In a recent issue of American Antiquity, two articles (Gill et al. 2021; Lyons et al. 2021) perpetuate the common misconception that dietary carbohydrates are an essential component of the human diet and that plants—the main source of dietary carbohydrates—must be consumed to promote health. In fact, carbohydrate is a nonessential macronutrient with adequate amounts of energy—the sole function of carbohydrates in the human diet—being produced via gluconeogenesis and ketogenesis in the absence of dietary carbohydrate. Additionally, both articles erroneously employ the term “dietary staple” in reference to geophyte consumption.

Dietary protein is considered more satiating than carbohydrate, and whey protein is more satiating than other protein sources. The purported satiating effect of whey protein may be due to direct effects of the unique mixture of proteins in whey, due to the effects of peptides released upon digestion and/or its amino acid composition. The objective of the present study was to compare the satiating effects of intact whey protein isolate (WPI) or a free amino acid mixture (AAM) simulating the amino acid composition of the WPI. A single-blind completely randomised block design included twenty, healthy, adult women (age 24·2 (sem 0·8) years) of normal weight (BMI 22·7 (sem 0·4) kg/m2). Following consumption of isoenergetic (approximately 1800 kJ) preload meals enriched (52 g amino acid equivalent) with WPI or AAM, consumption of an ad libitum test meal 120 min later and subjective feelings of appetite using visual analogue scales (VAS) were determined. There were no significant differences (P=0·24) in the ad libitum test meal intakes between the WPI (268·5 (sem 27·3) g) and the AAM (238·4 (sem 22·7) g) preload meals. Subjective VAS ratings of appetite did not differ significantly between the WPI and the AAM preload meals (P>0·05). Intact whey protein and a free AAM simulating the whey protein showed similar effects on satiety. This suggests that the satiating effect of whey protein may be related to its specific amino acid composition.

The present study examined the effect of milk phospholipids (milk-PL) on lipid metabolism and on other risk factors for CVD, in comparison with milk fat (control) or soya phospholipids (soya-PL), respectively. Two double-blind parallel-group intervention trials were conducted in overweight or obese male subjects. In the first trial (trial 1), sixty-two men consumed milk enriched with either 2 g milk-PL or 2 g milk fat (control) for 8 weeks. In trial 2, fifty-seven men consumed milk enriched with either 3 g milk-PL or 2·8 g soya-PL for 7 weeks. In trial 1, milk-PL as compared with control reduced waist circumference but did not affect plasma lipids (total, HDL- and LDL-cholesterol, total cholesterol:HDL-cholesterol ratio, TAG, phospholipids), apoB, apoA1, glucose, insulin, insulin sensitivity index, C-reactive protein, IL-6, soluble intracellular adhesion molecule and total homocysteine (tHcy). Serum activities of alanine transaminase and aspartate transaminase were not changed. Activity of γ-glutamyl transferase (GGT), a marker of fatty liver, increased in the control but not in the milk-PL group, with a significant intervention effect. In trial 2, milk-PL as compared with soya-PL did not affect the above-mentioned parameters, but decreased GGT. Subjects with the methylenetetrahydrofolate reductase mutations CT and TT had 11 % (P < 0·05) higher baseline tHcy concentrations than those with the wild-type CC. However, genotype did not modulate the phospholipid intervention effect on tHcy. In conclusion, supplementation with milk-PL as compared with control fat reduced waist circumference and, as compared with both control fat and soya-PL, GGT activity.

Non-enzymatic antioxidant capacity (NEAC) represents a sensitive biomarker measuring the in vivo antioxidant potential of vegetable foods. To evaluate the effectiveness of plant-derived foods and beverages on the plasma non-enzymatic antioxidant system, we analysed all literature published upto May 2010. Data were extracted by two authors independently, and the effect size was summarised using standardised mean differences by a random-effects model. For the analysis, eighty-eight studies were included, reporting a total number of 122 interventions and involving 2890 subjects. There was overall evidence of the effectiveness of fruit, vegetables, dietary patterns based on plant foods, red wine and tea in increasing plasma NEAC. No changes were found for chocolate and fruit juices. We observed an overall effect size three times higher in subjects with risk factors when compared with healthy subjects. Total radical-trapping antioxidant parameter, oxygen radical absorbance capacity and ferric-reducing antioxidant power methods showed a similar increase in plasma NEAC following dietary supplementation, whereas Trolox equivalent antioxidant capacity did not respond to dietary supplementation. Data from the present meta-analysis show that plant-derived foods represent an effective strategy to enhance an endogenous antioxidant network in humans. This is particularly evident in the presence of oxidative stress-related risk factors.

