رنده مقبل بن محمد القرشي

مجال
التميز

تميز دراسي وبحثي

البحوث المنشورة

البحث (1):

عنوان البحث:

Consumption
of a flavonoid-rich açai meal is associated with acute improvements in
vascular function and a reduction in total oxidative status in healthy
overweight men

رابط إلى البحث:

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تاريخ النشر:

28/09/2016

موجز عن البحث:

BACKGROUND:

Açai
(Euterpe oleracea) is a polyphenol-rich fruit marketed as beneficial for
health. Experimental data showing improvements in health markers arising from
açai consumption in humans is limited.

OBJECTIVE:

The
objective of the present study was to investigate the effect of açai
consumption on acute changes in vascular function and on other disease risk
markers, including postprandial plasma insulin, glucose, and oxidative
stress.

DESIGN:

Twenty-three
healthy male volunteers, aged 30-65 y and with a body mass index (in kg/m2)
of 25-30, completed a randomized, controlled, high-fat challenge,
double-blind, crossover, acute dietary intervention trial. The volunteers consumed
either an açai-based smoothie (AS) or a macronutrient-matched control
smoothie (PS) together with a high-fat breakfast meal challenge. The primary
endpoint was the assessment of endothelial function in the brachial artery by
flow-mediated dilatation (FMD).

RESULTS:

The
acute consumption of an AS containing 694 mg total phenolics improved
vascular function, with postprandial increases in FMD from baseline of 1.4%
at 2 h compared with 0.4% after consumption of the PS (P = 0.001) and
increases at 6 h of 0.8% for the AS compared with -0.3% for the PS (P <
0.001). There was also a significantly lower incremental area under the curve
(iAUC) for total peroxide oxidative status after açai consumption relative to
the control. No significant changes were observed in blood pressure, heart
rate, or postprandial glucose response. However, the first postprandial
insulin peak (after breakfast) and the iAUC for insulin were elevated for the
AS relative to the PS.

CONCLUSIONS:

In
this acute study in overweight men, açai consumption was associated with
improvements in vascular function, which may lower the risk of a
cardiovascular event. Future intervention studies, perhaps with a chronic
design, in wider populations and with other biomarkers of disease risk are
needed to fully elucidate the benefits of açai to health. This trial was
registered at clinicaltrials.gov as NCT02292329.

المؤتمرات العلمية:

المؤتمر (1):

عنوان المؤتمر:

7th  International conference on polyphenols and
Health

تاريخ الإنعقاد:

27/10/2015

مكان
الإنعقاد:

Tours, France

طبيعة المشاركة:

Poster presentation

عنوان المشاركة:

The digestive fate of polyphenols from açai
in a simulated model of the gastrointestinal tract

ملخص المشاركة:

Background: The
acai fruit (Euterpe oleracea Mart) is widely consumed in the amazon basin, it
is a rich source of polyphenols, fatty acids and carotenoids(1,2). The rich
purple colour of acai pulp is due to its high anthocyanin content.
Anthocyanins are thought to contribute to the fruits’ high antioxidant
capacity and their consumption is independently associated with protection
against disease (3). The assumption that the phytochemicals present in acai
are capable of exerting health benefits in man assumes that they are either
stable through the gastrointestinal tract or that their breakdown products
are also bioactive and bioavailable. We aimed to assess the fate (and likely
bioavailability) of acai polyphenols in a simulated model of the
gastrointestinal and a subsequent 24 hour faecal batch culture.

Aim: Having previously characterized
the polyphenols present in extracts of acai pulps, we aimed to assess the
fate (and likely bioavailability) of acai polyphenols in a 3 phase in vitro
model of the gastrointestinal tract.

