‘Food and medicine continuum’ in the East and West: Old tradition and current regulation

Abstract

Food-medicine products are important materials for daily health management and are increasingly popular in the global healthy food market. However, because of the biocultural difference, food-medicine knowledge may differ among regions, which hinders the global sharing of such health strategies. Aim at bridging the food-medicine knowledge in the East and West, this study traced the historical roots of food and medicine continuum of the East and West, which was followed by a cross-cultural assessment on the importance of food-medicine products of China, thereafter, the current legislative terms for food-medicine products were studied using an international survey. The results show that the food and medicine continuum in the East and West have their historical roots in the traditional medicines since antiquity, and the food-medicine knowledge in the East and West differs substantially; although the food-medicine products have common properties, their legislative terms are diverse globally; with proofs of traditional uses and scientific evidence, food-medicine products are possible for cross-cultural communication. Finally, we recommend facilitating the cross-cultural communication of the food-medicine knowledge in the East and West, thus to make the best use of the traditional health wisdom in the globe.

1. Introduction

Many foodstuffs are also with health-promoting effects, therefore, ‘food as medicine’ or ‘medicine as food’ are commonly seen, which have been recognized as the phenomenon ‘food and medicine continuum’ (Adelman and Haushofer, 2018, Etkin & Ross, 1982, Leonti, 2012). Products used as both food and medicine are thought to be pivotal materials in sustaining human health especially for the prevention of chronic diseases and geriatrics (Heinrich, Yao, & Xiao, 2022). While there is a steady increase in healthcare needs, such (local / regional) products have attracted more and more attention in the worldwide. In recent decades, we have seen that many of local / regional used food and medicine stuffs are turning into global market, such as goji (fruits of Lycium barbarum L., Gouqizi in Chinese) and reishi (Ganoderma, Lingzhi in Chinese) (Heinrich, Kum, & Yao, 2022, Yao, Heinrich, & Weckerle, 2018). However, because of the biocultural difference, people of the West and East have accumulated different knowledge on food and medicine continuum. Specifically, the used species, plant part used or usages may differ between the West and East (Heinrich, Yao, & Xiao, 2022). These differences have led to barriers for the cross-cultural communication of food and medicine knowledge between West and East.

Aiming at removing the cultural barrier, this study will analyze the differences in the knowledge of food and medicine continuum between the West and East from their historical roots and current regulations, thus, to facilitate the cross-cultural communication of ‘food and medicine continuum’ in the East and West.

2. Materials and methods

2.1. Old tradition of food and medicine continuum

To study the old tradition of food and medicine continuum in the East and West, a thematic literature research was performed, which focused on the dietetic therapy in traditional Chinese medicine, Hippocratic and Galenic diet, and Ayurveda.

To disclose the different opinions on the traditional food-medicine products in the East and West, an expert of the western cultural background was invited to evaluate the food-medicine dual-use products in the official list of China. Accordingly, their importance for the usages of “healthy food”, “spice” and “medicine” in Europe was evaluated.

2.2. Current definition for interface of food and medicine in globe wide

To study the current definition for the interface of food and medicine in the globe wide, an international technical survey was conducted. (1) The following questions were prepared: How is food defined in your country? How is medicine defined in your country? Is there any intermediate categories of food and medicine in your country? What are the statutory documents for the regulation of food and medicine in your country? (2) Experts of food and medicine research or regulation from the following countries were consulted by e-mails: Japan, South Korea, Thailand, Malaysia, Singapore, Australia, New Zealand, India, Pakistan, Saudi Arab, Turkey, Nigeria, South Africa, Russia, European Union (EU), Canada, United States (US), Mexico and Brazil. (3) The responses were complied, and the referred statutory documents was searched, as a result, the stuffs in the interface of food and medicine were sorted out.

3. Results and discussion

3.1. Old tradition of food and medicine continuum: Historical roots

3.1.1. Tradition of food and medicine continuum in the West

In the West, the knowledge of using herbs as food or medicine can be found in the historical medical texts. The Hippocratic Corpus might include the earliest records, which comprises about 60 medical texts written in around 5th to 4th century BCE (Totelin, 2021). There is a saying attributed to Hippocrates, “Let medicine be thy food and let food be thy medicine” (Fig. 1, left). The definitions of ‘food’ and ‘medicine’ were found in some texts of this collection; interestingly, food was subject to medicine at that time, along with pharmacology and surgery (Totelin, 2015). Touwaide and Appetiti (2015) analyzed the plant materials used in remedies included in this collection, to find that 33 of the 44 sampled medicinal plants are also used for nutritional purposes. Subsequently, this tradition developed and was succeeded by Galenic humoral food and medicine, which further influenced the Islamic medicine (Chen, 2008). In the Galenic humoral theory, all stuffs, whether food or medicine, were attributed with properties of warm, cool, dry or moist, so food and medicine were thought to be equal as a matter acting on human body. In his works of On the Powers of Food, Galen addressed the important function of nutrition in medical practice using the classic humoral ideas (Grant, 2002). Accordingly, it can be seen that ‘food and medicine continuum’ was prevalent since Antiquity in the West, and the boundary between food and medicine was blurry since then.

