Housing and Antiaging Medicine

Research on aging is showing remarkable progress, and it has become clear that the speed of aging is somewhat controlled by genetic pathways and biochemical processes. As indicated by “The Hallmarks of Aging” by López-Otín et al. there are nine common factors related to the aging of mammals [1]. Factors accelerating these include genetics, lifestyle, social systems, and in recent years, the impact from the environment, including its countermeasures, has been significantly increasing. In this section, we will discuss the impact of air quality in the environment, particularly PM2.5, on aging. Furthermore, the average time spent at home in our country is 17 h and 23 min, and since we spend more than 70% of the day at home (according to the 2021 Ministry of Health, Labour and Welfare White Paper), we will also mention measures focusing on housing. PM2.5 is a particulate matter with a diameter of 2.5 μm or less, and due to its small size, its impact on organisms is a concern. Regarding aging, PM2.5 affected the length of telomeres and the activity of telomerase, which are among the aging factors mentioned above [2]. In this study, primary human bronchial epithelial cells derived from healthy subjects or patients with chronic obstructive pulmonary disease (COPD) were differentiated and repeatedly exposed to PM2.5 concentrated from the atmosphere. As a result, although PM2.5 did not cause DNA strand breaks or chromosomal damage, as shown in Fig. 155.1, telomere length was found to shorten in response to exposure concentration and number of exposures. In addition to telomeres, research on DNA methylation, one of the epigenetic changes, is also progressing. A study was conducted on changes in mRNA expression in the hearts of zebrafish exposed to extracted organic matter (EOM) derived from PM2.5 [3]. As a result, exposure to EOM reduced SAM/SAH, a potential methylation indicator, and also suppressed the expression of DNA methyltransferase. In other words, EOM induced a wide range of DNA methylation changes. Research on the relationship between PM2.5 and allergies is progressing both experimentally and epidemiologically. For example, an in vitro study was conducted to evaluate the association between PM2.5 exposure and the onset of asthma [4]. The PM2.5 used in this study was collected in Nanjing, China, and made into a soluble substance. Human lung epithelial cells (BEAS-2B) were treated with soluble PM2.5, and cell survival rate and other factors were detected using Annexin V-FITC staining (apoptosis detection). As a result, exposure to soluble PM2.5 in vitro reduced survival rate and increased apoptosis of airway epithelial cells. Soluble PM2.5 reduced airway barrier function, accompanied by an increase in NF-κB (nuclear factor-κB) and MAPK (mitogen-activated protein By activating the kinase signaling pathway, it induces oxidative stress and enhances the expression of inflammation-inducing factors. It was shown that PM2.5 exposure increases the impact of allergen sensitization after respiratory exposure to allergens, leading to the onset of asthma. In response to these, attempts are now being made to suppress aging promotion and the onset of allergies and hatred by improving the living environment. In our country today, due to the improvement of building materials and insulation materials, and the advancement of construction methods and technologies, houses with high airtightness and good ventilation efficiency are widespread. In such a situation, houses equipped with air conditioning equipment using a HEPA filter (high efficiency particulate air filter) showed a high PM2.5 removal effect [5]. In this house, as shown in Fig. 155.2, during the intermediate period (when the air conditioner is not in use), PM2.5 was reduced by 96% in the living room and 97% in the master bedroom. During the air conditioning period (when the air conditioner is in use), PM2.5 was reduced by 99% in the living room and 98% in the master bedroom. Also, when mold was measured in this house equipped with a HEPA filter, as shown in Fig. 155.3, it was 2452 particles/m3 in the outside air, but achieved an air environment equivalent to a clean room (200 particles/m3 or less) such as a food factory indoors at 116 particles/m3. By the way, the same results were obtained for pollen. In current homes, not only air quality, but also stable temperature by whole-house air conditioning, and constant humidity achieved by collecting water with a desiccant (zeolite) and heating it are realized.