A study by researchers at UCLA found that stressful friendships lead to significantly high levels of a protein that causes inflammation in the body. Over time that can cause serious health problems including diabetes, heart disease, and cancer.

“This study is suggesting that there’s more to it than just a psychological impact, that it may be related to health outcomes and diseases that are very common and very severe,” Dr. Daniel Yadager explained.

Dr. Yadager said in addition to eating well and exercising, good relationships can be as important.

“This is also part of leading a healthy lifestyle, is to make sure you’re around people who are nurturing and supportive,” Dr. Yadager said.