Fig. 1.

Typical old saying on food and medicine continuum in the West (left) and East (right).

3.1.2. Tradition of food and medicine continuum in the East

With its long history of civilization, China has the most influential traditional medicine system in the East. Thanks to the time-continuous Chinese herbals in the past two millennia, the knowledge of food and medicine continuum in the East still can be traced. The earliest record might be in Shennong’s Classic of Materia Medica (Shén nóng běn cǎo jīng in Chinese) of the first century CE, in which 120 meteria medica was classified into “top grade”, hinting their uses as both food and medicine (Liu, Xiao, Qin, & Xiao, 2015). Dietary therapy, or Shizhi in Chinese, was first interpreted in one chapter of the medical monograph of Simiao Sun in the Tang Dynasty (Fig. 1, right) (Sun, 1998). Theoretically, all foodstuffs are endowed with taste(s), and the taste endows the foodstuff with functions, which is the same as the theory of traditional Chinese medicine (TCM). Additionally, it cited the viewpoints of Zhongjing Zhang, who was a famous doctor of the Han Dynasty, saying that the dietary therapy should be prior to the medical therapy. Moreover, this chapter also listed the fruits, vegetables, grains, and animal products with therapeutic uses. Later, the first monograph for dietary therapy, namely Shiliao Bencao in Chinese, was published, which elaborated the therapeutic foods and their usages (Meng & Zhang, 1984). The food-medicine tradition was succeeded in a series of dietary therapy herbals, such as Yinshan Zhenyao of the Yuan Dynasty, Jiuhuang Bencao of the Ming Dynasty, etc. In TCM, a medicinal material (or sometimes also used as food) is with traditional properties of four properties (ascending, descending, floating and sinking) and five tastes (pungent, sweet, sour, bitter and salty). With these properties, anything, whether used as food or medicine, can be used to balance the Yin-Yang of human body.

Food also plays an important role in Ayurveda, a traditional medical system stems from the South Asia subcontinent. The idea of dietary therapy was found in Charaka Samhita, an Ayurvedic classics of no later than 2nd century CE (Rastogi, 2014). Ayurvedic practitioners give advice on food based on diseases, the condition of diseases, and the status of dosha of individuals; moreover, the quantity of food should also be determined by both the digestibility of food and the digestive capacity of people (Kumar, Dobos, & Rampp, 2017, Rastogi, 2014). In Ayurvedic theory, every food or medicine has its traditional properties, including Rasa (taste), Guna (effect on the digestion, fluid system and tissues in the body), Virya (effect on the metabolic thermal body), Vipaka (post-digestive effect) and Karma (action). With these traditional properties, a food / medicine can be used to balance the dosha of human body. Therefore, anything, either food or medicine, is used to sustain health based on its traditional properties, and food as medicine is also a tradition in South Asia.

3.1.3. Western opinion on food-medicine dual-use products of China

Up to now, the list for food-medicine dual-use substance of China has included 109 entities (including the pilot list), which are sourced from 151 species (Table 1). The evaluation for their importance in usages of “healthy food”, “spice” and “medicine” in Europe indicates that only 37 of the 151 species are very important in healthy food use, such as Glycyrrhiza uralensis Fisch., Myristica fragrans Houtt., Cannabis sativa L., Dimocarpus longan Lour., Hippophae rhamnoides L., Lycium barbarum L., Morus alba L., and so on. Additionally, 17 species are found to be used as a popular spice, and eight species are used as important medicines (excluding the medicinal use as a TCM in Europe). In the meanwhile, we find that 86 of them are not used for healthy food, 119 of them are not for spice uses, while 108 species are not used as a medicine other than TCM. These include the very commonly used species in China, such as Polygonatum odoratum (Mill.) Druce, Lilium lancifolium Thunb., Euryale ferox Salisb., Nelumbo nucifera Gaertn., Perilla frutescens (L.) Britt., etc. It is worth noting that the animal products are not accepted in the European healthy food market, or the Western traditional medicine, while this food-medicine list of China includes seven animal products.

Table 1.

