Identify the Flaw in Causal Reasoning in Health Research

A health care researcher stated, "We found a strong correlation between daily exercise and improved mental health among participants in our study. Thus, incorporating an exercise regimen into daily routines will significantly enhance mental well-being for everyone."

This conclusion is based on the observation that individuals who engaged in regular physical activity reported lower levels of anxiety and depression compared to those who did not. However, the researcher did not account for other factors that might contribute to mental health outcomes, such as diet, social support, and pre-existing health conditions.