Supplementing your diet with sea squirts could reverse some of the effects of aging – including grey hair – a new study suggests. The marine organisms, which can be served raw, are known as meongage in Korea and hoya in Japan. The contain plasmalogens, which are important to body processes but decrease in quantity as people age. Scientists have found that boosting them may not just stop cognitive decline but reverse it. And mice fed with them grew new, thicker black hair.