The Role of Added Sugar and Salt in Dietary Patterns Linked to Stomach Cancer

Recent findings from a Brazilian study published in BMC Medicine suggest that added sugars and sodium play significant roles in the dietary patterns associated with stomach cancer, specifically gastric adenocarcinoma. This research emphasizes how unhealthy eating habits can increase cancer risk, while also revealing unexpected implications for individuals who adhere to what is typically considered a healthy diet.

The study categorizes dietary patterns into two distinct types: unhealthy dietary patterns (UDP) characterized by high consumption of processed meats, sugary carbonated beverages, and fast food, and healthy dietary patterns (HDP), which are rich in fruits and vegetables and low in sodium. Researchers found that individuals following an unhealthy dietary pattern have an elevated risk of developing gastric cancer, with the contribution of added sugars ranging from 7% to 21% of this risk. Interestingly, while a healthy diet typically lowers cancer risk, excessive sodium intake was identified as the primary factor mediating the risk of gastric adenocarcinoma among those with healthy eating habits.

Utilizing a comprehensive approach, the study involved a large sample of 1,751 individuals across four Brazilian cities--São Paulo, Goiânia, Fortaleza, and Belém--each with varying gastric cancer incidence rates. Gastric adenocarcinoma, which primarily develops in the stomach's innermost layer, accounts for over 90% of stomach cancer cases in Brazil. The National Cancer Institute (INCA) estimates approximately 21,000 new cases of stomach cancer in Brazil from 2023 to 2025, making it the sixth most prevalent cancer in the country, with a staggering five-year mortality rate of 75%.

Researchers employed exploratory factor analysis to identify dietary consumption patterns through a detailed food frequency questionnaire tailored for the diverse regions of Brazil. By performing a mediation analysis, the study aimed to clarify the direct and indirect effects of these dietary patterns on the risk of developing gastric cancer.

In discussing the unique dietary habits across Brazil, researchers noted that cultural differences significantly influence eating behaviors. For instance, individuals in Belém may have distinct dietary patterns compared to those in Goiânia or São Paulo, yet all can lead to similar health outcomes.

One of the lead researchers highlighted the significance of their findings in understanding the mechanisms behind gastric cancer through an epidemiological lens, which can inform public health strategies.

In terms of dietary components, sodium's role in carcinogenesis is particularly noteworthy. High sodium intake negatively impacts the gastric mucosa, leading to inflammation and facilitating the colonization of the Helicobacter pylori bacteria, which is linked to gastritis and other gastric complications. Chronic irritation of the gastric mucosa due to excessive sodium can lead to serious conditions such as atrophic gastritis, ultimately heightening cancer risk.

The study aligns with a national food survey indicating that approximately 60% of Brazilian adults exceed recommended sodium intake limits, primarily due to common foods such as bread, beans, rice, and various meats. Additionally, many products labeled as 'whole grain' also contain unexpectedly high sodium levels.

Addressing public health concerns, the researchers emphasized the need for comprehensive nutritional education. They argued for initiatives aimed at raising awareness about dietary risks, advocating for a balanced approach to informing the public about healthy eating practices without discouraging cultural dietary preferences.

Furthermore, Brazil's recent implementation of food labeling regulations aims to enhance consumer understanding of nutritional information. These regulations require clear indications on products containing high levels of sodium or added sugars, empowering consumers to make informed dietary choices.

To mitigate the risk of gastric cancer, the World Health Organization (WHO) recommends limiting sodium intake to less than 2 grams per day, which translates to approximately five small teaspoons of salt. However, current consumption patterns in Brazil nearly double this recommendation. For added sugars, the WHO advises that these should not exceed 10% of total daily caloric intake, equating to about 50 grams or ten teaspoons for an average 2,000-calorie diet.

In conclusion, the study advocates for targeted public health strategies aimed at reducing sodium and sugar consumption to lower the risk of gastric cancer, emphasizing the importance of informed dietary choices.