Skip to main content
NCBI home page
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1970 Jun;49(6):1135–1152. doi: 10.1172/JCI106329

The effects of unsaturated dietary fats on absorption, excretion, synthesis, and distribution of cholesterol in man

Scott M Grundy 1, E H Ahrens Jr 1
PMCID: PMC322581  PMID: 5422017

Abstract

Cholesterol balance studies were carried out in 11 patients with various types of hyperlipoproteinemia to determine the mechanism by which unsaturated fats lower plasma cholesterol. Unsaturated fats produced no increase in fecal endogenous neutral steroids in 10 of 11 patients and no decrease in absorption of exogenous cholesterol in 5 patients who received cholesterol in the diet. In 8 of 11 patients no changes occurred in excretion of bile acids during the period on unsaturated fat when plasma cholesterol was declining. However, in 3 of 11 patients small but significant increases in bile acid excretion were found during this transitional period; in 2 others increases also occurred after plasma cholesterol had become constant at lower levels on unsaturated fat.

Since the majority of patients showed no change in cholesterol or bile acid excretions during the transitional period, we propose that when excretion changes did occur they were probably not the cause of the plasma cholesterol change. Furthermore, turnover data and specific activity curves suggested that cholesterol synthesis was not influenced by exchange of dietary fats. Thus, excluding changes in excretion and synthesis, we conclude that it is most likely that unsaturated fats cause plasma cholesterol to be redistributed into tissue pools.

We have also examined the possibility that cholesterol which is redistributed into tissues could be secondarily excreted as neutral steroids or bile acids. In at least 5 of 11 patients excretion patterns were consistent with this explanation. However, we cannot rule out that excretion changes may have been due to alterations in transit time, to changes in bacterial flora, or to transitory changes in absorption or synthesis of cholesterol or bile acids.

Our conclusion that unsaturated fats cause a redistribution of cholesterol between plasma and tissue pools points to the necessity in future to explore where cholesterol is stored, to what extent stored cholesterol can be mobilized, and to define the factors governing these fluxes.

