Non-cigarette tobacco products: what have we learnt and where are we headed?

A wide variety of non-cigarette forms of tobacco and nicotine exist, and their use varies regionally and globally. Smoked forms of tobacco such as cigars, bidis, kreteks and waterpipes have high popularity and are often perceived erroneously as less hazardous than cigarettes, when in fact their health burden is similar. Smokeless tobacco products vary widely around the world in form and the health hazards they present, with some clearly toxic forms (eg, in South Asia) and some forms with far fewer hazards (eg, in Sweden). Nicotine delivery systems not directly reliant on tobacco are also emerging (eg, electronic nicotine delivery systems). The presence of such products presents challenges and opportunities for public health. Future regulatory actions such as expansion of smoke-free environments, product health warnings and taxation may serve to increase or decrease the use of non-cigarette forms of tobacco. These regulations may also bring about changes in non-cigarette tobacco products themselves that could impact public health by affecting attractiveness and/or toxicity.     

Pro-labour myometrial gene expression: are preterm labour and term labour the same?

Preterm labour (PTL) is the most important cause of neonatal morbidity and mortality. While some causes have been identified, the mechanisms involved remain elusive. This study investigates whether term labour (TL) is an appropriate model for PTL by examining pro-labour gene expression, using quantitative rtPCR, and protein synthesis, using Western analysis, in preterm and term myometrial samples obtained from the upper and lower uterine segments before and after the onset of labour. In the lower segment, the levels of prostaglandin H synthase type-2 (PGHS-2), interleukin-1beta (IL-1beta), IL-6 and IL-8 mRNA expression were significantly higher in TL compared with PTL samples. Compared with non-labour controls, the expression of IL-1beta and IL-8 mRNA was increased in both PTL and TL samples and the expression of PGHS-2 and IL-6 mRNA was increased in TL samples only. In the upper segment, there were no differences between PTL and TL samples and the mRNA expression of PGHS-2 and IL-1beta was increased in TL compared with term no labour samples. No effect of PTL or TL was seen on either oxytocin receptor or connexin-43 mRNA expression or protein levels. The multiple regression analysis and studies in primary cultures of uterine myocytes suggest that the inflammatory cytokines, IL-1beta and tumour necrosis factor-alpha, are the most important regulators of PGHS-2 and IL-8. Our data show that preterm and term labouring myometrium are significantly different and that the most marked labour-induced changes in gene expression are in the lower segment. These changes may occur in response to the release of inflammatory cytokines by the labour-associated inflammatory infiltration.     

Why do we like what we like?

Why do we find certain foods more pleasurable than others? Interactions of food components with human biology and with social and eating contexts give rise, in some predictable ways, to relatively stable individual food likes. While sensory and consumer research have traditionally focused on measuring existing likes, a better understanding of their basic determinants can provide ideas and tools to better predict and influence how likes may develop and change. The liking for a particular food or set of foods largely reflects the prevailing cultural environment and personal experiences, which generate variation in the opportunities and likelihood for specific biological predispositions and learning processes to operate with regard to particular foods. These learning processes may be largely influenced by the intrinsic orosensory or nutritional attributes of foods themselves, as well as characteristics of the situational contexts in which foods are experienced. Liking is one factor contributing to the desire to eat a food, and ultimately to food selection. Current knowledge of these processes is briefly reviewed, with suggestions of potential implications for understanding and predicting food acceptance and choice. © 2000 Society of Chemical Industry     

Dietary polyphenols against metabolic disorders: How far have we progressed in the understanding of the molecular mechanisms of action of these compounds?

The aim of this review was to critically assess the evidence supporting the metabolic and anti-inflammatory effects attributed to polyphenols and the potential mechanisms of action underlying these effects. The metabolic and anti-inflammatory properties of polyphenols and polyphenol-rich products have been shown mostly in rodents. These compounds appear to share multiple mechanisms of action at different body sites (gastrointestinal tract, microbiota, host organs) and the responsible molecules may be the original plant compounds, the microbial metabolites and (or) the host derived conjugates. Polyphenols may modify digestion and absorption of nutrients, microbiota composition and metabolism, and host tissue metabolic pathways but none of these mechanisms have been fully demonstrated in vivo and thus, more and better designed studies are needed. Furthermore, human clinical trials show inconsistent evidence of the metabolic and inflammation regulatory properties of polyphenols. Some of the principal limitations of these studies as well as recommendations to further progress in the understanding of the metabolic effects and mechanisms of action of polyphenols are discussed.     