Methods: Simulated
in vitro digestion (4) and faecal bacterial fermentations were conducted to
assess the stability and likely fate of polyphenols present in acai pulp.
Freeze- dried acai was incubated with pepsin, pH 2 (HCl) at 37°C for two
hours (simulating gastric conditions). The product was then digested by
pancreatin for 3h at pH 7.0 (simulating small intestine conditions). The
product was transferred to 1 kDa MWCO (molecular weight cut- off) dialysis
tubing and dialyzed against 10 mM NaCL overnight, and the remnants considered
likely to reach the large bowel. The remnant material was fermented for 24
hours in faecal pH- controlled anaerobic batch cultures using human faecal
samples from three different healthy human volunteers.

Results and Conclusion: We
observed a decrease in the polyphenol composition at each stage of the
digestive process. Following the gastric phase by ~39% decreased following
the small intestinal phase, which were about ~70% had been degraded in total
anthocyanins in acai after the small intestinal condition that may be occur
by increasing pH (7) or enzyme interaction in the small intestine. In the
simulated colonic fermentation, we observed a ~95.1% reduction in the
phenolics entering this phase after 24 hours. The anthocyanins were not
detectable after 8hrs although caffeic acid remained in the fermentation
supernatant at appreciable levels after 24 hours. Also, significantly higher
total SCFA concentrations were observed at 24h of fermentation with
pre-digested acai relative to the control fermentation. These data indicate
that a proportion of polyphenols from acai survive the digestive process and
may be utilized by the gut microbiota producing smaller phenolics such as
caffeic acid. Further work is needed to establish whether these surving
phenolics exert a prebiotic effect in the bowel.

المؤتمر (2):

عنوان المؤتمر:

16^th
ISANH Antioxidants Middle East World Congress

تاريخ الإنعقاد:

12/04/2016

مكان
الإنعقاد:

Dubai, UAE

طبيعة المشاركة:

Paper presentation

عنوان المشاركة:

The Effects of Consuming a Polyphenol Rich
Açai based Meal on Vascular Function

ملخص المشاركة:

Background:
Cardiovascular diseases (CVDs) caused 17.5 million deaths globally in 2012
alone. A diet low in fruit and vegetables and high in meat and processed
foods is implicated in CVD risk. Middle eastern countries are transitioning
towards this unhealthy western pattern of food consumption and the risk of
CVD, obesity and diabetes is subsequently on the rise. Evidenced based
guidance on health food consumption are therefore desirable. Açai is an
Amazonian fruit with a polyphenol rich phytochemical composition suggestive
of potential health benefits. These plant phenolic compounds are often
associated with reduced risk of several chronic diseases. There is however
almost no direct evidence demonstrating improvements in markers of
cardiovascular health arising from açai consumption in humans.

Aim: The aim of this study is to
investigate the beneficial effect of açai fruit intake on acute changes in
vascular function, and on other cardiovascular and metabolic disease risk
markers, including blood pressure, insulin and oxidative capacity in human
volunteers.

Design:
Twenty-three healthy male volunteers aged 30-65 y and with a body mass index
25-30 kg m2 completed a randomized, placebo controlled, high fat challenge,
double-blind crossover acute human intervention trial with a three week wash
out. The volunteers were randomized to consume either an açai based smoothie
(700 mg of polyphenols) or a macronutrient matched placebo smoothie (0 mg of
polyphenols) alongside a high fat breakfast meal challenge. The primary endpoint
was the assessment of endothelial function in the brachial artery using
flow-mediated dilatation (FMD).

Results: We observed
a significant improvement in vascular function (FMD) at 2, 4, 6 hours after
acai smoothie intake compared to control. We also report a significantly
lower incremental area under the curve (AUC) in plasma oxidative capacity
after the acai meal relative to placebo.

Conclusions: For
the first time, we demonstrate that consuming acai results in improvements in
a well validated marker of cardiovascular disease risk in overweight human
volunteers. In this acute study, açai consumption is associated with improved
arterial function, and a reduction in oxidative stress. Future dietary
intervention studies, perhaps with a chronic design, in wider populations and
with other biomarkers of disease risk are needed to fully elucidate benefits
to health benefits despite a lack of human intervention studies showing
health associated with consuming this food.