Dietary PUFA consumption protective against HNC, oesophageal adenocarcinoma

Eating fish and shellfish, especially nonfried fish high in n-3 and long-chain n-3 polyunsaturated fatty acids (PUFAs), may reduce the risk of head and neck cancer (HNC) and oesophageal adenocarcinoma (EA), according to a recent study.

Researchers collected baseline dietary data from 468,952 individuals participating in the NIH-AARP Diet and Health Study (1995-2011). Line items for fish intake comprised fried fish or fish sticks (including fried seafood or shellfish); other fish or seafood (not fried), such as flounder, cod, shrimp, clams, crabs, lobster and others; and tuna (canned) including in salads, sandwiches or casseroles. Total fish/shellfish intake included all types of finfish, shellfish and canned tuna.

Over a median follow-up of 15.5 years, there were 2,453 incident cases of HNC, 855 of EA, 267 of oesophageal squamous cell carcinoma (ESCC), 603 of gastric cardia (GCA), and 631 of gastric noncardia (NCGA) cancers.

On Cox proportional hazards regression analysis, the highest vs lowest intake quintile of long-chain n-3 PUFAs was associated with about 20-percent lower risks of HNC (hazard ratio [HR], 0.81, 95 percent confidence interval [CI], 0.71–0.92; p=0.0002) and EA (HR, 0.79, 95 percent CI, 0.64–0.98; p=0.03). Associations seen for nonfried fish were similar, but only for high intake.

Additionally, the ratio of long-chain n3:n6 was associated with a decreased HNC and EA risk. There were no consistent associations observed for gastric cancer.

The present data provides epidemiologic support that dietary modulation of inflammation, possibly through lipid mediators, may be an important metabolic pathway in the development of HNC and EA, according to the researchers. More studies are needed before definitive conclusions can be drawn about the role of dietary PUFAs and upper gastrointestinal cancers.