A recent meta-analysis of prospective cohort studies has not found an association between dietary saturated fat intake and CHD incidence. This funnelled the discussion about the importance of the recommendation to lower the intake of saturated fat for the prevention of CHD. At the same time a document of the European Food Safety Authority has suggested that specific quantitative recommendations are not needed for individual fatty acids but that more general statements can suffice. In this review, we discuss methodological aspects of the absence of association between SFA intake and CHD incidence in prospective cohort studies. We also summarise the results of the controlled dietary experiments on blood lipids and on CHD incidence in which saturated fat was replaced by either cis-unsaturated fat or carbohydrates. Finally, we propose a nutritionally adequate diet with an optimal fatty acid composition for the prevention of CHD in the context of dietary patterns. Such diets are characterised by a low intake of saturated fat, and as low as possible intake of trans-fat and fulfil the requirements for the intake of n-6 and n-3 fatty acids. No recommendation is needed for the intake of cis-MUFA.

This study aimed to evaluate the effect of milk fermented with Lactobacillus acidophilus 145 and Bifidobacterium longum BB536 on plasma lipids in a sample of adult women. A double-blind, placebo controlled, cross-over study (two periods of four weeks each separated by a 1-week washout period) was performed in 34 women, aged between 18 and 65 years. Group A consumed 125 g fermented milk three times a day for the first 4 weeks while group B consumed regular yoghurt under the same conditions. (Groups A and B switched products for the second treatment period). Women taking the test product with a baseline total cholesterol above 190 mg/dl showed a significant reduction in LDL cholesterol. HDL cholesterol was also reduced by the test product. We conclude that the fermented milk may help to reduce LDL levels in hypercholesterolemic adult women.

We examined the effects of adzuki bean resistant starch on serum cholesterol and hepatic mRNA in rats fed a cholesterol diet. The mRNA coded for key regulatory proteins of cholesterol metabolism. The control rats were fed 15 % cornstarch (basal diet, BD). The experimental rats were fed BD plus a 0·5 % cholesterol diet (CD), or a 15 % adzuki resistant starch plus 0·5 % cholesterol diet (ACD) for 4 weeks. The serum total cholesterol and VLDL + intermediate density lipoprotein + LDL-cholesterol levels in the ACD group were significantly lower than those in the CD group throughout the feeding period. The total hepatic cholesterol concentrations in the CD and ACD groups were not significantly different. The faecal total bile acid concentration in the ACD group was significantly higher than that in the BD and CD groups. Total SCFA and acetic acid concentrations in the ACD group were significantly higher than those in the CD group but there were no significant differences in the concentrations between the ACD and BD groups. The hepatic LDL-receptor mRNA and cholesterol 7α-hydroxylase mRNA levels in the ACD group were significantly higher than those in the CD group and the hepatic 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase mRNA level in the ACD group was significantly lower than in the CD group. The results suggest that adzuki resistant starch has a serum cholesterol-lowering function via enhancement of the hepatic LDL-receptor mRNA and cholesterol 7α-hydroxylase mRNA levels and faecal bile acid excretion, and a decrease in the hepatic HMG-CoA reductase mRNA level, when it is added to a cholesterol diet.

Milk fat contains considerable amounts of saturated fatty acids, known to increase serum cholesterol. Little is known, however, about the relative effect of different milk products on risk factors for CHD. The aim of the present study was to compare the effects of Jarlsberg cheese (a Norwegian variety of Swiss cheese) with butter on serum lipoproteins, haemostatic variables and homocysteine. A controlled dietary study was performed with twenty-two test individuals (nine men and thirteen women) aged 23–54 years. The subjects consumed three isoenergetic test diets, with equal amounts of fat and protein, and containing either cheese (CH diet), butter+calcium caseinate (BC diet) or butter+egg-white protein (BE diet). The study was a randomised cross-over study and the subjects consumed each diet for 3 weeks, with 1 week when they consumed their habitual diet in between. Fasting blood samples were drawn at baseline and at the end of each period. Serum was analysed for lipids and plasma for haemostatic variables and homocysteine. Total cholesterol was significantly lower after the CH diet than after the BC diet (−0.27 mmol/l; P=0.03), while the difference in LDL-cholesterol was found to be below significance level (−0.22 mmol/l; P=0.06). There were no significant differences in HDL-cholesterol, triacylglycerols, apo A-I, apo B or lipoprotein (a), haemostatic variables and homocysteine between the diets. The results indicate that, at equal fat content, cheese may be less cholesterol increasing than butter.

