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.

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 .

[1]  P. Goldschmidt-Clermont,et al.  The paraoxonase gene family and atherosclerosis , 2009, Current atherosclerosis reports.

[2]  D. Heistad,et al.  Novel aspects of oxidative stress in cardiovascular diseases. , 2009, Circulation journal : official journal of the Japanese Circulation Society.

[3]  F. Al-Said,et al.  Chemical composition and glycemic index of three varieties of Omani dates , 2009, International journal of food sciences and nutrition.

[4]  T. Hayek,et al.  Phenolic antioxidants and antiatherogenic effects of Marula (Sclerocarrya birrea Subsp. caffra) fruit juice in healthy humans. , 2008, Journal of agricultural and food chemistry.

[5]  A. Levy,et al.  Consumption of wonderful variety pomegranate juice and extract by diabetic patients increases paraoxonase 1 association with high-density lipoprotein and stimulates its catalytic activities. , 2008, Journal of agricultural and food chemistry.

[6]  J. Geleijnse,et al.  Flavonoids and cardiovascular health: which compounds, what mechanisms? , 2008, The American journal of clinical nutrition.

[7]  Ian Harvey,et al.  Flavonoids, flavonoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials. , 2008, The American journal of clinical nutrition.

[8]  A. Howell,et al.  Pomegranate juice sugar fraction reduces macrophage oxidative state, whereas white grape juice sugar fraction increases it. , 2006, Atherosclerosis.

[9]  T. Hayek,et al.  Anti-oxidative effects of pomegranate juice (PJ) consumption by diabetic patients on serum and on macrophages. , 2006, Atherosclerosis.

[10]  F. Tomás-Barberán,et al.  The flavonoid glycosides and procyanidin composition of Deglet Noor dates (Phoenix dactylifera). , 2006, Journal of agricultural and food chemistry.

[11]  E. Palevsky,et al.  Population dynamics of Oligonychus afrasiaticus in the southern Arava Valley of Israel in relation to date fruit characteristics and climatic conditions , 2005 .

[12]  F. Shahidi,et al.  Comparison of antioxidant activity, anthocyanins, carotenoids, and phenolics of three native fresh and sun-dried date (Phoenix dactylifera L.) varieties grown in Oman. , 2005, Journal of agricultural and food chemistry.

[13]  L. Ananthanarayan,et al.  Antioxidant activity of selected foodstuffs , 2004, International journal of food sciences and nutrition.

[14]  D. Gaitini,et al.  Pomegranate juice consumption for 3 years by patients with carotid artery stenosis reduces common carotid intima-media thickness, blood pressure and LDL oxidation. , 2004, Clinical nutrition.

[15]  M. Aviram,et al.  Oxidative Stress in Cardiovascular Disease: Role of Oxidized Lipoproteins in Macrophage Foam Cell Formation and Atherosclerosis , 2003 .

[16]  D. Mozaffarian,et al.  Cereal, fruit, and vegetable fiber intake and the risk of cardiovascular disease in elderly individuals. , 2003, JAMA.

[17]  Richard J. Marshall,et al.  The fruit of the date palm: its possible use as the best food for the future? , 2003, International journal of food sciences and nutrition.

[18]  T. Hayek,et al.  Antiatherosclerotic effects of licorice extract supplementation on hypercholesterolemic patients: increased resistance of LDL to atherogenic modifications, reduced plasma lipid levels, and decreased systolic blood pressure. , 2002, Nutrition.

[19]  P. Kris-Etherton,et al.  Evidence that the antioxidant flavonoids in tea and cocoa are beneficial for cardiovascular health , 2002, Current opinion in lipidology.

[20]  P. Vayalil.  Antioxidant and antimutagenic properties of aqueous extract of date fruit (Phoenix dactylifera L. Arecaceae). , 2002, Journal of agricultural and food chemistry.

[21]  M. Aviram,et al.  Nutritional Antioxidants Mechanisms of Action, Analyses of Activities and Medical Applications , 2001 .

[22]  A. Puri,et al.  Immunostimulant activity of dry fruits and plant materials used in indian traditional medical system for mothers after child birth and invalids. , 2000, Journal of ethnopharmacology.

[23]  B. La Du,et al.  Human serum paraoxonase (PON 1) is inactivated by oxidized low density lipoprotein and preserved by antioxidants. , 1999, Free radical biology & medicine.

[24]  J J Strain,et al.  The ferric reducing ability of plasma (FRAP) as a measure of "antioxidant power": the FRAP assay. , 1996, Analytical biochemistry.

[25]  M. Rashad,et al.  Studies on date waste dietary fibers as hypolipidemic agent in rats , 1996, Zeitschrift fur Ernahrungswissenschaft.

[26]  H. Esterbauer,et al.  A spectrophotometric assay for lipid peroxides in serum lipoproteins using a commercially available reagent. , 1989, Journal of lipid research.

[27]  B. Ames,et al.  Antioxidant defenses and lipid peroxidation in human blood plasma. , 1988, Proceedings of the National Academy of Sciences of the United States of America.

[28]  C. Kies.  Non-soluble dietary fiber effects on lipid absorption and blood serum lipid patterns , 1985, Lipids.

[29]  M. S. Blois,et al.  Antioxidant Determinations by the Use of a Stable Free Radical , 1958, Nature.

[30]  R. Blomhoff,et al.  Total antioxidant content of alternatives to refined sugar. , 2009, Journal of the American Dietetic Association.

[31]  M. Aviram,et al.  Dietary antioxidants and paraoxonases against LDL oxidation and atherosclerosis development. , 2005, Handbook of experimental pharmacology.

[32]  Z. Shraideh,et al.  Ultrastructural effects of date extract on Candida albicans , 2004, Mycopathologia.

[33]  T. Osawa.  [Oxidative stress and atherosclerosis]. , 1997, Nihon rinsho. Japanese journal of clinical medicine.

[34]  A. Smolen,et al.  Purification of human serum paraoxonase/arylesterase. Evidence for one esterase catalyzing both activities. , 1991, Drug metabolism and disposition: the biological fate of chemicals.

[35]  A. Sallal,et al.  Effect of date extract on growth and spore germination of Bacillus subtilis. , 1989, Microbios.

[36]  S. Aust,et al.  Microsomal lipid peroxidation. , 1978, Methods in enzymology.

[37]  V. L. Singleton,et al.  Colorimetry of Total Phenolics with Phosphomolybdic-Phosphotungstic Acid Reagents , 1965, American Journal of Enology and Viticulture.