Environmental Health and Preventive Medicine 

About: Environmental Health and Preventive Medicine is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Population & Public health. It has an ISSN identifier of 1342-078X. It is also open access. Over the lifetime, 1481 publications have been published receiving 25670 citations. The journal is also known as: Environ. health prev. med.

The physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing): evidence from field experiments in 24 forests across Japan.

Abstract: This paper reviews previous research on the physiological effects of Shinrin-yoku (taking in the forest atmosphere or forest bathing), and presents new results from field experiments conducted in 24 forests across Japan. The term Shinrin-yoku was coined by the Japanese Ministry of Agriculture, Forestry, and Fisheries in 1982, and can be defined as making contact with and taking in the atmosphere of the forest. In order to clarify the physiological effects of Shinrin-yoku, we conducted field experiments in 24 forests across Japan. In each experiment, 12 subjects (280 total; ages 21.7 ± 1.5 year) walked in and viewed a forest or city area. On the first day, six subjects were sent to a forest area, and the others to a city area. On the second day, each group was sent to the other area as a cross-check. Salivary cortisol, blood pressure, pulse rate, and heart rate variability were used as indices. These indices were measured in the morning at the accommodation facility before breakfast and also both before and after the walking (for 16 ± 5 min) and viewing (for 14 ± 2 min). The R–R interval was also measured during the walking and viewing periods. The results show that forest environments promote lower concentrations of cortisol, lower pulse rate, lower blood pressure, greater parasympathetic nerve activity, and lower sympathetic nerve activity than do city environments. These results will contribute to the development of a research field dedicated to forest medicine, which may be used as a strategy for preventive medicine.

Selenium: its role as antioxidant in human health

Abstract: Selenium (Se) is an essential trace element, and its low status in humans has been linked to increased risk of various diseases, such as cancer and heart disease. In recent years, Se research has attracted tremendous interest because of its important role in antioxidant selenoproteins for protection against oxidative stress initiated by excess reactive oxygen species (ROS) and reactive nitrogen species (NOS). The synthesis of selenoproteins requires a unique incorporation of amino acid selenocysteine (Sec) into proteins directed by the UGA codon, which is also a termination codon. Interest in Se research has led to the discovery of at least 30 selenoproteins; however, the biochemical functional roles of some of these selenoproteins are still unknown. Besides in the form of selenoproteins, Se can exist in many different chemical forms in biological materials either as organic Se compounds, such as selenomethionine and dimethylselenide, and inorganic selenites and selenates. In foods, Se is predominantly present as selenomethionine, which is an important source of dietary Se in humans, and also as a chemical form that is commonly used for Se supplements in clinical trials. Concern for potential deficiency diseases associated with low Se status has led to the establishment of the recommended daily requirements for Se in many countries. However, excess Se intakes through supplementation and its potential misuse as health therapy could also pose a risk of adverse health effects if its use is not properly regulated.

Effect of forest bathing trips on human immune function

Abstract: In Japan, a forest bathing trip, called “Shinrinyoku” in Japanese, is a short, leisurely visit to a forest; it is regarded as being similar to natural aromatherapy. This review focuses on the effects of forest bathing trips on human immune function. Beginning in 2005, adult Japanese individuals, both male and female, participated in a series of studies aimed at investigating the effect of forest bathing trips on human immune function. The subjects experienced a 3-day/2-night trip to forest areas, and blood and urine were sampled on days 2 (the first sampling during each trip) and 3 (the second sampling during each trip), and on days 7 and 30 after the trips. Natural killer (NK) activity, the numbers of NK, granulysin-, perforin-, and granzymes A/B-expressing lymphocytes in the blood, and the concentration of urinary adrenaline were measured. The same measurements were made before the trips on a normal working day as a control. The mean values of NK activity and the numbers of NK, granulysin-, perforin-, and granzymes A/B-expressing cells on forest bathing days were significantly higher than those on the control days, whereas the mean values of the concentration of urinary adrenaline on forest bathing days were significantly lower than that on the control days in both male and female subjects. The increased NK activity lasted for more than 30 days after the trip, suggesting that a forest bathing trip once a month would enable individuals to maintain a higher level of NK activity. In contrast, a visit to the city as a tourist did not increase NK activity, the numbers of NK cells, or the level of intracellular granulysin, perforin, and granzymes A/B. These findings indicate that forest bathing trips resulted in an increase in NK activity, which was mediated by increases in the number of NK cells and the levels of intracellular granulysin, perforin, and granzymes A/B.