Studies have suggested that two major milk constituents, casein and Ca, favourably affect postprandial responses. However, effects of milk on postprandial metabolism are unknown. We therefore investigated effects of using milk with a fat-containing meal on lipid and glucose responses in overweight men. To identify the constituent responsible for possible effects, we also studied responses to Ca and protein. A total of sixteen men (BMI >27 kg/m2) participated in four postprandial tests. They consumed a breakfast (44 g of fat) plus a drink: a control drink, low-fat milk or a protein and Ca drink (500 ml). Blood samples were taken before the meals and at regular time points during 6 h thereafter. Compared with control, the incremental AUC (iAUC) for serum TAG was increased by 44 % after the protein meal (P= 0·015). Although the iAUC were not different (P= 0·051), peak glucose concentrations were reduced by 24 % after protein intake, as compared with control (P= 0·021). The decrease of 18 % after milk intake did not reach statistical significance. Compared with the milk meal, the iAUC for insulin was 52 % lower after the control meal (P= 0·035) and 51 % after the protein meal (P= 0·005). The present results indicate that the intake of milk with a fat-containing meal enhances postprandial TAG and insulin responses and may blunt glucose increases. The protein fraction of milk seems to be the main determinant for the effects on TAG and glucose. Ca did not change any of the postprandial responses.

The consequences of early-life nutritional programming in man and other mammalian species have been studied chiefly at the metabolic level. Very few studies, if any, have been performed in the gastrointestinal tract (GIT) as the target organ, but extensive GIT studies are needed since the GIT plays a key role in nutrient supply and has an impact on functions of the entire organism. The possible deleterious effects of nutritional programming at the metabolic level were discovered following epidemiological studies in human subjects, and confirmed in animal models. Investigating the impact of programming on GIT structure and function would need appropriate animal models due to ethical restrictions in the use of human subjects. The aim of the present review is to discuss the use of pigs as an animal model as a compromise between ethically acceptable animal studies and the requirement of data which can be interpolated to the human situation. In nutritional programming studies, rodents are the most frequently used model for man, but GIT development and digestive function in rodents are considerably different from those in man. In that aspect, the pig GIT is much closer to the human than that of rodents. The swine species is closely comparable with man in many nutritional and digestive aspects, and thus provides ample opportunity to be used in investigations on the consequences of nutritional programming for the GIT. In particular, the ‘sow–piglets’ dyad could be a useful tool to simulate the ‘human mother–infant’ dyad in studies which examine short-, middle- and long-term effects and is suggested as the reference model.

Folic acid (pteroylmonoglutamic acid) has historically been used as the reference folate in human intervention studies assessing the relative bioavailability of dietary folate. Recent studies using labelled folates indicated different plasma response kinetics to folic acid than to natural (food) folates, thus obviously precluding its use in single-dose experiments. Since differences in tissue distribution and site of biotransformation were hypothesised, the question is whether folic acid remains suitable as a reference folate for longer-term intervention studies, where the relative bioavailability of natural (food) folate is assessed based on changes in folate status. Healthy adults aged 18–65 years (n 163) completed a 16-week placebo-controlled intervention study in which the relative bioavailability of increased folate intake (453 nmol/d) from folate-rich foods was assessed by comparing changes in plasma and erythrocyte folate concentration with changes induced by an equal reference dose of supplemental (6S)-5-methyltetrahydrofolic acid or folic acid. The relative increase in plasma folate concentration in the food group was 31 % when compared with that induced by folic acid, but 39 % when compared with (6S)-5-methyltetrahydrofolic acid. The relative increase in erythrocyte folate concentration in the food group when compared with that induced by folic acid was 43 %, and 40 % when compared with (6S)-5-methyltetrahydrofolic acid. When recent published observations were additionally taken into account it was concluded that, in principle, folic acid should not be used as the reference folate when attempting to estimate relative natural (food) folate bioavailability in longer-term human intervention studies. Using (6S)-5-methyltetrahydrofolic acid as the reference folate would avoid future results' validity being questioned.