Culinary herbs and spices: what can human studies tell us about their role in the prevention of chronic non-communicable diseases?

Culinary herbs and spices (CHS) are known primarily as flavour enhancers, and it is now well established that they possess bioactive properties that indicate that these foods may have a role to play in the prevention of non-communicable chronic diseases (CNCDs). Human studies are now beginning to provide insights into the significance of the potential health benefits of CHS in a dietary context, particularly concerning their antioxidant and anti-inflammatory properties and their impact on glucose homeostasis, appetite and the consumption of low/reduced fat, salt and sugar foods. However, these studies have also identified a number of factors that are very pertinent to furthering understanding of how CHS can be used for the maintenance of health and the prevention of CNCDs . The challenge for the next phase of studies will be how to incorporate, successfully, these factors into study methodology for investigating the preventative benefits of these foods. © 2019 Society of Chemical Industry     

Zinc and titanium oxides: promising UV-absorbers but what influence do they have on the intact skin?

Suspensions (20%) of microfine and ACS grade zinc oxide, or 20% titanium oxide in water, castor oil or polyethylene glycol were applied topically to rabbit skin over 4 h (1 day) or 2 h daily (3 days). Skin sites were analysed for metal uptake. Percutaneous absorption of the oxides was probably low, most remaining on the skin surface. Uptake patterns were influenced by the vehicles used. Appreciably more microfine zinc oxide was taken up by the skin in subacute studies. Local changes in trace metal concentration were construed as evidence of percutaneous absorption of zinc and titanium oxides. Further studies are indicated to validate the significance of these preliminary observations.     

Authors' perspective: what is the optimum intake of vitamin C in humans?

The recommended dietary allowance (RDA) of vitamin C has traditionally been based on the prevention of the vitamin C deficiency disease, scurvy. While higher intakes of vitamin C may exert additional health benefits, the limited Phase III randomized placebo-controlled trials (RCTs) of vitamin C supplementation have not found consistent benefit with respect to chronic disease prevention. To date, this has precluded upward adjustments of the current RDA. Here we argue that Phase III RCTs-designed principally to test the safety and efficacy of pharmaceutical drugs-are ill suited to assess the health benefits of essential nutrients; and the currently available scientific evidence is sufficient to determine the optimum intake of vitamin C in humans. This evidence establishes biological plausibility and mechanisms of action for vitamin C in the primary prevention of coronary heart disease, stroke, and cancer; and is buttressed by consistent data from prospective cohort studies based on blood analysis or dietary intake and well-designed Phase II RCTs. These RCTs show that vitamin C supplementation lowers hypertension, endothelial dysfunction, chronic inflammation, and Helicobacter pylori infection, which are independent risk factors of cardiovascular diseases and certain cancers. Furthermore, vitamin C acts as a biological antioxidant that can lower elevated levels of oxidative stress, which also may contribute to chronic disease prevention. Based on the combined evidence from human metabolic, pharmacokinetic, and observational studies and Phase II RCTs, we conclude that 200 mg per day is the optimum dietary intake of vitamin C for the majority of the adult population to maximize the vitamin's potential health benefits with the least risk of inadequacy or adverse health effects.     

Keeping mycotoxins away from the food: Does the existence of regulations have any impact in Africa?

Following the discovery of aflatoxins in the early 1960s, there have been many studies leading to the uncovering of many mycotoxins and the understanding of associated health effects in animals and humans. Consequently, there has been a global increase in the number of countries with mycotoxin regulations in foods. However, many African countries have only regulations for aflatoxins (or a few other mycotoxins) in specific foods, or no regulations at all. This paper critically reviews the challenges thwarting the establishment of mycotoxin regulations and their impacts on human dietary mycotoxin exposure in Africa. Mycotoxin regulatory limits for different countries are compared with mycotoxin tolerable daily intakes established by international food safety bodies taking into account consumption patterns. The agrarian setup, food insecurity, and mycotoxin analytical challenges in African countries are discussed; and more feasible mycotoxin dietary exposure reduction strategies are proposed.     

Novel foods and food ingredients: what is the mission of scientists and technologists?

