PDF
(Download)
|
- Pomegranate (Punica granatum, Lythraceae)
- Metabolic Syndrome
- Cardiovascular Risk Factors
|
Date:
09-15-2017 | HC# 051757-576
|
Re: Natural Pomegranate Juice Demonstrates a Beneficial Effect on Systolic and Diastolic Blood Pressure and hs-CRP, while also Increasing Triglycerides and VLDL Cholesterol
Moazzen
H, Alizadeh M. Effects of pomegranate juice on cardiovascular risk factors in
patients with metabolic syndrome: a double-blinded, randomized crossover
controlled trial. Plant Foods Hum Nutr.
June 2017;72(2):126-133.
Metabolic
syndrome is the name for a group of risk factors (high blood pressure,
increased blood levels of sugar and lipids, and excess body fat around the
waist) that increase the development of cardiovascular disease. Foods high in
polyphenols have high antioxidant and anti-inflammatory properties. Pomegranate
(Punica granatum, Lythraceae) fruit
juice may have cardiovascular benefits in relation to this issue. However, nutritionists
are concerned with pomegranate's simultaneous effect on the rise of glycemic
factors and sugar-dependent lipids; namely, triglycerides and very-low-density
lipoprotein cholesterol (VLDL-C). The purpose of
this randomized, double-blind, placebo-controlled, crossover study was to
evaluate the effect of pomegranate juice on cardiometabolic indices and
glycemic indices in patients with metabolic syndrome.
Patients
with metabolic syndrome (n = 32; aged 18-70 years) were recruited via
advertisement in Shabestar, Iran. This study took place between December 2012
and January 2013. Included patients had ≥ 3 of 5 components of metabolic
syndrome—namely, waist circumference > 88 cm for women and > 102 cm for
men, serum triglycerides ≥ 150 mg/dL, high-density lipoprotein (HDL) cholesterol
< 50 mg/dL for women and < 40 mg/dL for men, systolic blood pressure ≥ 135 mmHg
or diastolic blood pressure ≥ 85 mmHg, and fasting plasma glucose concentration
> 110 mg/dL. Excluded patients included those who were pregnant or breastfeeding;
consumed alcohol; had systemic, inflammatory, hepatic, or kidney diseases; and were
allergic to pomegranate juice or the pomegranate placebo. Patients were withdrawn
from the data analysis if during the study they had any change of diet, any
disease development, or had an increase in low-density lipoprotein (LDL) cholesterol
where medications were needed. Patients were treated with either 500 mL pure
pomegranate juice or placebo for 7 days, and, following a 7-day washout, they
received the opposite treatment.
Pomegranate juice was prepared by hand by the
researchers. The arils were removed from Shiraz pomegranates and were manually squeezed
to yield juice; no additives were used. The juice included anthocyanins, 100.46
mg/L; total phenolics, 69 mg/L; total flavonoids, 283.02; and antioxidant
capacity (DPPHsc [2,2-diphenyl-1-picrylhydrazyl radical scavenging activity]),
69%. Food engineers created a placebo formula to resemble the pomegranate juice
taste and color. The similarity of the placebo and pomegranate juice was
confirmed by 3 expert testers. The placebo was void of any polyphenols. The patients
were asked not to change their lifestyle, diet, or physical activity during the
study. Food intake and physical activities were recorded in a diary for 3 days
to ensure no changes were made during the study. Blood was drawn at baseline
and after 7 days of treatment to measure high-sensitivity C-reactive protein
(hs-CRP), fasting blood sugar, total cholesterol, blood insulin, triglycerides,
HDL, LDL, and VLDL. Blood pressure also was measured.
Thirty
patients were included in the final analysis; 1 patient was withdrawn due to
development of the flu and taking antibiotics, and 1 patient had emotional and
psychological problems. There was no change in intake of energy, carbohydrates,
protein, or fat. Triglyceride levels and VLDL were significantly higher after
pomegranate juice than after the placebo (P = 0.025 and P = 0.016,
respectively). Blood hs‑CRP was significantly lower after pomegranate juice
compared with baseline (P = 0.028) and placebo (P = 0.018). After pomegranate
juice consumption, systolic and diastolic blood pressure significantly
decreased compared to baseline and placebo (P < 0.001 for all). After
placebo, systolic blood pressure significantly decreased compared to baseline (P
= 0.007).
The
authors conclude that 500 mL/day of natural pomegranate juice had a beneficial
effect on systolic and diastolic blood pressure and hs-CRP, despite increasing
triglyceride and VLDL levels. Other studies report no effect of pomegranate
juice on hs-CRP, while one reported a beneficial effect in overweight and obese
individuals. The authors hypothesize that the difference between their findings
and other reports can be attributed to the high daily dose of pomegranate juice
in this study and the variety (Shiraz) of pomegranate used. It is not
surprising that the increase in triglycerides was accompanied by an increase in
VLDL because VLDL transports triglycerides. A meta-analysis concluded that the
significant increase of triglycerides could disappear with long-term use.1
The authors
state that, "This study showed that nutritionists, at least in the short-term,
were right in being concerned because consuming pomegranate juice, in addition
to having beneficial effects on blood pressure and inflammatory indices, has
harmful effects on triglyceride and VLDL-C which is due to its high level of fructose."
Long-term studies in a larger population are needed to confirm these short-term
results. The authors declare that they have no conflict of interests. The study
was funded by Urmia University of Medical Sciences; Urmia, Iran.
—Heather S. Oliff,
PhD
Reference
1Sahebkar A, Simental-Mendía LE, Giorgini P, Ferri C,
Grassi D. Lipid profile changes after pomegranate consumption: a systematic
review and meta-analysis of randomized controlled trials. Phytomedicine. 2016;23(11):1103-1112.
|