Apolipoprotein E (ApoE) genotype influence on the relationship between dietary risk factors for cardiovascular disease and blood serum lipid levels was investigated in 132 free-living individuals participating in the European Prospective Investigation of Cancer (EPIC) study. All subjects (age 40–69) were clinically healthy and provided information on their usual diet. ApoE genotype and serum lipid concentrations were determined in all subjects. Relationships of intake of dietary constituents with serum lipid levels were compared in different genotype groups. There was a significant correlation between total serum cholesterol and intake of energy derived from total fat (r 0·195; P 0·025) and saturated fat (r 0·174; P 0·046) in the cohort as a whole. However, individuals with the ApoE ε3/ε4 genotype displayed a much stronger positive correlation between LDL cholesterol level and the percentage of energy derived from intake of saturated fat (r 0·436; P 0·043). There were no significant associations in the groups with ε3/ε3 or ε2/ε2 & ε2/ε3 genotype. A significant positive correlation between alcohol consumption and HDL cholesterol level was present in individuals bearing ApoE ε2 allele. These findings support current public health recommendations that saturated fat consumption should be reduced in order to reduce coronary heart disease risk. Total cholesterol concentrations were positively related to saturated fat intake in the cohort as a whole, but elevated LDL cholesterol levels associated with high saturated fat intake can be expected particularly in those individuals who combine a ‘risky’ dietary behaviour with the presence of the ε4 variant of ApoE.

The effect of feeding live Lactobacillus reuteri cells containing active bile salt hydrolase (BSH) on plasma cholesterol levels was studied in pigs. During an experiment lasting 13 weeks, twenty pigs were fed on a high-fat, high-cholesterol, low-fibre diet for the first 10 weeks, and a regular pig diet for the last 3 weeks. One group of animals received, twice daily, 11·25 (SD 0·16) log10 colony forming units of the potential probiotic bacteria for 4 weeks (from week 3 until week 7). From week 8 onwards, the treated group was again fed on the same diet as the control group without additions. The total faecal Lactobacillus counts were only significantly higher in the treated pigs during the first 2 weeks of L. reuteri feeding. Based on limited data, it was suggested that the administered Lactobacillus species had caused a temporary shift within the indigenous Lactobacillus population rather than permanently colonizing the intestinal tract. The probiotic feeding brought about significant lowering (P ≤ 0·05) of total and LDL-cholesterol concentrations in the treated pigs compared with the control pigs, while no change in HDL-cholesterol concentration was observed. The data for faecal output of neutral sterols and bile salts were highly variable between the animals of each group, yet they indicated an increased output in the treated pigs. Although the blood cholesterol levels went up in both groups during the 3 weeks following the Lactobacillus administration period, significantly lower serum total and LDL-cholesterol levels were observed in the treated pigs. During the final 3 weeks of normalization to the regular diet, cholesterol concentrations significantly decreased in both animal groups and the differences in total and LDL-cholesterol concentrations between the groups largely disappeared.

Boiled coffee contains the lipid compounds cafestol and kahweol, which raise cholesterol strongly in man. These lipids are retained by paper filters. In a search for an animal model for the effect of coffee lipids on serum cholesterol concentrations, we fed hamsters (Mesocvicetus aurutus) and rats on mash diets consisting of a purified base diet and either boiled water, unfiltered boiled coffee or filtered boiled coffee. After a feeding period of 8 weeks there was no statistically significant effect of unfiltered boiled coffee on serum total cholesterol and triacylglycerol concentrations in either the hamsters or the rats. The level of serum cholesterol did respond predictably to the addition of cholesterol and/or saturated fatty acids to the diet. The lack of effect of unfiltered boiled coffee in the hamsters and the rats, when compared with the previously reported activity in humans, could not be explained by dosage, duration of treatment, mode of administration or by insufficient statistical power. It is concluded that hamsters and rats are insensitive to unfiltered boiled coffee and thus are unsuitable models for investigating its hyper- cholesterolaemic effect.

