Page 238 - EJMO-9-1

Eurasian Journal of Medicine and
Oncology
Grains, legumes, and gastric cancer

collectively suggest mechanisms by which refined grains, glycemic effects seen with refined grains. In contrast,
such as white bread, may increase GC risk. One key refined grains digest more quickly, causing glycemic
mechanism involves the rapid glycemic response triggered overload, increased plasma insulin, and elevated IGF-I, all
14
by refined grains, leading to increased plasma insulin of which can promote tumor cell growth. However, our
levels and compensatory elevations in IGF-I. 13,14 IGF-I, data did not show a protective effect from whole grains,
a mitogenic stimulant, promotes tumor cell growth and likely due to the low overall consumption of whole-
has been linked to cancer development. Refined grains grain foods in Jordan. This aligns with findings from
are also more easily digestible than whole grains, leading other studies where whole grains were protective only in
to glycemic overload that can exacerbate these effects. populations with consistent intake. 13
14
Furthermore, refined grain consumption is associated Although bulgur was unexpectedly insignificant in our
with deficiencies in protective micronutrients, including B study, it is important to note its potential role in cancer
vitamins and dietary fiber, which may reduce the stomach’s prevention based on other studies. For instance, a study
buffering capacity and increase vulnerability to mechanical by Tayyem et al. examined the relationship between
29
damage and acid-catalyzed nitrosation, further elevating bulgur and the risk of colorectal cancer. The study found
GC risk. 23,24 that while refined grains were associated with a higher
In contrast to white bread, our study found an inverse risk of colorectal cancer, whole grains, including bulgur,
association between moderate rice consumption and GC demonstrated a protective trend. Although the protective
risk in the second quartile of intake (OR = 0.38, p = 0.045), effect of bulgur itself was not statistically significant, the
although this protective effect was not observed in higher findings suggest that bulgur, as part of a whole-grain diet,
quartiles where rice intake showed a non-significant risk may contribute to reduced cancer risk, particularly when
increase. This finding differs from a case–control study compared to the elevated risks linked to refined cereals. 29
in Korea (440 cases and 485 controls), which reported a The association between grain type and GC risk has
positive link between rice consumption and GC risk. Our been widely explored in epidemiological studies, with
25
findings may reflect the impact of balanced carbohydrate notable regional variations. In Mediterranean populations,
intake, where moderate rice consumption avoids the adherence to the Mediterranean diet – characterized
glycemic overload and insulin spikes associated with cancer by high consumption of whole grains, legumes, and
development. In addition, rice is often consumed in Jordan vegetables – has been consistently associated with reduced
with other dietary components such as vegetables and GC risk. This protective effect is attributed to the high
vegetable stews, which may help buffer carcinogenic effects fiber and antioxidant content of these foods, which reduce
at moderate levels but could elevate risk when consumed inflammation and oxidative stress. For example, a meta-
in larger amounts. In higher rice consumption quartiles analysis of Mediterranean diet adherence reported a
24
(Q3 and Q4), the increased but non-significant risk may 30% reduction in GC risk among high-adherence groups
relate to practices in Jordan, such as reheating rice, which compared to low-adherence groups. Moreover, the
9
may increase exposure to bacterial contamination and Mediterranean dietary pattern demonstrated a significant
reduce nutrient quality. In contrast, studies from Asian reduction in the risk of GC in the third and fourth quartiles
23
populations, particularly in Korea and China, showed of participants in our study. After adjusting for factors
30
mixed findings regarding rice consumption. While some such as age, sex, BMI, smoking, marital status, total energy
studies associate white rice with increased GC risk due to its intake, education level, and physical activity, the ORs of
high glycemic index, others highlight the protective effects the third and fourth quartiles were 0.394 (95% CI: 0.211
of rice consumed alongside vegetables and legumes. 24,25 – 0.736) and 0.212 (95% CI: 0.107 – 0.419), respectively. 30
26
27
Research from countries such as Mexico and Turkey Regarding green peas, our study found a significant
suggests that refined grain consumption may increase association between green pea consumption and an
GC risk, while other studies highlight the protective increased risk of GC, particularly in the third quartile,
effects of whole grains. Whole grains, rich in dietary fiber, with an OR of 2.19 (CI, p = 0.004). This finding contradicts
vitamins, and minerals, may lower GC risk compared to previous studies that suggest a protective role of green peas
refined grains, which lack nutrient-dense bran and germ against cancer. This result may be better understood when
components. 10,14,28 A meta-analysis involving over 2.6 considering the typical dietary patterns in Jordan, where
million participants in the United States indicated that green peas are often consumed in dishes such as “Ouzi”
higher whole-grain intake is associated with reduced and “beef peas stew.” These meals typically combine
GC risk. Whole grains are linked to reduced systemic green peas with rice, which results in a high-starch, low-
28
inflammation and lower energy intake, without the rapid fiber diet. High-starch diets can lead to increased gastric

Volume 9 Issue 1 (2025) 230 doi: 10.36922/ejmo.6606