Some say

The phrase "some say" is often used to introduce an opinion, belief, or piece of information that is held or expressed by a group of people, without specifying exactly who those people are. It's a way to acknowledge that a certain idea or viewpoint exists and is believed by some individuals.

For example:

Some say that eating chocolate can improve your mood.

Some say that exercise is the best way to improve mental health.

Using "some say" can be helpful when discussing a topic where there are differing opinions or when the speaker wants to present a particular viewpoint without directly endorsing or refuting it. However, it's important to use this phrase with context and additional supporting information whenever possible because it can also be vague or speculative.