There is a well-established association between aging, arterial stiffness, endothelial dysfunction, oxidative stress and the ensuing increased cardiovascular risk. Agents with antioxidant activity can improve endothelial function and arterial stiffness. Açaí-juçara is a fruit rich in anthocyanins, which are powerful antioxidants, and its daily consumption may have beneficial effects on vascular health, especially on central pulse pressure and pulse wave velocity. As anthocyanins may improve vascular health, especially central pulse pressure, dietary intake of anthocyanin-rich foods may reduce cardiovascular risk. Thus, this study aimed to review the effects of dietary intake of anthocyanins and its potential associations with central blood pressure improvement in overweight and obese individuals.
The prevalence of overweight and obesity has increased exponentially in recent years. Obesity is characterized by excess accumulation of body fat and is associated with increased risk of morbidity and mortality . According to data from World Health Organization (WHO), in 2016, 39% of women and 39% of men aged 18 and over were overweight .
Obesity is strongly associated with cardiovascular outcomes. The mechanisms involved are complex and multifactorial. Some researchers suggest that obesity is a clinical condition associated with a low-intensity inflammatory state resulting from an imbalance between pro- and anti-inflammatory molecules due to increased production of pro-inflammatory molecules. Besides, visceral adiposity, glucose intolerance, hyperinsulinemia, hypertriglyceridemia and oxidative stress can lead to changes in vascular function . It is thus important to identify individuals with accelerated vascular aging for early specific interventions targeting multiple risk factors .
Changes in vascular function can be assessed through pulse
wave analysis. Pulse Wave Velocity (PWV) is an earlier marker of vascular wall changes  and it can be measured by applanation tonometry and an oscillometric method.
Experimental, epidemiological and clinical studies have shown that consumption of bioactive compounds present in fruits can decrease the oxidative damage and inflammation due to their antioxidant activity. The dietary intake of antioxidants can protect the body against the harmful effects of oxygen radicals with a positive impact on several chronic conditions including obesity, diabetes and neurodegenerative and cardiovascular diseases, and may improve endothelial function [6,7].
Açaí-juçara is the fruit of a Juçara palm tree (Euterpe Edulis Martius) that is rich in antioxidants, especially anthocyanins . Recent studies of anthocyanin-rich extracts have shown their potential antioxidant role with significant reduction of blood pressure, strong anti-inflammatory activity and decrease of oxidative stress [6,7]. Although daily intake of açaí may have cardiovascular benefits, its impact on central blood pressure parameters is still controversial. Thus, our study aimed to review the effects of anthocyanin intake and its potential associations with central blood pressure improvement in overweight and obese individuals.
Free radicals and Reactive Oxygen Species (ROS) are the
products of normal cellular metabolism. They are good for the
body and are involved in intercellular and intracellular signaling
as well as in the synthesis of major biological substances. However,
when the body is in an inflammatory state, ROS production is
exacerbated. Increased generation of ROS is a consequence of
body fat accumulation and may cause vascular damage leading to
endothelial dysfunction and increased atheroma plaque formation
and peripheral vascular resistance . This state, without an
adequate antioxidant response, can result in lipid peroxidation of
cellular membrane and oxidative stress [10,11].
The oxidative process causes damage to cells that progressively
lose their function and become apoptotic . Apoptosis in liver
cells or neurons in the hypothalamus impairs metabolic functions
due to an imbalance in the control of hunger/satiety and may
cause energetic imbalance and, consequently, lead to obesity
The endothelium is the cellular lining of the vascular wall that
has important functions such as vascular tonus regulation and
blood vessel protection. This protection occurs by a physiological
stimulus causing shear stress, i.e., when blood flow exerts a
frictional force on the endothelial cells, which increases blood
vessel dilation capacity and nitric oxide bioavailability .
Increased serum levels of inflammatory markers such as
interleukin-6 (IL-6) and C-reactive Protein (CRP) may cause
a reduction (downregulation) in nitric oxide production
due to inhibition of endothelial nitric oxide synthase. This
downregulation facilitates atheroma plaque formation and,
consequently, increases cardiovascular risk [16,17].
In addition to endocrine, inflammatory and vasoactive
endothelium-derived components, the vessel wall has structural
components that also play a role in vascular stiffening since
an imbalance in the synthesis of collagen and/or elastin may
contribute to decreased vascular distensibility .
Several studies have shown the relationship between oxidative
stress and free radical production in the pathophysiology
of vascular aging . Recently, it has been suggested that
vascular dysfunction along with increased arterial stiffness may
be associated with obesity and cardiovascular diseases. Some
researchers have reported increased arterial stiffness in obese
adults and children when compared with eutrophic individuals
Indirect methods have been proposed for assessing vascular
aging. PWV measurement is the current gold-standard to assess
arterial stiffness. Epidemiological evidence shows PWV is a
predictor of cardiovascular events/diseases . The pressurearea
relation of the cross-sectional area of an artery in response
to transmural pressure changes is a linear representation (PWV
= 0), which indicates arterial elasticity . A curvilinear tracing
denotes loss of arterial elasticity when PWV is >0 and is consistent
with vascular stiffness. Hence, PWV is a measurement used to
assess arterial stiffness. Blood pressure values are associated
with several aspects including flow pulsatility and pulsatile
modulation, which are directly related to vascular compliance and
arterial stiffness .
Central pulse pressure (cPP) is defined as the difference
between central Systolic Blood Pressure (SBP) and central
Diastolic Blood Pressure (DBP) and is determined by left ventricle
blood ejection into the aorta. cPP is the pulsatile component of
blood pressure curve; the static component is mean arterial
pressure . Furthermore, cPP is the summation of a forward
wave coming from the heart (so-called incident wave) and a
backward wave returning to the heart due vascular resistance
[27,28]. As vascular resistance increases, PWV increases and
the reflected wave occurs earlier resulting in increased SBP and
decreased DBP [23,27,29].
