Vikkie A. Mustad

The role of fatty acid saturation on plasma lipids, lipoproteins, and apolipoproteins: I. Effects of whole food diets high in cocoa butter, olive oil, soybean oil, dairy butter, and milk chocolate on the plasma lipids of young men☆

The present studies were conducted to evaluate the cholesterolemic effects of whole-food diets high in stearic acid. In study no. 1, normocholesterolemic young men were fed diets high in stearic acid provided by cocoa butter (CB); oleic acid provided by olive oil (OO); linoleic acid provided by soybean oil (SO); and myristic acid (and lauric acid) provided by dairy butter (B). In study no. 2, different subjects with similar baseline characteristics were fed diets high in stearic acid provided by milk chocolate (C), CB, CB+B (4:1, MIX), and myristic (and lauric) acid provided by B. Both studies used a randomized, crossover, double-blind experimental design, and experimental subjects (n = 18 for study no. 1 and n = 15 for study no. 2) in each study consumed every diet for 26 days with a 1-month wash-out period between each experimental period. The diets provided 37% of calories from fat, of which 81% was provided by the test fat. Ten ounces (280 g) C was provided daily by the C diet. In study no. 1, the B diet was hypercholesterolemic, whereas the SO diet was hypocholesterolemic, compared with the other diets. The OO and SO diets were hypocholesterolemic compared with the CB diet. Low-density lipoprotein (LDL) cholesterol levels, in general, paralleled the changes in plasma total cholesterol levels. SO significantly decreased apolipoprotein (apo) B levels compared with the other diets. Plasma very-low density lipoprotein (VLDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and apo A-I levels were unaffected by the experimental diets.(ABSTRACT TRUNCATED AT 250 WORDS)

Chocolate feeding studies: a novel approach for evaluating the plasma lipid effects of stearic acid.

Milk chocolate does not adversely affect plasma lipids and lipoproteins despite its relatively high content of saturated fatty acids (SFAs). Evidence from well-controlled feeding studies indicates that this unique response is due to the high proportion of stearic acid in milk chocolate. In experimental diets containing very high amounts (eg, 280 g/d, or 10 oz/d) and more typical amounts (46.2 g, or 1.65 oz) of milk chocolate, plasma total- and low-density-lipoprotein-cholesterol concentrations are not elevated. Furthermore, isoenergetic substitution of one milk chocolate bar per day for a high-carbohydrate snack in a National Cholesterol Education Program/American Heart Association Step 1 Diet does not adversely affect the cholesterol-lowering response. These findings indicate that stearic acid is not hypercholesterolemic as are the other long-chain SFAs. Thus, as illustrated by the different results generated from the predictive equations that group all long-chain SFAs vs those that consider stearic acid separately, grouping stearic acid with other SFAs appears to misrepresent the actual blood cholesterol response.

Effects of a milk chocolate bar per day substituted for a high-carbohydrate snack in young men on an NCEP/AHA Step 1 Diet.

This study compares the plasma cholesterol response with the isoenergetic substitution of a milk chocolate bar (46 g) given daily for a high-carbohydrate snack in healthy young men on a Step 1 Diet. Normocholesterolemic men (n = 42) were fed a Step 1 Diet for 21 d (run-in diet) followed by a 27-d experimental period during which they consumed the same diet plus either a milk chocolate bar or a high-carbohydrate snack; after this they consumed the run-in diet for 21 d followed by the other snack for 27 d. When subjects consumed a milk chocolate bar instead of the high-carbohydrate snack, high-density-lipoprotein (HDL) cholesterol was 0.08 +/- 0.03 mmol/L higher (P < 0.01) and plasma triglycerides were 0.06 +/- 0.03 mmol/L lower (P < 0.05). Substitution of a milk chocolate bar for a high-carbohydrate snack did not adversely affect the low-density-lipoprotein-(LDL) cholesterol response to a Step 1 Diet despite an increase in total fat and saturated fatty acid content of the diet. This response may be due to stearic acid.

