How to Have a Good Relationship with Sunlight: The NYT's Report on "Reevaluating Sunbathing" and the Latest Guide for Japanese People

In recent years, while excessive ultraviolet protection has been emphasized, the benefits of "moderate sunbathing" for health are being revisited. The New York Times, in its July 8, 2025 edition, highlighted the multifaceted benefits that go far beyond vitamin D production—such as lowering blood pressure, regulating the body clock, controlling immunity, and improving mental health—through the latest research and expert commentary. This article will explore, using the points from the aforementioned article as a guide, ① the mechanisms of physiological reactions triggered by sunlight, ② the amount of exposure needed to expect benefits, ③ the balance with skin cancer risk, and ④ practical methods tailored to Japan's climate and lifestyle, based on large-scale epidemiological studies involving 10,000 people and materials from the WHO and the Ministry of Health, Labour and Welfare. Even just 10 to 30 minutes of soft sunlight in the morning or evening can lower blood pressure by a few mmHg and regulate the secretion of the sleep hormone melatonin. Additionally, by wisely using sunscreen and clothing, one can enjoy the benefits while suppressing photoaging. By reading this article, you should be able to see a third option that is neither "staying in the shade only" nor "exposing yourself unprotected."