Processed food linked to multiple cancer risk

Dietary intake of the common food additive nitrates and nitrites, trans fatty acids, and artificial sweeteners was associated with an increased risk of multiple cancers, according to data from the large NutriNet-Santé cohort presented at SABCS 2021.

The population-based prospective cohort study involved more than 100,000 adults in France, whose 24h-dietary records were gathered to investigate the relationship between nutrition and health.

Compared with participants with no consumption of food additive, high intake of nitrates was associated with a significantly higher risk of breast cancer (hazard ratio [HR], 1.24; p=0.02), while nitrites was associated with an excess risk of prostate cancer (HR, 1.58; p=0.008) — especially for sodium nitrite (HR, 1.62; p=0.004). [SABCS 2021, abstract P1-09-01]

By contrast, no such associations were seen with exposure to nitrates and nitrites from natural sources.

A separate analysis focused on sweetener consumption also found similarly elevated risk of cancers. [SABCS 2021, abstract P1-09-02]

In general, participants who reported high intake of artificial sweeteners (above the median exposure) had a greater risk of developing cancer overall compared with individuals with no exposure (HR, 1.12; p-trend=0.005).

In particular, the increase in cancer risk was most prominent with the artificial sweeteners aspartame (HR, 1.20; p=0.001) and acesulfame-K (HR, 1.18; p=0.003). Specifically, both types of sweeteners were associated with increased risk of breast cancer (HR, 1.33; p=0.007 for aspartame and HR=1.39; p=0.003 for acesulfame-K) and obesity-related cancers (HR, 1.22; p=0.01 and HR, 1.23; p=0.01, respectively).

“In this large prospective cohort, artificial sweeteners [especially aspartame and acesulfame-K], which are found in >10,000 foods and beverage references worldwide, were associated with increased cancer risk,” said the researchers.

“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,” they stated.

Using the same cohort, the researchers conducted another study on the relationship between trans fatty acids and cancer risk. [SABCS 2021, abstract P3-12-35]

They found that individuals in the highest intake quartile of total trans fatty acids were more likely to develop prostate cancer than those in the lowest intake quartile (HR, 1.27; p-trend=0.005).

When stratified by the type of trans fatty acids, ruminant trans fatty acids were associated with an excess risk of cancer overall (HR, 1.16; p-trend=0.07), particularly for the conjugated linoleic acid isomers (HR, 1.19; p-trend=0.04).

Specifically, there was an excess risk of breast cancer with high trans fatty acid intake (HR, 1.35; p-trend=0.01 for ruminant trans fatty acids; HR, 1.29; p-trend=0.048 for conjugated linoleic acid isomers) — especially in premenopausal women (HR, 1.68; p-trend=0.02 and HR, 2.013; p-trend=0.003, respectively).

In addition, industrial trans fatty acids were also associated with an increased risk of cancer overall (HR, 1.18; p-trend=0.02 for transdocosenoic acid), breast cancer (HR, 1.30; p-trend=0.01 for isomer 18:2t; HR, 1.28; p-trend=0.02 for hexadecenoic acid), and prostate cancer (HR, 1.52; p-trend=0.07 for transdocosenoic acid).

“These results support the WHO's goal of achieving industrially produced trans fatty acids elimination from food supplies,” said the researchers. “Meanwhile, the consumption of food products containing partially-hydrogenated oils should be avoided.”