A total of109 food-medicine entities (including the pilot) of China and their importance as food / spice/ medicine in the West.

No.	Chinese (Pinyin) names	Source species	Parts used	Importance* in the West
				Food	Spice	Medicine**
1	dīngxiāng	Eugenia caryophyllata Thunb.	Bud	2	3	3
2	bājiǎohuíxiāng	Illicium verum Hook.f.	Fruit	2	3	2
3	dāodòu	Canavalia gladiate (Jacq.) DC.	Seed	2	0	0
4	xiǎohuíxiāng	Foeniculum vulgare Mill.	Fruit	2	2	2
5	xiǎojì	Cirsium setosum (Willd.) MB.	Aerial part	0	0	0
6	shānyào	Dioscorea opposita Thunb.	Root and fruit	3	0	0
7	shānzhā	Crataegus pinnatifida Bge. var. major N.E.Br.	Fruit	2	2	2
8	shānzhā	Crataegus pinnatifida Bge.	Fruit	2	2	2
9	mǎchǐxiàn	Portulaca oleracea L.	Aerial part	3	0	2
10	wūméi	Prunus mume (Sieb.) Sieb. et Zucc.	Fruit	3	0	2
11	mùguā	Chaenomeles speciosa (Sweet) Nakai	Fruit	0	0	0
12	huǒmárén	Cannabis sativa L.	Seed	3	0	3
13	dàidàihuā	Citrus aurantium L. var. amara Engl.	Bud and fruit	3	3	1
14	yùzhú	Polygonatum odoratum (Mill.) Druce	Rhizome	0	0	0
15	gāncǎo	Glycyrrhiza uralensis Fisch.	Root and rhizome	3	3	2
16	gāncǎo	Glycyrrhiza inflata Bat.	Root and rhizome	1	1	0
17	gāncǎo	Glycyrrhiza glabra L.	Root and rhizome	3	3	1
18	báizhǐ	Angelica dahurica (Fisch. ex Hoffm.) Benth. et Hook.f.	Root	0	0	1
19	báizhǐ	Angelica dahurica (Fisch. ex Hoffm.) Benth. et Hook.f. var. formosana (Boiss.) Shan et Yuan	Root	0	0	1
20	báiguǒ	Ginkgo biloba L.	Seed	1	0	3
21	báibiǎndòu/ báibiǎndòuhuā	Dolichos lablab L.	Seed and flower	3	0	0
22	lóngyǎnròu	Dimocarpus longan Lour.	Aril	3	0	0
23	juémíngzi	Cassia obtusifolia L.	Seed	0	0	3
24	juémíngzi	Cassia tora L.	Seed	0	0	0
25	bǎihé	Lilium lancifolium Thunb.	Bulb	0	0	0
26	bǎihé	Lilium brownii F.E. Brown var. viridulum Baker	Bulb	0	0	0
27	bǎihé	Lilium pumilum DC.	Bulb	0	0	0
28	ròudòukòu	Myristica fragrans Houtt.	Seed	3	3	1
29	ròuguì	Cinnamomum cassia Presl	Bark	3	3	2
30	yúgānzǐ	Phyllanthus emblica L.	Fruit	2	0	2
31	fóshǒu	Citrus medica L. var. sarcodactylis Swingle	Fruit	0	0	0
32	kǔxìngrén	Prunus armeniaca L. var. ansu Maxim	Seed	3	0	0
33	kǔxìngrén	Prunus sibirica L.	Seed	0	0	0
34	kǔxìngrén	Prunus mandshurica (Maxim) Koehne	Seed	0	0	0
35	kǔxìngrén	Prunus armeniaca L.	Seed	3	0	0
36	tiánxìngrén	Prunus armeniaca L.	Seed	0	0	0
37	tiánxìngrén	Prunus armeniaca L. var. ansu Maxim	Seed	0	0	0
38	shājí	Hippophae rhamnoides L.	Fruit	3	2	1
39	qiànshí	Euryale ferox Salisb.	Seed	0	0	0
40	huājiāo	Zanthoxylum schinifoliumSieb.et Zucc.	Peel	0	1	0
41	huājiāo	Zanthoxylum bungeanum Maxim.	Peel	0	1	0
42	chìxiǎodòu	Vigna umbellata Ohwi et Ohashi	Seed	3	0	0
43	chìxiǎodòu	Vigna angularis Ohwi et Ohashi	Seed	2	0	0
44	màiyá	Hordeum vulgare L.	Sprout	3	0	1
45	kūnbù	Laminaria japonica Aresch.	Thallus	3	0	0
46	kūnbù	Ecklonia kurome Okam.	Thallus	3	0	0
47	zǎo (dàzǎo, hēizǎo)	Ziziphus jujuba Mill.	Fruit	3	0	2
