Sugar and Cardiovascular Disease

T he purpose of this report is to review the effects of dietary sugar on health, with an emphasis on cardiovascular disease (CVD) and its risk factors.Although there are no dietary trials linking sugar consumption and CVD, there are several reasons why sugar consumption should be limited. DefinitionsThere are many, sometimes confusing, terms used in the literature.Simple carbohydrate (sugar) refers to mono-and disaccharides; complex carbohydrate refers to polysaccharides such as starch.Common disaccharides are sucrose (glucoseϩfructose), found in sugar cane, sugar beets, honey, and corn syrup; lactose (glucoseϩgalactose), found in milk products; and maltose (glucoseϩglucose), from malt.The most common naturally occurring monosaccharide is fructose (found in fruits and vegetables).The term dextrose is used to refer to glucose.Intrinsic or naturally occurring sugar refers to the sugar that is an integral constituent of whole fruit, vegetable, and milk products; extrinsic or added sugar refers to sucrose or other refined sugars in soft drinks and incorporated into food, fruit drinks, and other beverages. Sugar Consumption in the United StatesAdded sugar was not a significant component of the human diet until the advent of modern food-processing methods.Since then, the intake of sugar has risen steadily.The average US sugar utilization per capita on the basis of food disappearance data was 55 kg (120 lb) per year in 1970, and it reached 68 kg (150 lb) per year in 1995 (almost 0.5 lb per day). 1 Sugar (simple carbohydrate) intake averages 25% of total energy intake.Data from the 1989 to 1991 Continuing Survey of Food Intake by Individuals indicate that soft drinks and sugars added at the table (eg, sugar/ syrups and jams) are 2 of the top 4 carbohydrate sources for US adults. 2 Sugar and Coronary Heart DiseaseYudkin and colleagues in the 1960s 3 and 1970s 4 found that a higher intake of sugar was associated with increased CVD in both within-country and cross-country comparisons.A few recent studies have examined the link between sugar consumption and coronary heart disease (CHD).The Iowa Women's Health Study 5 showed no relation between the intake of sweets or desserts and risk of ischemic heart disease in 34 492 women monitored for 9 years.However, some major sources of sugar such as soft drinks were not considered.The Scottish Heart Health Study 6 of 10 359 men and women found that neither extrinsic nor intrinsic sugars were significant independent correlates of prevalent CHD after adjustment for other major risk factors, but the data were not adjusted for other dietary variables.A recent report from the Nurses' Health Study showed that women who consumed diets with a high glycemic load* (increased blood glucose excursions associated with intake of sweets or highly processed starches and sweets) had an increased CHD risk, with those in the highest quintile having a Ͼ2-fold risk during 10 years of follow-up.7 Simple carbohydrate alone was also predictive but did not reach statistical significance.This analysis controlled for total energy intake and other major dietary and nondietary risk factors. Dietary Sugar and Plasma LipoproteinsA number of studies link dietary sugar with adverse changes in lipoproteins.Several studies have shown an inverse association between dietary sucrose and high-density lipoprotein (HDL) cholesterol.8,9 Data from the Coronary Artery Risk Development In young Adults (CARDIA) study show aThe American Heart Association makes every effort to avoid any actual or potential conflicts of interest that may arise as a result of an outside relationship or a personal, professional, or business interest of a member of the writing panel.Specifically, all members of the writing group are required to complete and submit a Disclosure Questionnaire showing all such relationships that might be perceived as real or potential conflicts of interest.