The situation concerning world food production is changing dramatically. On the one hand, the world population is expected to grow still further, reaching about 8 billion people in the middle of the 21st century. Novel phenomena, such as ageing of the human population and excess weight in developing countries pose new nutrition problems. Food scares, which were enhanced by recent BSE and toxicological outbreaks, hinder the applicability of some solutions. Under these conditions, scientists and technologists should participate actively in the tasks of informing the population as well as finding new ways to provide people with the optimal amount of nutritious food.     

Exploring the nature of wine expertise: what underlies wine experts' olfactory recognition memory advantage?

To source the locus of the recognition memory advantage demonstrated by wine experts in a previous study [Chem. Senses 27 (2002) 747], we investigated recognition of wine-relevant odours as a function of wine expertise and type of encoding of the to-be-remembered odorants. Fourteen wine experts and 14 wine novices participated in tasks measuring olfactory threshold, odour recognition, and odour identification. Odour recognition memory was investigated as a function of type of encoding task, namely whether participants were required to identify an odorant or to judge an odorant in terms of its pleasantness. Wine-relevant odorants were sampled orthonasally by each participant in the semantic (identification), hedonic (pleasantness rating), and episodic (recognition) memory tasks. Results showed superior olfactory recognition by expert wine judges, despite their olfactory sensitivity, bias measures, and odour-identification ability being similar to those of novices. Contrary to a prediction that wine experts' recognition memory would not be influenced by type of odorant-encoding task, while novices' recognition memory would be inhibited by forced naming of odorants, both groups' olfactory recognition was facilitated by identifying odorants relative to judging odorants in terms of pleasantness. Ability to recognise odours and ability to name odours were not positively correlated, although novices' data showed a trend in this direction. The results imply that the source of superior odour recognition memory in wine experts was not due to enhanced semantic memory and linguistic capabilities for wine-relevant odours, but perceptual skill (e.g., olfactory imaging).     

Cured meat products without direct addition of nitrate or nitrite: what are the issues?

The growing popularity of food products marketed in the United States as "natural" and "organic" has resulted in a proliferation of marketing efforts to meet consumer demands for these foods. Because natural and organic foods are not permitted to use chemical preservatives, the traditional curing agents used for cured meats, nitrate and/or nitrite, cannot be added to natural and organic processed meat products. However, alternative processes that utilize ingredients with high nitrate content, such as vegetable-based ingredients, and a nitrate-reducing starter culture can produce processed meats with very typical cured meat properties. Because it is not possible to analytically measure the amount of nitrite produced by this process, several potential issues deserve consideration. Regulations, for example, should permit labeling that accurately reflects the process and products, manufacturing procedures must be standardized to achieve product consistency, marketing efforts should clearly communicate the nature of these products to consumers, product quality must be maintained, and microbiological safety must be assured.     

Heterologous expression and stability of the Escherichia coli β-galactosidase gene in Streptococcus lactis by translation fusion

An Escherichia coli/Streptococcus lactis shuttle vector for creating translation fusions to the E. coli galactosidase (lacZ) has been constructed. Random S. lactis chromosomal DNA fragments inserted upstream of the lacZ gene and in frame promote the expression of active galactosidase in both E. coli and S. lactis. One fusion pSK216 has been characterized by Western blotting to reveal a fusion protein of 116 kd. S. lactis LM0230, a plasmidless lac⁻ derivative of S. lactis C2 when carrying pSK216, exhibits a Lac⁺ phenotype suggesting the presence of a chromosomally encoded lactose permease. Further evidence for this lactose permease system is provided by assay of lactose uptake by S. lactis LM0230. In the absence of selection pSK216 was less stable in S. lactis LM0230 than its derivative pSK41. The growth rate of S. lactis LM0230 carrying pSK216 is slower in comparison to the plasmid-free strain. Two genetic events were observed, the deletion of the lacZ gene and the loss of the entire plasmid. These results indicate that recombinant plasmids are unstable in S. lactis and imply that there is an obstacle in the genetic engineering of lactic acid bacteria.     

Proposed mandatory fortification of the UK diet with folic acid: have potential risks been underestimated?

This article discusses the recent consultation by the UK Department of Health and Food Standards Agency on the risk-benefit of a whole population strategy for increased intake of folic acid via the fortification of flour. The potential benefit of folic acid in relation to decreased incidence of Neural Tube Defects in the newly born is contrasted to the potential risk of increasing permanent neuropathy (nerve damage) in those suffering from vitamin B₁₂ deficiency. Questions are also raised with regard to the potential risk of folic acid addition in the context of pre-existing malignant neoplasms, and the incidence of dichorionic twin births.