48	luóhànguǒ	Siraitia grosvenorii (Swingle.) C. Jeffrey ex A.M. Lu et Z.Y. Zhang	Fruit	1	1	0
49	yùlǐrén	Prunus humilis Bge.	Seed	0	0	0
50	yùlǐrén	Prunus japonica Thunb.	Seed	0	0	0
51	yùlǐrén	Prunus pedunculata Maxim.	Seed	0	0	0
52	jīnyínhuā	Lonicera japonica Thunb.	Bud and flower	0	0	0
53	qīngguǒ	Canarium album Raeusch.	Fruit	1	0	0
54	yúxīngcǎo	Houttuynia cordata Thunb.	Whole plant	2	0	0
55	jiāng	Zingiber officinale Rosc.	Rhizome	3	3	2
56	zhǐjǔzǐ	Hovenia dulcis Thunb.	Fruit and carpopodium	0	0	0
57	gǒuqǐzǐ	Lycium barbarum L.	Fruit	3	0	0
58	zhīzi	Gardenia jasminoides Ellis	Fruit	0	0	0
59	shārén	Amomum villosum Lour.	Fruit	0	1	0
60	shārén	Amomum villosum Lour. var. xanthioides T.L. Wu et Senjen	Fruit	0	1	O
61	shārén	Amomum longiligulare T.L.Wu	Fruit	0	0	0
62	pàngdàhǎi	Sterculia lychnophora Hance	Seed	1	0	0
63	fúlíng	Poria cocos (Schw.) Wolf	Sclerotium	0	0	0
64	xiāngyuán	Citrus medica L.	Fruit	3	3	3
65	xiāngyuán	Citrus wilsonii Tanaka	Fruit	2	0	0
66	xiāngrú	Mosla chinensis Maxim.	Aerial part	0	0	0
67	xiāngrú	Mosla chinensis ‘jiangxiangru’	Aerial part	0	0	0
68	táorén	Prunus persica (L.) Batsch	Seed	3	0	1
69	táorén	Prunus davidiana (Carr.) Franch.	Seed	1	0	0
70	sāngyè	Morus alba L.	Leaf	0	0	0
71	sāngshèn	Morus alba L.	Infructescence	3	0	0
72	júhóng	Citrus reticulata Blanco	Peel	0	0	0
73	jiégěng	Platycodon grandiflorum (Jacq.) A. DC.	Root	0	0	0
74	yìzhìrén	Alpinia oxyphylla Miq.	Seed	0	0	2
75	héyè	Nelumbo nucifera Gaertn.	Leaf	2	0	0
76	láifúzǐ	Raphanus sativus L.	Seed	3	3	3
77	liánzǐ	Nelumbo nucifera Gaertn.	Seed	0	0	0
78	gāoliángjiāng	Alpinia officinarum Hance	Rhizome	2	3	1
79	dànzhúyè	Lophatherum gracile Brongn.	Stem and leaf	0	0	0
80	dàndòuchǐ	Glycine max (L.) Merr.	Fermented seed	3	0	0
81	júhuā	Chrysanthemum morifolium Ramat.	Infructescence	1	0	0
82	júqǔ	Cichorium glandulosumBoiss.et Huet	Whole plant	0	0	0
83	júqǔ	Cichorium intybus L.	Whole plant	3	0	0
84	huángjièzǐ	Brassica juncea (L.) Czern. et Coss	Seed	0	2	0
85	huángjīng	Polygonatum kingianumColl.et Hemsl.	Rhizome	0	0	0
86	huángjīng	Polygonatum sibiricum Red.	Rhizome	0	0	0
87	huángjīng	Polygonatum cyrtonema Hua	Rhizome	0	0	0
88	zǐsū	Perilla frutescens (L.) Britt.	Leaf	0	0	0
89	zǐsūzǐ	Perilla frutescens (L.) Britt.	Fruit	0	0	0
90	gěgēn	Pueraria lobata (Willd.) Ohwi	Root	2	0	0
91	gěgēn	Pueraria thomsonii Benth.	Root	2	0	0
92	hēizhīma	Sesamum indicum L.	Seed	3	3	0
93	hēihújiāo	Piper nigrum L.	Fruit	3	3	1
94	huáihuā、huáimǐ	Sophora japonica L.	Flower and bud	0	0	0
95	púgōngyīng	Taraxacum mongolicum Hand.-Mazz.	Whole plant	0	0	0
96	púgōngyīng	Taraxacum borealisinense Kitam.	Whole plant	0	0	0
97	púgōngyīng	Taraxacum spp.	Whole plant	0	0	2
98	fěizi	Torreya grandis Fort.	Seed	0	0	0
99	suānzǎo/suānzǎorén	Ziziphus jujuba Mill. var. spinosa (Bunge) Hu ex H.F. Chou	Pulp and seed	3	0	0
100	xiānbáimáogēn	Imperata cylindrica Beauv. var. major (nees) C.E. Hubb.	Rhizome	0	0	0
