Why is there contradictory studies on nearly every health topic? one study says omega 3 is good and then another says it offers no benefits. what's up

Knowledge developmen: On the cutting edge of research, there will be uncertainty. Studies are done in different ways, and sometimes results appear to conflict. There are some results that are accepted widely (aspirin prevents heart attacks for people with heart disease) and others that we need to know more about (especially for less common illnesses).

Beyond a reasonable: I know, it's frustrating isn't it? Honestly, I think the answer lies in statistical significance. Scientific research questions are set up to try to give definitive answers, answers that are likely to be true & not the result of chance. How well the study is designed (how many are studied, how big a change in the outcome is desired, etc) often determines whether it is positive or negative.

Uncertainty: The acquisition of knowledge is not a linear march forward. Think of it as a wave front during a rising tide: it ebbs and flows but gradually progresses. You're right about Omega 3s-we don't have the final answer. There are many other examples. If you want relative certainty, read only medical textbooks and avoid new studies and, especially, the latest journalism!