Clark Skeaff

• University of Otago

Aims To quantify and compare energy utilization associated with prolonged sitting alone, or interrupted with regular activity breaks and/or an additional bout of continuous physical activity. Methods and results Thirty six adults (11 males, BMI 24.1 ± 4.6) completed four, interventions: (1) prolonged sitting (SIT), (2) sitting with 2-min of walkin...

Regular activity breaks increase energy expenditure; however, this may promote compensatory eating behaviour. The present study compared the effects of regular activity breaks and prolonged sitting on appetite. In a randomised, cross-over trial, 36 healthy adults (BMI (Body Mass Index) 23.9 kg/m2 (S.D. = 3.9)) completed four, two-day interventions:...

Commentary on: Ramsden CE, Zamora D, Majchrzak-Hong S, et al. Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968–73). BMJ 2016;353:i1246. Replacement of a proportion of saturated fat with polyunsaturated fats is a cornerstone of dietary recommendations for the prevention of c...

Aim: The association between fetal vitamin D [25-hydroxyvitamin D (25(OH)D)] exposure and early child growth and neurodevelopment is controversial. The aim of this study was to investigate the association between cord blood 25(OH)D and birth size, childhood growth and neurodevelopment. Methods: Cord blood samples from 1040 Australian women enrol...

Objective To estimate the folate status of New Zealand women of childbearing age following the introduction, in 2010, of a new voluntary folic acid fortification of bread programme. Design The 2011 Folate and Women’s Health Survey was a cross-sectional survey of women aged 18–44 years carried out in 2011. The survey used a stratified random sampli...

Objective: To describe trends in serum cholesterol and dietary fat intakes for New Zealand adults between 1989 and 2008/09. Methods: Serum total cholesterol concentrations and dietary fat intakes were analysed for 9,346 New Zealanders aged 15-98 years (52% women) who participated in three national surveys in 1989, 1997 and 2008/09. Results: Po...

Background: In recent years the role of vitamin D status in early life on the development of allergic disease has generated much interest. The aim of this study was to determine whether cord blood vitamin D concentrations were associated with risk of early childhood allergic disease. Methods: Measurements of cord blood 25-hydroxyvitamin D [25(OH...

In order to prevent overweight and obesity in the general population we need to understand the relationship between the proportion of energy from fat and resulting weight and body fatness in the general population. To assess the effects of proportion of energy intake from fat on measures of weight and body fatness (including obesity, waist circumfe...

Observational studies have implicated low serum vitamin D (25-hydroxyvitamin D (25(OH)D)) levels in the development of mood disorders. Postpartum depression (PPD) is an important public health issue, although little is known about its association with serum 25(OH)D. To determine the association between 25(OH)D at delivery and the subsequent risk of...

Background: The apolipoprotein E (APOE) ε4 genotype is associated with an increased risk of Alzheimer's disease. In community surveys, older adults with this genotype have been found to have lower scores on neuropsychological tests than those who do not. It is possible that this is the consequence of subclinical changes in cognition in those perso...

Erythrocytes, compared with plasma, are considered more robust markers of n-3 (ω-3) polyunsaturated fatty acid (PUFA) intake, because dietary-induced change in fatty acid composition takes longer to complete. The extent to which this applies to intakes of saturated fatty acid (SFA) or n-6 PUFA is unclear. We compared the pattern of change over time...

National data on the blood folate status of New Zealand adults is lacking. The objective of this study was to describe the blood folate status and examine the predictors of blood folate status in a national sample of adults from New Zealand, a country with voluntary folic acid fortification. The 2008/09 New Zealand Adult Nutrition Survey was a nati...

Sedentary behavior is a risk factor for cardiometabolic disease. Regularly interrupting sedentary behavior with activity breaks may lower this risk. We compared the effects of prolonged sitting, continuous physical activity combined with prolonged sitting, and regular activity breaks on postprandial metabolism. Seventy adults participated in a rand...

Objective To investigate the relation between total fat intake and body weight in adults and children. Design Systematic review and meta-analysis of randomised controlled trials and cohort studies. Data sources Medline, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials to June 2010. Inclusion criteria Randomised controlled tria...

