.