Can stem cell therapy slow down ALS?
Stem cell therapy has not yet been proven effective in ALS patients; the method appears to be safely feasible, but whether it slows the disease is currently unknown.
In animal research, stem cell therapy looks promising. In mice with an ALS-like condition, treatment with mesenchymal stem cells improved both survival and motor function. Notably, the stem cells barely take up residence in the nervous system itself. They appear to work through indirect pathways, such as dampening inflammation, lowering a substance that damages nerve cells (glutamate), and reducing oxidative stress in the spinal cord.
In humans, the data are far more modest. Small early studies, with seven to a handful of patients, tested whether stem cells could be safely injected into the spinal cord. Both neural stem cells and mesenchymal stem cells proved technically feasible to administer without major direct safety risks. However, none of these studies were designed to measure whether patients actually benefited.
Whether stem cell therapy slows ALS in humans has not yet been demonstrated. Randomised studies, in which one group of patients receives the treatment and a comparable group does not, have not been completed to date. Without that comparison, it is impossible to conclude that the treatment works.
Scientists also expect that stem cells alone will probably not be enough, given how complex ALS is. They are thinking about combinations with other agents, such as substances that protect nerve cells or suppress inflammation. What such a combination should look like remains completely open.
This answer is based on eight review studies and a handful of early clinical studies in small groups of patients. The animal research is more consistent and more advanced; the clinical data are limited to safety observations in very small numbers of participants. No completed randomised study in humans is available, which means that cause and effect in humans cannot be established.
Do mesenchymal stem cells help against frailty in older adults?
Mesenchymal stem cells appear to be safe in the short term in frail older adults and demonstrably reduce inflammatory markers in the blood, but whether they genuinely help against frailty has not yet been established. Until larger and longer studies are available, this remains a promising but still experimental direction.
Can you remove microplastics from your blood vessels?
There is still too little research to answer this question.
Does linoleic acid in tissue increase the risk of skin cancer?
There are preliminary indications that higher linoleic acid levels are associated with a higher melanoma risk, but the evidence is too thin and inconsistent to justify avoiding linoleic acid. Those concerned about skin cancer would benefit more from ensuring adequate vitamin D intake and protection against UV radiation.