A new study has found that a constituent of the herb comfrey, known as allantoin, can extend the lifespan of worms by about 20% by mimicking the effects of caloric restriction. Caloric restriction has been found to extend the lifespans of several animal species, from worms up to mammals, but is one of the least pleasant anti-aging remedies. Fortunately, at least for worms, those given allantoin lived for 28.32 days, compared to 23.14 days for the wild-type worms and 27.01 for the calorie-restricted worms. This was an increase in lifespan by 21.86%, to be exact. Movement had also improved in comparison to the non-treated worms, at least for a while.
In Australia, comfrey is only "allowed" for topical and cosmetic use, but grows very well so many people have it in their backyards for personal use regardless of whether they are going to make a face cream with it or eat it. This also makes the above study especially relevant, as comfrey is much more accessible than the prescription drugs that have been found in this and other research to have antiaging effects (do you have a rapamycin tree?). Comfrey has been clinically proven to relieve pain and inflammation in muscles and joints, such as in arthritis, sprains and strains. For example, a study of 120 patients with acute back pain found that a cream containing comfrey root fluid extract reduced pain during "active standardised movement" by 95%, compared to 37% with placebo. The comfrey cream was also superior in all secondary outcomes compared to the placebo, and began to work within one hour! Using the same preparation, another double-blind trial was conducted on 220 people with knee osteoarthritis. Scores of pain and pain on movement decreased by 54.7% in the treatment group and 10.7% in the placebo group, while scores in an osteoarthritis index score dropped by 58% in the treatment group and 14.1% for placebo. Quality of life and joint movement also improved more in the comfrey patients. Additionally, comfrey was found to be superior to diclofenac in another trial. Comfrey root has also been used for knee joint injuries and non-active gonarthrosis, as well as in the treatment of tendinitis syndrome, insect bites, mastitis, fractures, skin inflammation, multiple abscesses of sweat glands, gangrenous ecthymas, furuncles, dicubital ulcers and chronic varicose ulceration, in both trials and individual case reports. Reports of "liver damage" from comfrey use, which is why we cannot legally prescribe it internally, were based on baby rats being given doses far exceeding what is humanly possible, and possibly reports from people who already had liver conditions and were therefore more vulnerable to any possible adverse effects. But it seems to work best in a cream anyway.