**12. Results**

of available carbohydrate in a certain amount of food and its GI divided by 100 [83]. Low GIbased diets tend to maintain glucose and insulin at a moderate level avoiding the hypergly‐ caemic state [84]. This is based on advantages of the GI concept: i) GI and GL are determined both on single and mixed meals; ii) they permit proper selection and combination of low and high GI foods to achieve good glycaemic control and prevent hyperglycaemia; iii) they prevent fear of excessive intake of low or high GI foods and resultant hypoglycaemia/hyperglycaemia; and iv) hyperinsulinaemia is abated when both GI and GL are considered in dietary counsel‐ ling. The link between GI and GL simply means that although both GI and GL elicit information on carbohydrate content of foods in relation to their blood glucose response. GI is associated with the quality of carbohydrate in a food/meal while GL relates to the overall quantity of carbohydrate in the same food/meal [85]. However, when these low GI (low GL) foods are habitually consumed in large amounts, high glycaemic effect may manifest over time. Based on this, attention is drawn to researchers on the limitation of the use of glycaemic index values alone in diabetes management. The practical application of the Gl, used in combination with other information on food composition, is promising in guiding good food choices, especially for people with diabetes. Englyst et al. [87] proposed the inclusion of rapidly digested starch (RDS) and slowly digested starch (SDS) to account for limitations of GI. More recently, resistant starch (RS) has received attention as one of the components of carbohydrate foods that are closely linked to glycaemic control [86]. Salijata *et al*. [34] observed that the justification of similarity of RS with NSP is that RS assays as insoluble fibre and has the physiological benefits of soluble fibre. They reviewed the importance of high amylose content and high amy‐ lose:amylopectin ratio in foods/diets in the post-pandrial glycaemic and insulinaemic respons‐ es. A higher amylose lowers digestibility of starch due to positive correlation between amylose level and formation of RS [88]. Plants with these hypoglycaemic activities collectively exert their effects in two major ways. They either improve insulin sensitivity to glucose at the peripheral cells to increase glucose uptake and reduce hyperglycaemia. Or, they act on insulin production-related actions to improve insulin production and control of blood sugar homeo‐

72 Antioxidant-Antidiabetic Agents and Human Health

Evans et al. [60] has reported that pathogenesis of diabetes is better appreciated and should be discussed in line with hyperglycaemia and elevated free fatty acid in the blood in relation to oxidative stress and production of free radicals. Some plants with hypolipidaemic activities were included by several authors as those that may assist in diabetes control. This is because diabetes and cardiovascular disease are closely related. The active ingredients identified *in vivo* for this purpose are antioxidants (vitamin A, beta-carotene, vitamin E and tannins) [89, 90]. The degree of these constituents in foods and their relative importance varies with the chemical compound, specie, part and age of the plant as well as environment. From the above perspective, the following operational definition will be used for documenting the antidiabetic potential/effects of identified plant foods. *Anti-diabetic plant foods/diets* are those plant foods/ diets that contain any of the chemical compounds, shown to reduce hyperglycaemia or induce hypoglycaemia through their effect on the improvement of insulin resistance or insulin supply

stasis.

to the peripheral cells.

