SUCROSE, STARCH AND HYPERLlPlDEMlA In two- to three-week studies with young men an excessive consumption of energy was associated with hyperlipidernia when sucrose replaced the starch in the diet
Key Words: sucrose, starch, blood lipids, energy intake, cholesterol, triglycerides
Large loads of dietary carbohydrate have been shown by several workers' t o have effects on the blood lipid pattern. Many of these studies involved the comparison of the effects following starch or sucrose ingestion. These studies show that sucrose loads induced a rise in the plasma lipids. Other studies on plasma lipids compared the effects of complex (i.e. polysaccharides) carbohydrates in the diet with diets containing simple sugars either as mono- or disaccharides.' Some studies suggested that part of the difference between a polysaccharide such as starch and simple sugars may be due to differences in the rate of digestion and absorption although a strong lipogenic effect of the fructose moiety of sucrose was also present. The results obtained in other studies have not been so clear cut and the position has been clouded by the development of controversy regarding the significance of these findings in the etiology of coronary heart disease. Some work suggested that the hyperlipidemia observed when excessive sucrose is consumed is due to an increased energy intake and not to the source per ~ e In . ~a recent paper D. J. Naismith and co-workers5 describe the results of three experiments in which the interrelations of energy intake and sucrose versus starch effects have been studied. The subjects were healthy male students who were subjected to close dietary supervision during the course of the study. In the first study 23 subjects consumed their self-selected diet for seven days; a propor44
NUTRfTfON REVIEWSIVOL. 33. NO. PfFEBRUARY 1975
tion of the starch in their customary diet was then replaced with an equicaloric amount of sucrose. This was done so that other changes in the diet were kept to a minimum. The exchange involved approximately 200 g of starch. The subjects consumed these modified diets for a further 14 days after which they returned to their usual diet for another 14 days. Blood was taken a t the beginning and end of the first seven days, and a t the ends of the two other dietary treatments and analyzed for t o t a I ch o Iestero I, t r i glycerides, and phospholipids. A second identical study with ten subjects was then carried out in which the blood cholesterol was fractionated into free and esterified components. In the third experiment involving 12 subjects, the energy intake of each subject was increased by 1800 kcal per day for 21 days using the usual components of their diet. Six of the subjects had their sucrose intake reduced during this overfeeding and the remainder had it raised by dietary manipulations. In the first experiment the energy intakes on the high sucrose diet were, on the average, virtually the same as on the selfselected diet. The sucrose intake was trebled, increasing from 100 to 300 g per day, and the proportion of the dietary energy f r o m carbohydrate increased slightly a t the expense of the energy from fat. The blood lipids showed significant rises in total cholesterol, triglycerides, and phospholipids on the high-sucrose diet and the concentrations returned to the preliminary levels on return to the subjects' usual diets.
The results from the second study were very similar. Fractionation of cholesterol showed that the rise occurred almost exclusively in the esterified fraction. In the third experiment the six subjects on the low-sucrose diet increased their energy intake by some 1700 kcal per day, their starch intake increased from 123 to 221 per day , and the sucrose intake fell from 73 t o 41 g. The proportion of energy from carbohydrate on the diet fell and was accompanied by an increased f a t intake. In the other six subjects energy intake was increased by a similar amount, starch intake was reduced from 172 t o 45 g, and sucrose increased from 110 to 329 g. The changes in the proportions of energy from carbohydrates and f a t were similar to those in the low-sucrose group. The triglyceride levels rose significantly during the over-eating on the high-sucrose diet and returned t o normal levels when the subjects returned t o their normal diet. The changes on the low-sucrose diet were not significant although a small rise did occur. The changes in the plasma cholesterol values were similar, being about 50 percent above the normal levels during over-eating the high-sucrose diet and again returning t o normal on the normal diet. No changes o f significance occurred on the low-sucrose diet. The results obtained in this study demonstrate a hyperlipidemic effect associated with the replacement of starch in the diet with sucrose. These changes occurred in the three major lipid fractions in the blood and fractionation of the total cholesterol showed that the rise was confined to the esterified fraction. Increasing the energy intake by 60 percent above normal had l i t t l e or no effect on the plasma triglycerides or cholesterol unless it was associated with an increased sucrose intake. The group receiving the low sucrose diet had an increased f a t intake of some 120 g per day, yet this did not produce any hyperlipidemic effect This paper shows that increased consumption of sucrose compared with starch has a significant effect on the plasma lipids