Inflammation and cancer

Abstract: Infection and inflammation account for approximately 25% of cancer-causing factors. Inflammation-related cancers are characterized by mutagenic DNA lesions, such as 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) and 8-nitroguanine. Our previous studies demonstrated the formation of 8-oxodG and 8-nitroguanine in the tissues of cancer and precancerous lesions due to infection (e.g., Opisthorchis viverrini-related cholangiocarcinoma, Schistosoma haematobium-associated bladder cancer, Helicobacter pylori-infected gastric cancer, human papillomavirus-related cervical cancer, Epstein-Barr virus-infected nasopharyngeal carcinoma) and pro-inflammatory factors (e.g., asbestos, nanomaterials, and inflammatory diseases such as Barrett’s esophagus and oral leukoplakia). Interestingly, several of our studies suggested that inflammation-associated DNA damage in cancer stem-like cells leads to cancer development with aggressive clinical features. Reactive oxygen/nitrogen species from inflammation damage not only DNA but also other biomacromolecules, such as proteins and lipids, resulting in their dysfunction. We identified oxidatively damaged proteins in cancer tissues by 2D Oxyblot followed by MALDI-TOF/TOF. As an example, oxidatively damaged transferrin released iron ion, which may mediate Fenton reactions and generate additional reactive oxygen species. Dysfunction of anti-oxidative proteins due to this damage might increase oxidative stress. Such damage in biomacromolecules may form a vicious cycle of oxidative stress, leading to cancer development. Epigenetic alterations such as DNA methylation and microRNA dysregulation play vital roles in carcinogenesis, especially in inflammation-related cancers. We examined epigenetic alterations, DNA methylation and microRNA dysregulation, in Epstein-Barr virus-related nasopharyngeal carcinoma in the endemic area of Southern China and found several differentially methylated tumor suppressor gene candidates by using a next-generation sequencer. Among these candidates, we revealed higher methylation rates of RAS-like estrogen-regulated growth inhibitor (RERG) in biopsy specimens of nasopharyngeal carcinoma more conveniently by using restriction enzyme-based real-time PCR. This result may help to improve cancer screening strategies. We profiled microRNAs of nasopharyngeal carcinoma tissues using microarrays. Quantitative RT-PCR analysis confirmed the concordant downregulation of miR-497 in cancer tissues and plasma, suggesting that plasma miR-497 could be used as a diagnostic biomarker for nasopharyngeal carcinoma. Chronic inflammation promotes genetic and epigenetic aberrations, with various pathogeneses. These changes may be useful biomarkers in liquid biopsy for early detection and prevention of cancer.

Suicidal risk factors and completed suicide: meta-analyses based on psychological autopsy studies

Abstract: The purpose of the present review is to evaluate the effects of common risk factors for suicide by meta-analyses using data extracted from studies based on the psychological autopsy method. We focused on five common risk factors of suicide: substance-related disorders, mood disorders, adverse marital status, adverse employment status, and self-harm behaviors. A total of 24 articles were identified from MEDLINE in which the crude odds ratio (OR) could be calculated for the above five risk factors through 30 April 2007, using such search keywords as “suicide,” “psychological autopsy,” and “case-control study.” Overall, both substance-related disorders [OR = 5.24; 95% confidence interval (CI) = 3.30–8.31] and mood disorders [OR = 13.42; 95% CI = 8.05–22.37] were strongly associated with suicidal risk. Suicidal attempt and deliberate self-harm, which can directly lead to completed suicide, have been shown to be very strongly associated with suicidal risk [OR = 16.33; 95% CI = 7.51–35.52]. Effects of social factors such as adverse marital and employment status were relatively small. As substance-related disorders and mood disorders were strongly associated with an increased risk of completed suicide, the comorbidity of these two disorders should be paid a maximum attention. The effective prevention of suicide depends on whether we can successfully incorporate these personal factors as well as social factors into an adequate multi-factorial model.