Supplementary information

A genetic variant at codon 200 (Pro200Leu) of the gene encoding for glutathione peroxidase 1 (GPx1), a selenium-dependent enzyme, is associated with lower enzyme activity; however, the evidence is limited to in vitro and observational studies. Objective: The objective was to determine whether the GPx1 Pro200Leu genetic variants modify the response...

Daily supplementation with folate increases erythrocyte folate concentrations; however, the time to reach steady-state concentrations has not been empirically demonstrated. Previous predictions of time to steady state or time to 90% steady-state concentration, based on modeling changes in erythrocyte folate during short-term trials, range widely fr...

Serum fatty acids are increasingly used in cross-sectional surveys and cohort studies as biomarkers of dietary fat intake; however, it is currently difficult to judge whether an individual has low or high fatty acid status, or whether the distribution of fatty acids of a group of people is low or high due to a lack of appropriate reference values....

Vitamin D insufficiency during pregnancy has been associated with a number of adverse outcomes for both mother and child. Vitamin D insufficiency has been well described in many populations of both pregnant and non-pregnant women of childbearing age, but there is a lack of data on women living in South-East Asia. We measured plasma 25-hydroxyvitami...

The assessment of suspected dementia often involves the analysis of change scores from neuropsychological tests administered on two occasions. Frequently, no information is available to allow the significance of a change to be evaluated. Our aim was to prepare data useful for estimating the statistical significance of retest changes for persons old...

Wholegrain intake is inversely related to weight gain over time, but little information is available on the role of pulses in weight control. To compare weight loss, metabolic outcomes, and nutrient intakes in obese people assigned to a diet rich in pulses and wholegrains or a control diet. Randomized controlled study of 18 months with 113 voluntee...

Elevated plasma total homocysteine (tHcy) is a risk factor for vascular disease but lowering tHcy with B-vitamins, including folate, has generally not reduced vascular events in secondary prevention trials. Elevated plasma S-adenosylhomocysteine (AdoHcy) concentration may be a more sensitive indicator of vascular disease than plasma tHcy. However,...

Low vitamin D status in women of childbearing age may have implications for health. Vitamin D status of New Zealanders (NZ), based on low serum 25-hydroxyvitamin D (25OHD) is suboptimal. Vitamin D status may be improved with supplements and/or fortified foods. Recently an Adequate Intake (AI) for Australia and NZ was set at 5 microg/d vitamin D. We...

Serum 25-hydroxyvitamin D (25OHD) concentrations are lower in Pacific people compared to Caucasians living in New Zealand. However, there are no data on the 25OHD concentrations of Pacific people living in the Pacific Islands. To assess the vitamin D status of indigenous and Indian Fijian women living in Fiji by measuring 25OHD concentrations. 25OH...

The use of serum fatty acid biomarkers in nutritional epidemiology is increasingly common; however, there is an absence of scientific evidence to substantiate whether the measurement of fatty acids as molecular percentages (which is the conventional approach) or as absolute concentrations is more informative. To advance understanding about this fun...

Expert groups and public health authorities recommend that trans-fatty acid (TFA) intakes from industrially produced partially hydrogenated vegetable oils (PHVOs) should be less than 1% of total energy intake. The starting point for any regulatory or nonregulatory response to this recommendation is to assess the extent of the problem by determining...

The purpose of the WHO scientific review on trans fatty acids (TFAs) was to examine the evidence generated since the 1993 Joint FAO/WHO Expert Consultation on Fats and Oils in Human Nutrition, and to inform member countries on the health consequences of TFAs consumption that have emerged since the last report was released. The new information was d...

A number of approaches have been initiated by governmental and public health organizations in different countries to reduce trans-fatty acid (TFA) intakes. These have included nutrition recommendations with regard to TFAs and general nutrition recommendations regarding the selection of healthy fats, programmes to raise awareness about the adverse e...

Parathyroid hormone concentration (PTH) is elevated in vitamin D insufficiency and when prolonged, this condition leads to reduced bone mass and possibly osteoporosis. The threshold of 25-hydroxyvitamin D above which PTH plateaus, is a criterion often used to define vitamin D adequacy. To determine whether the higher rates of vitamin D inadequacy r...