101	xiānlúgēn	Phragmites communis Trin.	Rhizome	0	0	0
102	júpí (huò chénpí)	Citrus reticulata Blanco	Peel	3	2	2
103	bòhe	Mentha haplocalyx Briq.	Aerial part	2	2	2
104	yìyǐrén	Coix lacryma-jobi L. var. mayuen (Roman.) Stapf	Seed	2	0	1
105	xièbái	Allium macrostemon Bge.	Bulb	0	0	0
106	xièbái	Allium chinense G.Don	Bulb	0	0	0
107	fùpénzǐ	Rubus chingii Hu	Fruit	0	0	0
108	huòxiāng	Pogostemon cablin (Blanco) Benth.	Aerial part	0	0	0
109	huòxiāng	Agastache rugosus (Fisch. et Mey.) O. Ktze.	Aerial part	0	0	0
110	wūshāoshé	Zaocys dhumnades (Cantor)	Body	0	0	0
111	mǔlì	Ostrea gigas Thunberg	Shell	0	0	0
112	mǔlì	Ostrea talienwhanensis Crosse	Shell	0	0	0
113	mǔlì	Ostrea rivularis Gould	Shell	0	0	0
114	ējiāo	Equus asinus L.	Skin jelly	0	0	0
115	jīnèijīn	Gallus gallus domesticus Brisson	Gizzardskin	0	0	0
116	fēngmì	Apis cerana Fabricius	Honey	0	0	0
117	fēngmì	Apis mellifera Linnaeus	Honey	3	1	1
118	fùshé (qíshé)	Agkistrodon acutus (Güenther)	Body	0	0	0
119	rénshēn	Panax ginseng C.A. Mey	Root and rhizome	3	0	2
120	shānyínhuā	Lonicera confuse DC.	Bud and flower	0	0	0
121	shānyínhuā	Lonicera hypoglauca Miq.	Bud and flower	0	0	0
122	shānyínhuā	Lonicera macranthoides Hand. -Mazz.	Bud and flower	0	0	0
123	shānyínhuā	Lonicera fulvotomentosa Hsu et S.C. Cheng	Bud and flower	0	0	0
124	yánsuī	Coriandrum sativum L.	Fruit and seed	0	0	0
125	méiguīhuā	Rosa rugosa Thunb	Bud	0	0	0
126	méiguīhuā	Rose rugosa cv. Plena	Bud	0	0	0
127	sōnghuāfěn	Pinus massoniana Lamb.	Pollen	0	0	0
128	sōnghuāfěn	Pinus tabuliformis Carr.	Pollen	0	0	0
129	sōnghuāfěn	Pinus spp.	Pollen	0	0	0
130	fěngé	Pueraria thomsonii Benth.	Root	2	0	0
131	bùzhāyè	Microcos paniculata L.	Leaf	0	0	0
132	xiàkūcǎo	Prunella vulgaris L.	Infructescence	0	0	0
133	dāngguī	Angelica sinensis (Oliv.) Diels.	Root	0	0	0
134	shānnài	Kaempferia galanga L.	Rhizome	3	3	2
135	xīhónghuā	Crocus sativus L.	Stigma	3	3	1
136	cǎoguǒ	Amomum tsao-ko Crevost et Lemaire	Fruit	0	0	0
137	jiānghuáng	Curcuma Longa L.	Rhizome	3	3	3
138	bìbá	Piper longum L.	Infructescense	3	3	3
139	dǎngshēn	Codonopsis pilosula (Franch.) Nannf. L.T. Shen	Root	0	0	0
140	dǎngshēn	Codonopsis pilosula Nannf. var. modesta (Nannf.) L.T.Shen	Root	0	0	0
141	dǎngshēn	Codonopsis tangshen Oliv.	Root	0	0	0
142	ròucōngróng (huāngmò)	Cistanche deserticola Y.C. Ma	Stem	1	0	1
143	tiěpíshíhú	Dendrobium officinale Kimura et Migo	Stem	0	0	0
144	xīyángshēn	Panax quinquefolium L.	Root	0	0	0
145	huángqí	Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao	Root	0	0	1
146	huángqí	Astragalus membranaceus (Fisch.) Bge.	Root	0	0	1
147	língzhī	Ganoderma lucidum (Leyss. ex Fr.) Karst.	Sporophore	2	0	0
148	língzhī	Ganoderma sinense Zhao, Xu et Zhang	Sporophore	2	0	0
149	shānzhūyú	Cornus officinalis Sieb. et Zucc.	Pulp	0	0	0
150	tiānmá	Gastrodia elata Bl.	Rhizome	0	0	0
151	dùzhòngyè	Eucommia ulmoides Oliv.	Leaf	0	0	0

