Nutraceuticals in immune health: beyond vitamins and minerals

Recently, there has been increasing interest in and research on how the immune system can be supported.       . 

This has included exploring the use of nutraceuticals, products derived from food sources that support general health and wellbeing.

Nutraceutical is a term that combines “nutrition” and “pharmaceutical” and was coined in 1989 by Stephen DeFelice, MD and founder of the Foundation for Innovation in Medicine (FIM).

The Nutrients Journal¹ also describes how nutraceuticals are different from functional foods. While functional foods are foods in their whole form and eaten as part of the regular diet, nutraceuticals provide a concentrated form of an ingredient formulated into supplement form targeted to provide therapeutic benefits. A 2021 article in the Journal of Food Science and Nutrition Journal² explains that nutraceuticals are bioactive compounds found in fortified foods, dietary supplements, and herbal products. The paper further describes nutraceuticals as any whole food – not an isolated nutrient or vitamin – that is concentrated and repackaged in a non-food format like a capsule. 

Nutraceuticals are typically consumed in addition to a regular diet. 

A 2021 review paper in the Molecules Journal³ states that nutraceuticals contain many bioactive derivatives from food sources with therapeutic properties that influence the immune system. These products include antioxidants, phytochemicals, fatty acids, amino acids, prebiotics and probiotics. 

This paper examined various nutraceuticals which were shown to support immune function.      . The nutraceuticals in the study included resveratrol, lycopene, glucosamine, Korean red ginseng, beta carotene, and quercetin.

A 2023 review⁴ published in the Preventive Nutrition and Food Science Journal summarised the results of clinical studies on various nutraceuticals and found that they support immune system function.

Several nutraceuticals, such as vitamins, mineral salts, polyunsaturated omega-3 fatty acids, many phytocompounds, and probiotic strains, have the most consolidated evidence in humans

Phytochemicals

These compounds in plants have received increasing interest due to their potential effects as antioxidants, anti-inflammatories, and supporting      immune function. The Nutrients Journal¹ found studies that show phytochemicals can exert similar effects to prebiotics to inhibit pathogenic bacteria and stimulate the growth of beneficial bacteria. 

The 2023 review published in the Preventive Nutrition and Food Science Journal,²  found a range of phytochemicals to show promising effects for immune support, including quercetin, probiotics, prebiotics, resveratrol, and curcumin. Phytocompounds from ginger and echinacea, for example, were found to reduce the incidence of colds. Phytocompounds from ashwagandha and garlic showed increased production of white blood cells. Papaya was found to support the immune response, while phytochemicals from fungi were found to stimulate the immune system. 

Beta-glucan

Beta-glucan is a natural polysaccharide, a type of carbohydrate found in plant cell walls, mainly in oats, barley, and wheat.

Foods that contain beta-glucan include yeast, cereals, seaweed, fungi, and certain bacteria. According to a 2023 review paper in the Pharmaceutics Journal,⁵ beta glucan has positive health effects. 

A 2019 paper⁶ published in the Annals of the National Institute of Hygiene states these benefits as immune support and antioxidant properties. The paper also found that beta-glucan is classified as a prebiotic, which stimulates the growth of good bacteria while hindering the growth of pathogens. It also plays an important role in supporting a healthy gastrointestinal tract, which is significant given what we now understand about the relationship between gut health and immune health.

The Pharmaceutics Journal⁵ explains that regulating the human body’s immune response with beta-glucans is promising. It could help improve the body’s immune status and provide new avenues for clinical treatments, including anti-inflammatory types.

• Selenium has antioxidant functions of neutralising free radicals, to protect from cell damage. 
• Curcumin has antioxidant and anti-inflammatory properties, as the Pharmaceuticals Journal⁵ explains.
• Zinc is another antioxidant, to help defend the cells from damage caused by free radicals.
• Vitamin D: According to the Preventive Nutrition and Food Science Journal review⁴, vitamin D supports the immune system.
• Vitamin C: Studies⁷ have shown that supplementing with vitamin C reduces the duration and severity of the upper respiratory tract, including the common cold.
• Vitamin E is a potent antioxidant, and according to a Cleveland Clinic⁸ article, vitamin E should come from food rather than supplements.