科学的に証明された「風邪に効くもの」と「効かないもの」

風邪の予防や対症療法で、実際に効果があるものはどれで、「効くと言われているのに実は効果が期待できないもの」はどれなのだろうか。

カナダの医学誌「Canadian Medical Association Journal（カナディアン・メディカル・アソシエーション・ジャーナル」に発表された、風邪に関する研究結果の検証記事からご紹介しよう。

風邪の予防に効果的なのは、何と言っても、手洗いだ。それと、子どもの場合は（おそらく大人にも言えることだが）、亜鉛を摂取すると、風邪をひく割合と学校の病欠日数を減らせるかもしれない。

また、乳酸菌など、人体に好影響をもたらす微生物を摂取する「プロバイオティクス」も良いという。とはいえ、検証した研究ではそれぞれ異なる種類のバクテリアが用いられているため、単純に比較することは難しいようだ。

では、風邪をひいてしまったらどうすればいいのだろうか。5歳以上であれば、抗ヒスタミン剤を含んだ鼻づまりの薬か、鎮痛剤の両方、またはいずれか一方が有効だという。

イブプロフェンおよびアセトアミノフェンは、痛みや熱の緩和に非常によく効く（子どもの熱を下げたい場合は、イブプロフェンの方が効果が高い）。

イプラトロピウムが配合された鼻腔用スプレーは、鼻水の症状は和らげてくれるものの、鼻づまりには効かない。

効果がない薬としては、咳止め薬が挙げられている。大人の場合は多少の効果が期待できるらしいが、子どもには効かないという。1歳以上の子どもの咳を抑えたいなら、はちみつの方がいいだろう（はちみつにはボツリヌス菌がまれに眠った状態で含まれている場合があるため、1歳未満の子供には与えてはいけない）。

胸に塗る咳止め薬やうがい、朝鮮ニンジン、ホメオパシー、さらにはビタミンCや抗生物質などは、風邪の症状を和らげるという確実な証拠は見つかっていない。

検証を行なった研究者は、同誌でこう述べている。「大半の代替療法は、その効果の有無を断定できない。鼻洗浄、加湿、漢方薬、アメリカ先住民のハーブと呼ばれるエキナセアなど、どれも研究結果に一貫性がないからである」

数々の研究結果を対象にした今回の検証は、カナダのアルバータ大学およびニュージーランドのオークランド大学の研究者たちによって行なわれた。

[(English)　日本語版：遠藤康子/ガリレオ]

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