The amount and the type of dietary protein could play a role in determining the quantity of skeletal muscle mass. The aim was to examine the relationship between the type of protein intake and the level of muscle mass in healthy omnivorous and vegetarian Caucasian women. The design of the present study was an observational and cross-sectional study. Twenty-one omnivores (Om) and nineteen vegetarians (Ve) were recruited. Muscle mass index (urinary creatinine), dietary intake (5 d dietary records) and biochemical analyses (hormone, phyto-oestrogen and lipid profiles) were obtained. We found differences between groups for muscle mass (Ve: 18 kg v. Om: 23 kg; P = 0·010), muscle mass index (Ve: 6·7 kg/m2v. Om: 8·3 kg/m2; P = 0·002), animal protein intake in g/d (P = 0·001) and in g/kg body weight per d (P = 0·003), plant protein intake in g/d (P = 0·015) and in g/kg body weight per d (P = 0·007), the animal:plant protein intake ratio (P = 0·001) and sex hormone-binding globulin (SHBG) (P = 0·001). Muscle mass index still correlated with animal protein intake in g/d (P = 0·001) and in g/kg body weight per d (P = 0·008), and the animal:plant protein intake ratio (P = 0·007) even after controlling for SHBG and plant protein intake. Finally, animal protein intake (g/d) was the independent predictor of muscle mass index (adjusted r2 0·42). Thus, a vegetarian diet is associated with a lower muscle mass index than is an omnivorous diet at the same protein intake. A good indicator of muscle mass index in women seems to be animal protein intake.

Numerous mechanisms have been proposed to explain the anti-carcinogenic effects of Se, among them altered carcinogen metabolism. We investigated the effect of Se supplementation on activities of glutathione peroxidase (GPX), glutathione reductase (GR) and glutathione S-transferase (GST) in different blood compartments, and expression of selected phase 1 and phase 2 genes in leucocytes (GPX1, γ-glutamylcysteine ligase catalytic subunit (GCLC), AP-1 transcription factor Fos-related antigen 1 (Fra1), NAD(P)H:quinone oxidoreductase (NQO1), and aryl hydrocarbon receptor repressor (AhRR)). Healthy elderly Danes (n 105; age 71·3 (sd 4·26) years; 36 % reporting use of multivitamin/mineral supplements) participated and were supplemented daily for 5 years with placebo, 100 μg, 200 μg or 300 μg Se as Se-enriched yeast (SelenoPrecise®). Blood samples were collected after 5 years of intervention. When all four groups were compared we found no effect of Se supplementation on plasma GPX or GR, on erythrocyte GPX, GR or GST, or on thrombocyte GR or GST. We found increased thrombocyte GPX activity at the two highest dosage levels in women only, but not in men. No effects on GPX1, NQO1 or AhRR gene expression were found. When all Se-supplemented groups were pooled we found significant down regulation of the expression of some phase 2 genes (GCLC, Fra1). A significant increase in AhRR gene expression with smoking was found but was independent of Se supplementation. Down regulation of phase 2 genes could increase the risk of cancer. However, further studies are needed to establish whether the observed effect in leucocytes reflects a similar expression pattern in target tissues.

