Frequent consumption of fizzy drinks and fruit juice has been linked to a higher risk of stroke, according to recent research. The study further indicated that drinking over four cups of coffee daily may also elevate stroke risk.
Research conducted globally, led by the University of Galway alongside McMaster University in Canada and a worldwide network of stroke researchers, has revealed that regularly consuming fizzy drinks or fruit juice can increase the likelihood of having a stroke.
Additionally, the study found that exceeding four cups of coffee a day also raises the risk of experiencing a stroke.
These findings stem from two analyses within the INTERSTROKE research project, with the effects of fizzy drinks, fruit juice, and water published in the Journal of Stroke, and the tea and coffee findings appearing in the International Journal of Stroke.
A stroke happens when the brain’s blood supply is interrupted, leading to damage of brain cells. It can be categorized as ischemic stroke, which is typically caused by a blood clot, or intracerebral hemorrhage, which involves bleeding within the brain tissue.
INTERSTROKE represents one of the largest worldwide studies examining stroke risk factors, encompassing nearly 27,000 participants across 27 countries, including around 13,500 individuals who suffered their first stroke.
Participants hailed from diverse geographical and ethnic backgrounds, each with varying cardiovascular risk levels, including those from Ireland and the UK.
The study focusing on fizzy drinks and fruit juice consumption discovered:
- Both sugar-sweetened and artificially sweetened fizzy drinks were associated with a 22% increased risk of stroke, particularly for those consuming two or more drinks daily.
- The strongest correlation between fizzy drinks and stroke risk was observed in Eastern/Central Europe, the Middle East, Africa, and South America.
- Many products labeled as fruit juice often use concentrates and contain added sugars and preservatives, potentially negating the advantages usually linked to fresh fruit and increasing stroke risk instead.
- Fruit juice drinks were associated with a 37% higher risk of stroke due to bleeding (intracranial hemorrhage), with the risk tripling for those consuming two drinks daily.
- Women displayed a higher risk of stroke from bleeding (intracranial hemorrhage) tied to fruit juice/drinks consumption.
- Drinking more than seven cups of water daily was linked to a lower risk of clot-related strokes.
Lead researcher Professor Andrew Smyth, Clinical Epidemiology Professor at the University of Galway and Consultant Physician at Galway University Hospitals, stated: “Not all fruit drinks are created equal — fresh squeezed fruit juices are likely to provide health benefits, while those made from concentrates with added sugars and preservatives may be detrimental. Our research also indicates that the likelihood of stroke rises with the frequency of fizzy drink consumption.”
“As a medical professional and a researcher in stroke risk, we urge everyone to limit their intake of fizzy and fruit drinks and consider opting for water instead.”
The study examining coffee and tea intake revealed:
- Drinking over four cups of coffee a day raised the chance of stroke by 37%, with no increased risk associated with lower consumption.
- Tea consumption correlated with an 18-20% reduction in stroke risk.
- Consuming 3-4 cups of black tea, including varieties like Breakfast and Earl Grey, was linked to a 29% lower stroke risk.
- Drinking 3-4 cups of green tea was associated with a 27% lower risk of stroke.
- Adding milk to tea might diminish or negate the beneficial effects of its antioxidants, leading to a loss of the reduced stroke risk.
- Geographical variations were significant; tea was linked with a lower stroke risk in China and South America, yet a higher risk in South Asia.
Co-leader of the INTERSTROKE study, Professor Martin O’Donnell, Executive Dean of the College of Medicine, Nursing, and Health Sciences at the University of Galway and Consultant Stroke Physician at Galway University Hospitals, stated: “One of INTERSTROKE’s primary goals is to provide actionable insights on reducing stroke risk. While hypertension remains a crucial risk factor, adopting a healthy lifestyle that includes mindful dietary choices and physical activity can further lower our stroke risk. This latest study contributes valuable information about healthy beverage consumption choices.”