Full text

PDF
1135

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. ABEL L. L., LEVY B. B., BRODIE B. B., KENDALL F. E. A simplified method for the estimation of total cholesterol in serum and demonstration of its specificity. J Biol Chem. 1952 Mar;195(1):357–366. [PubMed] [Google Scholar]
  2. AHRENS E. H., Jr, DOLE V. P., BLANKENHORN D. H. The use of orally-fed liquid formulas in metabolic studies. Am J Clin Nutr. 1954 Sep-Oct;2(5):336–342. doi: 10.1093/ajcn/2.5.336. [DOI] [PubMed] [Google Scholar]
  3. ANTONIS A., BERSOHN I. The influence of diet on fecal lipids in South African white and Bantu prisoners. Am J Clin Nutr. 1962 Aug;11:142–155. doi: 10.1093/ajcn/11.2.142. [DOI] [PubMed] [Google Scholar]
  4. AVIGAN J., STEINBERG D. Effects of saturated and unsaturated fat on cholesterol metabolism in the rat. Proc Soc Exp Biol Med. 1958 Apr;97(4):814–816. doi: 10.3181/00379727-97-23887. [DOI] [PubMed] [Google Scholar]
  5. Avigan J., Steinberg D. Sterol and bile acid excretion in man and the effects of dietary fat. J Clin Invest. 1965 Nov;44(11):1845–1856. doi: 10.1172/JCI105292. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. BLOOMFIELD D. K. CHOLESTEROL METABOLISM. 3. ENHANCEMENT OF CHOLESTEROL ABSORPTION AND ACCUMULATION IN SAFFLOWER OIL-FED RATS. J Lab Clin Med. 1964 Oct;64:613–623. [PubMed] [Google Scholar]
  7. Bieberdorf F. A., Wilson J. D. Studies on the mechanism of action of unsaturated fats on cholesterol metabolism in the rabbit. J Clin Invest. 1965 Nov;44(11):1834–1844. doi: 10.1172/JCI105291. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Connor W. E., Witiak D. T., Stone D. B., Armstrong M. L. Cholesterol balance and fecal neutral steroid and bile acid excretion in normal men fed dietary fats of different fatty acid composition. J Clin Invest. 1969 Aug;48(8):1363–1375. doi: 10.1172/JCI106102. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. DANIELSSON H., ENEROTH P., HELLSTROM K., LINDSTEDT S., SJOVALL J. On the turnover and excretory products of cholic and chenodeoxycholic acid in man. J Biol Chem. 1963 Jul;238:2299–2304. [PubMed] [Google Scholar]
  10. Davignon J., Simmonds W. J., Ahrens E. H. Usefulness of chromic oxide as an internal standard for balance studies in formula-fed patients and for assessment of colonic function. J Clin Invest. 1968 Jan;47(1):127–138. doi: 10.1172/JCI105703. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. EDELMAN I. S., LEIBMAN J. Anatomy of body water and electrolytes. Am J Med. 1959 Aug;27:256–277. doi: 10.1016/0002-9343(59)90346-8. [DOI] [PubMed] [Google Scholar]
  12. ENEROTH P., HELLSTROEM K., RYHAGE R. IDENTIFICATION AND QUANTIFICATION OF NEUTRAL FECAL STEROIDS BY GAS-LIQUID CHROMATOGRAPHY AND MASS SPECTROMETRY: STUDIES OF HUMAN EXCRETION DURING TWO DIETARY REGIMENS. J Lipid Res. 1964 Apr;5:245–262. [PubMed] [Google Scholar]
  13. FRANTZ I. D., Jr, CAREY J. B., Jr Cholesterol content of human liver after feeding of corn oil and hydrogenated coconut oil. Proc Soc Exp Biol Med. 1961 Apr;106:800–801. doi: 10.3181/00379727-106-26479. [DOI] [PubMed] [Google Scholar]
  14. Fredrickson D. S., Levy R. I., Lees R. S. Fat transport in lipoproteins--an integrated approach to mechanisms and disorders. N Engl J Med. 1967 Jan 19;276(3):148–contd. doi: 10.1056/NEJM196701192760305. [DOI] [PubMed] [Google Scholar]
  15. GERSON T., SHORLAND F. B., ADAMS Y. The effects of corn oil on the amounts of cholesterol and the excretion of sterol in the rat. Biochem J. 1961 Dec;81:584–591. doi: 10.1042/bj0810584. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. GOLDSMITH G. A., HAMILTON J. G., MILLER O. N. Lowering of serum lipid concentrations: mechanisms used by unsaturated fats, nicotinic acid, and neomycin: excretion of sterols and bile acids. Arch Intern Med. 1960;105:512–517. [PubMed] [Google Scholar]
  17. GORDON H., LEWIS B., EALES L., BROCK J. F. Dietary fat and cholesterol metabolism; faecal elimination of bile acids and other lipids. Lancet. 1957 Dec 28;273(7009):1299–1306. doi: 10.1016/s0140-6736(57)91636-7. [DOI] [PubMed] [Google Scholar]
  18. GRUNDY S. M., AHRENS E. H., Jr, MIETTINEN T. A. QUANTITATIVE ISOLATION AND GAS--LIQUID CHROMATOGRAPHIC ANALYSIS OF TOTAL FECAL BILE ACIDS. J Lipid Res. 1965 Jul;6:397–410. [PubMed] [Google Scholar]
