やはり一に食養生、ニに薬…ですね。
最近のあるコホート研究から。
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新型コロナウイルス感染症（COVID-19）のリスクや重症度と、食事の質や貧困度との関連性を前向きコホート研究で検討した。スマートフォンを用いたCOVID-19症状研究の参加者59万2571例の食事データを解析し、健康的な植物性食品中心の食事スコアで評価した。
その結果、388万6274人月を追跡調査し、COVID-19症例3万1815例を確認した。食事スコアが最低四分位群の参加者に比べると、質が高い食事の参加者はCOVID-19罹患（ハザード比0.91、95％CI 0.88-0.94）、重症COVID-19（同0.59、0.47-0.74）のリスクが低かった。食事の質低下と生活貧困度上昇が複合した場合は、それぞれ単独のリスク関連性を合計した場合よりもCOVID-19に対するリスクの関連性が高かった（相互作用のP＝0.005）。食事スコアの最低四分位群と最高四分位群に対応する1万人月当たりの絶対超過率は、低貧困地域の居住者22.5（95％CI 18.8-26.3）、高貧困地域の居住者40.8（同31.7-49.8）だった。
Diet quality and risk and severity of COVID-19: a prospective cohort study
Objective: Poor metabolic health and unhealthy lifestyle factors have been associated with risk and severity of COVID-19, but data for diet are lacking. We aimed to investigate the association of diet quality with risk and severity of COVID-19 and its interaction with socioeconomic deprivation.
Design: We used data from 592 571 participants of the smartphone-based COVID-19 Symptom Study. Diet information was collected for the prepandemic period using a short food frequency questionnaire, and diet quality was assessed using a healthful Plant-Based Diet Score, which emphasises healthy plant foods such as fruits or vegetables. Multivariable Cox models were fitted to calculate HRs and 95% CIs for COVID-19 risk and severity defined using a validated symptom-based algorithm or hospitalisation with oxygen support, respectively.
Results: Over 3 886 274 person-months of follow-up, 31 815 COVID-19 cases were documented. Compared with individuals in the lowest quartile of the diet score, high diet quality was associated with lower risk of COVID-19 (HR 0.91; 95% CI 0.88 to 0.94) and severe COVID-19 (HR 0.59; 95% CI 0.47 to 0.74). The joint association of low diet quality and increased deprivation on COVID-19 risk was higher than the sum of the risk associated with each factor alone (Pinteraction=0.005). The corresponding absolute excess rate per 10 000 person/months for lowest vs highest quartile of diet score was 22.5 (95% CI 18.8 to 26.3) among persons living in areas with low deprivation and 40.8 (95% CI 31.7 to 49.8) among persons living in areas with high deprivation.
Conclusions: A diet characterised by healthy plant-based foods was associated with lower risk and severity of COVID-19. This association may be particularly evident among individuals living in areas with higher socioeconomic deprivation.