Accurate assessment of fat intake is essential to examine the relationships between diet and disease risk but the process of estimating individual intakes of fat quality by dietary assessment is difficult. Tissue and blood fatty acids, because they are mainly derived from the diet, have been used as biomarkers of dietary intake for a number of year...

To assess the folate and vitamin B12 status of a group of Vietnamese women of reproductive age and to estimate the rate of neural tube defects (NTD) based on red blood cell (RBC) folate concentrations. A representative sample of non-pregnant women (15-49 years) living in Hanoi City (n 244) and Hai Duong Province (n 245). RBC folate, plasma vitamin...

We aimed to describe the vitamin D status of young women living in two Chinese cities in the spring--Beijing in the north (latitude 39 degrees north) and Hong Kong (latitude 22 degrees north) in the south. We also examined the relationship between serum 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations to determine a threshold for se...

We examined the relationship between vitamin D and skin color measured by reflectance colorimetry at an exposed and un-exposed site in 321 people. Exposed but not unexposed skin color was associated with better vitamin D status. Sun-exposure was more important than natural skin color in determining vitamin D status in our population. Vitamin D is o...

There is evidence to suggest that folate, homocysteine, or both affect the (n-3) long chain PUFA composition of tissues; however, this evidence is derived largely from experiments with animals and small observational studies in humans. Results from randomized controlled trials are needed. The objective of this study was to determine whether homocys...

Normative data are presented for the Penn State Worry Questionnaire (PSWQ) from 255 healthy New Zealanders over the age of 65. The PSWQ was administered during the course of a two-year trial of the effect on cognition and mood of lowering homocysteine levels using vitamin and folate supplements. The scale proved to have good internal consistency, a...

To describe the vitamin D status of women living in two Asian cities,--Jakarta (6 degrees S) and Kuala-Lumpur (2 degrees N), to examine the association between plasma 25-hydroxyvitamin D and parathyroid hormone (PTH) concentrations, and to determine a threshold for plasma 25-hydroxyvitamin D above which there is no further suppression of PTH. Also,...

Data on the prevalence of micronutrient deficiencies in children in Mongolia is limited. We therefore determined the prevalence of anaemia, iron deficiency anaemia (IDA), and deficiencies of iron, folate, vitamin A, zinc, selenium, and vitamin D among young Mongolian children. Anthropometry and non-fasting morning blood samples were collected from...

A higher proportion of n-3 long-chain PUFA in tissue lipids has been associated with a lower risk of CVD and some cancers. Diet is an important predictor of n-3 long-chain PUFA composition; however, the importance of non-dietary factors such as sex and age is unclear. We measured the proportion of n-3 long-chain PUFA in serum phospholipid, choleste...

Evidence from observational studies suggests that there is an association between n-3 long-chain polyunsaturated fatty acids and depression; however, this association has yet to be examined in a population-based study. The objective was to assess whether n-3 long-chain polyunsaturated fatty acids in serum phospholipids are associated with mental an...

An issue that often confronts the clinician referred an elderly person for neuropsychological assessment is how to interpret the significance of changes in test scores over time. In this report, data useful for estimating the statistical significance of changes on the Rey Auditory Verbal Learning Test (AVLT) are presented. The sample tested compris...

An elevated circulating homocysteine concentration is associated with the risk of cardiovascular disease. The mechanism by which an elevated homocysteine increases cardiovascular risk is unclear but may be mediated in part by elevating blood pressure. It is well established that supplements containing folate, vitamins B-12, and B-6 lower homocystei...

Periconceptional folic acid reduces neural tube defect (NTD) risk. Red blood cell folate concentration is inversely associated with NTD risk. In many countries there is a lack of information on NTD rates. Red cell folate status in women of childbearing age may be a surrogate for NTD rates and may be helpful in identifying countries or regions most...

In recent prospective studies, higher homocysteine concentrations were shown to be a risk factor for osteoporotic fractures in older persons. Supplements containing folate and vitamins B-12 and B-6 lower homocysteine concentrations. The objective of the study was to determine in healthy older persons whether lowering homocysteine with B vitamins af...

