Evolution, Medicine, and Public Health最新文献

Lay summary: Through an online survey of nutrition and dietetic professionals and students, we learned there is interest to incorporate evolutionary medicine into the nutrition and dietetics field and education programs.

Background and objectives: Evolutionary medicine is an emerging field that examines the evolutionary significance of modern disease to develop new preventative strategies or treatments. While many areas of interest in evolutionary medicine and public health involve diet, we currently lack an understanding of whether nutrition and dietetics professionals and students appreciate the potential of evolutionary medicine.

Methodology: Cross-sectional online survey to measure the level of appreciation, applicability and knowledge of evolutionary medicine among nutrition and dietetics professionals and students. We then examined the relationships between support of evolutionary medicine and (i) professionals and students, (ii) US region, (iii) religious belief and (iv) existing evolutionary knowledge.

Results: A total of 2039 people participated: students (n = 893) and professionals (n = 1146). The majority of the participants agree they are knowledgeable on the theory of evolution (59%), an understanding of evolution can aid the nutrition and dietetics field (58%), an evolutionary perspective would be beneficial in dietetics education (51%) and it is equally important to understand both the evolutionary and direct causes of disease (71%). Significant differences in responses between professionals and students suggest students are currently learning more about evolution and are also more supportive of using an evolutionary perspective. Whereas differences in responses by US region were minimal, differences by religious belief and prior evolutionary knowledge were significant; however, all responses were either neutral or supportive at varying strengths.

Conclusion and implications: There is interest among professionals and students to incorporate evolutionary medicine into the nutrition and dietetics field and education programs.

Lay Summary: Different species of vertebrates have conditions similar to human obesity, insulin resistance and type 2 diabetes. Increasing number of studies are now revealing that the causes and interrelationships between these states are substantially different in different species. Comparative physiology may turn out to be an eye opener for evolutionary theories of diabetes. Obesity induced insulin resistance is believed to be central to type 2 diabetes. Recent work on Mexican cavefish, Astyanax mexicanus, has revealed a hyperglycemic phenotype similar to human type 2 diabetes but here insulin resistance is the cause of obesity rather than an effect. Instead of developing diabetic complications, the hyperglycemic fish lead a healthy and long life. In addition to fish, insulin resistance in hibernating bears, dolphins, horses, bonnet macaques and chimpanzees demonstrate that the relationship between diet, obesity, insulin sensitivity and diabetes is widely different in different species. Evolutionary hypotheses about type 2 diabetes should explain these differences.

Background and objectives: The underlying reasons why some women experience debilitating premenstrual symptoms and others do not are largely unknown. Here, we test the evolutionary ecological hypothesis that some negative premenstrual symptoms may be exacerbated by the presence of chronic sexually transmitted infections (STIs).

Methodology: 34 511 women were recruited through a digital period-tracker app. Participants were asked: (i) Have you ever been diagnosed with a STI? (ii) If yes, when was it, and were you given treatment? Those data were combined with longitudinal cycle data on menstrual bleeding patterns, the experience of pain and emotions and hormonal contraceptive use.

Results: 865 women had at least two complete menstrual cycle data and were eligible for analysis. Before diagnosis, the presence of an infection predicts a ca. 2-fold increase in the odds of reporting both headache, cramps and sadness during the late luteal phase and sensitive emotions during the wider luteal phase. After diagnosis, the odds of reporting negative symptoms pre-menstrually remain unchanged among STI negative individuals, but the odds of reporting sensitive emotions decrease among STI positive individuals receiving a treatment. No relationships between STIs, pain and emotions are observed among hormonal contraceptive users.

Conclusions and implications: The results support the idea that a negative premenstrual experience might be aggravated by the presence of undiagnosed STIs, a leading cause of infertility worldwide. Caution is warranted in extrapolating the results as the data are self-reported, inflammatory levels are unknown and the tracker is biased towards recording negative premenstrual symptoms among Western individuals.

