Apparently we live in the time of post-truth and alternative facts. However, we do not have to take this lying down. What we, the scientific community, can offer is a viable alternative, meaning real facts. There are two things that are critical in this: what to do when faced with outright lies or opinions parading as facts and what to offer in their place. The key to both issues is bias. Alternative facts consciously ignore biases and their effects. Somehow a personal gut feeling just trumps scientific reasoning. The best thing we can do is to accept the existence of biases and to try and minimise their effects in what we do. One way to do this is by means of systematic review. It is a means of abstracting a higher level of truth from multiple scientific studies that each examine a similar issue. Whilst synthesising their results and formulating overall conclusions, one explicitly displays the biases affecting both the existing research (what others have done) and the process of synthesis (what you do to combine the results of the studies in one conclusion).
For example, a Cochrane review found high quality evidence that the use of blunt needles appreciably reduces the risk of exposure to blood and bodily fluids for surgeons and their assistants over a range of operations. High quality evidence means that the finding is not significantly affected by biases in the evidence or in the process to combine their results. Future research is unlikely to change this conclusion. Conversely another Cochrane review found very low quality evidence that bullying behaviours may be prevented in the workplace. Future research is very likely to change this conclusion. Know thyself and be open about your failings. That is a sound basis for true facts.