Nutrition challenges & COVID-19: Boost your immune system

Coronavirus is among a new breed of modern viruses for which medical science does not yet have any specific treatment or medication. This is similar to the period 1940s to 1960s when we were plagued with polio, whooping cough, measles, chicken pox, and similar epidemics, now under control with vaccinations.

Many who lack immune competence will succumb and die, and the vulnerable groups are usually the very old and the very young. In young children, the infectious diseases then resulted in undernutrition or protein-energy malnutrition (PEM) in a large proportion of our children (some 50 per cent). It has taken us these many years to really understand the effects and proper treatment of PEM while this nutrition condition ravaged our children affecting brain size, learning ability, propensity to a violent temperament, and other lowered performance factors.

Immune competence is a factor of nutritional status, i.e. we all need to eat healthily. It is the interpretation of ‘healthy eating’, however, that has created the many anomalies of nutrition today. The most common medical sign of the severity of poor eating is weight status. The main nutrition treatment or interpretation of healthy eating under PEM was to eat more energy nutrients to gain weight. Hence, more fat and sugar were added to porridge, more protein and even more salt to make food palatable for eating. Eating more and more has now led to a swinging of the pendulum from far left to far right, with more obesity and chronic diseases such as diabetes and hypertension.

The new fashionable advice is now to eat less – less fat, less sugar, less carbohydrate, protein, salt, that lead to popular ‘crash diets’, which result in emaciated bodies lacking immune competence from imbalanced eating. This is counteracted by more mass media advice –‘eat healthy food’. This is interpreted as more fresh foods like fruits, vegetables, provisions, plant-based diets with less red meat (more fish), less processed food such as flour, cornmeal, rice, and so on. This is the exact opposite of the former advice for treating PEM.

This propensity to extremes must now be tempered by our better scientific understanding of nutritional needs. Rather than shifting the pendulum back to the far left, we need more rational eating by understanding that the best nutritional advice is not one-size fits all and simple mass media messages, but to seek the personal diet that best meets your nutritional needs under varying circumstances. The fact is, we have what is known as a double burden of disease that requires a range of strategies best provided by qualified nutrition practitioners, who should be made available and affordable to the general public in our schools, workplaces, communities, and wherever the human need exists that requires disease prevention and health-promotion guidance.

Managing viral infections and COVID-19

As said before, to boost the immune system, to resist and overcome these new viruses, requires nutrition preparation and ‘balanced’ eating. All the nutrients must be in adequate amounts verified by detailed computations of daily dietary intakes and/or by blood tests. One lesson learnt from Chik-V was that the blood level indicating the ratio of sodium to potassium may have determined whether the old survived or not. Patients taking diuretics to flush out sodium found the potassium levels way higher than should be, relative to sodium/salt, which had been curtailed by the typical hypertensive diet. This was made worse by hydrating with coconut water, high in potassium, rather than with plain water.

Advice to boost immune status varies according to your weight category. For those of normal weight and still ‘well’, immune function improved with less protein intake to as low as eight per cent relative to carbohydrate, i.e. a vegetarian diet. The very overweight may benefit from intermittent fasting (please consult a professional), but severe deprivation compromises immune function. Certainly, underweight as well as obesity is related to lower immune response and the diet requires adequate intake of leader nutrients such as iron, zinc, calcium, vitamins, A, C certain B vitamins like folic acid, B12, B6. You have to strike a balance. Some people who are underweight are metabolically obese and cannot just eat more food to gain weight but must balance energy nutrients and exercise (the team approach is useful).

Persons already emaciated will need general supplements to boost immune function. Food selection for high nutrient intake must also be balanced. For instance, red meats provide much needed iron and zinc, and beef liver is the richest animal source of iron, zinc, and vitamin A. While white fish is high in protein and B vitamins, they lack iron, calcium, and zinc provided by canned fatty bony fish such as sardines and mackerel. Good plant sources of these nutrients are legumes and dark, green leafy vegetables like callaloo and pakchoi. But if your kidneys are sluggish (renal disease), these are the very foods you need to have measured to control the potassium intake.

Likewise, such persons must be careful in selection of fruits and vegetables. The yellow ones like pumpkin, carrot, and pawpaw will provide vitamin A with moderate potassium. Healthy eating advice of ‘just eat plenty vegetables’ is not enough. Levels of intake are more important than just foods rich in the desired nutrients. Consult a qualified nutrition practitioner.

Patricia Thompson is executive director of Jamaica Island Nutrition Network.