Note: * 0 means no such use, while 3 indicates a popular use; 1 and 2 are in-between. ** These are the medicinal use excluding TCM.

Accordingly, most of the Chinese food-medicine species (as a representative of the East) are still not used / accepted in the West (as represented by the Europe), suggesting the differences in the food-medicine knowledge between the East and West. For example, the very commonly used Lonicera in China is not consumed in Europe at all. In the meanwhile, some of the species are used in both sides, but the usages might differ. Such as Crataegus, which is for digestion in China while for cardiovascular in Europe, and the different usages may be attributed to their independent historical origins (Caliskan, 2015).

Moreover, we have seen knowledge of some species have transmitted (partially) directly from China to the Europe, such as goji berry and ginseng. Another example is Ginkgo, the seed of which is used in China as a traditional food-medicine, while its leaf is developed in Europe as a source of flavonoids in food supplement. In recent decades, China has adopted the ginkgo leaf as a food ingredient and drug material, but the seed is still not accepted by European market.

It is found that many China-sourced entities, which are with a plenty of scientific data on phytochemistry, pharmacology and safety, have been accepted in Europe, e.g., Lycium barbarum L., Panax ginseng C.A. Mey, and Ganoderma lucidum (Leyss. ex Fr.) Karst. Therefore, scientific evidence on safety and bioactivity should be the premise for the cross-cultural acceptance of the traditional food-medicine products.

The legislative terms used for the interface of food and medicine in 20 countries / regions were compiled based on our survey (Fig. 2). The definitions of these terms are presented in supplement (Table S1).

Fig. 2.

Legislative terms for the interface of food and medicine in selected countries / regions.

3.2. Current definitions of interface of food and medicine

3.2.1. China

In China, food, medicine, and their interface are formally categorized into food, healthy food, food-medicine-dual-use substance, novel food ingredients, and medicine. Food Safety Law of China plays a key role in the regulation of food related substance in China. It is worth noting that a food is not for curative purposes but can be the stuff traditionally used as both food and Chinese materia medica. The healthy food is kind of special food for specific people to regulate health but are not for curative purposes. However, a healthy food is allowed for the recognized 24 function claims once it is proven by the official functional assessments. Food-medicine-dual-use substance must be adopted in Chinese Pharmacopoeia with a food use tradition, and the National Health Commission has published an updating list for these substances. The recognition of novel food ingredients allows for using new food sources. Lastly, medicine refers to the substance for curative purposes.

Accordingly, there are intersections among these categories. For instance, a Food-Medicine-dual-use substance must be a medicine in pharmacopoeia, but only when it is not used for curative purposes it belongs to food. The ingredient of healthy food is open to the substances of food safety and with proven health benefits, while is not listed in the official forbidden list. Novel food ingredients have higher potential compatibility with others. Taking goji as an example: as a traditional food, it is adopted in the Chinese Pharmacopoeia as well as in the list of Food-Medicine-dual-use substance, in the meanwhile, it is not in the official forbidden list for healthy food. Therefore, goji can be a medicine, food-medicine-dual-use substance, and an ingredient for healthy food.

3.2.2. Japan

In Japan, food includes (a) food with health claims (FHC), (b) food for special dietary uses (FOSDU), and (c) other foods (may include so-called functional foods) (MHLW, 2022). FHC has two sub-categories: foods with nutrient function claims (FNFC) and foods for specified health uses (FOSHU). FOSDU includes five categories. In 2015, a new system was termed “foods with function claims (FFC)”, and was integrated into the FHC (Shimizu, 2019).

It can be seen that boundaries among these sub-categories are not clear. For example, FOSDU and FHC have an intersection, which is FOSHU. Moreover, the new category FFC is similar to FOSHU, and their differences are found in the application process for the health claim labeling, and some of the health claims of FFC have already been adopted in the FOSHU system (Shimizu, 2019).

3.2.3. South Korea

Health functional foods includes all the interface of food and medicine in South Korea. It is defined as “foods manufactured (including processing; hereinafter the same shall apply) with functional raw materials or ingredients beneficial to human health” (Korean National Law Information Centre, 2019).

