Researchers in China studied over 3,700 older adults to see if eating watermelon could help prevent muscle loss, a common problem in aging. They found that people who ate watermelon regularly had significantly lower chances of developing sarcopenia—a condition where muscles weaken and shrink with age. Those eating watermelon 2-3 times per week had about half the risk compared to people who never ate it. While this is promising news, the study only shows a connection between watermelon and muscle health, not proof that watermelon directly causes the benefit. Scientists think a special compound in watermelon called L-citrulline might be responsible for protecting muscles.

The Quick Take

  • What they studied: Whether eating watermelon helps older people maintain their muscle strength and mass as they age
  • Who participated: 3,733 older adults in Tianjin, China with an average age of about 66 years old
  • Key finding: Older adults who ate watermelon 2-3 times per week had 51% lower chances of developing muscle loss compared to those who never ate watermelon. Even eating it once a week showed benefits with a 28% lower risk.
  • What it means for you: Adding watermelon to your diet a few times a week may help protect your muscles as you get older, though more research is needed to prove this works. This is especially relevant for older adults concerned about maintaining strength and independence.

The Research Details

This was a cross-sectional study, which means researchers took a snapshot in time of a large group of older Chinese adults and looked at their eating habits and muscle health. They asked participants how often they ate watermelon using a detailed food questionnaire, then divided them into three groups: those who almost never ate it, those who ate it once a week or less, and those who ate it 2-3 times per week. The researchers then measured who had sarcopenia (muscle loss) using standard medical tests.

The scientists used statistical methods to account for other factors that might affect muscle health, including age, exercise habits, smoking, medical conditions, and overall diet quality. This helps isolate whether watermelon specifically was connected to better muscle health or if other factors were responsible.

This approach is valuable because it looks at real people in their everyday lives rather than just studying isolated nutrients in a lab. By examining a large population of 3,700+ people, the findings are more likely to apply to other older adults. The study also looked at dose-response—meaning they checked if eating more watermelon led to better results, which strengthens the evidence.

The study was conducted in a real-world population with careful measurement of muscle health using established medical criteria. The large sample size and adjustment for multiple factors that could influence results are strengths. However, because this is a cross-sectional study, it shows association (connection) rather than causation (proof that watermelon causes the benefit). People with better muscle health might simply choose to eat healthier foods like watermelon, rather than watermelon protecting their muscles.

What the Results Show

Among the 3,733 older adults studied, about 12.6% had sarcopenia (muscle loss). When comparing watermelon eaters to non-eaters, the results were striking: people who ate watermelon once a week or less had 28% lower odds of having sarcopenia. Those who ate it 2-3 times per week had even better results—51% lower odds of muscle loss.

The relationship showed a clear dose-response pattern, meaning more watermelon consumption was linked to better muscle health. This pattern strengthens the evidence because it suggests a real biological relationship rather than a random finding. The statistical significance was very strong (p < 0.001), meaning there’s less than a 0.1% chance these results happened by random chance.

These findings suggest that regular watermelon consumption may be protective against age-related muscle loss in older adults. The researchers believe this may be due to L-citrulline, an amino acid in watermelon that plays a role in muscle protein production and blood flow.

The study found that the protective effect of watermelon was consistent across different age groups and remained significant even after accounting for other dietary factors and lifestyle habits. This suggests watermelon’s benefit isn’t simply because people who eat watermelon have better overall diets, but rather something specific about watermelon itself may be helpful.

This research adds to growing evidence that whole foods—rather than single nutrients taken as supplements—may be most beneficial for health. Previous studies have shown that L-citrulline and related compounds support muscle function, but this is one of the first large population studies specifically examining watermelon and age-related muscle loss. The findings align with research showing that plant-based foods rich in bioactive compounds help maintain muscle health in aging.

The biggest limitation is that this study shows association, not causation. We cannot prove that watermelon prevents muscle loss—only that people who eat watermelon tend to have less muscle loss. It’s possible that people with better muscle health simply choose to eat more watermelon and other healthy foods. The study was conducted only in China, so results may not apply equally to other populations with different genetics or diets. Additionally, watermelon consumption was based on self-reported eating habits, which can be inaccurate. The study was also a snapshot in time, so we don’t know if eating watermelon over many years actually prevents muscle loss.

The Bottom Line

Based on this research, older adults may benefit from including watermelon in their diet 2-3 times per week as part of a healthy eating pattern. However, this should not replace established muscle-building strategies like resistance exercise and adequate protein intake. The evidence is moderate—this is one good study, but more research is needed before making strong claims. Watermelon should be viewed as a potentially helpful addition to a healthy lifestyle, not a treatment for existing muscle loss.

This research is most relevant for older adults (65+) concerned about maintaining muscle strength and independence. It’s also interesting for anyone interested in functional foods and healthy aging. People with existing sarcopenia should discuss dietary changes with their doctor. Those with diabetes should be mindful of watermelon’s sugar content, though the fiber helps moderate blood sugar impact.

If watermelon does help preserve muscle, benefits would likely develop gradually over months to years of regular consumption, not days or weeks. Maintaining muscle requires consistent effort over time through both diet and physical activity.

Want to Apply This Research?

  • Track watermelon consumption frequency (times per week) alongside a simple muscle strength measure like how many stairs you can climb comfortably or how easily you can stand from a chair. Record weekly for 8-12 weeks to see if patterns emerge.
  • Set a goal to eat watermelon 2-3 times per week during summer and fall months when it’s fresh and affordable. Add it to your grocery list on shopping days, or set phone reminders to include it in meals or snacks.
  • Track watermelon intake monthly and combine with quarterly assessments of physical function (like walking speed or ability to do daily activities). Note any changes in energy levels or how you feel during physical activity. Share trends with your healthcare provider during annual check-ups.

This research shows an association between watermelon consumption and lower rates of muscle loss in older adults, but does not prove that watermelon prevents or treats sarcopenia. This study cannot establish cause and effect. Anyone concerned about muscle loss, weakness, or sarcopenia should consult with their healthcare provider for proper diagnosis and treatment. This information is not a substitute for medical advice. Always speak with your doctor before making significant dietary changes, especially if you have diabetes, kidney disease, or are taking medications. While watermelon is generally safe and healthy, individual responses may vary.