Background and objectives: The rate of evolution of drug resistance depends on the fitness of resistant pathogens. The fitness of resistant pathogens is reduced by competition with sensitive pathogens in untreated hosts and so enhanced by competitive release in drug-treated hosts. We set out to estimate the magnitude of those effects on a variety of fitness measures, hypothesizing that competitive suppression and competitive release would have larger impacts when resistance was rarer to begin with. Methodology: We infected mice with varying densities of drug-resistant Plasmodium chabaudi malaria parasites in a fixed density of drug-sensitive parasites and followed infection dynamics using strain-specific quantitative PCR. Results: Competition with susceptible parasites reduced the absolute fitness of resistant parasites by 50-100%. Drug treatment increased the absolute fitness from 2- to >10 000-fold. The ecological context and choice of fitness measure was responsible for the wide variation in those estimates. Initial population growth rates poorly predicted parasite abundance and transmission probabilities. Conclusions and implications: (i) The sensitivity of estimates of pathogen fitness to ecological context and choice of fitness measure make it difficult to derive field-relevant estimates of the fitness costs and benefits of resistance from experimental settings. (ii) Competitive suppression can be a key force preventing resistance from emerging when it is rare, as it is when it first arises. (iii) Drug treatment profoundly affects the fitness of resistance. Resistance evolution could be slowed by developing drug use policies that consider in-host competition.

Background and objectives: The body mass index (BMI) is an established anthropometric index for the development of obesity-related conditions. However, little is known about the distribution of BMI within a population, especially about this distribution's temporal change. Here, we analysed changes in the distribution of height, weight and BMI over the past 140 years based on data of Swiss conscripts and tested for correlations between anthropometric data and standard blood parameters.

Methods: Height and weight were measured in 59 504 young Swiss males aged 18-19 years during conscription in 1875-79, 1932-36, 1994 and 2010-12. For 65% of conscripts in 2010-12, results of standard blood analysis were available. We calculated descriptive statistics of the distribution of height, weight and BMI over the four time periods and tested for associations between BMI and metabolic parameters.

Results: Average and median body height, body weight and BMI increased over time. Height did no longer increase between 1994 and 2010-12, while weight and BMI still increased over these two decades. Variability ranges of weight and BMI increased over time, while variation of body height remained constant. Elevated levels of metabolic and inflammatory blood parameters were found at both ends of BMI distribution.

Conclusions and implications: Both overweight and underweight subgroups showed similar changes in inflammation parameters, pointing toward related metabolic deficiencies in both conditions. In addition to environmental influences, our results indicate a potential role of relaxed natural selection on genes affecting metabolism and body composition.

Night terrors, also known as sleep terrors, are an early childhood parasomnia characterized by screams or cries, behavioral manifestations of extreme fear, difficulty waking and inconsolability upon awakening. The mechanism causing night terrors is unknown, and a consistently successful treatment has yet to be documented. Here, we argue that cultural practices have moved us away from an ultimate solution: cosleeping. Cosleeping is the norm for closely related primates and for humans in non-Western cultures. In recent years, however, cosleeping has been discouraged by the Western medical community. From an evolutionary perspective, cosleeping provides health and safety benefits for developing children. We discuss night terrors, and immediate and long-term health features, with respect to cosleeping, room-sharing and solitary sleeping. We suggest that cosleeping with children (≥1-year-old) may prevent night terrors and that, under certain circumstances, cosleeping with infants (≤11-months-old) is preferable to room-sharing, and both are preferable to solitary sleeping.

Cancer cells have a parasitic propensity in the primary host but their capacity to transit between individuals is severely restrained by two factors: a lack of a route for viable cell transfer and immune recognition in allogeneic, secondary recipients. Several examples of transmissible animal cancers are now recognised. In humans, the only natural route for transmission is via the haemochorial placenta which is permissive for cell traffic. There are three special examples of this occurring in utero: maternal to foetus, intraplacental twin to twin leukaemias and choriocarcinoma-extra-embryonic cells to mother. We discuss the rare circumstances under which such transmission occurs.