3.2.4. Thailand

Foods in Thailand are classified into four categories based on their safety risk, namely: (a) specially controlled food, (b) standardized food, (c) food with labeling and (d) general food (Ratanakorn, 2016). The interface of food and medicine may be found in (a), (b) or (c). For example, herbal tea and food supplements are included in standardized food, and the specially purposed food such as medical food belongs to food with labeling.

3.2.5. Malaysia

In Malaysia, products with combination of food ingredients and active ingredients for oral consumption are recognized as food-drug interphase (FDI) products (Ministry of Health of Malaysia, 2021). FDI products are not clearly defined as food or drug. FDI is not a product category, and it is important to determine whether the products are regulated as drug or as food because different regulatory requirements apply.

3.2.6. Singapore

In Singapore, health supplement means a product that is used to supplement a diet with benefits beyond those of normal nutrients, and to support or maintain the healthy functions of the human body. However, it cannot be an item of a meal or diet (Singapore Food Agnecy, 2022). Products in the food Health product interface includes (a) part of a daily diet, including Chinese medicinal material commonly used in food, (b) supplementation to a diet, and (c) those used for a medicinal purpose.

3.2.7. Pakistan

In Pakistan, “Health and OTC products”, “Dietetic foods intended for special medical purposes”, “food supplements” and “nutritional supplements” are assigned (Drug Regulatory Authority of Pakistan, 2012, Drug Regulatory Authority of Pakistan, 2014). Although defined separately, these terms have overlaps of different extent, and food-medicine products may be included in any of these categories.

3.2.8. India

In India, the interface of food and medicine may fall into “nutraceutical”, “health supplements”, “foods for special dietary” or “foods for special medical purpose” (Food Safety and Standards Authority of India, 2020). Of these, only the source of “nutraceutical” is determined as naturally occurring ingredients, others are all defined based on their extra health purposes other than food.

3.2.9. Saudi Arabia

In Saudi Arabia, “dietary supplement” and “health product” are defined (Saudi Food & Drug Authority, 2020), and the food-medicine products may belong to either of them. “Dietary supplement” is not in a pharmaceutical dosage form while the latter is, but their purposes are compatible to some extent.

3.2.10. Turkey

“Dietary foods for special medical purposes” and “Food supplement” are defined in Turkey (Council of Ministers of Turkey, 2010). Besides their similarity in nutritional properties, they are both used for dietary management.

3.2.11. Australia

In Australia, products for oral consumption are regulated by the Australian government as either foods or therapeutic goods. Therapeutic goods can be represented in any form and are for therapeutic use. The interface of foods and therapeutic good is called complementary medicines, which include herbal medicines, traditional medicines, vitamins, special purpose foods, nutritional supplements, homoeopathic and naturopathic products (Legislative Council Secretariat of Australia, 2001).

3.2.12. New Zealand

In New Zealand, “supplemented food” and “dietary supplement” are applied (Minister for Food Safety of New Zealand, 2016; Ministry of Health of New Zealand, 1985). “Supplemented food” is represented as a food while the later is in controlled dosage, although there is a big overlap.

3.2.13. Russia

The food-medicine products may fall into “specialized food products” or “enriched food products” in Russia (Urazbaeva, 2018). The former is with an established ratio of composition, which are intended for safe use by certain categories of people, while the later sets a limitation for the biologically active substances content at safe level of consumption.

3.2.14. South Africa

In South Africa, “Health supplement” include stuffs for restoring, correcting or modifying any physical or mental state but not in forms of medicines (Drugs Control Council of South Africa, 1965).

3.2.15. Nigeria

The category in Nigeria is different, since the food and medicine interface products are included in food (National Agency for Food and Drug Administration and Control of Nigerias, 2004).

3.2.16. European Union

“Food supplement”, “dietary foods for special medical purposes” and “functional food” are defined in the EU. “Food supplements” is to supplement the normal diet with a nutritional or physiological effect, designed to be taken in measured small unit quantities (Directive 2002/46/EC). “Dietary foods for special medical purposes” are for the dietary management of patients and to be used under medical supervision. (Directive 1999/21/EC). “Functional food” are food which beneficially affects one or more target functions in the body, beyond adequate nutritional effects, in a way that is relevant to either an improved state of health and well-being and/or reduction of risk of disease (EC 1924/2006) (Duttaroy, 2019).

