A new study by researchers at Weill Cornell Medicine-Qatar (WCM-Q) has revealed the specific effects of two popular varieties of dates on human metabolism for the first time.

The WCM-Q researchers analysed a wide range of small molecules, called metabolites, which enter the bloodstream and remain in circulation for up to two hours after eating Khalas and Deglet Nour dates.

Blood samples were collected from 21 healthy volunteers at five time-points following the ingestion of a glucose drink (used as control), Khalas dates and Deglet Nour dates. Each volunteer was tested after ingesting each of the three products, with intervals of at least one week between each product. The Khalas and Deglet Nour date varieties were chosen because of their distinct genetic and metabolic profiles and commercial importance.

Overall, the researchers found that 36 metabolites significantly increased in the bloodstream, of which some were specific to date fruit consumption. Several were metabolites of known polyphenols, such as caffeic acid, which can be beneficial for those with complex chronic diseases, given its anti-oxidative and anti-inflammatory properties. The researchers also found that serotonin present in Deglet Nour dates quickly broke down into its metabolite (5-hydroxyindolacetate) following ingestion.

This information implies that these dates are not useful as a serotonin supplement in healthy individuals for mood, appetite and sleep regulation. Compared to Khalas dates and the glucose drink, Deglet Nour also led to a sharp increase in blood sucrose levels.

Dr Karsten Suhre of WCM-Q, is one of the lead authors of the study, now published in the Journal of Functional Foods. Dr Suhre, one of the world’s foremost researchers in the field of metabolomics, said that the findings of the paper could be useful for clinicians when determining the impact of these metabolites in the management of complex diseases.

Dates are believed to be one of the world’s oldest cultivated food crops and have special cultural significance for the Middle East. Khalas dates are prized for their deep reddish-brown colour, moistness and hearty flavour; while the Deglet Nour variety are known as the ‘Queen of Dates’ and are famed for their light, translucent colouring and honey-like taste. Dates were recently proposed as being a ‘functional food’ as they may provide health benefits that go beyond essential nutrition and may help reduce chronic disease risk or otherwise optimise health.

Dr Suhre added that the design of the study is extremely versatile and could be used in the future to assess other functional foods and evaluate their potential health benefits.

Other researchers of the study include Sweety Mathew, Joel Malek, Anna Halama, Sara Abdul Kader, Minkyung Choi and Robert Mohney. The study was entitled ‘Metabolic Changes of the Blood Metabolome after a Date Fruit Challenge’.

This research was supported by a National Priorities Research Programme – Exceptional Programme grant (NPRPX-014-4-001) from Qatar National Research Fund, a member of Qatar Foundation. The research team and WCM-Q are grateful for the support of QNRF, making this translational research possible.

The research paper can be read in full through this link.