If by "can we trust the analyst recommendations" you mean "are they right 100% of the time" the answer is absolutely no. Analysts are human and make mistakes, some more than others. There are many stories of "superstar managers" that make killings for several straight years, then have a few bad years and lose it all back.
However, don't take "you can't trust them" to mean that they are nefarious in some way. While there may be some that recommend stocks for selfish purposes, I suspect that the vast majority are just going off what information they have, and can't predict market behavior or future performance with perfect accuracy.
Look at many analysts' recommendations. Do your own analysis. If you're still not comfortable buying individual stocks, then don't buy them. Buy index funds if you are satisfied with market returns, or other mutual funds if you want to invest in specific sectors. Or at the very least make sure you are sufficiently diversified so that you don't lose your entire investment by one bad decision. One rule of thumb is to not have more than 10% of your entire portfolio in any one company.