Researchers in Vietnam studied over 4,000 people to see if eating certain healthy fats could protect against stomach cancer. They found that people who ate more monounsaturated fats—the good fats found in foods like olive oil, avocados, and nuts—had a significantly lower risk of developing stomach cancer. The more of these healthy fats people consumed, the better the protection appeared to be. This discovery could help people in developing countries reduce their stomach cancer risk through simple dietary changes.

The Quick Take

  • What they studied: Whether eating monounsaturated fats (healthy fats with one bend in their chemical structure) could help prevent stomach cancer
  • Who participated: 1,182 Vietnamese people who had been diagnosed with stomach cancer and 2,965 healthy Vietnamese people without stomach cancer, matched for comparison
  • Key finding: People who ate the most monounsaturated fats had about 57% lower risk of stomach cancer compared to those who ate the least. The protection increased steadily as people ate more of these healthy fats.
  • What it means for you: Eating more foods rich in monounsaturated fats like olive oil, avocados, and nuts may help reduce stomach cancer risk. However, this study was done in Vietnam, so results may differ in other populations. Talk to your doctor before making major dietary changes.

The Research Details

This was a case-control study, which means researchers compared two groups of people: those who had stomach cancer and those who didn’t. They asked both groups detailed questions about what they ate using a food frequency questionnaire—basically a checklist of foods with portion sizes. By comparing eating patterns between the two groups, researchers could see if certain foods were linked to lower cancer risk.

The study took place in Vietnam and included 1,182 people newly diagnosed with stomach cancer and 2,965 healthy people without cancer. Researchers carefully matched the healthy people to the cancer patients by age and sex to make fair comparisons. They then used statistical methods to calculate how much lower the cancer risk was for people eating more monounsaturated fats.

Monounsaturated fats are a specific type of healthy fat found mainly in plant oils, nuts, seeds, and avocados. These fats have one ‘bend’ in their molecular structure, which gives them special health properties like reducing inflammation and lowering cholesterol.

Case-control studies are useful for studying diseases like cancer because they compare people who already have the disease with similar people who don’t. This helps identify dietary patterns that might protect against the disease. By studying a specific population in Vietnam, researchers could account for local eating habits and genetic differences that might affect cancer risk differently than in other countries.

This study has several strengths: it included a large number of participants (over 4,000 people), used a validated food questionnaire to measure diet, and found a clear pattern where more fat intake meant lower cancer risk. However, because it’s a case-control study, researchers had to rely on people remembering what they ate in the past, which can be inaccurate. The study was done only in Vietnam, so results may not apply equally to other populations with different diets and genetics.

What the Results Show

The main finding was clear and strong: people who ate more monounsaturated fats had significantly lower stomach cancer risk. When researchers compared people eating the most monounsaturated fats to those eating the least, the high-fat group had only 43% of the cancer risk—meaning a 57% reduction in risk.

The protection increased steadily as people ate more of these healthy fats. People in the second-highest fat group had 35% lower risk, those in the middle group had 47% lower risk, and those in the second-lowest group had 14% lower risk. This steady pattern suggests the relationship is real and not due to chance.

This protective effect was similar for both men and women, and it worked equally well for younger people (under 60) and older people (60 and above). The consistency across different groups strengthens the finding.

The study found that the protective effect of monounsaturated fats was consistent across all subgroups examined. Whether looking at men or women separately, younger or older adults, or different regions within Vietnam, the pattern remained the same. This consistency suggests the benefit isn’t limited to one particular group but may apply broadly.

Previous research on monounsaturated fats and stomach cancer has shown mixed results across different countries. This study adds important evidence from a Vietnamese population, where stomach cancer rates are higher than in many Western countries. The strong protective effect found here is more convincing than some previous studies, possibly because Vietnamese diets and the study population are different from those in other countries.

The main limitation is that this study relied on people remembering what they ate, which can be inaccurate. People with stomach cancer might remember their diet differently than healthy people, which could bias the results. The study was done only in Vietnam, so the findings may not apply equally to people in other countries with different diets, genetics, and lifestyles. Additionally, while the study shows an association between monounsaturated fats and lower cancer risk, it cannot prove that these fats directly cause the risk reduction—other factors in people’s diets or lifestyles could be responsible.

The Bottom Line

Based on this research, increasing your intake of monounsaturated fats through foods like olive oil, avocados, nuts, and seeds appears to be a reasonable dietary strategy for stomach cancer prevention. This recommendation has moderate confidence because the study showed a clear pattern, but it was conducted in one population. The evidence suggests aiming to include these healthy fats regularly in your diet rather than occasionally.

This research is most relevant to people of Vietnamese descent or those living in similar regions with comparable diets and stomach cancer rates. It’s also useful for anyone concerned about stomach cancer prevention, particularly those with family history of the disease. People with existing digestive conditions should consult their doctor before significantly increasing fat intake. This research is less directly applicable to people in Western countries where stomach cancer rates are much lower and diets are already different.

Cancer prevention is a long-term process. You wouldn’t expect to see immediate health changes from dietary modifications. Benefits from increased monounsaturated fat intake would likely develop over months to years of consistent dietary changes. Think of this as a long-term investment in your health rather than a quick fix.

Want to Apply This Research?

  • Track daily servings of monounsaturated fat sources: count servings of olive oil, avocados, nuts, seeds, and fatty fish. Aim to include at least 2-3 servings daily and monitor consistency over weeks and months.
  • Replace saturated fats (butter, fatty meats) with monounsaturated fat sources in 2-3 meals per week, gradually increasing to daily inclusion. Start by adding olive oil to salads, snacking on nuts, or including avocado in meals.
  • Weekly check-ins on monounsaturated fat intake consistency, monthly reviews of dietary pattern changes, and quarterly assessments of overall diet quality. Track not just the fats themselves but also overall diet improvements and how you feel.

This research suggests a potential association between monounsaturated fat intake and reduced stomach cancer risk in Vietnamese populations, but it does not prove cause-and-effect. These findings should not replace medical advice from your healthcare provider. If you have concerns about stomach cancer risk, a family history of cancer, or existing digestive conditions, consult your doctor before making significant dietary changes. This study was conducted in Vietnam and may not apply equally to all populations. Always discuss dietary modifications with a healthcare professional, especially if you have existing health conditions or take medications.