The concept of food groups of plant origin was used to present the results on documentation of Nigerian indigenous plant foods and those with anti-diabetic potentials. This was to encourage increased diversification and culinary uses. These food groups include fruits, vegetables, spices and condiments, grain legumes, nuts and oil seeds as well as starchy roots/ tubers/fruits and cereals. Forty-eight families of plant foods were identified. Out of 241 plant species (spp) identified, 80 fruits, 77 vegetables, 68 spices and condiments, 22 grain legumes/ nuts/oil seeds and 19 starchy roots/tubers/fruits and cereals were documented. Twelve out of 22 grain legumes/nuts/oil seeds and 11 out of 19 roots/tubers/cereals were soup thickeners. Only 3 spp of fruits, 16 spp of vegetables, 27 spp of spices/condiments/grain legumes and 10 spp of starchy staples have anti-diabetic potentials *in vivo or in vitro* (Table 1]. Twenty-five indigenous diets as consumed had anti-diabetic effects (Tables 2]. Three of the *Candida tropicalis* fermented low GI starchy staple (cassava/maize/sorghum) flours were used to formulate high dietary fibre diets using food-based approach of 10% protein and 20g total dietary fibre/1000kcal in a 1:2 ratio of soluble: insoluble dietary fibre. The diets were composed of fermented cassava/maize/sorghum flours (commonly used to prepare thick paste tradition‐ ally known as "foofoo". They are eaten with traditional soup blended with *Cola gigantea* flour (a soup thickener) and other standard ingredients for rat bioassay to mimick traditional diets as consumed. These diets reduced post-prandial blood glucose concentrations of the diabetesinduced adult rats. More of the most commonly consumed vegetables than fruits were cultivated. The indigenous diets that had anti-diabetic effects did not contain any fruit group in their various recipes. They contained vegetables as part of the ingredients. This observation supports the report by Ene-Obong et al. [39]. It showed that fruit consumption was conspicu‐ ously absent in a survey of commonly consumed foods in all the 6 geo-political zones in Nigeria. The implication is that fruit intake as source of anti-oxidants and phytochemicals in Nigeria is disturbingly low and needs urgent intervention strategies. The low percentage of plants with proven anti-diabetic potentials underscores the need to explore anti-diabetic potentials of Nigerian rich biodiversity towards diversification of their utilization to optimize their health benefits. One significant observation (Table 2] is that apart from the *Afzelia*-cowpea pudding, all the diets investigated by various authors were based on starchy staples. These foods have high nutrient density and are consumed frequently and appreciably. They serve as desirable vehicles to improve utilization and consumption of phytochemical – and antioxidant–rich indigenous foods for improved diabetes control and prevention. However, the limitation of the work is that the identified diets were mostly reports from diets consumed in Southern Nigeria. There are wide variations in recipes used for the same traditional diets in many ethnic groups in Nigeria. The diets in this study may serve more or less as preliminary and/or available research work rather than representive of all Nigerian traditional diets. Another limitation is the differences in their concept and determination of "50g of digestible carbohydrate" of reference and experimental foods/diets. Some studies correctly determined the digestible carbohydrate contents of the food samples used, and some simply obtained the carbohydrate content by difference (proximate analysis). These discrepancies in the analytical methods pose some problems in the use of such available data. It calls for further clinical evidence-based studies to authenticate these claims for proper application in culinary practices and optimization of their health benefits.

**Family name**

Myrtaceae

Chrysobalanaceae

Bombacaceae

Cucurbitaceae

Cucurbitaceae

Cucurbitaceae

Labiatae

Tiliaceae

FRUITS

VEGETABLES

**Botanical name**

*Psidium guajava Linn.*

*Parinari curatollifolia*

*Adansonia digitata*

> *Citrulus lanatus*

*Telfairia occidentalis*

*Momordica charantia*

*Vernonia amygdalina*

*Occimum gratissimum*

> *Gnetum africana*

*Corchorus olitorus*

**C/W/ S**

C

W

W

C

C

S

S

W

**Part studied and form in which the food was prepared for assay**

> Fruit and fruit juice

Fresh fruit,

Leaves extract

Ground leaves pulp

Ground leaf pulp

Ground leaf pulp

Ground leaf pulp

Ground leaf pulp

**Type of assay (AM = animal model)**

Oleaceae *Carica papaya* W Fruit *In vivo* Dietary fibre Not determined [95]

*In vivo*

*In vitro; In vivo* (AM)

In vitro

*In vitro*

*In vitro*

*In vitro*

**Potential active ingredients**

**Anti-diabetic property**

http://dx.doi.org/10.5772/57240

(humans) [96, 97]

Anti-Diabetic Effects of Nigerian Indigenous Plant Foods/Diets

*In vivo* Mucilage Anti-hyperglycaemic [99]

Antioxidant; anti-

hyperglycaemic [101, 102]

hyperglycaemic [45, 24]

Hypoglycaemic [102, 103]

Not determined [102]

Not determined [102]