Diets enriched in retrograded amylose (RS3) have been shown to lower serum cholesterol concentrations in rats. The possibility was tested that this hypocholesterolaemic effect of RS3 is caused by an increase in excretion of neutral steroids and/or bile acids. Six groups of ten rats were fed on purified diets containing either 12 or 140 g RS3/kg solid ingredients with and without added cholesterol (5 g/kg). Low-RS3 diets, with and without added cholesterol, to which the bile-acid-binding resin cholestvramine (20 g/kg) was added, were used as reference. The high-RS3 diets v. the low-RS3 diets tended to reduce the increase in the total serum cholesterol concentration during the course of the experiment (P = 0 067), decreased serum triacylglycerol concentrations, raised total neutral steroids and total bile acids in caecal contents and faecal excretion of total bile acids, but lowered faecal excretion of neutral steroids. In addition, the serum concentration of total 3α-bile acids was markedly raised by the high-RS3 diets. The high-RS3 diets raised the faecal excretion of lithocholic and muricholic acids, but lowered that of hyodeoxycholic acid, and increased the caecal amounts of lithocholic, ursodeoxycholic, β-muricholic and ω-muricholic acids. Apart from the stimulation of faecal bile acids excretion, the effects of cholestvramine on bile acid metabolism differed at various points from those of RS3. Cholesterol feeding had predictable effects on cholesterol metabolism and led to greater elevating effects of RS3 on the faecal and caecal amounts of muricholic acids. The results suggest that the serum-cholesterol-lowering effect of high-RS3 diets may be explained by an increased influx of neutral steroids and bile acids into the caecum, and increased faecal excretion of bile acids, and/or by an altered intestinal bile acid profile.

Broiler chickens were fed on a control diet based on maize or on diets including conventionally-dried (standard pulp) or vacuum-dried (Fipec pulp) sugar-beet pulp at inclusion levels of 23, 46 and 92 g/kg. Diets were fed ad lib. except for half of the chickens fed on the control diet which were fed twice daily at a restricted level. Although not statistically significant, chickens given the 23 g sugar-beet pulp/kg diets generally consumed more feed, had increased body weights and converted feed more efficiently at both day 14 and 21 than those fed on the control diet or diets including 46 or 92 g sugar-beet pulp/kg. Ileal digestibilities of organic matter, crude fat and crude protein generally decreased with increasing levels of sugar-beet pulp in the diet. Birds fed on diets including sugar-beet pulp had reduced total serum cholesterol concentrations. There were only minor differences obtained in production responses, serum cholesterol concentrations, digestibilities and carcass composition between chickens fed on the two types of beet pulp, indicating that the different drying procedures had very little influence on the product. High triacylglycerol and total serum cholesterol concentrations obtained for the restricted level-fed chickens demonstrated a meal frequency factor.

The effects of zero-erucic acid rapeseed oil and rapeseed oil-containing margarine on plasma fatty acid composition and serum cholesterol were studied in butter users (n 43). Compliance to the substitution was followed by fatty acid analysis of total plasma and plasma phospholipids. The amount of substitute fats represented, on average, 21% of total fat and 8% of total energy intake. Changes in the relative fatty acid composition of plasma phospholipids indicated further fatty acid metabolism, and were closely related to the serum cholesterol level. The reduction in saturated fatty acids led to a significant increase in the proportion of n-3 and n-6 polyunsaturated fatty acids (PUFA) with the rapeseed oil diet, whereas the margarine caused a significant rise in n-6 PUFA only. The increase in the proportions of the two PUFA families occurred in accordance with their competitive order, most completely with the rapeseed oil diet. When butter was replaced by rapeseed oil, low-density-lipoprotein-cholesterol decreased by an average of 9.1% without a reduction in high-density-lipoprotein-cholesterol. During margarine substitution the reduction was 5.2%, on average. Of the plasma phospholipids, α-linolenic acid and the linoleic:stearic acid ratio, but not oleic acid, were the components most significantly correlated with serum cholesterol levels or the decrease in these levels. The results show that rapeseed oil can act primarily as a source of essential fatty acids, rather than that of monoenes, in the diet of butter users.