Cancer Risk Tied to Some Manufactured Foods

SAN ANTONIO – In a large prospective, international cohort, food additive nitrates and nitrites, artificial sweeteners (especially aspartame and acesulfame-K), and dietary trans fatty acids were found to be associated with increased cancer risks.

The findings were reported in three poster presentations (P1-09-01, P1-09-02 and P3-12-35) at the 2021 San Antonio Breast Cancer Symposium from the ongoing French NutriNet-Santé web-based study of 171,000 people that was launched in France in 2009 to investigate nutrition and health relationships. The authors of the analyses note that while evidence of deleterious health effects has been established for the dietary focus of their studies, and cancer risks have been suspected, strong evidence of a cancer association has been lacking.

Nitrates and nitrites are used in processed meats to increase shelf life and to avoid bacterial growth, said Eloi Chazelas, PhD, Nutritional Epidemiology Research Team (EREN) at Sorbonne Paris Nord University. Dr. Chazelas looked at consumption of nitrites and nitrates through repeated 24 hour dietary records, linked to a comprehensive food composition database. The study’s main outcome measure was adjusted associations between nitrite and nitrate exposures and the risk of cancer (overall and by main cancer sites).

During follow-up, 966 breast and 400 prostate cancers were diagnosed among 3,311 first incident cancer cases. Breast cancer risk was elevated (HR=1.24 , P=0.02) among higher consumers of nitrates from food additives, especially with potassium nitrate consumption (HR=1.25 [1.04-1.50], P=0.01). Elevated prostate cancer risk was associated with nitrites (HR=1.58 [1.14-2.18], P=0.008), specifically for sodium nitrite (HR=1.62 [1.17-2.25], P=0.004). Nitrates and nitrites from natural sources were not associated significantly with higher cancer risk, Dr. Chazelas said.

He and his team found that food additive nitrates were positively associated with breast cancer risk, and food additive nitrites were positively associated with prostate cancer risk. “While these results need confirmation in other large-scale prospective studies, they provide new insights in a context of lively debate around the ban of nitrite additives in the food industry,” said Dr. Chazelas, who is a doctoral candidate at Sorbonne Paris Nord University.

In “Breast and prostate cancer risk associated with nitrites and nitrates from food additives (P1-09-01),” the study included 102,046 adults from the French NutriNet-Santé prospective cohort (2009-2021). It examined associations between artificial sweetener intakes (total from all dietary sources, the most frequently consumed ones [aspartame e951, acesulfame-K e950 and sucralose e955]) and cancer risk (overall and by sites: breast, prostate and obesity-related cancers).

Overall cancer risk in people who consumed higher amounts of total sweeteners (i.e. above the median exposure in consumers) was elevated (n=2,527 cases, hazard ratio=1.12, 95 percent confidence interval=1.00-1.25, P-trend=0.005), especially for aspartame (HR=1.20 [1.05-1.38] P=0.001) and acesulfame-K (HR=1.18 [1.04-1.34] P=0.003). Elevated breast cancer risks (among 723 cases) were observed for total sweeteners (HR=1.25 [1.02-1.53] P=0.01), for aspartame (HR=1.33 [1.05-1.69] P=0.007), and for acesulfame-K (HR=1.39 [1.11-1.74] P=0.003). Also, obesity-related cancers (1,509 cases) were increased for total sweeteners (HR=1.16 [1.00-1.33] P=0.02), for aspartame (HR=1.22 [1.02-1.45] P=0.01) and for acesulfame-K (HR=1.23 [1.04-1.45] P=0.01).

Artificial sweeteners are found in more than 10,000 foods and beverages, said Charlotte Debras, a doctoral candidate in nutritional epidemiology at Sorbonne Paris Nord University. “These findings provide important and novel insights for the ongoing re-evaluation of food additive sweeteners by the European Food Safety Authority and other health agencies globally,” she said.

Trans Fatty Acid Intakes and Cancer Risk

Investigating associations between trans fatty acid intake (total ruminant [rTFAs], industrial [iTFAs], and corresponding specific isomers and cancer risk), the analysis of Gaëlle Wendeu-Foyet, PhD, Sorbonne Paris Nord University, found a total of 3,374 incident cancer cases (982 breast, 405 prostate) in an overall population of 104,909. Dietary intake of total TFAs was associated with higher prostate cancer risk (hazard ration for quartile 4 versus 1: 1.27, 1.11-1.77 P-trend=0.005). Also, rTFAs were associated with increased overall cancer risk (1.16, 1.02-1.32 P-trend=0.07), in particular the conjugated linoleic acid isomers (CLA) (1.19, 1.04-1.36 P-trend=0.04). These associations were specifically observed for breast cancer (rTFAs: 1.35, 1.06-1.72 P-trend=0.01; CLA: 1.29, 1.00-1.66 P-trend=0.048), in particular before menopause (rTFAs: 1.68, 1.06-2.67 P-trend=0.02; CLA: 2.013, 1.25-3.23 P-trend=0.003). Several iTFAs were associated with overall (1.18, 1.06-1.31 P-trend=0.02 for transdocosenoic acid), breast (isomer 18:2t: 1.30, 1.06-1.58 P-trend=0.01; hexadecenoic acid: 1.28, 1.05-1.56 P-trend=0.02) and prostate (transdocosenoic acid: 1.52, 1.09-2.12 P-trend=0.07) cancer risks.

“These results support the WHO’s goal of achieving elimination from food supplies of industrially produced TFAs,” Dr. Foyet said. “The consumption of food products containing partially hydrogenated oils should be avoided.”

Nutrition, along with avoiding tobacco intake, is one of the main modifiable risk factors for chronic diseases. “There is a lot at stake in terms of prevention. This requires a combination of actions at the individual level to the public level by informing the public through food labeling,” Debras said.

“It also requires influencing the context in which citizens evolve by encouraging manufacturers to improve their products (pricing policies, commitment charters for product reformulation, etc.), and limiting advertising and marketing for products of poor nutritional quality (especially among children),” she said.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.