Not determined [102]

paste High viscosity Not determined [98]

C Seeds flour *In vitro* Dietary fibre Not determined [100]

High phytochemical constituents (alkaloids, tannins, flavonoids, steroids, anthacyanin, carotenoides)

<sup>S</sup> Fruit extract *In vivo* Phytochemicals Anti-oxidant, anti-

High phytochemical constituents (alkaloids, tannins, flavonoids, steroids, anthacyanin, carotenoides)

> The same constituents

> The same constituents

> The same constituents

**References**

75


tubers/fruits and cereals. Forty-eight families of plant foods were identified. Out of 241 plant species (spp) identified, 80 fruits, 77 vegetables, 68 spices and condiments, 22 grain legumes/ nuts/oil seeds and 19 starchy roots/tubers/fruits and cereals were documented. Twelve out of 22 grain legumes/nuts/oil seeds and 11 out of 19 roots/tubers/cereals were soup thickeners. Only 3 spp of fruits, 16 spp of vegetables, 27 spp of spices/condiments/grain legumes and 10 spp of starchy staples have anti-diabetic potentials *in vivo or in vitro* (Table 1]. Twenty-five indigenous diets as consumed had anti-diabetic effects (Tables 2]. Three of the *Candida tropicalis* fermented low GI starchy staple (cassava/maize/sorghum) flours were used to formulate high dietary fibre diets using food-based approach of 10% protein and 20g total dietary fibre/1000kcal in a 1:2 ratio of soluble: insoluble dietary fibre. The diets were composed of fermented cassava/maize/sorghum flours (commonly used to prepare thick paste tradition‐ ally known as "foofoo". They are eaten with traditional soup blended with *Cola gigantea* flour (a soup thickener) and other standard ingredients for rat bioassay to mimick traditional diets as consumed. These diets reduced post-prandial blood glucose concentrations of the diabetesinduced adult rats. More of the most commonly consumed vegetables than fruits were cultivated. The indigenous diets that had anti-diabetic effects did not contain any fruit group in their various recipes. They contained vegetables as part of the ingredients. This observation supports the report by Ene-Obong et al. [39]. It showed that fruit consumption was conspicu‐ ously absent in a survey of commonly consumed foods in all the 6 geo-political zones in Nigeria. The implication is that fruit intake as source of anti-oxidants and phytochemicals in Nigeria is disturbingly low and needs urgent intervention strategies. The low percentage of plants with proven anti-diabetic potentials underscores the need to explore anti-diabetic potentials of Nigerian rich biodiversity towards diversification of their utilization to optimize their health benefits. One significant observation (Table 2] is that apart from the *Afzelia*-cowpea pudding, all the diets investigated by various authors were based on starchy staples. These foods have high nutrient density and are consumed frequently and appreciably. They serve as desirable vehicles to improve utilization and consumption of phytochemical – and antioxidant–rich indigenous foods for improved diabetes control and prevention. However, the limitation of the work is that the identified diets were mostly reports from diets consumed in Southern Nigeria. There are wide variations in recipes used for the same traditional diets in many ethnic groups in Nigeria. The diets in this study may serve more or less as preliminary and/or available research work rather than representive of all Nigerian traditional diets. Another limitation is the differences in their concept and determination of "50g of digestible carbohydrate" of reference and experimental foods/diets. Some studies correctly determined the digestible carbohydrate contents of the food samples used, and some simply obtained the carbohydrate content by difference (proximate analysis). These discrepancies in the analytical methods pose some problems in the use of such available data. It calls for further clinical evidence-based studies to authenticate these claims for proper application in culinary practices

74 Antioxidant-Antidiabetic Agents and Human Health

and optimization of their health benefits.


