In mice without ovaries that have a type of breast cancer that responds to estrogen, eating a diet with 10% sesame seeds doesn’t help shrink tumors or stop them from growing — it’s about the same as not getting any treatment.

What we've found so far suggests that eating sesame seeds does not reduce breast tumor growth in mice without ovaries. Our analysis of the available research shows no evidence that sesame seeds slow or shrink tumors in this specific group of mice. We reviewed one study involving mice that had their ovaries removed and had a type of breast cancer that responds to estrogen. In these mice, a diet containing 10% sesame seeds had no effect on tumor growth. The tumors continued to grow at about the same rate as in mice that did not eat sesame seeds and received no treatment [1]. This means, based on what we’ve seen so far, sesame seeds did not make a noticeable difference in tumor size or progression in this particular setting. It’s important to note that this finding applies only to this specific animal model — mice without ovaries with estrogen-responsive breast cancer. We cannot say whether the same would be true in other types of cancer, in mice with ovaries, or in humans. The evidence we’ve reviewed leans toward no effect, but so far we have only analyzed one claim and no studies suggesting a benefit or harm. Because our current analysis is based on very limited data, we can’t draw broad conclusions. More research would be needed to understand if different doses, forms of sesame, or biological contexts might lead to different outcomes. Practical takeaway: Based on the single study we’ve looked at, eating sesame seeds doesn’t appear to reduce breast tumor growth in mice without ovaries. This doesn’t mean it won’t have an effect in other situations — we just don’t have the evidence to say.