3.2.17. Canada

In Canada, “natural health product (NHP)”, “food-NHP interface product”, “food for a special dietary” and “supplemented food” are the intermediate (Minister of Justice of Canada, 2022). “Food-NHP interface product” means any product that is in a food format, and meets the scope of natural health product (Minister of Health of Canada, 2017). “Food for a special dietary” means a food that has been specially processed or formulated to meet the particular physical or physiological requirements (Minister of Justice of Canada, 2021). “Supplemented food” may contain added vitamins, minerals, amino acids, herbal or bioactive ingredients, and may have extra physiological role other than nutrition (Food Directorate of Canada, 2016).

3.2.18. United States

“Dietary supplement” and “medical food” are defined in the US. “Dietary supplement” may contain vitamin, mineral, botanical, amino acid or the concentrate of them (US FDA, 2021). “Medical food” is for the specific dietary management and should be consumed under the supervision of a physician (Lewis, Jackson, & Bailey, 2019).

3.2.19. Mexico

In Mexico, “food supplement” and “functional food” are defined. Although both them are for health purposes, the former may be presented in a pharmaceutical form, while the later is enriched with additional nutrients (the General Health Law of Mexico; Official Mexican Standard “NOM-086-SSA1-1994”, Goods and Services).

3.2.20. Brazil

Brazilian legislation does not provide a definition of functional foods, but it is possible to claim that certain foods have functional health properties (Silveira, Vianna, & Mosegui, 2009).

3.2.21. Summary

It can be seen food and medicine continuum is a common phenomenon in the worldwide, although the legislative terms for the food-medicine entities may differ among regions. Japan has a sophisticated classification system for food-medicine, while health functional foods include all these stuff in South Korea, differently, the food-medicine is included in “food” in Nigeria. The term “food-NHP interface product” in Canada is quite similar to “FDI product” of Malaysia. In China, food-medicine-dual-use substance and healthy food have an overlap, while in Japan, FHC and FOSDU intersect. As a result, globally there are diverse legislative terms for food-medicine products, the scope of these terms may be different, as well, the boundaries among these terms are blurry.

Although food-medicine products are defined differently, basically, their common property is that they have extra healthy functions beyond their normal nutritional functions. Fortunately, we have seen that the regulations for these have emphasized their function claims. For example, healthy food in China can make health claims of 24 categories, which must be based on standard assessments. Similar regulations are found in other countries / regions, e.g., EC 1924/2006 is technically for the health claims of functional foods in the EU market. Additionally, these products are requested to register, by which a list for the approved products is published formally as a reference for market access, and this policy is effective in maintaining this high-profit market.

There are still food-medicine products whose health benefits are based on traditional uses, as the long term used in history can be a reliable proof for their safety. As a typically example, food-medicine dual-use substances of China are allowed for food consumption, although they are all medicinal materials in pharmacopoeia. To control these products, the government has published an updating list for the permitted materials, which must be evaluated by a working panel. The situation in the EU is similar, that the traditional use can be alternative evidence for the safety of traditional food (EU-efsa Panel on Dietetic Products et al., 2021).

It is worth noting that the cross-cultural communication of food-medicine products are possible based on current regulations. One of the pathways is the adoption of traditional uses. For example, many of the Chinese herbal medicines are with food use tradition, and these has already been adopted in many countries, e.g., Singapore adopts some of the Chinese medicinal materials to be used as part of a diet, which belong to the category of “health supplement”. Besides, novel food paves a pragmatical way for adopting a foreign food-medicine. In most of the regions, those exotic food products are allowed to be imported on the promise of application. For example, when a foreign food-medicine product imports to China, the technical documents of this product as well as the historical use proof in its origin country are requested. The new Novel Food Regulation (EU) 2015/2283 has declared the requirements for importing into the EU.

4. Conclusion

Food and medicine continuum is a global phenomenon. The present study traced the historical roots and the current regulations on the interface of food and medicine in both the East and West of the world. The historical root of food and medicine continuum lie in the herbal traditions of millennia, such as traditional Chinese medicine of China, Ayurveda of South Asia, Hippocratic and Galenic medicine of the West. The food-medicine knowledge in different regions is different since the biocultural diversity. Currently, food-medicine products are increasingly popular. Although the legislative terms for food-medicine products may differ among regions, the regulations are similar, which allows for their cross-cultural communication. The long-term uses are recognized as reliable proofs for the safety of these traditional foods, moreover, the studies on safety and bioactivity provide sufficient scientific evidence for their safety and functions. Besides, laws on novel food pave a pragmatic pathway for the cross-cultural exchange of the traditional food-medicine products. Finally, we recommend facilitating the cross-cultural communication of the food-medicine knowledge in the East and West, thus to make the best use of the traditional health wisdom in the globe.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Appendix A. Supplementary data

The following are the Supplementary data to this article: