The Luxembourg Institute of Health has reported the findings of two new nutrition studies developed at its Department of Population Health, with the aim of determining the effects of various drinks on the risk of cardiovascular disease.

The studies were conducted by senior researcher Dr. Ala'a Alkerwi of the Epidemiology and Public Health Research Unit, with the first study examining the effect of regular tea and coffee consumption on blood pressure, and the second determining a possible association between the consumption of soft drinks and the onset of metabolic syndromes.

The study of coffee and tea consumption was developed by Dr. Alkerwi and his team from a national ORISCAV-LUX (Compliance Risk and Cardio-Vascular Health Luxembourg) survey, conducted between 2007 and 2008 with 1,432 adult Luxembourgish residents as participants.

Results showed that tea was found to have a protective impact on health, with regular consumption thereof associated with low systolic blood pressure and pulse pressure, the latter being the difference between systolic and diastolic pressure readings. However, coffee consumption was found to have no significant effect on blood pressure.

"Daily consumption of a decilitre of tea, which corresponds to half a cup, reduces systolic blood pressure by 0.6mm Hg and the differential pressure by 0,5mm Hg," explained Dr. Alkerwi. "Such a reduction is relatively modest from the perspective of the individual, but it is relevant when considering cardiovascular health at the population level. Unfortunately tea is not the favourite hot drink of Luxembourg residents. 88% of ORISCAV-LUX participants are coffee lovers. Only 36% drink tea regularly."

The second study involved a comparative analysis on the consumption of non-alcoholic carbonated drinks, conducted with 1,323 participant in Luxembourg (ORISCAV-LUX) and 803 participants in Maine and New York (Maine-Syracuse Longitudinal Study).

"We tested the association between the regular consumption of fizzy beverages and the presence of metabolic syndrome," reported Dr. Alkerwi. "A person is seen to be affected by a metabolic syndrome if they have at least three of the five metabolic risk factors: abdominal obesity, high glucose levels on an empty stomach, high blood pressure, high levels of triglycerides and low HDL, which is the 'good' cholesterol."

The study identified the similarities and differences between the two cases which were geographically-distant and culturally-distinct with regards to nutritional habits and lifestyle. Contrary to expectations, more people have consumed carbonated soft drinks in the Luxembourg sample (60%) than in its United States counterpart (43%). However, the figures for those who regularly consumed soft drinks were higher in the US population. Additionally, the prevalence of metabolic syndromes was significantly greater in the United States sample, at 44%, than that of Luxembourg, at 26%. In both populations, it was found that individuals who consume at least one fizzy drink a day incur a higher risk of metabolic diseases two times greater than those who do not.

"A surprising result of our study is that people drinking diet soft drinks also have a higher risk," reported Dr. Alkerwi.

For the research project on the effects of nutrition on cardio-vascular issues, Dr. Ala'a Alkerwi worked closely with international partners and were the result of a long-term collaboration with Professor Merrill Elias of the University of Maine in the U.S., and Dr. Georgina Crichton of the University of South Australia.

 

Photo by Luxembourg Institute of Health