The New Zealand Ministry of Health advises that all women planning a pregnancy take a folic acid supplement to reduce the risk of having a neural tube defect (NTD)-affected pregnancy. There is little information available to determine if women are following this advice. The purpose of this study was to determine periconceptional folic acid use amon...

Scores on neuropsychological tests are often used to detect abnormal changes in cognition in older persons. Accordingly, it is important to have normative data that allow the abnormality of a test score to be determined precisely and accurately. Regression equations that estimate an expected score based on demographic or premorbid factors can be an...

Vitamin D plays an important role in bone health. Our purpose was to measure serum 25-hydroxyvitamin D concentrations and their determinants in a national sample (n=2,946) of New Zealanders aged 15 years and over. Mean (99% CI) serum 25-hydroxyvitamin D concentrations were 47 (45-50) nmol/l in women and 52 (49-55) nmol/l in men. Mean concentrations...

Beta-casein is a cow's milk protein that occurs predominantly in two forms, A1 and A2. Epidemiological evidence suggests that per capita consumption of beta-casein A1 is associated with national mortality rates from ischaemic heart disease. A biological mechanism was proposed after rabbits fed diets containing beta-casein A2 had lower serum cholest...

The contribution of the home use of margarines, made with partially hydrogenated vegetables oils, to total trans fatty acid intake is difficult to determine using dietary assessment because food composition databases are incomplete for trans fatty acids; moreover, hidden fats in manufactured foods may be the predominant sources of trans fatty acids...

Some individuals respond to a greater extent than others to changes in dietary fat and cholesterol even when dietary intake is consistent. A prospective study has been undertaken in which two groups of individuals according to cholesteryl ester transfer protein (CETP) genotype were compared in terms of plasma lipid response to altering the nature o...

The results of observational studies suggest that plasma homocysteine concentrations are inversely related to cognitive function in older people. Our objective was to test the hypothesis that lowering the plasma homocysteine concentration improves cognitive function in healthy older people. We conducted a two-year, double-blind, placebo-controlled,...

The dietary-induced changes in the fatty acid composition of plasma, platelet, and erythrocyte lipids were measured as a function of time. Healthy adults consumed a diet rich in saturated fat (18% total energy, TE) for 19 d and then crossed over, without washout, to a diet rich in (n-6) polyunsaturated fat (10% TE) for a further 19 d. The fatty aci...

Northern tuatara Sphenodon punctatus punctatus survive on about 26 islands off the north-east coast of the North Island, New Zealand. These rare, lizard-like reptiles include seabirds in their diet. The presence of the Pacific rat Rattus exulans on some islands has been implicated in the decline of tuatara populations through predation and competit...

The aim of this study was to determine 25- hydroxyvitamin vitamin D concentrations and their determinants in a national sample of New Zealand children aged 5-14 y. The 2002 National Children's Nutrition Survey was designed to survey New Zealand school aged children, including over-sampling of Mäori and Paci fic children to allow ethnic-specific ana...

Cited By :18, Export Date: 12 June 2016, CODEN: AJCNA, Correspondence Address: Skeaff, C.M.; Department of Human Nutrition, University of Otago, PO Box 56, Dunedin, New Zealand; email: murray.skeaff@stonebow.otago.ac.nz, Chemicals/CAS: linoleic acid, 1509-85-9, 2197-37-7, 60-33-3, 822-17-3; myristic acid, 1715-79-3, 544-63-8; cholesterol, 57-88-5;...

New Zealand children, particularly those of Māori and Pacific ethnicity, may be at risk for low vitamin D status because of low vitamin D intakes, the country's latitude (35-46 degrees S), and skin color. The aim of this study was to determine 25-hydroxyvitamin D concentrations and their determinants in a national sample of New Zealand children age...

The aim of the study was to determine the effects on plasma cholesterol of replacing a plant sterol-enriched fat spread with carbohydrate-rich foods relative to a diet high in saturated fat. Twenty-nine men and women, from the general community, with mean age (SD) 48 (14)y, body mass index 29.0 (6.2)kg/m(2), and plasma total cholesterol concentrati...

