Effects of Date (Phoenix dactylifera L., Medjool or Hallawi Variety) Consumption by Healthy Subjects on Serum Glucose and Lipid Levels and on Serum Oxidative Status: A Pilot Study

Abstract

The present pilot study analyzed, for the first time, the in vivo effect of Medjool or Hallawi date consumption by healthy subjects on serum glucose, lipids, and oxidative stress. Total phenolics concentration in the Hallawi versus Medjool dates was greater by 20-31%. The major proportion of the soluble phenolics in both date varieties consisted of phenolic acids, mainly ferulic acid and coumaric acid derivatives, and also chlorogenic and caffeic acid derivatives. Unlike the Medjool dates, Hallawi dates contained a significant proportion of catechins as well. In addition, both varieties contained a quercetin derivative. Both date varieties possess antioxidative properties in vitro, but the ferric ion reducing antioxidant power of Hallawi versus Medjool dates was higher by 24%. Ten healthy subjects consumed, for a period of 4 weeks 100 g/day of either Medjool or Hallawi dates. The date consumption did not significantly affect the subjects' body mass index (BMI), their serum total cholesterol, or their cholesterol levels in the VLDL, LDL, or HDL fractions. Most important, fasting serum glucose and triacylglycerol levels were not increased after consumption of either date variety, and serum triacylglycerol levels even significantly (p < 0.05) decreased, by 8 or 15% after Medjool or Hallawi date consumption, respectively. Basal serum oxidative status was significantly (p < 0.01) decreased by 33%, as compared to the levels observed before consumption, after Hallawi (but not Medjool) date consumption. Similarly, the susceptibility of serum to AAPH-induced lipid peroxidation decreased by 12%, but only after Hallawi date consumption. In agreement with the above results, serum activity of the HDL-associated antioxidant enzyme paraoxonase 1 (PON1) significantly increased, by 8%, after Hallawi date consumption. It is concluded that date consumption (and mainly the Hallawi variety) by healthy subjects, despite their high sugar content, demonstrates beneficial effects on serum triacylglycerol and oxidative stress and does not worsen serum glucose and lipid/lipoprotein patterns, and thus can be considered an antiatherogenic nutrient .

A review of the chemistry and pharmacology of the date fruits (Phoenix dactylifera L.)

“…The presence of higher phenolic concentration, catechins (antioxidants) as well as the different absorption, metabolism and bioactivity of the various phenolic compounds in Hallavi dates, attributes to the increased antioxidant property, higher FRAP as well as serum high density lipoprotein-associated PON1 activity as compared to the Medjool variety. These results justifies the various in vitro studies; showing that dates in general and the Hallawi variety in particular are beneficial and can be included in our regular diet, without having to worry on its adverse affects (Rock et al, 2009).…”

“…Recently, Rock et al (2009) studied the effect of two varieties of dates (Medjool and Hallawi) on serum oxidative status, glucose and lipid levels in healthy human subjects. The volunteers were advised to consume 100 g/day of either variety of dates for a period of 4 weeks, after which they were tested for variations in the mentioned serum parameters.…”

Effect of Algerian Varieties Dates on Glycemic, Arterial Blood Pressure and Satiety Responses

“…Other components such as polyphenols, potassium, magnesium, sodium, and vitamins found at low variable concentrations in date may be responsible of the following biological properties. Polyphenols protect against oxidative stress 9 , and possess some anti-high blood pressure effects 10 . The considerable amount of potassium and magnesium has protective role in cardiovascular diseases in general and high blood pressure in particular 11 Ascorbic acid and pyridoxine are able to reduce blood pressure 12,13 .…”

The Middle Eastern and biblical origins of the Mediterranean diet

“…The above antioxidant activity is attributed to the wide range of phenolic compounds present in dates, including p-coumaric, ferulic and sinapic acids, as well as flavonoids and procyanidins (30,31) . Aviram et al (32) showed for the first time the in vivo beneficial effect of Medjool or Hallawi date varieties, despite very high content of sugars, consumed by healthy subjects on serum glucose, lipids and oxidative stress. Both date varieties possessed antioxidative properties in vitro, but their antioxidant properties in vivo were unknown.…”