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J L Buttriss

Publications and source records attributed to J L Buttriss.

5 recordsLinked to original sources
PubMed1997

Food and nutrition: attitudes, beliefs, and knowledge in the United Kingdom.

In a study of 1700 members of the UK general public in 1992 in which face-to-face interviews were conducted, factors thought important in a healthy diet were (in descending order) more fiber, less sugar, less fat, less salt, and more starchy foods. Of common nutritional terms there was most confidence in explaining the meaning of fiber and least in the meaning of monounsaturated fatty acids. Most nutritional information came from the media but the credibility of this information was low. Fifty-three percent said that a conversation with their general practitioner (GP) was a source of advice they trusted. In a survey of 150 GPs and 50 practice nurses in 1992, lack of confidence was found to be common concerning the meaning of several nutritional terms, especially extrinsic sugars, NSP (nonstarch polysaccharide), and trans fatty acids. GPs were confident they could explain the link between diet and heart disease but were not sure about the value of starch in the diet. Both GPs and practice nurses were dissatisfied with their training in nutrition, both before and after registration. General practice staff thought that personal ill health was the most important motivator for dietary change among their patients. They thought that apathy and dietary conservatism were the most common barriers to people changing their diet. However, the public positioned lack of knowledge as the biggest obstacle. Surveys reported here showed that people's knowledge of sources of fat, calcium, and iron is often unreliable.

Adult↗
PubMed1988

The alpha-tocopherol and phospholipid fatty acid content of rat liver subcellular membranes in vitamin E and selenium deficiency.

(1) Rats were given a diet deficient in vitamin E and selenium, or diets supplemented with either or both of these nutrients. The livers were subfractionated by standard procedures, and the purity of the fractions was assessed by marker enzyme techniques. alpha-Tocopherol was measured and profiles of phospholipid fatty acids were determined. (2) All the organelles studied were severely depleted of alpha-tocopherol in the rats deprived of vitamin E: no organelle was particularly severely depleted. There was a large rise in the alpha-tocopherol content in organelles of rats deprived of selenium but given adequate amounts of vitamin E, suggesting an increased uptake or mobilization of tocopherol to compensate for the detrimental effects of selenium deficiency. (3) The following general conclusions were reached from the results of the phospholipid fatty acid analyses. (i) vitamin E deficiency caused a consistent fall in the polyunsaturated fatty acid (PUFA) content (13-66% of the control level); (ii) selenium deficiency alone caused no consistent effect on phospholipid PUFA in the fractions studied; (iii) double deficiency of vitamin E and selenium caused a consistent rise in the proportion of PUFA in the fractions studied, ranging from 11 to 311%. (4) The result given in 3(i) is consistent with peroxidative destruction of membrane phospholipid PUFA during vitamin E deficiency. The result in 3(iii) is paradoxical: a possible explanation is that during severe disruption of antioxidant defences, there is an overshoot in the increased incorporation of unsaturated fatty acids into the membrane phospholipids, or in the chain-elongation and desaturation process required for the formation of PUFA, which may require vitamin E and/or selenium for its regulation.

Animals↗
PubMed1988

The relationship between alpha-tocopherol and phospholipid fatty acids in rat liver subcellular membrane fractions.

(1) A method was devised for the subfractionation of normal rat liver and for the subfractionation of the mitochondrial fraction into inner and outer membrane fractions. The purity of the fractions was assessed using marker enzyme measurements. (2) alpha-Tocopherol was measured in all the fractions by a sensitive HPLC technique. Profiles of phospholipid fatty acids were also determined by gas-liquid chromatography in all the fractions, and these values were calculated in terms of the percentage of each fatty acid in the total fatty acid of the fraction, as well as of the mass of each fatty acid per mumol of phospholipid phosphorus. Tocopherol values were expressed as the mass of tocopherol per g wet liver and per mumol of phospholipid phosphorus. (3) The results show that the mitochondrial and microsomal fractions were the major tocopherol-containing fractions, and both the inner and outer mitochondrial fractions contained substantial amounts of alpha-tocopherol. (4) The mitochondrial and microsomal fractions also had the highest levels of polyunsaturated fatty acids (PUFA) in their phospholipid fraction, especially 20:4 and 22:6, which were particularly localised in the inner mitochondrial membrane fraction. The high inner mitochondrial and microsomal PUFA levels were particularly apparent when the sum of all the unsaturated fatty acids with three or more double bonds was calculated. (5) Calculation of molar ratios of of some phospholipid fatty acids to alpha-tocopherol gave values of the order of several thousand to one. (6) It is concluded that the protective effect of each molecule of alpha-tocopherol must be exerted towards a large number of molecules of membrane unsaturated fatty acids simultaneously. This perhaps implies specific localisation of tocopherol in regions of membrane particularly liable to attack, such as might be expected to occur close to respiratory enzymes that can donate electrons to molecular oxygen.

Animals↗