  19. Grundy S. M., Ahrens E. H., Jr, Davignon J. The interaction of cholesterol absorption and cholesterol synthesis in man. J Lipid Res. 1969 May;10(3):304–315. [PubMed] [Google Scholar]
  20. Grundy S. M., Ahrens E. H., Jr Measurements of cholesterol turnover, synthesis, and absorption in man, carried out by isotope kinetic and sterol balance methods. J Lipid Res. 1969 Jan;10(1):91–107. [PubMed] [Google Scholar]
  21. Grundy S. M., Ahrens E. H., Jr, Salen G. Dietary beta-sitosterol as an internal standard to correct for cholesterol losses in sterol balance studies. J Lipid Res. 1968 May;9(3):374–387. [PubMed] [Google Scholar]
  22. HAUST H. L., BEVERIDGE J. M. Effect of varying type and quantity of dietary fat on the fecal excretion of bile acids in humans subsisting on formula diets. Arch Biochem Biophys. 1958 Dec;78(2):367–375. doi: 10.1016/0003-9861(58)90361-8. [DOI] [PubMed] [Google Scholar]
  23. Hellström K., Lindstedt S. Studies on the formation of cholic acid in subjects given standardized diet with butter or corn oil as dietary fat. Am J Clin Nutr. 1966 Jan;18(1):46–59. doi: 10.1093/ajcn/18.1.46. [DOI] [PubMed] [Google Scholar]
  24. LEWIS B., PILKINGTON T. R., HODD K. A. A mechanism for the action of unsaturated fat in reducing the serum cholesterol. Clin Sci. 1961 Apr;20:249–254. [PubMed] [Google Scholar]
  25. LINDSTEDT S. The turnover of cholic acid in man: bile acids and steroids. Acta Physiol Scand. 1957 Sep 17;40(1):1–9. doi: 10.1111/j.1748-1716.1957.tb01473.x. [DOI] [PubMed] [Google Scholar]
  26. Lindstedt S., Avigan J., Goodman D. S., Sjövall J., Steinberg D. The effect of dietary fat on the turnover of cholic acid and on the composition of the biliary bile acids in man. J Clin Invest. 1965 Nov;44(11):1754–1765. doi: 10.1172/JCI105283. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. MIETTINEN T. A., AHRENS E. H., Jr, GRUNDY S. M. QUANTITATIVE ISOLATION AND GAS--LIQUID CHROMATOGRAPHIC ANALYSIS OF TOTAL DIETARY AND FECAL NEUTRAL STEROIDS. J Lipid Res. 1965 Jul;6:411–424. [PubMed] [Google Scholar]
  28. Moore R. B., Anderson J. T., Taylor H. L., Keys A., Frantz I. D., Jr Effect of dietary fat on the fecal excretion of cholesterol and its degradation products in man. J Clin Invest. 1968 Jul;47(7):1517–1534. doi: 10.1172/JCI105845. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. SPRITZ N., AHRENS E. H., Jr, GRUNDY S. STEROL BALANCE IN MAN AS PLASMA CHOLESTEROL CONCENTRATIONS ARE ALTERED BY EXCHANGES OF DIETARY FATS. J Clin Invest. 1965 Sep;44:1482–1493. doi: 10.1172/JCI105255. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. SPRITZ N. EFFECT OF FATTY ACID SATURATION ON THE DISTRIBUTION OF THE CHOLESTEROL MOIETY OF VERY LOW DENSITY LIPOPROTEINS. J Clin Invest. 1965 Feb;44:339–347. doi: 10.1172/JCI105147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Salen G., Ahrens E. H., Jr, Grundy S. M. Metabolism of beta-sitosterol in man. J Clin Invest. 1970 May;49(5):952–967. doi: 10.1172/JCI106315. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Sodhi H. S., Wood P. D., Schlierf G., Kinsell L. W. Plasma, bile and fecal sterols in relation to diet. Metabolism. 1967 Apr;16(4):334–344. doi: 10.1016/0026-0495(67)90045-5. [DOI] [PubMed] [Google Scholar]
  33. Spritz N., Mishkel M. A. Effects of dietary fats on plasma lipids and lipoproteins: an hypothesis for the lipid-lowering effect of unsaturated fatty acids. J Clin Invest. 1969 Jan;48(1):78–86. doi: 10.1172/JCI105976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. TIDWELL H. C., McPHERSON J. C., BURR W. W., Jr Effect of the saturation of fats upon the disposition of ingested cholesterol. Am J Clin Nutr. 1962 Aug;11:108–114. doi: 10.1093/ajcn/11.2.108. [DOI] [PubMed] [Google Scholar]
  35. WILSON J. D., SIPERSTEIN M. D. Effect of saturated and unsaturated fats on hepatic synthesis and biliary excretion of cholesterol by the rat. Am J Physiol. 1959 Mar;196(3):599–602. doi: 10.1152/ajplegacy.1959.196.3.599. [DOI] [PubMed] [Google Scholar]
  36. Wood P. D., Shioda R., Kinsell L. W. Dietary regulation of cholesterol metabolism. Lancet. 1966 Sep 17;2(7464):604–607. doi: 10.1016/s0140-6736(66)91924-6. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES