Immunity and Nutrition: During #COVID19, immunity is the most used word. This thread will discuss:
1. Different types of #Immunity & how they work?
2. Role of protein, energy deficiency
3. Role of fatty acids
4. Role of obesity.
In next thread we will discuss Vitamins & Minerals.

1. Different type of immunity:
A. Innate immunity: 1st line of defense against foreign substances & pathogenic microorganisms. It is an immediate, nonspecific defense that does not involve immunologic memory of pathogens.

B. Adaptive immunity: Also called acquired immunity, a 2nd line of defense against pathogens, takes several days or weeks to fully develop. It involves antigen-specific responses & immunologic 'memory'. Faster and stronger because antigens are 'remembered.' B & T cells based.

2. Protein-Energy Malnutrition: Protein-energy malnutrition (PEM) is a common nutritional problem that principally affects young children and the elderly. PEM significantly increases susceptibility to infection by adversely affecting both innate immunity and adaptive immunity.

3. Fatty Acids in Immunity: Experimental studies have shown that several types of dietary lipids (fatty acids) can modulate the immune response. Fatty acids that have this role include the long-chain polyunsaturated fatty acids (PUFAs) of the omega-3 and omega-6 classes.

4. Obesity & Immunity: Overnutrition and obesity have been shown to alter immunocompetence. Obesity is associated with macrophage infiltration of adipose tissue; macrophage accumulation in adipose tissue is directly proportional to the degree of obesity.

In this regard, it's important to correct both undernutrition and overnutrition to ensure optimum immune function. Immunity is not a magic bullet that can appear instantly during a disease. Immunity needs to be inculcate slowly w/ a nutritious diet & healthy lifestyle.