**Botanical name**

*Zingiber officinale*

*Piper nigrum* C

*guineense*

*Cissus pulponea syn. rotundofolia*

*Pleurotus tuberegium*

> *Afzelia Africana*

*Brachystegia nigerica* Hoyle ex A. P. D. Jones

*Detarium microcarpum*

*Mucuna pruriens* (L.) D. C. var. utilis

> *Mucuna sloanei* Fawcett

*Vigna unguiculata* (L.) Walp var. *unguiculata*

*unguiculata*

Piperaceae *Piper*

Vitaceae

Basidiomycetes

Caesalpiniaceae

Caesalpiniaceae

Caesalpiniaceae

Fabaceae

Fabaceae

Fabaceae

Fabaceae *Vigna*

**C/W/ S**

W

W

C

**Part studied and form in which the food was prepared for assay**

> Fresh or dried rhizome powder

Fruit extract

Fruit extract

Sclerotium flour

W Stem flour

**Type of assay (AM = animal model)**

*In vivo* (AM)

**Potential active ingredients**

High viscosity,

W Seeds flour *In vitro* Dietary fibre Hypoglycaemic [42, 73]

W Seeds flour *In vitro* Dietary fibre Not determined [42]

W Seeds flour *In vitro* Dietary fibre Hypoglycaemic [42, 73]

C Seeds flour *In vitro* Dietary fibre Not determined [42]

C Seeds flour *In vitro* Dietary fibre Not determined [42]

<sup>C</sup> Seeds flour *In vivo* Dietary fibre Antihyperglycaemic,

C Seeds flour *In vivo* Not determined

**Anti-diabetic property**

http://dx.doi.org/10.5772/57240

*In vivo* Not determined Antihyperglycaemia [24, 47]

Anti-Diabetic Effects of Nigerian Indigenous Plant Foods/Diets

*In vitro* Flavonoids Anti-oxidant [45]

*In vitro* Flavonoids Anti-oxidant [45]

*In vitro* Dietary fibre Not determined [42]

dietary fibre Hypoglycaemic [70]

anti-hyperlipidaemic [106, 109]

[109]

Antihyperglycaemia, antihyperlipidaemia

**References**

77


Alliaceae

Euphorbiaceae

**Botanical name**

76 Antioxidant-Antidiabetic Agents and Human Health

*santalinoides*

*Pterocarpus mildbreadii*

*Abelmoschus esculentus*

*Solanium melongena*

*Solanum tuberosum*

> *Moringa olifera*

*Allium cepa var. aggregatum*

*Ricinus communis*

*Gongronema latifolium*

> *Murraya koenigii*

Alliaceae *Allium sativa* C

Fabaceae *Pterocarpus*

**C/W/ S**

W

S

S

W

C

C

W

SPICES AND CONDIMENTS/ GRAIN LEGUMES, NUTS, OIL SEEDS

Bulb extract

Seeds extract

Ground leaves pulp

Leaves extract

**Part studied and form in which the food was prepared for assay**

Ground leaf pulp

Ground leaf pulp

Leaves and seeds extracts

Dried bulb powder

W Pod

**Type of assay (AM = animal model)**

*In vitro*

*In vitro*

*In vivo* (animal model)

<sup>C</sup> fruit *In vitro* Phytochemical

*In vivo* in human & AM

*In vivo* (human & AM)

*In vivo* (human/A M)

> *In vivo* (AM)

> *In vivo* (AM)

**Potential active ingredients**

> The same constituents

> The same constituents

Mucilage, dietary fibre

(anthocyanin)

C Stem *In vitro* Resistant starch Anti-hyperglycaemic [45]

Phytochemicals

Anthocyanins

Anthocyanins (allicin)

Not determined

High phytochemical constituents (alkaloids, tannins, flavonoids, steroids, anthacyanin, carotenoides)

**Anti-diabetic property**

Not determined [102]

Not determined [102]

Anti-oxidant [45]

Antioxidant antihyperglycaemic

Antihyperglycaemia; anti-lipidaemia

Anti-

Antihyperglycaemia [47]

Anti-

Not determined Hypoglycaemic [24, 47]

hyperglycaemia [24, 47]

hyperglycaemia [108]

Not determined [102]

**References**

[99, 104, 105, 106]

[107]


