Tuesday, 25 July 2017

Re: Satiety Effects of Baobab Fruit in Healthy Adults

  • Baobab (Adansonia digitata, Malvaceae)
  • Satiety
Date: 07-14-2017HC# 061741-572

Garvey R, Clegg M, Coe S. The acute effects of baobab fruit (Adansonia digitata) on satiety in healthy adults. Nutr Health. June 2017;23(2):83-86.
Excessive weight gain is involved in many chronic and acute diseases, ranging from type 2 diabetes to congestive heart failure, several types of cancer, arthritis, gastrointestinal disease, and many others. Baobab (Adansonia digitata, Malvaceae) is a unique tree native to Sub-Saharan Africa. The tree's fruits have a high polyphenol content and consist of about 44% soluble and insoluble dietary fibers. Both dietary fiber and polyphenols have been associated with increased feelings of satiety, potentially reducing hunger, and are thus of interest in alternative weight-control approaches.
The authors conducted a single-blind, randomized, crossover study at the Nutrition Laboratory in the Functional Food Centre of Oxford Brookes University (Oxford, United Kingdom). They compared the effects of consuming 15 g of baobab fruit powder (Baobab Superfruit Powder; Minvita; Watford, United Kingdom) in a breakfast drink ("smoothie") with those of consuming a control smoothie. Subjects meeting inclusion criteria were 18-40 years of age, had a body mass index [BMI] 18-30 kg/m2, were not taking prescription medicines, had no genetic or metabolic diseases, were not pregnant or lactating, and were unrestrained eaters.*
Both the control and test smoothies contained 44.2 g carbohydrates, although they differed in other parameters. The control drink consisted of 327 mL orange (Citrus sinensis, Rutaceae) juice (Tesco; Hertfordshire, United Kingdom) and 100 g frozen mango (Mangifera indica, Anacardiaceae) (Tesco); the test smoothie had the same amount of mango, 300 mL orange juice, and 15 g baobab fruit powder. The test smoothie contained 1914 μg/mL polyphenols and the control drink contained 776 μg/mL polyphenols. Total energy in the control smoothie was 213.8 kcal and in the test drink, 227.5 kcal. Total fiber in the test smoothie was 11.9 g compared to the control drink's 2.6 g. The test drink was higher in vitamin C content than the control drink (172 mg vs. 135.1 mg, respectively), had more protein (3.55 g vs. 1.6 g, respectively), and weighed less (415 g vs. 427 g, respectively).
On the first study day, subjects were weighed and measured and completed a health questionnaire and the Dutch Eating Behavior Questionnaire. Subjects were asked to limit caffeine and alcohol intake and avoid strenuous physical activity the day before each study session; they also fasted the night before each session. At the beginning of the first session, subjects completed a 24-hour dietary recall and were asked to follow the same diet the day before their second session.
Twenty healthy subjects (including 13 females) each drank 2 separate smoothies on 2 different days separated by at least 3 days. Subjects were given 15 minutes to consume the smoothie, then provided 250 mL water to drink. Two hours after each smoothie was consumed, subjects ate an ad libitum meal made of up pre-selected sandwiches. Sandwiches for the ad libitum meal were selected by each subject from 7 options, all of which were matched for calories. Subjects had 30 minutes to eat and were told to eat until they felt comfortably full. Leftovers were weighed and calories consumed were calculated.
Subjects rated their feelings of satiety using a paper 100-mm visual analog scale (VAS) just before consuming each smoothie, every 15 minutes following consumption for 1 hour, and every 30 minutes for the second hour before the ad libitum meal was served. A VAS was also used to rate the palatability and pleasantness of each smoothie.
There were no significant differences in energy intake or total carbohydrate, fat, or protein intake at ad libitum meals consumed after the test smoothie and the control drink (P=0.052). There were no significant differences in any appetite score except hunger (P<0.05), greater after the control smoothie than the test drink. There were no significant differences in VAS scores for either palatability or pleasantness of the 2 drinks.
The significant reduction in hunger after drinking the baobab smoothie may have been due to delayed gastric emptying of this fiber-rich product. In the only other study known to assess baobab's effect on satiety, also conducted by these authors, baobab was given in a drink along with bread, and no significant effect on satiety was found. Polyphenols in the test drink may have reduced glycemic response; foods with a lower glycemic index are associated with greater satiety. Also, previous studies show that normal mechanisms of satiety may be overridden by a free meal. This may have been the case in this study, where food intake at the ad libitum meal was the same after each smoothie, but hunger was significantly less after the test drink. More research on baobab's effects on hunger should be pursued.
—Mariann Garner-Wizard
*No summary of this biodata is provided. Since the study took place in a university setting, it is possible that most subjects in this small group were students. Including data about the subjects' ages, BMIs, etc., would have been useful in assessing the generalizability of results.
Editorial Comment:
In one instance in this report, the opposite word of what was clearly intended was used. The article states that previous studies found "that reduced [italics added] feelings of satiety using VAS are not always accompanied by a reduced energy intake at a subsequent meal." The statement applies to increased feelings of satiety.