Reduced Sugar Intake Helps Prevent Fatal Heart Attacks and Strokes

A recent analysis indicates that limiting intake of refined sugar to at most 10% of all calories reduces the risk of experiencing a fatal cardiovascular event.

According to new research published in the Journal of the American Medical Association, excess sugar intake could be more harmful than has been previously reported.

Investigators looked at the association between incidence of cardiovascular disease—related mortality and sugar intake among participants in the United States National Health and Nutrition Examination Survey. In more than 10,000 individuals over a period of more than 163,000 person-years, the risk of cardiovascular disease–related mortality increased as the portion of all calories derived from sugar increased. The trend remained significant even after investigators adjusted for between-group differences in age, sex, or ethnicity.¹

Among those for whom sugar accounted for at least one-fourth of total caloric intake, the risk of mortality over the median 14.6-year follow-up period was more than double the mortality risk among people for whom sugar accounted for less than a tenth of total daily caloric intake (hazard ratio [HR] = 2.43, 95% CI 1.63 to 3.62; P <.001). In another analysis, the addition of a single 360-mL sugar-sweetened beverage each day of the week increased one’s mortality risk by 29% (95% CI, 4% to 60%).¹

It is important for patients to understand the meaning of the 29% increase in the risk of cardiovascular-related mortality with excess sugar-sweetened beverage intake. Because the hazard ratio is a time-independent statistic, one way to imagine the increase in risk is in terms of a coin toss. If all lifestyle factors were equal between 2 people, the first person to experience a cardiovascular-related death would be selected randomly—equivalent to flipping a coin.²

In fact, compared with people who do not drink sugary beverages, people who drink a 140-calorie sugary beverage daily will die of a fatal stroke or heart attack first in 56% of cases—not 50% of cases, as would be expected if sugary beverages were harmless. In other words, daily sugary beverage intake weights the odds of a fatal stroke or heart attack in favor of the person who consumes sugar-containing beverages.^1,2

The effect is more dramatic when differences in sugar intake are more pronounced. People who consume at least one-fourth of their total caloric intake in the form of sugar have just a 29% chance of staying free of a fatal heart attack or stroke longer than people whose sugar intake makes up less than a tenth of their caloric intake.^1,2

Current recommendations for sugar consumption are inconsistent. As noted by the authors, the World Health Organization recommends limiting sugar intake to less than a tenth of calories, while the Institute of Medicine advises limiting sugar intake to less than one-fourth of calories. Adding to the confusion, the American Heart Association recommends that daily sugar intake be kept under 150 calories per day for men and under 100 calories for women. The results of this large study suggest that keeping sugar intake under a tenth of caloric intake may be the best course of action.¹

References

1. Yang Q, Zhang Z, Gregg EW, Flanders WD, Merritt R, Hu FB. Added sugar intake and cardiovascular diseases mortality among US adults [published online February 3, 2014]. JAMA Intern Med. Accessed February 6, 2014.

2. Spruance SL, Reid JE, Grace M, Samore M. Hazard ratio in clinical trials. Antimicrob Agents Chemother. 2004;48(8):2787-2792.