Ask an Expert: Study links sugary drinks and heart risks
Q: A new study published in March says that drinking one sugar-sweetened beverage per day can increase the risk of coronary artery disease by 20 percent. I'm concerned about my heart risks – should I give up soda?
Answered by Aly Rahimtoola, M.D., FACC, cardiologist, Providence Heart Clinic at The Oregon Clinic Gateway
We all should be worried about our risk of coronary artery disease. CAD is heart disease caused by atherosclerosis, or hardening of the arteries leading to the heart, and it is the No. 1 killer of both men and women in the United States.
The study, which came from the Harvard School of Public Health and was published in the American Heart Association journal Circulation, is definitely intriguing. Based mainly on the health journals of 43,000 men over 22 years, it found that drinking 12 ounces of sugar-sweetened sodas, sports drinks, energy drinks or fruit drinks daily was associated with a 20 percent higher risk of CAD. Other studies have found a similar association in women.
But studies like this need to be kept in the proper perspective. Showing a moderate association is a long way from proving that one thing causes another. Cutting out sugary beverages may be a good health move for many reasons, but it will not prevent heart disease all by itself.
If you are serious about reducing your heart risks, you have much bigger fish to fry – or better, to broil – than worrying about an occasional soda or sports drink. Hundreds of studies over several decades have identified eight major risk factors that are known to increase the likelihood of developing atherosclerosis. They suggest that if you can keep the following eight factors under control, you can slash your risk of CAD – and of all chronic diseases – by 80 percent or more. Now those are some powerful numbers.
At first glance, the numbers in the beverage study look impressive. But contrast that single study with more than half a century of research on smoking, which concludes that the risk of death from CAD – as well as the risk of death from all causes – is 62 percent higher among smokers than nonsmokers. In addition, volumes of studies have shown that when people quit smoking, their risk of CAD and other diseases goes down. No similar studies exist to offer any clues about the effects of giving up soda. In all the research on smoking, the associations with CAD are so strong, and the breadth of research so robust, that smoking is believed absolutely to be causative, rather than just casually associated with CAD. If you smoke, quitting will have the most profound effect on reducing your heart risks.
- Being overweight or obese
Advocacy groups who claim that being overweight is not harmful to your health are dead wrong. The link between obesity and CAD is as clear as the link between smoking and CAD. A Study looking at body mass index, or BMI – a calculation of body fat based on a person's height and weight – shows that for every 5 percent increase in BMI, your risk of heart attack, sudden cardiac death and other adverse heart events goes up by 39 percent. Find out what your BMI is. If it's over 25, get serious about bringing it down into the healthy range of 19 to 25.
- High blood pressure
We don't always know what causes high blood pressure, but studies do tell us that treating it prevents strokes, heart failure and CAD. Get your blood pressure checked every year to make sure it doesn't sneak up on you. If it's getting into the pre-hypertensive range (> 120/80) or the high range (> 140/90), work with your doctor to find the right combination of lifestyle changes and medications to lower your blood pressure.
- High cholesterol
There is a very strong link between high cholesterol levels and developing CAD. Reducing the amount of saturated fat (see factor No. 5) and cholesterol in your diet is the first step to keeping cholesterol in line. Exercise is a big help, too. If those changes don't do the trick, talk to your doctor about cholesterol-lowering medications – they have been shown to prevent heart attacks. Don't know your cholesterol numbers? See your doctor to find out.
- High-fat diet
Research shows that a diet that is high in saturated fat (animal fats such as butter, full-fat milk and cheese, fried foods and fatty cuts of meat) and trans fat (margarines and baked goods that list "partially hydrogenated vegetable oil" as an ingredient) also is high in heart risks. For a happier heart, focus your diet on fruits and vegetables, whole grains, skinless chicken and fish, nuts and seeds, legumes such as black beans and chickpeas, fat-free milk and yogurt, and heart-healthy mono-unsaturated fats such as olive and canola oils.
- Physical inactivity
Sometimes it's not what you do, but what you don't do, that's bad for your heart. Doing nothing, physically, increases your risk of CAD. Multiple studies have shown that men and women who exercise the most have the lowest incidence of CAD. Choose an activity that you like enough to do regularly – walking, running, swimming, bicycling, basketball, you name it – and do it for 30 or 40 minutes a day on most days of the week. Keep it aerobic by exercising to the point where you feel a little sweaty and a little out of breath. If you're not active now, work your way up to that level gradually, and talk to your doctor first if you have a medical condition.
Diabetes more than doubles your risk of having a heart attack or stroke. One study found that people with diabetes who have never had a heart attack or other CAD event have the same risk level as non-diabetics who have already had a heart attack or CAD event. If you have diabetes, work with your doctor or a diabetes educator to do everything you can to control it. If you don't have diabetes, keep it that way by exercising regularly, following a healthy diet and keeping your BMI in the healthy range.
- Alcohol consumption
People who drink alcohol moderately may have a slightly lower risk of dying from heart disease and stroke than people who don't drink at all. I don't advise non-drinkers to start drinking just for the modest heart benefits. But if you do enjoy an alcoholic beverage every now and then, studies show that keeping it moderate may do your heart some good. Moderate drinking is defined as four to seven alcoholic beverages a week. An alcoholic beverage is defined as one beer, 5 ounces of wine, or 1-1/2 ounces of hard alcohol.
So, getting back to your original question, should you kick the can? Sure. Giving up sugary drinks – or at least cutting way back on them – is an easy way to cut empty calories from your diet, which can help with two of the "big eight" priorities: preventing obesity and diabetes. But if weight and diabetes aren't issues, and you already exercise regularly, minimize saturated and trans fats in your diet, avoid smoking, consume alcohol only moderately, and maintain healthy blood pressure and cholesterol levels, then I wouldn't spend too much time worrying about an occasional soda.