Are All Scientific Studies Reliable?

In a word - no. Results of medical and lifestyle studies that could help us decide how to live healthier lives are a dime a dozen on the internet. Instead of taking these results at face value and perhaps changing your behavior, it is best to think about if the results are completely valid or not. Then you can decide if the study was good science or flawed in some respect. And believe me all studies that post headline-making results are not good science. Here are a few things to look for so you can decide: 1. look first at possible conflicts of interest. Who funded the study? How would gain from the results? if you read report of the fantastic health benefits of coffee, it should be a red flag if that study was funded by Starbucks! 2. how large a study was it and for how long? it makes sense that a study of 9 people done over a weekend might be a lot less accurate than one done with 10,000 people over 30 years. 3. how was the study conducted? If, for example, participants were asked to fill out a questionnaire about how many times in the past year they ate meat, I would question the accuracy of the data, because memories can be bad. 4. was it a double blind study? The double blind study is the gold standard in research. This means that the person who is conducting the study as well the person in the study both do not know who is receiving a particular treatment. For instance if there is a placebo and a real drug given randomly to participants, neither the giver not the taker know who got the real drug and who got the placebo. This way the person giving the drug out as well as the one taking it does not expect a certain outcome. 
This type of thinking through studies and even polls works well not just for scientific papers but for any results that come out trying to influence you. Like a study showing that the best cars are made by Ford. Who funded the study (was it Ford?), If it was a poll who did they ask? Maybe they just polled 100 Ford dealership owners?
So we should be look a little deeper into any research or claims  in order to determine if the results are valid. Its healthy to have a degree of skepticism.