and that this effect is not related to the level o f energy intake. The practical significance of these kinds o f studies remains obscure. Although sucrose and starch are normal constituents of practically all diets, the consumption of as much as 300 g of sucrose must be relatively rare. The question remains whether variations in the amount of sucrose consumed by most individuals has any significant effect upon blood lipid levels. The perm an e nce o f carbohydrate induced changes in blood lipid levels is also a matter of debate.6 A better understanding of metabolic pathways responsible for the effects of different carbohydrates upon serum lipids would be helpful in resolving the questions repeatedly raised in this area. 0
1. I. MacDonald and D. M. Braithwaite: The Influence of Dietary Carbohydrate on the Lipid Pattern in Serum and Adipose Tissue. Clin. Sci. 27: 23-30, 1964 2. M. A. Antar and M. A. Ohlson: Effect of Simple and Complex Carbohydrates upon Total Lipids, Nonphospholipids, and Different Fractions of Phospholipids of Serum in Young Men and Women. J. Nutrition 85: 329-337, 1965 3. D. J. Naismith and I. A. Rana: Sucrose and Hyperlipidaemia. 11. The Relationship between the Rates of Digestion and Absorption of Different Carbohydrates and Their Effect on Enzymes of Tissue Lipogenesis. Nutrition Metab. 16: 285-294, 1974 4. J. I. Mann and A. S. Truswell: Effects of lsocaloric Exchange of Dietary Sucrose and Starch on Fasting Serum Lipids, Postprandial Insulin Secretion and Alimentary Lipaemia in Humar: Subjects. Brit J. Nutrition 27: 395-405, 1972 5. D. J. Naismith, A. L. Stock, and J. Yudkin: Effects of Changes in the Proportions of Dietary Carbohydrates and in Energy Intakes on the Plasma Lipid Concentrations in Healthy Young Men. Nutrition Metab. 16: 295-304, 1974 6. R. B. McGandy, D. M. Hegsted, and F. J. Stare: Dietary Fats, Carbohydrates and Atherosclerotic Vascular Disease. New Engl. J. Med 277: 417-419, 469-471, 1968 NUTRITION REVIEWSNOL. 33, NO. 2fFEBRUARY 1975
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Key Words: sucrose, starch, blood lipids, energy intake, cholesterol, triglycerides
Large loads of dietary carbohydrate have been shown by several workers' t o have effects on the blood lipid pattern. Many of these studies involved the comparison of the effects following starch or sucrose ingestion. These studies show that sucrose loads induced a rise in the plasma lipids. Other studies on plasma lipids compared the effects of complex (i.e. polysaccharides) carbohydrates in the diet with diets containing simple sugars either as mono- or disaccharides.' Some studies suggested that part of the difference between a polysaccharide such as starch and simple sugars may be due to differences in the rate of digestion and absorption although a strong lipogenic effect of the fructose moiety of sucrose was also present. The results obtained in other studies have not been so clear cut and the position has been clouded by the development of controversy regarding the significance of these findings in the etiology of coronary heart disease. Some work suggested that the hyperlipidemia observed when excessive sucrose is consumed is due to an increased energy intake and not to the source per ~ e In . ~a recent paper D. J. Naismith and co-workers5 describe the results of three experiments in which the interrelations of energy intake and sucrose versus starch effects have been studied. The subjects were healthy male students who were subjected to close dietary supervision during the course of the study. In the first study 23 subjects consumed their self-selected diet for seven days; a propor44
NUTRfTfON REVIEWSIVOL. 33. NO. PfFEBRUARY 1975
tion of the starch in their customary diet was then replaced with an equicaloric amount of sucrose. This was done so that other changes in the diet were kept to a minimum. The exchange involved approximately 200 g of starch. The subjects consumed these modified diets for a further 14 days after which they returned to their usual diet for another 14 days. Blood was taken a t the beginning and end of the first seven days, and a t the ends of the two other dietary treatments and analyzed for t o t a I ch o Iestero I, t r i glycerides, and phospholipids. A second identical study with ten subjects was then carried out in which the blood cholesterol was fractionated into free and esterified components. In the third experiment involving 12 subjects, the energy intake of each subject was increased by 1800 kcal per day for 21 days using the usual components of their diet. Six of the subjects had their sucrose intake reduced during this overfeeding and the remainder had it raised by dietary manipulations. In the first experiment the energy intakes on the high sucrose diet were, on the average, virtually the same as on the selfselected diet. The sucrose intake was trebled, increasing from 100 to 300 g per day, and the proportion of the dietary energy f r o m carbohydrate increased slightly a t the expense of the energy from fat. The blood lipids showed significant rises in total cholesterol, triglycerides, and phospholipids on the high-sucrose diet and the concentrations returned to the preliminary levels on return to the subjects' usual diets.