**Botanical name**

Poaceae *Zea mays* C

Poaceae *Sorghum*

Euphorbiaceae

Musaceae

groups

*bicolor*

*Manihot esculenta*

*Ipomea batatas*

*Musa paradisica*

*Abrus precatorius*

C = Cultivated; W = Wild; Semi-wild = S

C

C

C

**C/W/ S**

Poaceae *Oryza sativa* C Seeds flour *In vivo*

**Part studied and form in which the food was prepared for assay**

Seeds, *Candida tropicalis* fermented flour

Seeds, *Candida tropicalis* fermented flour

Roots, *Candida tropicalis* fermented flour

Leaf and stem extracts; stem

<sup>C</sup> Unripe fruit flour

Seeds flour

*In vivo* (AM)

*In vivo* (animal model)

*In vivo* (AM)

**Table 1.** List of identified Nigerian indigenous plant foods (single foods) with anti-diabetic potentials/effects by food

**Type of assay (AM = animal model)**

Seeds flour *In vitro* Dietary fibre

**Potential active ingredients**

Dietary fibre, polyphenols and phytic acid

*In vitro* Dietary fibre, low GI Not determined [120]

*In vitro* Dietary fibre, low GI Not determined [120]

*In vitro* Dietary fibre, low GI Not determined [120]

Anti-oxidant,

Anti-oxidant,

Not determined Hypoglycaemic [24, 114]

hypoglycaemia; [24, 121]

hypoglycaemia [89]

Flavones ; dietary fibre

Saponins, flavonoids, tannins & alkaloids

**Anti-diabetic property**

http://dx.doi.org/10.5772/57240

Anti-Diabetic Effects of Nigerian Indigenous Plant Foods/Diets

Antihyperglycaemia

Anti-hyperglycaemic [119]

**References**

79

[116, 117, 118]


Fabaceae

Lauraceae

Papilionaceae

Papilionaceae

Dioscoreaceae

Dioscoreaceae

Papilionaceae *Cajanus cajan*

**Botanical name**

78 Antioxidant-Antidiabetic Agents and Human Health

(L.) Walp var. *dekindtiana*

*Arachis hypogea* (L.)

(L.)

*gabonensis*

*wombulu*

*Bielschmedia gabonensis* (Meisn) Benth. ex Hook. f.

*Sphenostylis sternocarpa* (a. Rich.) Harms

*Vigna subterranean* (L.) Verdc.

(L.) Millip.

STARCHY/ROOTS/TUBERS/FINGERS & CEREALS

*Dioscorea documentum*

> *Dioscorea alata*

Sterculiaceae *Cola gigantea* <sup>W</sup> Seeds flour *In vitro* High viscosity,

C

Sterculiaceae *Garcina cola* <sup>C</sup> Nuts Not determined Anti-oxidant,

*In vivo* (AM)

Tubers extract

Fabaceae *Glycine max.*

Irvingiaceae *Irvingia*

Irvingiaceae *Irvingia*

**C/W/ S**

**Part studied and form in which the food was prepared for assay**

**Type of assay (AM = animal model)**

<sup>C</sup> Seeds flour *In vitro* Soluble dietary

<sup>S</sup> Seeds flour *In vitro* Soluble dietary

<sup>W</sup> Seeds flour *In vitro* High viscosity,

**Potential active ingredients**

C Seeds flour *In vitro* Mucilage Not determined [38]

C Seeds flour *In vitro* Dietary fibre Not determined [110]

dietary fibre, low GI

<sup>C</sup> Seeds flour *In vitro* Dietary fibre Antihyperglycaemia,

<sup>C</sup> Seeds flour *In vitro* Dietary fibre Antihyperglycaemia,

C Seeds flour *In vivo* Dietary fibre Anti-hyperglycaemic [42]

dietary fibre, low GI

C Tuber flour *In vitro* Dietary fibre Not determined [115]

**Anti-diabetic property**

fibre Anti hypoglycaemic [106, 111]

fibre Anti-hypoglycaemic [106, 111]

Not determined [112]

anti-hyperlipidaemic [109]

anti-hyperlipidaemic [106, 109]

Not determined [112]

[113, 114, 24]

hypoglycaemic

Alkaloids Hypoglycaemic [24]

**References**

**Table 1.** List of identified Nigerian indigenous plant foods (single foods) with anti-diabetic potentials/effects by food groups


