The evidence just keeps mounting that sugar-laden soft drinks – which include pop, energy drinks and vitamin waters – aren't good for your health. Drink them often and studies suggest you're more likely to experience weight gain, not to mention develop Type 2 diabetes, high blood pressure, high cholesterol, gout and coronary heart disease.
A new study conducted in 127,456 healthy men and women, has linked soft drinks – sugar-sweetened and diet – with a higher risk of stroke. The findings also revealed that substituting coffee or skim milk for soft drinks guards against stroke.
In Canada one stroke occurs every 10 minutes, about 50,000 a year. The majority – 80 per cent – are ischemic strokes caused when a blood clot interrupts blood flow to the brain. Hemorrhagic strokes, caused by uncontrolled bleeding in the brain, account for the remaining 20 per cent of strokes.
Risk factors for stroke include high blood pressure, high cholesterol, diabetes, smoking, excess alcohol, stress and being overweight. After age 55 the risk of stroke doubles every 10 years.
The study, published in the May issue of the American Journal of Clinical Nutrition, followed men and women for up to 28 years. Higher intakes of both sugar-sweetened and low-calorie soft drinks increased the risk of stroke.
Men who drank at least one serving (e.g. one glass, bottle or can) of a sugar-sweetened soft drink each day had an 8 per cent higher stroke risk compared to men who didn't drink any. Women saw their risk increase by 19 per cent.
Drinking one or more diet soft drinks a day also upped stroke risk by 10 per cent in men and 18 per cent in women.
Sugar-sweetened soft drinks were associated with ischemic stroke whereas diet soft drinks were linked to hemorrhagic stroke.
Once consumed, soft drinks cause a rapid increase in blood glucose (sugar) and insulin, the hormone that removes glucose from the bloodstream. Over time, this can impair the body's ability to use insulin and cause inflammation. These two changes influence hardening of the arteries, the stability of fatty plaques in artery walls and blood clotting – all risk factors for stroke.
There's also concern than high-fructose corn syrup in soft drinks can cause metabolic changes that increase the likelihood of stroke.
As well, because the body doesn't regulate our intake of sugary drinks in the same way as foods – liquid calories don't put the brakes on our appetite – drinking them could lead to excess calories and weight gain.
Regular and diet colas are also a potential source of advanced glycation products, complexes of proteins and sugar that trigger inflammation and free radical damage in the body.
Replacing one serving of regular soft drink with a serving of caffeinated or decaffeinated coffee lowered the risk of stroke by 10 per cent. Swapping coffee for diet soft drinks reduced stroke risk by 11 to 13 per cent.
Coffee contains natural compounds called chlorogenic acids, antioxidants thought to dampen inflammation in the body and improve how the body uses insulin. Coffee is also a source of magnesium, a mineral linked to blood sugar regulation and healthy blood pressure.
If you don't like coffee, consider drinking skim milk. In the study it was associated with an 11 per cent lower risk compared to diet soft drinks.
Low-fat dairy products were also found to reduce the risk of stroke in a decade-long study of nearly 75,000 healthy men and women published earlier this month in the journal Stroke. People who drank low-fat milk and ate low-fat yogurt and cheese were 13 per cent less likely to have an ischemic stroke than people who consumed the least.
The benefits of low-fat dairy foods are likely due to their calcium, potassium, magnesium and vitamin D content, nutrients that lower blood pressure.
It's estimated that eating a healthy diet, quitting smoking and increasing exercise can reduce your risk of stroke by 50 per cent. When it comes to diet strategies, the following can help.
Avoid sugary drinks Avoid sugar-sweetened beverages including pop, fruit drinks, iced tea, vitamin waters, energy drinks and sports drinks. Avoid diet soft drinks too. Replace with water, low-fat milk, unflavoured soy beverages, or unsweetened coffee and tea.
Include low fat dairy Include three serving servings of low-fat dairy in your daily diet. Choose skim or 1 per cent milk, yogurt and cottage cheese with 1 per cent milk fat (MF) or less, and hard cheese with less than 10 per cent MF content. (One cup of milk or three-quarters of a cup of yogurt equals one serving.) Increase fruits and vegetables Fruits and vegetables are an excellent source of potassium, a mineral that helps keep blood pressure in check. They also supply fibre, folate and antioxidants, nutrients that keep blood vessels healthy.
Recent studies suggest that apples, pears and citrus fruit are especially protective of stroke, thanks to their flavonoid content.
Eat a daily minimum of seven servings of fruits and vegetables. (One serving equals ½ cup raw or cooked vegetables, 1 cup of salad greens, 1 medium sized fruit and 1 cup chopped fruit.) Boost magnesium Higher intakes of magnesium are associated with a lower risk of stroke. Magnesium is needed to regulate blood pressure and blood glucose and helps reduce inflammation.
The best food sources of magnesium include black beans, chickpeas, kidney beans, navy beans, soybeans, firm tofu, spinach, Swiss card, halibut, almonds, cashews, sunflower seeds, yogurt, wheat bran and wheat germ.
Reduce sodium The American Heart Association recommends limiting sodium to 1,500 milligrams a day for cardiovascular health, a limit that's lower than the Institute of Medicine's daily upper limit of 2300 milligrams for North Americans. (The Institute of Medicine sets recommended dietary allowances used by both the United States and Canada.) The link between excess sodium and hypertension is well known. Research has also linked high daily salt intakes – 4,000 milligrams or higher compared to 1,500 milligrams or less – with a substantially greater risk of stroke. One teaspoon of table salt contains about 2,300 mg of sodium.
Read nutrition labels to choose foods that have less sodium per serving. Cut down on processed foods and restaurant meals.
Leslie Beck, a Toronto-based dietitian, is the national director of nutrition for Body Science Centers, medical clinics focusing on healthy aging (www.BSC5.com).
Leslie Beck