To determine the serum vitamin B(12) status of older New Zealanders and to assess the impact of atrophic gastritis on vitamin B(12) status. A cross-sectional nationally representative population-based survey. Serum vitamin B(12) concentrations were used to assess vitamin B(12) status. The presence and severity of atrophic gastritis was classified u...

Daily consumption of 400 microg folic acid prior to conception and during early pregnancy is recommended for the prevention of neural tube defects (NTD). Strategies to increase folic acid consumption include supplements and fortified foods. Milk is consumed by women and can be fortified with folic acid but little is known about the effect of fortif...

As part of a study of the effect of lowering homocysteine concentrations on the cognition of the elderly, the Geriatric Depression Scale (GDS) and Cognitive Failures Questionnaire (CFQ) were administered to a sample of persons over the age of 65. Normative data from 272 healthy study volunteers, screened for the presence of major medical, neurologi...

Our aim was to determine if a once-a-week folic acid supplement increases women's red blood cell folate to concentrations (>905 nmol/l) that are associated with a low risk of bearing a child with a neural tube defect. Randomized control trial. General community. In total, 114 nonpregnant women (18-40 y) volunteers, with red blood cell folate concen...

To determine the effects on plasma cholesterol concentration of replacing cows' dairy fat with sheep's dairy fat. Randomised crossover dietary intervention. General community, Dunedin, New Zealand. Volunteer sample of 41 healthy adults with initial plasma cholesterol concentration between 4.8 and 7.8 mmol/l. Participants were asked to follow a self...

Iron deficiency anemia (IDA) is common in pregnant women, but previous trials aimed at preventing IDA used high-dose iron supplements that are known to cause gastrointestinal side effects. The objective was to assess the effect on maternal IDA and iron deficiency (ID, without anemia) of supplementing pregnant women with a low dosage (20 mg/d) of ir...

Women of reproductive age are advised to consume supplements or fortified foods containing at least 400 microg/d folic acid for the prevention of neural tubes defects. Concerns exist about the adverse effects of folic acid on zinc status. Seventy-eight women (18 to 49 y) were assigned for 12-wk to receive either a placebo or a 400 microg/d folic ac...

To compare the efficacy of a weekly high-dose (2,800 microg) folic acid supplement with a daily (400 microg) folic acid supplement in lowering homocysteine concentrations in healthy women of childbearing age. Free-living healthy women of childbearing age (n = 138) were randomized to receive a weekly (2,800 microg), a daily (400 microg) folic acid s...

The primary aim of this study was to assess the biochemical vitamin B12 and folate status of a representative group of elderly women (70-80 y) living in Dunedin, New Zealand. A second aim was to determine the prevalence of hyperhomocysteinaemia and to explore the determinants of homocysteine (hcy) concentration in this population. A cross-sectional...

To determine the effect of a plant sterol-enriched spread on plasma cholesterol concentrations when replacing butter or a standard polyunsaturated spread in a diet containing 30% of energy fat. Parallel butter phase followed by double-blind, randomized, cross-over polyunsaturated spread phases. General community. Volunteer sample of 50 free-living...

Background - Cross cultural comparisons and ecological studies indicate an inverse association between the incidence of post partum depression and consumption of long chain omega-3 fatty acids, such as docosahexaenoic acid (DHA). However, evidence from prospective studies is lacking. Objective - To determine is there is an association between major...

Background - Buccal cells have been used as biomarkers of n-3 long chain polyunsaturated fat intake but more information is needed to document their usefulness as markers of saturated fat and linoleic acid intake. Objective - To measure the effect of a saturated fat or a linoleic acid rich diet on the fatty acid composition of buccal cells. Design...

The natural diastereoisomer [6S]-5-methyltetrahydrofolate ([6S]-5-MTHF) may be a safer fortificant than folic acid for neural tube defect (NTD) prevention because it is unlikely to mask vitamin B-12 deficiency. An inverse relationship between NTD risk and blood folate concentrations has been reported. In this randomized, placebo-controlled, double-...

