A major study following over 200,000 people for 13 years found that eating lots of ultra-processed foods (like packaged snacks, fast food, and sugary drinks) was linked to a higher risk of suicide attempts. People who ate the most processed foods were 63% more likely to attempt suicide compared to those who ate the least. The good news: replacing just one-fifth of processed foods with whole foods like fruits, vegetables, and unprocessed meats could cut suicide attempt risk by 23%. The study suggests that inflammation in the body might partly explain this connection, though more research is needed to fully understand how diet affects mental health.
The Quick Take
- What they studied: Whether eating ultra-processed foods (packaged, ready-to-eat foods with lots of additives) affects the risk of suicide attempts, and if body inflammation plays a role in this connection
- Who participated: Over 208,000 adults from the UK Biobank study who were tracked for an average of 13 years starting in 2006. Participants ranged in age and background, representing a large cross-section of the UK population
- Key finding: People who ate the most ultra-processed foods had a 63% higher risk of attempting suicide compared to those who ate the least. For every increase in processed food consumption, suicide attempt risk went up by 20%. However, replacing 20% of processed foods with whole foods reduced suicide attempt risk by 23%
- What it means for you: While this doesn’t prove that junk food causes suicide attempts, it suggests that eating more whole foods and fewer processed foods may be one way to protect mental health. This is especially important for people struggling with depression or suicidal thoughts. Talk to a doctor or mental health professional if you’re having thoughts of suicide—diet is just one part of mental health care
The Research Details
This was a long-term follow-up study called a cohort study, which means researchers tracked the same group of people over many years. Starting in 2006, over 208,000 people from the UK Biobank answered questions about what they ate and provided health information. Researchers then watched to see who attempted suicide over the next 13 years on average.
To measure processed food intake, scientists calculated what percentage of each person’s diet came from ultra-processed foods—things like packaged snacks, sugary cereals, fast food, and drinks with added sugar. They divided people into five groups based on how much processed food they ate, from lowest to highest consumption.
The researchers used a statistical method called Cox proportional hazards models to figure out if eating more processed food was connected to higher suicide attempt rates. They also tested what would happen if people replaced some processed foods with whole foods like fresh fruits, vegetables, and unprocessed meats. Finally, they looked at whether inflammation in the body might explain part of this connection.
This research approach is important because it follows real people over a long time period, which gives us better information than just asking people about their habits once. By tracking 208,000 people for 13 years, the researchers could see actual patterns between diet and suicide attempts. The study also looked at whether replacing processed foods with whole foods could help, which gives practical advice people can actually use. Understanding how diet might affect mental health is crucial because suicide is a serious public health problem, and if diet plays even a small role, it’s worth studying.
This study has several strengths: it’s very large (over 200,000 people), it followed people for a long time (13 years), and it used careful statistical methods. The journal (American Journal of Clinical Nutrition) is well-respected in nutrition science. However, the study can’t prove that processed food causes suicide attempts—it only shows a connection. People who eat more processed food might differ in other ways (like exercise, stress, or sleep) that also affect suicide risk. The study relied on people remembering what they ate, which isn’t always accurate. Also, only 545 suicide attempts occurred during the study, which is relatively small compared to the total number of participants, so the results need to be confirmed by other research.
What the Results Show
The main finding was clear: people who ate the most ultra-processed foods had significantly higher suicide attempt risk. Specifically, those in the highest group of processed food consumption had a 63% increased risk compared to those in the lowest group. This means if the lowest group had 10 suicide attempts per 100,000 people, the highest group might have about 16 attempts per 100,000.
When researchers looked at it another way—measuring how much processed food each person ate as a percentage of their total diet—they found that for every increase in processed food consumption, suicide attempt risk went up by 20%. This suggests a dose-response relationship, meaning the more processed food someone eats, the higher their risk appears to be.
The most encouraging finding was about food substitution: if someone replaced just 20% of their processed food intake with whole foods (like fresh produce and unprocessed proteins), their suicide attempt risk dropped by 23%. This suggests that even modest dietary changes might have protective effects.
The researchers also investigated whether inflammation in the body explained this connection. They found that inflammatory markers (signs of inflammation in blood tests) accounted for only about 0.7% to 1.5% of the increased risk. This means inflammation plays a very small role in explaining why processed food consumption is linked to suicide attempts—there are likely other mechanisms at work that researchers don’t yet fully understand.
The study examined several other aspects of the data. Researchers looked at different types of inflammatory markers and found that the connection between processed foods and suicide attempts remained fairly consistent across different measures. They also analyzed whether the relationship was different for men versus women, and whether age affected the results. The findings were generally similar across these different groups, suggesting the connection between processed food and suicide attempt risk isn’t limited to just one type of person. The study also confirmed that the relationship held true even after accounting for other factors like body weight, physical activity, and smoking status.
