Effects of Physical Activity on Mental Health via Inflammatory Response Mechanisms: Approach to Mental Health Problems from an Evolutionary and Adaptive Perspective

Abstract

現代日本では精神的不調を訴える人が増加していることが社会問題となっている．その背景には，近代的な生活様式と，適応進化の過程で獲得した身体機能の間にミスマッチが生じていることが原因の一つである可能性がある．代表的なミスマッチとして，身体活動不足がある．先進国の人々の身体活動量は，現存する狩猟採集民と比較して大幅に少ない．この身体活動不足は身体の慢性炎症と関係し，さらに，慢性炎症は気分の低下や精神障碍の発症をまねくとされる．反対に，身体活動は抗炎症作用を介して，精神的不調の予防や改善に有用であることが期待される．炎症は生物学的に根底的な機能であるため，身体活動は，多様な人々に広く適応可能な精神的不調改善のための応用に繋がる可能性がある．しかし，身体活動は，強度が高いと最中・直後に負の感情変化をもたらし得る．この機序における炎症反応の役割は明らかではない．このことは当該分野に残された課題である．The increasing number of people suffering from mental health issues has become a social problem in Japan. One possible cause of these mental health problems is a mismatch between the modern lifestyle and physical functions developed through adaptive evolution. A typical example of this mismatch is the lack of physical activity. The physical activity levels of people in developed countries are much lower than those of present-day hunter-gatherer societies. This physical inactivity is associated with chronic inflammation in the body, which may have a negative impact on mood and mental health disorders. Conversely, physical activity is thought to be beneficial for preventing and alleviating mental health problems through its anti-inflammatory effects. As inflammation is a fundamental biological function, physical activity may have the potential to improve mental health across diverse populations. However, high-intensity physical activity can lead to negative emotional changes during or immediately after the activity. The role of the inflammatory response in this mechanism remains unclear