**Name of local diet as consumed/ snacks/drinks**

*(Corchorus olitorius)* soup

Fermented cassava flour with *'ewedu' (Corchorus olitorius)* soup

Maize flour with *'ewedu' (Corchorus olitorius)* soup

Fermented cassava flour with "ogbono soup

Plantain flour with 'ogbono'soup

Fermented cassava flour with "egusi soup'

Plantain flour with 'egusi soup'

> Fermented cassava flour with pepper soup

Plantain flour with pepper soup

**Description of diet**

prepared with *Corchorus olitorius* leaves, tomato sauce, beef, salt, local spices

Cooked, thick paste made from *Manihot esculenta* tuber flour (*lafun)*consumed with traditional soup prepared with *Corchorus olitorius* leaves

Cooked, thick paste made from *Zea mays* flour consumed with raditional soup prepared with *Corchorus olitorius* leaves

Cooked, thick paste made from *Manihot esculenta* flour (*lafun)* consumed with traditional soup prepared with Irvingia spp seeds

Cooked, thick paste made from *Musa parasidiaca* flourconsumed with traditional soup prepared with *Irvingia* spp seeds

Cooked, thick paste made from *Manihot esculenta* root flourconsumed with traditional soup prepared with *Colocynthis citrillus* seeds

Cooked, thick paste made from *Musa parasidiaca* flourconsumed with traditional soup prepared with *Colocynthis citrillus* seeds other ingredients

Cooked, thick paste made from *Manihot esculenta* root flourconsumed with traditional soup prepared with *piper spp* and other ingredients

Cooked, thick paste made from *Musa parasidiaca* flourconsumed with traditional soup prepared with *piper spp* and other ingredients

**Type of assay AM= animal model**

> *In vivo* (humans)

> *In vivo* (humans)

> *In vivo* (humans)

> *In vivo* (humans)

> *In vivo* (humans)

> *In vivo* (humans)

> *In vivo* (humans)

> *In vivo* (humans)

**Potential active ingredients**

Anti-Diabetic Effects of Nigerian Indigenous Plant Foods/Diets

High viscosity; reduced digestibility

High viscosity; reduced digestibility

High viscosity; reduced digestibility

High viscosity; reduced digestibility

High viscosity; reduced digestibility

High viscosity; reduced digestibility

**Anti-diabetic property**

http://dx.doi.org/10.5772/57240

Low GI Hypoglycaemic [127]

Low GI Hypoglycaemic [127]

Hypoglycaemic [128]

Hypoglycaemic [128]

Hypoglycaemic [128]

Hypoglycaemic [128]

Hypoglycaemic [128]

Hypoglycaemic [128]

**Ref.**

81


**Name of local diet as consumed/ snacks/drinks**

80 Antioxidant-Antidiabetic Agents and Human Health

*Detarium macrocarpum* soup meal

*Detarium* bread meal

*Sphenostylis sternocarpa* gruel

*Afzelia-*cowpea moi-moi

Gari with *afang* soup

Pounded yam with *edikang ikong* soup

*Ekpang nkukwo*

Plantain porridge with beans

*Afzelia*-plantain based biscuits

Yam flour with *'ewedu'*

**Description of diet**

Traditional soup prepared with *Detarium* seed flour, meat, fish, red palm oil, salt, spinach, fresh tomatoes, waterand consumed with boiled *Oryza sativa* seeds

Breadrolls prepared with *Detarium* seed flour and other basic bread ingredients (hydrogenated fat, improver, fresh yeast, water)

Gruelprepared with *Sphenostylis* seed flour and water to produce a gruel

Moi-moi (*V. unguiculata* seed pudding) prepared with *Afzelia* seed flour

Gari *with Gnetum africanum* leaf-based traditional soup prepared with modified recipe by Ana (125)

*Talinum triangulare* and *Telfairia occidentali*s leaves-based traditional soup prepared with modified recipe by Ana (125) and consumed with boiled yam (*Dioscorea rotundata)* tuber pounded into a thick dough