Replacing saturated fat with polyunsaturated fat reduces plasma cholesterol concentrations; however, it has not been well documented how rapidly the decline occurs nor how long is required to reach the maximum cholesterol-lowering effect. The aim of the present study was to determine the time course of change in plasma cholesterol concentrations wh...

The purpose of the present experiment was to determine if the fatty acid composition of plasma and erythrocyte lipids remains stable when stored at -80 degrees C. This was accomplished by repeating the fatty acid analysis of plasma and erythrocyte samples that had been analysed originally as part of two separate experiments. The original plasma and...

The present randomised, crossover study sought to determine the effect of meals rich in safflower oil and olive oil (60 g) which had been heated for 8 h at 210 degrees C and the corresponding unheated oils on copper ion oxidation of dilute serum from 16 healthy men. Four hours after the meals rich in the heated oils, there were significant decrease...

To examine, in free-living adults eating self-selected diets, the effects on plasma cholesterol of substituting saturated fat rich foods with either n-6 polyunsaturated or monounsaturated fat rich foods while at the same time adhering to a total fat intake of 30-33% of dietary energy. Two randomised crossover trials. General community. Volunteer sa...

To investigate the efficacy of, first, a dietary regimen involving increased consumption of iron-rich foods and enhancers of iron absorption and decreased consumption of inhibitors of iron absorption and, second, a low dose iron chelate iron supplement, for increasing iron stores in young adult New Zealand women with mild iron deficiency (MID). The...

To determine whether dietary modification rather than use of supplements can raise indices of vitamin E status to potentially cardioprotective levels. Eight week randomised controlled trial with parallel treatments to compare increased use of vitamin E-rich foods, supplementation with 200 IU of vitamin E, and a placebo. Dunedin, New Zealand. Ninety...

Reductions in red meat and increases in cereals in the diet may compromise the intake and bioavailability of Zn. In this cross-sectional study of 330 premenopausal New Zealand women aged 18--40 years, we have assessed the inter-relationships among dietary intakes (via computer-administered food-frequency questionnaire), biochemical Zn status, and a...

To investigate the role of blood loss and diet in the aetiology of mild iron deficiency (MID) in premenopausal New Zealand women. Mild iron deficiency was defined as low, but not necessarily exhausted, iron stores (i.e. serum ferritin <20 microg/L) in the absence of anaemia (i.e. haemoglobin > or =120 g/L). Cross-sectional study of a volunteer samp...

To measure the average serum concentration of total cholesterol and high density lipoprotein cholesterol in a representative sample of New Zealanders. Serum total and high density lipoprotein cholesterol levels were measured in a representative sample of 1,412 men and 1,741 :women aged 15 years or older who participated in the National Nutrition Su...

There are no definitive explanations as to why individuals with hypercholesterolemia, a major cardiovascular risk factor, respond differently to dietary change. Fifty five free-living individuals completed a double crossover trial with two dietary regimens, a high saturated fat diet (providing 21% energy from saturated fat and 3% energy from polyun...

To investigate (i) dietary patterns associated with consumption of vegetable oils rich in monounsaturated fatty acids (MUFA), and (ii) the risk of prostate cancer associated with consumption of these oils. A population-based case-control study was conducted in Auckland, New Zealand, involving 317 prostate cancer cases and 480 controls. A food-frequ...

To determine the relative validity of an iron food frequency questionnaire (iron FFQ) designed to assess intakes of dietary iron and its absorption modifiers. A computer-administered food frequency questionnaire was designed to estimate intake of total, non-haem, haem and meat iron as well as dietary components which influence iron absorption (vita...

Tuatara (Sphenodon, Order Sphenodontia) are rare New Zealand reptiles whose conservation involves captive breeding. Wild tuatara eat seabirds, which contain high levels of the long-chain n-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These fatty acids are absent from the captive diet, and consequ...

This population-based case-control study investigated associations between prostate cancer risk and dietary intake of the carotenoids beta-carotene and lycopene and their major plant food sources, including carrots, green leafy vegetables, and tomato-based foods. The study was carried out in Auckland, New Zealand, during 1996-1997 and recruited 317...