New research has linked frequent consumption of fizzy drinks and fruit juice with an increased risk of stroke.
Drinking more than four cups of coffee a day could also increase the risk of a stroke, while tea in the right qualities and regular water consumption could guard against the condition.
A series of studies led by the University of Galway and conducted under the INTERSTROKE project were reported in the latest Journal of Stroke and International Journal of Stroke.
INTERSTROKE is an international study of risk factors for stroke. It involves almost 27,000 people in 27 countries, including around 13,500 people who have experienced their first stroke.
“Fizzy drinks, including both sugar-sweetened and artificially sweetened such as diet or zero sugar, were linked with a 22 percent increased chance of stroke, and the risk increased sharply with two or more of these drinks a day,” the latest study report said.
“The link between fizzy drinks and chance of stroke was greatest in Eastern/Central Europe and Middle East, Africa, and South America.”
Stroke occurs when the blood supply to part of the brain is cut-off and damages brain cells.
The researchers said many products marketed as fruit juice were made from concentrates and contained added sugars and preservatives. This may offset the benefits usually linked with fresh fruit.
Fruit juice drinks were linked with a 37 percent increase in chance of stroke due to bleeding (intracranial haemorrhage). With two of these drinks a day, the risk triples.
Other findings included:
- Drinking more than seven cups of water a day was linked with reduced odds of having a stroke caused by a clot
- Drinking more than four cups of coffee a day increased the chance of stroke by 37 percent, but not this risk was not found for lower intakes
- Drinking tea was linked with a reduced chance of stroke by 18-20 percent
- Drinking 3-4 cups per day of black tea – including Breakfast and Earl Grey teas, but not green tea or herbal teas – was linked with a 29 percent lower chance of stroke
- Drinking 3-4 cups per day of green tea was linked with a 27 percent lower chance of stroke
Lead researcher Andrew Smyth said the results showed “not all drinks are created equal”.
“Freshly squeezed fruit juices are most likely to bring benefits, but fruit drinks made from concentrates, with lots of added sugars and preservatives, may be harmful,” Professor Smyth said.
“Our research also shows that the chance of stroke increases the more often someone consumes fizzy drinks.
“As a doctor and as someone who has researched the risk of stroke, we would encourage people to avoid or minimise their consumption of fizzy and fruit drinks, and to consider switching to water instead.”
The full report is on the University of Galway website.