Seasonal variation in parameters related to coronary heart disease risk in young men

Seasonal variation in the plasma lipids and lipoproteins is reported in the literature. Whether this variation is the result of changes in diet or other factors has not been adequately addressed. We investigated the effects of a controlled diet on the seasonal variation in the levels of plasma lipids and apolipoproteins and also on the excretion of urine metabolites of TXA2 and PGI2 in healthy males. Two well-controlled diet studies were conducted to evaluate effects of dietary fatty acids on plasma lipids (Studies 1 and 2; n = 33) and eicosanoid excretion (Study 2 only; n = 15). Participants consumed whole-food test diets in a randomized, four-period crossover design during each 26-day experimental period. A non-intervention control group also participated in each study (Study 1, n = 12; Study 2, n = 11). Blood was collected monthly and analyzed for plasma lipids and apolipoproteins A-1 (Apo A-1) and B100 (Apo B). Twenty-four hour urine samples were collected monthly only in Study 2 and analyzed for TXB2 and 6-keto-PGF1 alpha by RIA. Seasonal fluctuations were observed in all subjects in plasma Apo A-1 (zenith = July, with 95% CI June-July; P < 0.05) and Apo B (zenith = October, 95% CI September-November, P < 0.05). Although there was no significant variation in plasma cholesterol levels, the increase in Apo B is consistent with an increase in LDL particle number during the fall/winter. Additionally, excretion of both eicosanoid metabolites and the ratio of 6-keto-PGF1 alpha/TXB2 was markedly elevated in July (95% CI June-July, P < 0.001). Three seasonal fluctuations were observed both in participants who consumed a highly-controlled experimental diet and in the non-intervention controls. Thus, these results suggest a diet-independent seasonal variation in parameters thought to be involved in coronary heart disease risk status. An understanding of these variations is important not oly for clinical evaluation and metabolic study design issues, but more importantly, to clarify their clinical significance with the seasonal incidence of CHD events.

Comparison of the effects of diets rich in stearic acid versus myristic acid and lauric acid on platelet fatty acids and excretion of thromboxane A2 and PGI2 metabolites in healthy young men

The present study compared the effects of diets rich in stearic acid (C18:0) versus one high in lauric and myristic acid (C12:0, C14:0) on platelet phospholipid fatty acid levels and concentrations of urinary thromboxane B2 (TXB2) and 6-keto-PGF1 alpha, which are stable metabolites of thromboxane A2 (TXA2) and PGI2 and indicators of cardiovascular hemostasis. A diet high in dairy butter (B) was the source of C12:0 and C14:0; C18:0 was provided by diets high in cocoa butter (CB), milk chocolate (CHOC) or CB+B in a 4:1 ratio (MIX). A randomized, crossover double-blind experimental design was used. Experimental subjects (n = 15) consumed each diet for 26 days, with a 1-month washout period between each experimental period. Urine and blood were collected from each subject at the beginning and end of each dietary period. Urinary TXB2 and 6-keto-PGF1 alpha were analyzed by radioimmunoassay (RIA). There were no effects of diet on the 24-hour excretion of either metabolite or on the ratio of 6-keto-PGF1 alpha/TXB2, even though there were significant changes in the eicosanoid precursor, arachidonic acid (C20:4n-6), in platelet phospholipids. C20:4n-6 levels increased (44.8% +/- 1.0% to 47.1% +/- 1.3%; P < .05) in the phosphatidylethanolamine phospholipid subclass in subjects on the B diet and decreased in the phosphatidylcholine subclass on the CB diet (16.5% +/- 1.0% to 14.2% +/- 1.1%; P < .05) compared with baseline values.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Individual Fatty Acids on Chronic Diseases

It is clear that there are remarkably diverse biological effects elicited by the individual fatty acids found commonly in the diet. Some fatty acids increase risk factors for certain chronic diseases whereas others are protective. This article discusses our present understanding of how fatty acids affect risk factors for important chronic diseases.

Effects of Dietary Stearic Acid on Plasma Lipids and Thrombosis

Saturated fatty acids are known to elicit a hypercholesterolemic response. This article describes a series of studies designed to test the hypothesis that stearic acid has a neutral effect on blood lipids and does not promote platelet aggregation, two major risk factors for coronary heart disese.

Glycemia Targeted Specialized Nutrition (GTSN) improves postprandial glycemia and GLP-1 with similar appetitive responses compared to a healthful whole food breakfast in persons with type 2 diabetes: a randomized, controlled trial

Abstract Background: For people with type 2 diabetes mellitus (T2DM), the frequency and/or composition of the morning meal may be especially important as the disease associated hormonal and metabolic perturbations