Flavourings, Colourings and Sweeteners Linked to Higher Depression Risk

The research was published in 2026 in the European Journal of Nutrition. It is an observational study in people, using data from the UK Biobank. That means it tracked what people ate and what happened to them later. It cannot prove that any food or ingredient causes depression.

The team, led by Blumenthal and colleagues, analysed 171,818 adults. All had completed at least one detailed online questionnaire about what they ate the previous day. People with depression or diabetes at the start were excluded. Participants were followed for an average of 10.7 years, and 5,424 of them developed depression. Cases were identified from linked health records, using diagnosis codes for a depressive episode or recurrent depressive disorder.

Most studies treat ultra-processed food as one big group. This one did not. The researchers used 'markers' of ultra-processed food. These are ingredients that signal a food is ultra-processed, such as flavours, colouring agents and sweeteners. They sorted the markers into ten categories and 39 specific markers. Each was measured as a share of a person's total food intake by weight.

Three categories stood out. Higher intake of flavour, colouring agent and sweetener markers was linked to a higher risk of incident depression, and the risk rose with intake in a dose-dependent way. We do not give specific hazard ratios here, because they could not be confirmed from the study text available to us.

Hazard ratios in this study are relative, not absolute. For each marker, the authors set the lowest hazard ratio across the range of intake, called the nadir, to 1, and compared other intake levels against it. A hazard ratio compares the rate of new cases between groups over time. A higher value means a higher rate of new diagnoses in the higher-intake group, but it does not by itself say how many more people will be affected in absolute terms.

The picture was not the same for every marker. The authors conclude that only certain markers are associated with incident depression. We cannot say from the material available which other categories showed no link, or whether any showed non-linear patterns.

The researchers adjusted for age, sex, body mass index, smoking, alcohol, physical activity, income, education, general health and other factors. They also ran sensitivity checks, including excluding people with follow-up shorter than two years, to reduce the chance that early illness changed diets. Even so, other differences between people could still explain some of the link.

There are other limits, and this is where the argument is weakest. Food intake was estimated from questionnaires covering a single previous day, and ingredients were matched to products sold by two UK supermarkets, so they are estimates rather than exact measures. The data cannot say which ingredient, if any, is responsible. Foods with these additives may also differ from other foods in ways the study did not capture.

For you

For personal health, the finding is a prompt rather than a rule. It points to where researchers might look first when asking how diet affects mood. The authors say it offers an initial framework for choosing which markers to prioritise in efforts to cut ultra-processed food and in future mechanistic research.

Next, watch for studies that test these ingredients directly, and for repeat analyses in other countries and diets, which would show whether the pattern holds.

Removing Brain Immune Cells Restored Two Hours of Sleep in Alzheimer's Mice Gut Bacteria and Chemicals Differ in Mild Cognitive Impairment, Small Study Finds Starting Statins Soon After Diabetes Diagnosis Linked to Less Dementia Flavourings, Colourings and Sweeteners Linked to Higher Depression Risk Older Adults on Self-Chosen Vegan Diet Lost Leg Muscle in 12 Weeks Topical Vitamin K2 Cream Improved Wrinkles and Firmness in Small Trial Staying Active Over Years Linked to 44% Lower Frailty Risk East Germans Who Faced Covert State Repression Still Report More Stress Four Cardio Styles Compared: High-Intensity Intervals Beat Moderate Intervals on Fitness AI Predicted Brain Amyloid From Blood Tests, but Faltered on New Patients Boosting Gene ZNF865 With CRISPR Reversed Aging Signs in Degenerated Spinal Disc Cells Review of 26 Cohorts Links Time-Restricted Eating to Better Blood Sugar Years of Fitbit Data Link Steady Daily Rhythms to Slower Biological Aging Review of Nine Meta-Analyses Links Hearing Loss to 43% Higher Dementia Odds UK Biobank Study of 170,000 Women Links HRT to Higher Cardiovascular Risk Small Trial Finds Ultra-Processing Alone Did Not Change Short-Term Satiety Combining Cardio and Strength Training Beats Cardio Alone in Heart Rehab 20-Gram Protein Dose Failed to Boost Muscle Building in Older Men Mediterranean Diet Linked to Slightly Younger DNA-Based Aging Readings in Study Gut Microbes May Shape How Environmental Toxicants Affect the Brain, Review Says Review Says Simply Raising NAD+ or SIRT1 May Not Slow Ageing Review Calls Chronic Stress Before Surgery a Possible Modifiable Heart Risk Review Maps How CRISPR Delivery Could Target Aging's Hallmarks Deep Learning Model Melody Reads DNA Code to Predict Methylation Patterns Mostly-Easy Polarized Training Beat Threshold Workouts on Endurance Markers, Not VO2max Trump Executive Order Creates New NIH Division and Task Force on Women's Health Review of 46 Studies Finds Ultra-Processed Food Heart Research Methodologically Weak Review Finds No Consistent Epigenetic Age Reversal From Antioxidant Supplements Time-Restricted Eating Raises Ketones, Modestly Calms Inflammation, Review Finds Gut-Made Short-Chain Fatty Acids Linked to Brain Protection in Low Blood Flow