How Nutrition Affects Your Immunity – And the Role of Food in Reducing the Risk of Infection

Have you considered your nutritional habits and daily meal rhythm recently? If you’re working remotely, your eating habits may have changed due to the pandemic. Many of us have skipped meals because of having too many meetings in a row or because there is no time for preparing a proper lunch. It’s okay, it has happened to all of us but as it seems that conquering Coronavirus is more like a marathon than a sprint, we need to start valuing those lifestyle factors that maintain our wellbeing – and nutrition is definitely one of those.

Role of food and nutrient deficiencies

Food gives us energy, but it also has a central role in the maintenance of health where all the nutrients are needed for proper functioning of the body. The ingestion of foods with immune-modulating activities is considered as an efficient way to prevent immune functions from declining. Also, it reduces the risk of infection. We know well that undernutrition causes nutrient deficiencies. But also, overnutrition leads to nutrient deficiencies if our diet is monotonous and nutrient poor. A complex syndrome of multiple nutrient deficiencies creates a state called malnutrition. It shouldn’t be considered as energy and protein deficiency alone and it doesn’t apply only to young children in developing countries but also to all age groups in all populations of the world. There exists a vicious circle of these two as infection and malnutrition aggravate each other.

We need all the important macronutrients and micronutrients to let our immunity to flourish as they regulate immune responses through different ways. Vitamins, minerals, proteins, carbohydrates and lipids (building blocks of fat), enhance parameters of acquired immunity. Insufficient intake of energy and macronutrients combined or alone with deficiencies in specific micronutrients impairs our immune system and suppresses immune functions that are fundamental to our immune defence.

Micronutrients that boost our immunocompetence

Even though most of the nutrients seem to play an important role in maintaining and supporting our immune system, there exists a crucial role of several micronutrients in the maintenance of immunocompetence. These are vitamins A, B₂, B₆, B₁₂, C, E, beta-carotene, folic acid, iron, zinc, and selenium. When following a healthy balanced diet, required daily intake of these micronutrients is mainly met. Healthy diet is made of combination of different foods, including staple foods (e.g. whole-grain wheat, barley, rye, starchy tuber or roots), legumes (e.g. lentils, beans), vegetables, fruits, berries and foods from animal sources (e.g. fish, meat, eggs, milk).

By following a diet with high amounts of colourful fruits, berries, and vegetables, it is easier to get needed daily doses of essential micronutrients covered. Eat a rainbow a day is a simple rule linked to fruit and vegetable consumption. This means it’s superior to eat red, purple/blue, orange/yellow, green and brown/white fruits and vegetables daily to meet the nutritional recommendations of micronutrients. Generally, vitamin C and zinc are the micronutrients which have been taken as supplements when trying to avoid a flu. However, they don’t reduce the infection rate, but vitamin C seems to reduce the time and stress of incidents whereas zinc prevents infections in the long-term, and it speeds up viral diseases and alleviates symptoms.

Say no to fast weight-loss diets – choose high-quality macronutrients

Fast weight-loss diets should be avoided to maintain good immunity as losing weight quickly and restricting great amounts of energy results in impaired immunity. Instead of concentrating on energy restriction, concentrate on the quality of macronutrients. Replace saturated fats with unsaturated vegetable fats and vegetable oils. Good sources of such are olive oil, nuts, and seeds for example. At the same time, also reduce your consumption of processed meat or choose a good quality product with reduced level on saturated fat. Choose whole grains at least for half of your daily grain products and favour lean protein sources.

Remember to look at the big picture

Most important is to look at the big picture, not only the single nutrients. As well as nutrient deficiency also overloading of certain nutrients can lead to reduced immune responses as they have certain thresholds for ingestion. For healthy people who follow healthy food principles with no restrictions in their diet, there is no need to take nutrition supplements. Consuming nutritional elements through natural foods will prevent individual from the side effects of overuse. A healthy immune system supported with nutrient-rich food lets us feel well and allows us to use our energy in a more efficient manner.

Next time when you eat, value the health-maintaining effect of food and feel the nourishing and energising effect of it. Allow yourself peaceful moments and real pauses when you eat and don’t multitask. All of us benefit from mindful eating but especially if you have problematic eating behaviours such as binge eating, stress eating or emotional eating, I encourage you to eat mindfully and study mindful eating techniques.

Take home message:

1. Eat combination of different foods on a regular basis.
2. Consume healthy diet which consists of staple foods, legumes, vegetables, fruits, and foods from animal sources.
3. Instead of dieting, concentrate on macronutrient quality.
4. Eat more colourful fruits, berries and vegetables to achieve required daily intake of essential micronutrients.
5. Eat mindfully.
6. Start with small changes towards healthier diet and don’t stress about food.