Dietary intake of phytochemical bioactive compounds such
as antioxidants present in foods has been shown to reduce
oxidative damage and decrease inflammation. The intake of
antioxidants is believed to have positive effects on several chronic
conditions including obesity, diabetes and neurodegenerative and
cardiovascular diseases .
Endogenous antioxidants do not provide full protection of
cell components and thus exogenous antioxidants that come from
foods are essential for the prevention and repair of ROS damage
[30-32]. The intake of foods rich in antioxidants can favorably
affect lipid and glucose metabolism and contribute to reducing
metabolic syndrome risk . Studies have shown that frequent
consumption of antioxidant foods may restore damage resulting
from oxidative and inflammatory responses, improve vascular
protection and decrease the risk of obesity-related conditions
Anthocyanins are natural red to purple pigments
(phytochemicals) that have antioxidant activity. The antioxidant
properties of these compounds are related to their phenolic
structure that transfers electrons from hydrogen atoms of the
hydroxyl group on the aromatic ring . They act as both free
radical “sequesters” and metal chelators, acting at initiation and
propagation of oxidation . They are extremely important
for free radical defense mechanism in conjunction with other
enzymatic (superoxide dismutase, catalase and glutathione
peroxidase) and non-enzymatic defenses (ascorbic acid and
There are no recommended Dietary Reference Intake (DRI)
values for phytochemicals. It has been demonstrated that synthetic
antioxidants can prevent or attenuate ROS harmful effects both
in vivo and in vitro. Studies have reported anti-inflammatory,
cardioprotective and anti-obesogenic benefits of dietary intake of
phytochemical compounds, especially anthocyanins, in the human
According to the European Food Safety Authority and FAO/
WHO Expert Committee on Food Additives (JECFA), the daily
consumption of anthocyanins (2.5mg/kg body weight) is safe.
In their review study, Pojer found that toxicity risks of dietary
supplementation of anthocyanins are extremely low and even an
intake of 160mg twice a day (320mg/day) was well-tolerated with
no reported side effects .
Fairlie-Jones et al.  conducted a meta-analysis of
randomized controlled trials to assess the effect of anthocyaninrich
extracts on vascular function in adults. Their results
support the findings that anthocyanins may improve vascular
health, especially flow-mediated dilation with acute and chronic
supplementation and PWV with acute supplementation .
In a cross-sectional study of 1,898 women from the UK
Adult Twin Registry (TwinsUK), higher anthocyanin intake was
associated with significantly lower central SBP, lower PWV and
reduced arterial stiffness .
Natural foods as antioxidant sources have gained increasing
attention . Açaí is a fruit rich in anthocyanins. There are
two species: conventional açaí (Euterpe Oleracea Mart) and
açaí-juçara from Juçara palm tree (Euterpe Edulis Martius). The
dry matter content of açaí-juçara has high content of phenolic
compounds, such as ellagic acid and anthocyanins, and exhibits
potent antioxidant activity .
Anthocyanins found in the açaí-juçara pulp vary from 60mg
to 410mg/100g wet matter and the antioxidant content shows
seasonal and harvest area variation [43,44]. In addition to its high
content of anthocyanins, açaí-juçara is a natural source of fibers,
oleic and linolenic acid and other micronutrients such as vitamin
Many studies have evaluated the dose-response relationship
and effects/effectiveness of antioxidant supplementation in the
human body  and in animals . It has been demonstrated
that dietary supplementation of 2% and 6% lyophilized açaí in
apolipoprotein E-deficient (ApoE -/-) mice improved their lipid
profile and antioxidant defense and showed a hypoglycemic effect
. Another study found that dietary intake of anthocyanins
at 0.90 mg/day was associated with reduced risk of developing
cardiovascular disease in post-menopausal women .
Significant lower levels of fasting plasma glucose, insulin,
cholesterol, triglycerides, exhaled nitric oxide metabolites
(breath) and ultra-sensitive plasma CRP (hs-CRP) were found in
overweight individuals following a 30-day intake of 100mL of açaí
pulp twice a day . Other studies have demonstrated reductions
in fasting blood glucose and insulin levels, total cholesterol, LDLcholesterol
and total cholesterol-to-HDL ratio and, therefore,
reduced markers of metabolic syndrome risk [32,34].
Furthermore, the consumption of açaí has been associated with
decreased insulin and glucose levels in overweight men. Evidence
shows that dietary intake of açaí containing approximately 690
mg of phenolics and anthocyanins is associated with improvement
in vascular function. This benefit appears to be associated with
improvement of redox status .
Structural degenerative damage of arterial elastic components
is little reversible with drug therapies currently available. It is
thus extremely important to assess the impact of preventive
interventions for reducing vascular stiffness and accelerated
vascular aging. Dietary intake of anthocyanin-rich foods has
shown several health benefits and may reduce cardiovascular
risks. The effects of anthocyanin intake, especially açaí-juçara, on
central blood pressure parameters should be further investigated
in randomized controlled trials to support the assumed benefits
of arterial stiffness improvement.
Huber K (2016) Avaliação de Produto Diet a Base de Açaí Juçara (Euterpe Edulis Martius) e seus efeitos antiobesogênico, anti-inflamatório e antioxidante em adolescentes obesos. Tese de Doutorado. Unicamp. Faculdade de Engenharia de Alimentos. Campinas.
Novello AA (2011) Extração de antocianinas dos frutos do açai da Mata Atlântica (Euterpe Edulis Martius) e sua atuação nas atividades antioxidante e antiaterogênica em camundongos ApoE -/-. Dissertação de Mestrado. Universidade Federal de Viçosa, Viç