Saturated fat intake ups risk of several cancers

Individuals with high intakes of total and saturated fats are at increased risks of several cancers, according to a study. On the other hand, polyunsaturated fat intake appears protective.

A team of investigators searched PubMed, Embase, Web of Science, and the Cochrane Library from inception through September 2025 for systematic reviews and meta-analyses of observational or interventional studies assessing dietary fat intakes in relation to cancer incidence. They assessed the quality of methodology using AMSTAR-2 and evaluated evidence certainty with GRADE.

Twenty-three systematic reviews and meta-analyses met the eligibility criteria.

Higher intake of total fat correlated with elevated risks of bladder (relative risk [RR], 1.28, 95 percent confidence interval [CI], 1.04‒1.58), breast (RR, 1.10, 95 percent CI, 1.05‒1.16), gastric (RR, 1.18, 95 percent CI, 1.00‒1.39), and esophageal cancer (RR, 1.31, 95 percent CI, 1.13‒1.49) and non-Hodgkin lymphoma (RR, 1.26, 95 percent CI, 1.12‒1.42).

Saturated fatty acid intake also correlated with increased risks of breast (RR, 1.10, 95 percent CI, 1.03‒1.17), gastric (RR, 1.31, 95 percent CI, 1.09‒1.58), liver (RR, 1.34, 95 percent CI, 1.06‒1.69), and esophageal cancer (RR, 1.88, 95 percent CI, 1.28‒2.77).

Furthermore, monounsaturated fatty acid intakes showed a positive association with esophageal (RR, 1.70, 95 percent CI, 1.01‒2.84) and breast cancer (RR, 1.08, 95 percent CI, 1.01‒1.16) but an inverse association with skin cancer (RR, 0.90, 95 percent CI, 0.85‒0.96). Notably, polyunsaturated fatty acid intake appeared to protect against gastric cancer (RR, 0.77, 95 percent CI, 0.65‒0.92).

“Dietary fats may influence carcinogenesis through pathways involving lipid metabolism, oxidative stress, and inflammation,” the investigators said.