Researchers in South Korea studied over 44,000 adults to see how different types of plant-based eating affected how long people lived. They tracked people for about 8 years and found that those who ate more healthy plant foods—like whole grains, fruits, and vegetables—had a lower chance of dying from any cause, especially heart disease. Interestingly, eating lots of unhealthy plant foods like sugary snacks and refined grains actually increased the risk. The key takeaway: it’s not just about eating plants, but eating the right kinds of plants that matters for living a longer, healthier life.

The Quick Take

  • What they studied: Whether eating more plant-based foods helps people live longer, and whether the type of plant foods matters (healthy vs. unhealthy plant foods)
  • Who participated: Over 44,000 Korean adults who completed detailed food diaries. Researchers followed them for an average of 8.3 years to see who stayed healthy and who passed away
  • Key finding: People who ate the most healthy plant foods had a 18% lower risk of dying from any cause and a 37% lower risk of dying from heart disease compared to those who ate the least. However, people who ate the most unhealthy plant foods had a 90% higher risk of heart disease death
  • What it means for you: Eating more plants is good for you, but focus on whole foods like vegetables, fruits, and whole grains rather than processed plant-based snacks and refined carbohydrates. This may help you live longer and reduce heart disease risk, though individual results vary based on overall lifestyle

The Research Details

This was a long-term follow-up study using data from South Korea’s national health surveys between 2007 and 2015. Researchers asked over 44,000 adults what they ate in a single day, then tracked whether those people stayed alive or passed away over the next several years (through 2019). They created three different ‘plant-based diet scores’ to measure: (1) how much plant food someone ate overall, (2) how much healthy plant food they ate (vegetables, fruits, whole grains, legumes), and (3) how much unhealthy plant food they ate (refined grains, sugary drinks, desserts). They then used statistical methods to see if people with higher scores in each category had different risks of dying.

The researchers were careful to account for other factors that affect how long people live, like age, exercise, smoking, and income. They used a method called ‘Cox proportional hazards modeling’ which is a standard way to compare death rates between groups over time. This approach allowed them to see the independent effect of plant-based eating separate from other lifestyle factors.

This research approach matters because it follows real people over many years rather than just looking at one moment in time. This gives us much stronger evidence about whether eating plants actually affects how long people live. By separating healthy plant foods from unhealthy ones, the study shows that not all plant-based eating is equal—the quality matters just as much as the quantity

This study has several strengths: it included a very large number of people (44,291), followed them for years, and used official death records rather than relying on people to report their own health. The study was published in Scientific Reports, a reputable journal. However, the study was done in South Korea, so results may not apply equally to other populations with different diets and genetics. Also, the study only measured what people ate on one day, which might not represent their typical eating habits perfectly

What the Results Show

During the 8+ year follow-up period, 2,302 people died. People who ate the most healthy plant foods had a 23% lower chance of dying from any cause compared to those who ate the least (this difference was statistically significant, meaning it’s unlikely to be due to chance). For heart disease deaths specifically, the benefit was even stronger—a 37% lower risk.

In contrast, people who ate the most unhealthy plant foods (like sugary snacks and refined grains) had a 17% higher risk of dying from any cause and a 90% higher risk of dying from heart disease. These increases were also statistically significant.

The overall plant-based diet score (combining all plant foods) showed a 23% lower risk of death from any cause. The researchers found a clear trend: as people ate more healthy plants, their risk went down steadily. As people ate more unhealthy plants, their risk went up steadily.

The study found that the protective effect of healthy plant foods was strongest for heart disease deaths, suggesting that plant-based eating particularly benefits heart health. The harmful effect of unhealthy plant foods was also most pronounced for heart disease, indicating that refined carbohydrates and sugary foods are especially risky for the heart. The study did not find significant associations with cancer deaths, suggesting the plant-based diet effect is primarily related to heart health

This research aligns with previous studies showing that plant-based diets are associated with lower heart disease risk. However, this study adds important nuance by distinguishing between healthy and unhealthy plant foods. Previous research sometimes grouped all plant foods together, which could mask the harmful effects of processed plant foods. This study’s finding that unhealthy plant foods increase mortality risk is consistent with growing evidence that refined carbohydrates and ultra-processed foods are harmful, even when they’re technically plant-based

The study measured diet using only one day of food recall, which may not represent what people typically eat. The study was conducted in South Korea, so results may differ for people of other ethnicities with different traditional diets. The researchers couldn’t prove that the diet caused the longer lifespan—only that it was associated with it. People who eat healthy plant foods might also exercise more or have other healthy habits. The study couldn’t account for all possible factors affecting lifespan, though researchers tried to control for major ones

The Bottom Line

Based on this research (moderate confidence level), consider increasing your intake of whole plant foods like vegetables, fruits, whole grains, beans, and legumes. At the same time, reduce consumption of processed plant foods like sugary drinks, refined grains, and plant-based desserts. This approach may help you live longer and reduce your risk of heart disease. However, this should be part of an overall healthy lifestyle that includes exercise, not smoking, and managing stress

This research is relevant to anyone interested in living longer and preventing heart disease, particularly adults. It’s especially important for people with family histories of heart disease or those already at risk for cardiovascular problems. However, if you have specific health conditions or dietary restrictions, consult with your doctor or dietitian before making major diet changes. This research doesn’t mean you need to become completely vegetarian—it shows that eating more plant foods, especially healthy ones, is beneficial

Health benefits from dietary changes typically take weeks to months to become noticeable (like improved energy or digestion), but the major benefits for heart health and longevity develop over years. Don’t expect immediate results, but consistent healthy eating habits compound over time. Research suggests that meaningful cardiovascular benefits can develop within 3-6 months of sustained dietary improvement

Want to Apply This Research?

  • Track daily servings of healthy plant foods (vegetables, fruits, whole grains, legumes) separately from processed plant foods. Aim to log at least 5 servings of whole plant foods daily while keeping processed plant foods to fewer than 2 servings per day
  • Set a weekly goal to try one new whole plant food you haven’t eaten before—whether it’s a new vegetable, grain, or legume. Use the app to log it and rate how much you enjoyed it, building a personalized list of healthy plant foods you actually like eating
  • Review your plant food intake weekly using the app’s reports. Track the ratio of healthy to unhealthy plant foods consumed. Set monthly challenges to gradually increase healthy plant food servings while decreasing processed plant foods. Monitor energy levels and any health markers (like blood pressure if you track it) to notice personal benefits over time

This research shows an association between plant-based eating and longer lifespan, but cannot prove that diet alone causes these outcomes. Individual results vary based on genetics, overall lifestyle, and other health factors. This information is for educational purposes and should not replace professional medical advice. If you have existing health conditions, take medications, or are considering major dietary changes, consult with your healthcare provider or registered dietitian before making changes. This study was conducted in a Korean population; results may not apply equally to all ethnic groups or populations with different baseline diets.