Baobab, or the tree of life, has been providing people with a nutritional food source for thousands of years. Many of those who add baobab fruit to their diet believe it has had health benefits. Nutritional research scientists are starting to study the baobab fruit to see if these people’s beliefs can be substantiated.

Here you will find a collection of some of the latest research into the health benefits of the baobab fruit. As research into the health benefits of the baobab fruit is relatively new, it should be considered directional and not definitive.

 

 

Research on the health benefits of the baobab fruit

Investigation of polyphenol synergism for reducing sugar release from white bread

Abstract:

Polyphenols are known to exhibit a number of health promoting effects such as reducing the postprandial glycaemic response. It has been proposed that polyphenols in combination, as found together naturally in foods exert synergistic health effects compared to isolated polyphenols. In the body, polyphenols undergo structural changes throughout digestion which can alter their bioavailability and thus their health impact.

Previous results from our lab found that after being baked into white bread in isolation, the polyphenol rich green tea extract (GTE) at 0·4%, grape seed extract (GSE) at 0·2%, resveratrol (RES) at 0·22% and baobab fruit extract (BAO) at 1·88% reduced rapidly digestible starch (RDS)(1,2). RDS takes place 20 minutes into the duodenal stage of digestion when sugar release is most pronounced and therefore contributes greatest to the glycaemic index (GI) of the food. Using the same optimal isolated extract doses for reducing sugar release from bread in previous studies (with a 75% variation to increase the variety of extract combinations used), the objective was to determine if polyphenol rich extracts showed a synergistic effect in reducing sugar release from high GI white bread.

Bioaccessibility of polyphenols was analysed using an in vitro digestion model adapted from Ryan et al.(3) to determine the stability of polyphenols throughout the digestive process. RDS sugar release was measured using the method by Mishra & Monro(4) followed by a colourimetric method by Englyst & Hudson(5).

Bioaccessibility increased for all extracts (p < 0·05; non-significant for RES) illustrating that polyphenols become potentially more available in the body throughout digestion. Although polyphenol rich extracts in isolation were shown to reduce sugar release from high GI bread, in combination there was no reduction. Therefore, many factors must be considered when using polyphenols as functional food additives.

1. Coe S & Ryan L (2013) Proc Nutr Soc, 72, E201.
2. Coe S et al. (2013) Nutr Res, 33, 888–896.
3. Ryan L et al. (2008) Pla Food Hum Nutr, 63, 127–133.
4. Mishra S & Monro JA (2009) J Cereal Sci, 50, 61–66.
5. Englyst HN & Hudson GJ (1987) Food Chem, 24, 63–76.

Copyright©2015 Proceedings of the Nutrition Society


Authors:

Shelly Coe

  • Functional Food Centre, Department of Sport and Health Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford OX3 0BP

Lisa Ryan

  • Functional Food Centre, Department of Sport and Health Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford OX3 0BP
  • Department of Nutrition and Dietetics, Monash University, Faculty of Medicine, Nursing and Health Sciences, Vic 3168, Australia
Research on the health benefits of the baobab fruit

Sugar release from various starch rich foods with added polyphenol extracts

Abstract:

The glycaemic index (GI) provides a measure of the increase in blood glucose (BG) levels after consumption of a food. Starch rich foods with high GI values cause a rapid rise in BG and frequent consumption of these types of foods can increase the risk of developing type 2 diabetes. Therefore, any compound that can decrease this rise in BG may prove beneficial in reducing the risk of certain disease states. Polyphenols are plant secondary metabolites found ubiquitously in plants and have been found to reduce the release of sugars for absorption into the body from starch rich foods, either by inhibiting digestive enzymes(1) or by binding to the starch molecules in the food and reducing their breakdown(2). Unpublished results from our lab have shown that certain polyphenol rich extracts such as green tea extract (GTE), grape seed extract (GSE), resveratrol and baobab fruit extract have been shown to decrease the amount of reducing sugars released from white bread (GI of 100) after being baked into the bread. The aim of this study was to determine if the same four polyphenol rich extracts could reduce sugar release from other medium/high GI, starch rich foods such as white flatbread (GI of approximately 72) and gluten free white bread (GI of approximately 70).

Extracts were baked into all starch food systems at GTE 0.40%, GSE 0.20%, Baobab fruit 1.88% and Resveratrol 0.22%. The in vitro digestion method adapted by Mishra & Monro(3) was used, followed by a colourimetric method by Englyst & Hudson(4) to determine total reducing sugars released throughout digestion at the salivary phase, the gastric phase and 20, 60 and 120 minutes into the duodenal phase. Sugar release at 20 minutes into the duodenal phase was considered the stage corresponding to GI and was therefore used to measure any reduction in sugar release(5). Sugar release was expressed in mg per gram of bread sample.

All extracts significantly (p<0.05) reduced sugar release from white bread at 20 minutes into duodenal digestion. There was no reduction in 20 minute sugar release for any of the extracts, in either the flat bread or the gluten free bread, compared to the control. Polyphenol rich extracts can reduce the release of sugar available for absorption only from certain high GI starch rich foods, and therefore show potential in reducing the glycaemic response in humans. Future work will look at increasing the dose of extract added into foods on sugar release, and also at the potential of polyphenols on sugar release from other medium to high GI, starch rich foods.