Cocoayam *(Colocasia esculentum) corm*/ wateryam (*Dioscorea alata) tuber* pudding prepared with modified recipe by Ana (125)

*Musa paradisiaca* fruit cooked with *V. unguiculata* to produce a savoury dish with modified recipe Ana (125)

*Afzelia* seed and plantain (*Musa paradisiaca*) finger flours prepared with other basic biscuit ingredients (baking fat, salt and water without sugar)

Cooked, thick paste made from *Dioscorea rotundata* tuber flour (*amala*) consumed with traditional soup

**Type of assay AM= animal model**

*In vivo*

*In vivo*

*In vivo*

*In vivo*

*In vivo*

*In vivo* (humans)

**Potential active ingredients**

(humans) Dietary fibre Hypoglycaemic [122]

(humans) Dietary fibre Anti-hyperglycaemic [123]

(humans) Dietary fibre Anti-Hyperglycaemic [124]

(humans) Dietary fibre Anti-Hyperglycaemic [72]

*In vivo* (AM) Not determined Anti-Hyperglycaemic [126]

*In vivo* (AM) Not determined Anti-Hyperglycaemic [126]

*In vivo* (AM) Not determined Anti-Hyperglycaemic [126]

*In vivo* (AM) Not determined Anti-Hyperglycaemic [126]

(humans) Dietary fibre Anti-Hyperglycaemic [71]

Low GI Hypoglycaemic [127]

**Anti-diabetic property**

**Ref.**


**Name of local diet as consumed/ snacks/drinks**

C = Cultivated; W = Wild; Semi-wild = S

therapeutic potentials.

of traditional diets as consumed in Nigeria.

**Description of diet**

protein and 20g total dietary fibre/ 1000kcal

**13. Conclusions and recommendations**

**Table 2.** List of identified Nigerian indigenous plant-based diets with anti-diabetic effects

**Type of assay AM= animal model**

Diet therapy, undisputedly, has long been recognized as key tool in the clinical management of diabetes. The challenge centres on how to translate the existing scientific evidence into practical terms for individual and household application in the management of diabetes mellitus. Relatively, a few clinical studies were published in Nigeria. Widely used parameters for diabetes-related clinical studies in Nigeria are post-prandial blood glucose response, antioxidant activity, lipid profiles and GI of diets. Most of the studies conducted on single foods were on dietary fibre. Much more indepth research is needed on phytochemical constituents of the rich national flora as regards phytochemical index and diabetes control. This is because health benefits of these indigenous plants are of public health importance. Based on recent documentation, Nigeria is rich in varieties of plant foods. Only a few varieties or cultivars were captured relative to diverse nature of Nigeria. It has generated a database for future investi‐ gations. Relevant research outputs on the plant foods would encourage diversification and increase consumption to maintain dietary adequacy and optimize their health benefits/

Much of the *in vivo* studies on antidiabetic effects of indigenous diets were conducted on human subjects. Levels of incorporation of fruits and vegetables into the traditional recipes are inadequate. The recipes used for traditional diets vary from one region/ethnic group to another in Nigeria. The variations in recipes for these diets might influence their nutrient concentrations and effects on blood glucose level. It is imperative to fill this gap using FBDG. This guideline proposed by FAO/WHO/UNU [76] has not been embraced and applied widely to enhance their health benefits in communities despite its advantages over the traditional and orthodox medicine. Rat study model to simulate this approach using high dietary fibre plantbased diet showed that traditional mixed diet as consumed can attenuate post-prandial blood glucose concentration in diabetic adult rats. There is research need to focus on wider varieties

The goal for optimizing the use of indigenous plants with anti-diabetic potentials to control and prevention type 2-diabetes rests on conducting controlled clinical trials using food-based approach as the last step to establish their efficacy in humans. Evidently, these diets adequate

**Potential active ingredients**

Anti-Diabetic Effects of Nigerian Indigenous Plant Foods/Diets

**Anti-diabetic property**

http://dx.doi.org/10.5772/57240

**Ref.**

83


**Table 2.** List of identified Nigerian indigenous plant-based diets with anti-diabetic effects