The results from the second study were very similar. Fractionation of cholesterol showed that the rise occurred almost exclusively in the esterified fraction. In the third experiment the six subjects on the low-sucrose diet increased their energy intake by some 1700 kcal per day, their starch intake increased from 123 to 221 per day , and the sucrose intake fell from 73 t o 41 g. The proportion of energy from carbohydrate on the diet fell and was accompanied by an increased f a t intake. In the other six subjects energy intake was increased by a similar amount, starch intake was reduced from 172 t o 45 g, and sucrose increased from 110 to 329 g. The changes in the proportions of energy from carbohydrates and f a t were similar to those in the low-sucrose group. The triglyceride levels rose significantly during the over-eating on the high-sucrose diet and returned t o normal levels when the subjects returned t o their normal diet. The changes on the low-sucrose diet were not significant although a small rise did occur. The changes in the plasma cholesterol values were similar, being about 50 percent above the normal levels during over-eating the high-sucrose diet and again returning t o normal on the normal diet. No changes o f significance occurred on the low-sucrose diet. The results obtained in this study demonstrate a hyperlipidemic effect associated with the replacement of starch in the diet with sucrose. These changes occurred in the three major lipid fractions in the blood and fractionation of the total cholesterol showed that the rise was confined to the esterified fraction. Increasing the energy intake by 60 percent above normal had l i t t l e or no effect on the plasma triglycerides or cholesterol unless it was associated with an increased sucrose intake. The group receiving the low sucrose diet had an increased f a t intake of some 120 g per day, yet this did not produce any hyperlipidemic effect This paper shows that increased consumption of sucrose compared with starch has a significant effect on the plasma lipids
and that this effect is not related to the level o f energy intake. The practical significance of these kinds o f studies remains obscure. Although sucrose and starch are normal constituents of practically all diets, the consumption of as much as 300 g of sucrose must be relatively rare. The question remains whether variations in the amount of sucrose consumed by most individuals has any significant effect upon blood lipid levels. The perm an e nce o f carbohydrate induced changes in blood lipid levels is also a matter of debate.6 A better understanding of metabolic pathways responsible for the effects of different carbohydrates upon serum lipids would be helpful in resolving the questions repeatedly raised in this area. 0
1. I. MacDonald and D. M. Braithwaite: The Influence of Dietary Carbohydrate on the Lipid Pattern in Serum and Adipose Tissue. Clin. Sci. 27: 23-30, 1964 2. M. A. Antar and M. A. Ohlson: Effect of Simple and Complex Carbohydrates upon Total Lipids, Nonphospholipids, and Different Fractions of Phospholipids of Serum in Young Men and Women. J. Nutrition 85: 329-337, 1965 3. D. J. Naismith and I. A. Rana: Sucrose and Hyperlipidaemia. 11. The Relationship between the Rates of Digestion and Absorption of Different Carbohydrates and Their Effect on Enzymes of Tissue Lipogenesis. Nutrition Metab. 16: 285-294, 1974 4. J. I. Mann and A. S. Truswell: Effects of lsocaloric Exchange of Dietary Sucrose and Starch on Fasting Serum Lipids, Postprandial Insulin Secretion and Alimentary Lipaemia in Humar: Subjects. Brit J. Nutrition 27: 395-405, 1972 5. D. J. Naismith, A. L. Stock, and J. Yudkin: Effects of Changes in the Proportions of Dietary Carbohydrates and in Energy Intakes on the Plasma Lipid Concentrations in Healthy Young Men. Nutrition Metab. 16: 295-304, 1974 6. R. B. McGandy, D. M. Hegsted, and F. J. Stare: Dietary Fats, Carbohydrates and Atherosclerotic Vascular Disease. New Engl. J. Med 277: 417-419, 469-471, 1968 NUTRITION REVIEWSNOL. 33, NO. 2fFEBRUARY 1975
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