During the last decade it has become obvious that, while our lifestyle, including diet, stress, smoking, medical issues, exercise, and genetics are major determinants of human health status, it is diet that plays a central role. The effect of nutrition on human health has received substantial attention, and even ‘traditional’ medicinal philosophies that state that diet and nutrients play only limited roles in human health is being revised. In most developed countries nutritional practices have changed the focus from combating nutrient deficiencies to addressing nutrient requirements for maintaining good health throughout life. The role of selenium (Se) in human health and diseases has been discussed in detail in several recent reviews, with the main conclusion being that Se deficiency is recognised as a global problem which needs solving urgently. Analysing recent publications that relate human health to useful poultry products, it is evident that Se-enriched eggs can be used as an important delivery system of this trace mineral for humans. In particular, developments and commercialisation of organic forms of selenium has initiated a new era in the availability of selenium-enriched products. It has been shown that egg selenium content can be easily manipulated to give increased levels, especially when organic selenium is included in hen's diet at levels that provide 0.3-0.5 ppm Se in feed. As a result, technology for the production of eggs delivering ~50% (30-35 μg) of the human selenium RDA have been developed and successfully tested. Currently companies all over the world market Se-enriched eggs including the UK, Ireland, Malaysia, Thailand, Australia, Turkey, Russia and Ukraine. Prices for enriched eggs vary from country to country, typically being similar to free-range eggs. The scientific, technological and other advantages and limitations of producing designer/modified eggs as functional foods are discussed in this paper.

Agriculture faces a multitude of challenges in the 21st century, and new tools are needed to help determine how it should respond. Among these challenges is a need to reconcile how human food consumption patterns should change to both improve human nutrition and reduce agriculture's environmental footprint. A complete-diet framework is needed for better understanding how diet influences demand for a fundamental agricultural resource, land. We tested such a model, measuring the impact of fat and meat consumption on the land requirements of food production in New York State (NYS). Analysis was confined to this geographic area to simplify the modeling procedure and to examine the state's ability to reduce environmental impact by supplying food locally. Per capita land resource requirements were calculated with a spreadsheet model for 42 diets ranging from 0 to 381 g d−1 (0 to 12 oz d−1) of meat and eggs and 20 to 45% total calories from fat. Many of these diets meet national dietary recommendations. The potential human carrying capacity of the NYS land base was then derived, based on recent estimates of available agricultural land. A nearly fivefold difference (0.18–0.86 ha) in per capita land requirements was observed across the diets. Increasing meat in the diet increased per capita land requirements, while increasing total dietary fat increased the land requirements of low meat diets but reduced the land needed for high meat diets. Higher meat diets used a larger share of the available cropland suited only to pasture and perennial crops. Thus, only a threefold difference was observed for the potential number of people fed from the NYS land base (2.0–6.2 million). In addition, some high-fat vegetarian diets supported fewer people than lower fat diets containing 63–127 g d−1 of meat (approximately one- to two-thirds of the national average per capita consumption in the US). These results support the assertion that diet should be considered in its entirety when assessing environmental impact. To more completely understand how diet influences land requirements and potential carrying capacity, this model should be applied across a larger geographic area that encompasses a wider variety of climates and soil resources. To better understand the ability of a local region to supply more of its own food, the model should be moved into a geospatial framework.

Introduction. Fruit and vegetable consumption is now more than ever before understood, along with physical exercise, to be among the factors ensuring well-being. Cross-cultural epidemiological studies reveal a preventive effect of this consumption on certain human pathologies, whence the emergence of preventive nutrition. Changes in biodiversity dietary intake. Industrially-processed products, undergoing a greater or lesser degree of refinement, were developed during the last century; they focused on a few productive species and varieties. The concept of high-calorie foods, an energy source, which has been prevalent in dietetics over the past few decades, had minimised the role of fruit and vegetables in the diet, due to their low calorie content. Plant biodiversity in foodstuffs originating from the American tropics. There are few cultivated major species and varieties in terms of biodiversity. 40% of the edible plant species in the world today originate from the American tropics. Of the planet's 250 000 estimated plant species, 100 000 are believed to be from the Americas. Preserving the beneficial properties of processed products. To improve recovery of the properties of the fresh resource for the consumer, innovation in the processing methods is required, with unit operations ensuring the best possible preservation of the healthy compounds. Conclusion and prospects. Communication on fruit and vegetables has not enjoyed the same research and publicity resources as many processed products. Knowledge of and information on food resources, diet and health have become a major challenge. The relative wealth of the plant biodiversity from the American tropics represents a heritage we need to reharness.