1. Tadera K, Minami Y, Takamatsu K & Matsuoka T (2006) J Nutr Sci Vitamin, 52, 149–153.
2. Yuste P, Longstaff M & McCorquodale C (1992) Brit J Nutr, 67, 57–65.
3. Mishra S & Monro JA (2009) J Cereal Sci, 50, 61–66.
4. Englyst HN & Hudson GJ (1987) Food Chem, 24, 63–76.
5. Englyst KN, Englyst HN, Hudson GJ, Cole TJ & Cummings JH (1999) AJCN, 69, 448–454.

Copyright©2013 Proceedings of the Nutrition Society


Authors:

Shelly Coe

  • Functional Food Centre, Department of Sport and Health Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford OX3 0BP, UK

Lisa Ryan

  • Functional Food Centre, Department of Sport and Health Sciences, Oxford Brookes University, Gipsy Lane, Headington, Oxford OX3 0BP, UK
Research on the health benefits of the baobab fruit

The acute effect of a baobab fruit (Adansonia digitata) smoothie on cognitive function in healthy adults

Abstract:

The baobab fruit is high in both dietary fibre and polyphenols. Results from previous studies show that foods rich in low glycaemic dietary fibre(1) and those that are abundant in polyphenols(2), can improve cognitive function. The aim of the study was to measure the effect of baobab fruit extract on different measures of cognition in healthy adults. This study was a one-day single blind randomised crossover design (3 day washout) conducted on 20 participants (7 men, 13 women; aged 21–40 year; BMI 18–30 kg/m2). Participants were randomised to consume either a test smoothie consisting of 15g of baobab extract (1914μg/ml polyphenols) or a control smoothie without the addition of baobab (776μg/ml polyphenols), on different days in the morning after an overnight fast at Oxford Brooke University. Cognitive tests were administered 90 mins post consumption after a brief familiarisation of the tests. Cognitive measures were based on previous literature into polyphenols, and included executive function utilising the Stockings of Cambridge test(3) and spatial working memory (PsychoPy v1·82) designed by the researchers(4).

Results are means and standard deviations (SD) of all measures after the consumption of control and baobab smoothies in Percentages (%), Seconds (s) or Milliseconds (ms). Stockings of Cambridge (SOC); Response (Resp).* = p < 0·05 performed significantly better. PsychoPy and SOC test data were analysed using a Wilcoxon – Signed Rank test. Consumption of the baobab enriched smoothie significantly reduced movement duration (p < 0·05) but also increased unsuccessful move type in the Stockings of Cambridge test (p < 0·05). There were no significant differences between testing order. Compared with the taste and nutrient matched control, there were several trends in favour of the baobab smoothie (albeit not significant). Baobab consumption administered at 15 g in a smoothie significantly improved reaction time in executive planning tests, but also increased the amount of unsuccessful move types. This research has positive implications for the use of baobab consumption first thing in the morning for improving cognitive function in the hours post prandial.

References
1. Ingwerson et al. (2007) Appet 49, 240–244.
2. Lamport et al. (2012) Nutr Aging 1, 5–25.
3. File et al. (2005) Menopa 12, 193–201.
4. Field et al. (2011) Phys Behav 103, 255–60.

Copyright©2017 Proceedings of The Nutrition Society – https://doi.org/10.1017/S0029665117000167


Authors:

Shelly Coe

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK

A. Bycroft

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK
Research on the health benefits of the baobab fruit

The acute effects of baobab fruit (Adansonia digitata) on satiety in healthy adults

Abstract:

Background: The baobab fruit is high in both dietary fibre and polyphenols and therefore may increase satiety. The aim of the study was to measure the effects of baobab fruit extract on satiety. Methods: The study was conducted on 20 healthy participants. The study was a one-day single-blind crossover design. Participants were randomised to either a test smoothie consisting of 15 g of baobab extract or a control smoothie without the addition of baobab. Subjective ratings of satiety were taken on visual analogue scales immediately pre-consumption and then post-consumption, and energy intake at a post ad libitum meal was recorded. Results: Subjective measures of hunger were reduced following the test smoothie compared with the control (p < 0.05). There was no significant difference in calorie intake at an ad libitum meal. Conclusions: This research has positive implications for the use of baobab for reducing hunger, possibly having a positive effect on weight maintenance.

