What are nutraceuticals?

Nutraceuticals are foods associated with physiologic optimisation, well-being or health. They are used to prevent deficiencies and manage diseases. The term is poorly defined and not clearly classified. Natural compounds from plants or animals can exert physiological effects; best examples are vitamins. Here, we define the terms we use for the Institute NaturScience and explain their meaning.

What are nutraceuticals?

The term "nutraceutical" is not well defined yet appears with increasing frequency in literature. Many definitions have been proposed, discussed, and discarded (Frank et al., 2020). Generally, nutraceuticals are foods, food compounds, herbs, spices or plant extracts that have been associated with medical or health benefits (Santini et al., 2018). Nutraceuticals are seen as hybrids between food and pharmaceuticals by some (Helal et al., 2019).

Since a consensus on the definition is pending, we define our own using other works as base (Frank et al., 2020, Dillard & German, 2000, Aronson, 2017, Das et al., 2012). Our definitions are described below to generate an understanding of the meaning we place behind the respective terms. We begin with the origin. In this section, only plant-derived compounds will be discussed. Animal derived compounds find their space on The Institute NaturScience under "Human Milk Composition" (). We know that most vitamins and minerals are also present in plants yet take milk composition as leading.

Plant–derived compounds can be split into spices, herbs and plant extracts. They contain molecules – bioactive compounds – that have biological activity and exert physiological effects. A good example – although not discussed here – are vitamins: essential for the human body, needed for physiological processes and their deficiency is compromising health. Biological activity could also mean that processes are supported, eased, facilitated or hindered (Frank et al., 2020). An example are human milk oligosaccharides () that affect colonic microbiome populations and increase short-chain fatty acid production, which in turn has been associated with physiological improvements (Kunz, 2012, Yu et al., 2013, Harmsen et al., 2000). Last are nutraceuticals, a term that we use for foods that contain one or more bioactive compounds and have been investigated clinically.

Plant extracts

Plants extracts are components that are extracted from herbs and other plants often known from traditional (Chinese) medicine. In such extracts, bioactive compounds can be concentrated and/or processed to increase their amount of intake or their bioavailability. Reproducible extraction and concentration control are especially important to provide efficacy (Sasidharan et al., 2011).

Bioactive compounds

Bioactive compounds are animal- or plant-derived food components that exert a health benefit other than their sole dietary value. Commonly they occur in low concentrations in food and have a biological activity within the human body (Frank et al., 2020). Health benefits include the absence of side effects or synergies with a medical treatment. They may improve the health value of the individual, the diet and medical conditions and should be "easily available and economically affordable" (Chauhan et al., 2013).
Within the Institute NaturScience, a bioactive compound has biological activity and exerts physiological effects. These can be beneficial or harmful by enhancing or hindering processes within the human body. Supplementation of bioactive compounds serves prevention of nutritional deficits that may lead to a disease like iron deficiency anaemia (), shorten disease episodes, relieve symptoms, and generally support the management of medical conditions. The needs for a bioactive compound or their impact are age-, population-, or risk-group dependent. Individual responses are possible.


The term has been long debated and many definitions have been suggested. Frank and colleagues propose that nutraceuticals are "a compound or mixture of compounds present in food or food supplements intended to exert a therapeutic effect". This definition is based on their proposed use because this implies a beneficial effect on health or disease that is substantiated through clinical data (Frank et al., 2020). Nutraceuticals are "neither nutritious nor pharmaceuticals" (Aronson, 2017).


The term phytocomplex is used in relation to components in plant extracts, herbs and spices. It is defined as "a combination of different substances, both active principles and other plant components". The combination of biological active and inactive substances can lead to synergistic effects within the phytocomplex that can support the health benefits of bioactive compounds (Donno et al., 2015).
We use the term to describe a combination of plant components that comprise biologically active and inactive substances, which is often used to confer health benefits rather than using the bioactive component alone. An example is the silymarin phytocomplex of at least four flavonolignans. One of these four molecules – silybin – is a bioactive compound and used as part of the phytocomplex to manage liver disease or induce milk flow () (Soleimani et al., 2019, Wilinska & Schleußner, 2015). 

To learn more about silymarin, check the Paper Synopsis Soleimani (), which summarises safety aspects of oral or intravenous silymarin in liver disease or the Paper Synopsis Wilinska (), which summarises a review on silymarin as galactogogue (milk inducer).


Galactogogue, silybin, silymarin, milk inducer