The objective of the present work was to assess the relationship between serum Se concentrations and environmental determinants (i.e. lifestyle, social activity, geographic region, urban status, education, familial status, physical activity, BMI, tobacco, and food and alcohol consumption). Baseline results from 13017 subjects (7876 women aged 35–60 and 5141 men aged 45–60) who participated in the SU.VI.M.AX (Supplémentation en Vitamines et Minéraux Antioxydants) study were analysed. Fewer than 2% of the volunteers had a serum Se status under 0·75μmol/l, which has been quoted as the cut-off of biological Se sub-deficiency. Women had significantly lower serum Se concentrations than men (1·09 (sd 0·19) μmol/l (n 7423) and 1·14 (sd 0·20) μmol/l (n 4915), P<0·0001, respectively). Significant differences in serum Se concentrations were observed between geographic areas. In both sexes, the serum Se concentration increased with alcohol, meat and fish consumption, and decreased with smoking. In premenopausal women, the serum Se concentration was higher in contraceptive-pill users than in non-users. In women only, age was associated with increased serum Se concentrations, and obesity (BMI≥30kg/m2) was associated with decreased serum Se levels. In men, we observed a decrease in serum Se concentrations with increased consumption of vegetables and fruits. In conclusion, though few of the volunteers participating in the SU.VI.M.AX study had Se status in the sub-deficiency range, 83% of women and 75% of men had serum concentrations below the value considered optimal for glutathione peroxidase activity. The largest Se associations in both sexes were found with regions, smoking, alcohol, meat and fish consumption. Further studies are needed to understand the difference in Se status between genders.

Introduction. Les effets de la consommation de fruits et légumes vis-à-vis de pathologies ont été déjà mis en évidence par de nombreuses études dans lesquelles, en particulier, la consommation de la pomme a pu être corrélée à un effet protecteur significatif. Le document présente une synthèse des résultats qui ont été obtenus à l'issue de cette série d'études. Les fractions nutritionnellement actives de la pomme. Les apports de la pomme en glucides, polyphénols, minéraux, anions organiques et vitamines ont été successivement analysés et commentés en fonction des effets de ces éléments sur la santé humaine. Les effets santé potentiels de la pomme. Les effets protecteurs de la pomme vis-à-vis du risque cardiovasculaire ont été tout d'abord exposés ; des effets plus spécifiques ont ensuite été passés en revue : effets sur le statut insulinique et sur le statut antioxydant, effets antiacidosiques et impact sur les fermentations digestives dans le côlon. Conclusion. La pomme possède, d'un point de vue nutrition préventive, des potentialités très intéressantes. Un grand nombre d'effets santé qui lui sont attribués dépendrait d'interactions entre divers nutriments comme, par exemple, les interactions entre les fibres et certains polyphénols. Ces interactions sont encore mal connues ; leur étude semble prometteuse et pourrait être transposée à de nombreux aliments d'origine végétale.

Starch and fibre can be extracted, using wet or dry processes, from a variety of grain legumes and used as ingredients for food. a-Galactosides can be isolated during wet processes from the soluble extract. Starch isolates or concentrates are mostly produced from peas, whereas dietary fibre fractions from peas and soyabean are commercially available. The physico-chemical characteristics of fibre fractions very much depend on their origin, outer fibres being very cellulosic whereas inner fibres contain a majority of pectic substances. Inner fibres are often used as texturing agents whereas outer fibres find their main uses in bakery and extruded products, where they can be introduced to increase the fibre content of the food. Most investigations on impacts on health have been performed on soyabean fibres. When positive observations were made on lipaemia, glucose tolerance or faecal excretion, they were unfortunately often obtained after non-realistic daily doses of fibres. Legume starches contain a higher amount of amylose than most cereal or tuber starches. This confers these starches a lower bioavailability than that of most starches, when raw or retrograded. Their low glycaemic index can be considered as beneficial for health and especially for the prevention of diseases related to insulin resistance. When partly retrograded, these starches can provide significant amount of butyrate to the colonic epithelium and may help in colon cancer prevention. a-Galactosides are usually considered as responsible for flatus but their apparent prebiotic effects may be an opportunity to valorize these oligosaccharides.