Copyright© 2017 Sage Journals – Nutrition & Health – https://journals.sagepub.com/home/nah


Authors:

Shelly Coe

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK

Miriam Clegg

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK

Rebecca Garvey

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK
Research on the health benefits of the baobab fruit

The polyphenol-rich baobab fruit (Adansonia digitata L.) reduces starch digestion and glycemic response in humans

Abstract:

The baobab fruit (Adansonia digitata L.) is found throughout regions of Africa and is becoming increasingly recognized for its high nutrient and polyphenol content. Polyphenols have been beneficial for their effects on reducing the glycemic response (GR) and for improving various other metabolic parameters. Based on previous research, it was hypothesized that the baobab fruit extract would reduce starch digestion in vitro and would show potential for reducing the GR and for increasing satiety and diet-induced thermogenesis in humans. Six extracts of baobab from 6 different locations in Africa were measured for their antioxidant and polyphenol content using the ferric ion–reducing antioxidant power and the Folin-Ciocalteu methods, respectively. Baobab extract was baked into white bread at different doses to determine the optimal dose for reducing starch breakdown and sugar release from white bread after an in vitro digestion procedure. In vivo, baobab extract was consumed in solution at both a low-dose (18.5 g) and a high-dose (37 g) aqueous drink in 250 mL of water along with white bread, and resulting GR, satiety, and postprandial energy expenditure were measured. All extracts in this study were shown to be good sources of polyphenols. Baobab fruit extract added to white bread at 1.88 % significantly (P < .05) reduced rapidly digestible starch from white bread samples. In vivo, the baobab fruit extract at both low and high doses significantly (P< .05) reduced GR, although there was no significant effect on satiety or on energy expenditure.

Copyright © 2013 Elsevier Inc. All rights reserved. – https://doi.org/10.1016/j.nutres.2013.08.002


Authors:

Shelly Coe

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK

Lisa Ryan

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK
  • Department of Nutrition and Dietetics, Monash University, VIC 3168, Australia

Miriam Clegg

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK

Mar Armengol

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK
Research on the health benefits of the baobab fruit

Impact of polyphenol-rich sources on acute postprandial glycaemia: a systematic review

Abstract:

Increasingly, evidence suggests a role for polyphenols in blood glucose control. The objective of this systematic review was to evaluate the effect of polyphenol-rich sources in combination with carbohydrate sources on resulting postprandial glycaemic and insulin responses. A literature search was conducted using Medline, CINHAL and Web of Science databases. Selected studies included randomised controlled trials in which the association of polyphenol-containing food or beverage consumption with a carbohydrate source and effect on acute postprandial glycaemia and/or insulin was reported. A total of thirteen full articles were included in the review. Polyphenol sources included coffee, black tea, fruit juice, plant extracts, berries and different rye breads, and carbohydrate sources included bread, pancakes and simple sugars such as sucrose, glucose and fructose. Although glycaemic and insulin responses differed depending on the polyphenol–carbohydrate combination, overall, polyphenol sources were shown to reduce the peak and early-phase glycaemic response and maintain the glycaemic response in the later stages of digestion. To a lesser extent, polyphenol sources were also shown to reduce peak insulin response and sustain the insulin response, especially when consumed with bread. This review supports epidemiological data suggesting that polyphenols in foods and beverages may have a beneficial effect on reducing the risk of type 2 diabetes. However, the extent of this effect is variable depending on the polyphenol and carbohydrate source.

©Journal of Nutritional Science (2016), vol. 5, e24


Authors:

Shelly Coe

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK

Lisa Ryan

  • Department of Nutrition and Dietetics, Monash University, 264 Ferntree Gully Rd., Notting Hill, VIC 3168, Australia
  • Department of Natural Sciences, Galway-Mayo Institute of Technology, Dublin Rd., Galway, Ireland
Research on the health benefits of the baobab fruit

White bread enriched with polyphenol extracts show no effect on glycemic response or satiety, yet may increase postprandial insulin economy in healthy participants

Abstract:

Extracts from different plant sources have been shown to modify starch digestion from carbohydrate-rich foods and lower resulting glycemia. It was hypothesized that extracts rich in polyphenols, added to white bread, would improve the glycemic response and insulin response and increase satiety in healthy participants. An in vitro dose-response analysis was performed to determine the optimal dose of a variety of extracts (baobab fruit extract, green tea extract, grape seed extract, and resveratrol) for reducing rapidly digestible starch in white bread. The 2 extracts with the greatest sugar reducing potential were then used for the human study in which 13 volunteers (9 female and 4 male) were recruited for a crossover trial of 3 different meals. On separate days, participants consumed a control white bread, white bread with green tea extract (0.4%), and white bread with baobab fruit extract (1.88%). Glycemic response, insulin response, and satiety were measured 3 hours postprandially. Although enriched breads did not reduce glycemic response or hunger, white bread with added baobab fruit extract significantly (P < .05) reduced the total (0-180 minutes) and segmental insulin area under the curve at 0 to 90, 0 to 120, and 0 to 150 minutes, and therefore reduced the amount of insulin needed for a given blood glucose response. This preliminary research suggests that there is potential for baobab fruit extract added into white bread to improve insulin economy in healthy adults.

© 2015 Elsevier Inc. All rights reserved. – https://doi.org/10.1016/j.nutres.2015.10.007


Authors:

Shelly Coe

  • Functional Food Centre, Oxford Brookes University, Gipsy Lane, Oxford OX3 OBP, UK

Lisa Ryan

  • Department of Nutrition and Dietetics, Monash University, 264 Ferntree Gully Rd., Notting Hill, VIC 3168, Australia
  • Department of Natural Sciences, Galway-Mayo Institute of Technology, Dublin Rd., Galway, Ireland