This research builds on earlier studies showing that ultra-processed foods are linked to depression and anxiety. Previous research has shown that processed foods high in sugar and low in nutrients can affect brain chemistry and mood. This new study extends that work by looking specifically at suicide attempts, which is a more serious outcome than just depression or anxiety. The finding that inflammation plays only a small role is somewhat surprising, since many researchers expected inflammation to be a bigger factor. This suggests that processed foods might affect mental health through other pathways, such as effects on gut bacteria, blood sugar control, or nutrient deficiencies. The study’s finding that replacing processed foods with whole foods reduces risk aligns with other research showing benefits of healthy eating patterns like the Mediterranean diet.
This study has important limitations to keep in mind. First, it can only show that processed food consumption and suicide attempts are connected—it cannot prove that processed food causes suicide attempts. People who eat more processed food might also have other risk factors for suicide, like depression, stress, or social isolation, that the study didn’t fully account for. Second, the study relied on people remembering and reporting what they ate, which is often inaccurate. People might not remember exactly how much processed food they consumed months or years earlier. Third, the study only included people from the UK, so results might not apply to other countries with different food systems or populations. Fourth, only 545 suicide attempts occurred during the 13-year study, which is relatively small, so the results need to be confirmed by other research. Finally, the study couldn’t determine whether people changed their diets during the follow-up period, so it’s measuring baseline diet rather than actual eating patterns over time.
The Bottom Line
Based on this research, eating fewer ultra-processed foods and more whole foods appears to be beneficial for mental health, though this should be part of a comprehensive approach to mental wellness. The evidence suggests replacing processed foods with whole foods like fresh fruits, vegetables, legumes, nuts, and unprocessed meats. However, this research alone shouldn’t be used as a treatment for suicide risk—professional mental health care is essential. If you or someone you know is having thoughts of suicide, contact a mental health professional or crisis hotline immediately. Diet may be one helpful factor among many, including therapy, medication, social support, and stress management. The confidence level for these findings is moderate—the study is large and well-designed, but it shows association rather than causation, and results need confirmation from other research.
Everyone should care about this research, especially people who are struggling with depression, anxiety, or suicidal thoughts. People with a family history of suicide or mental health problems might find this information particularly relevant. Parents and educators should know about this connection, as it highlights another reason to encourage healthy eating in children and teens. Healthcare providers treating depression or suicide risk should consider discussing diet as one part of a comprehensive treatment plan. However, this research shouldn’t replace professional mental health treatment. People without mental health concerns can also benefit from eating less processed food for overall health. This research is NOT a substitute for emergency mental health care—if someone is in immediate danger, call emergency services or a suicide prevention hotline.
If someone starts eating less processed food and more whole foods, they shouldn’t expect immediate changes in mood or mental health. Brain chemistry and mental health improvements typically take weeks to months to become noticeable. Some people might notice improved energy, better sleep, or slightly improved mood within 2-4 weeks of dietary changes. More significant mental health improvements might take 2-3 months or longer. It’s important to be patient and combine dietary changes with other mental health strategies like therapy, exercise, sleep, and social connection. If someone is having suicidal thoughts, they need immediate professional help—dietary changes alone are not sufficient treatment.
Want to Apply This Research?
- Track the percentage of meals that contain ultra-processed foods versus whole foods. For example, users could rate each meal on a scale (0% processed to 100% processed) and aim to reduce the processed food percentage by 10-20% each week. Alternatively, track the number of whole food meals per day and set a goal to increase from current baseline to 2-3 whole food meals daily.
- Users can start by identifying one ultra-processed food they eat regularly and replacing it with a whole food alternative. For example: replace sugary cereal with oatmeal and fruit, replace packaged snacks with nuts and fresh fruit, or replace fast food with home-cooked meals. The app could provide simple whole food recipes and shopping lists to make this easier. Users could also set reminders to prepare whole foods in advance, like meal prepping on weekends.
- Over 4-12 weeks, track both dietary changes and mood/mental health metrics (like mood rating, energy level, sleep quality, and anxiety level). Users should note any patterns between days with higher processed food intake and days with lower mood or energy. The app could generate weekly reports showing the correlation between diet quality and mental health indicators. This personalized feedback helps users see the connection between their eating habits and how they feel, which can motivate continued dietary improvements.
This research shows an association between ultra-processed food consumption and suicide attempt risk, but does not prove that processed foods cause suicide attempts. This information is for educational purposes only and should not replace professional medical or mental health care. If you are having thoughts of suicide or self-harm, please contact a mental health professional, call the National Suicide Prevention Lifeline (988 in the US), or go to your nearest emergency room immediately. Diet is one factor that may support mental health, but it is not a substitute for therapy, medication, or other professional mental health treatments. Always consult with your doctor or mental health provider before making significant dietary changes, especially if you have existing health conditions or take medications. This study was conducted in the UK and may not apply to all populations.