How HDL Cholesterol May Help Explain Why Exercise Supports Mental Health
Regular physical activity is consistently linked to lower rates of depression, and most of us have felt the mood lift that comes after a good workout. But the mechanisms behind this relationship are still being untangled. A new study published in The American Journal of Clinical Nutrition indicates that HDL cholesterol (often called "good" cholesterol) may help explain part of the connection.
About the study
Researchers wanted to understand not just whether exercise is linked to lower depression risk, but how that link might work. To explore this, they used mediation analysis, a statistical approach that tests whether a third variable (in this case, HDL cholesterol) helps explain the relationship between two others (physical activity and depression).
HDL, or high-density lipoprotein1, is best known for its role in cardiovascular health. It helps transport cholesterol away from the arteries and back to the liver for disposal, which is why higher levels are generally considered protective for heart health. But emerging research suggests HDL may also play a role in brain function, as it has potentially anti-inflammatory effects2 and supports vascular health in the brain.
The team analyzed data from more than 16,000 adults in the National Health and Nutrition Examination Survey to test whether HDL levels account for some of the association between physical activity and depression.
Higher HDL, lower depression risk
Adults who met physical activity guidelines (and participated in at least 150 minutes of physical activity a week) had a 57% lower prevalence of depression compared to those who were less active. Higher HDL cholesterol levels were also independently associated with lower odds of depression.
When researchers ran their analysis, they found that HDL accounted for a small but statistically significant portion of the exercise-depression relationship. So, part of the reason exercise may protect against depression could involve its effects on HDL.
What this means for the exercise-mood connection
Depression is complex, and exercise likely supports mental health through multiple pathways including neurotransmitter changes, reduced inflammation, improved sleep, and stress regulation, among others.
Movement influences markers like HDL, which may have their own protective effects on the brain. And heart health, metabolic health, and mental health are all connected. Improving one of them also has positive impacts on the others.
How to support both movement and HDL
If you're looking to support both physical activity and healthy HDL levels, a few strategies can help:
- Prioritize aerobic exercise: Activities like walking, cycling, swimming, and dancing are particularly effective at raising HDL levels.
- Add strength training: Resistance exercise supports metabolic health and complements cardio for overall benefits.
- Include healthy fats: Olive oil, avocados, nuts, and fatty fish can support HDL when part of a balanced diet.
- Limit refined carbohydrates: Excess sugar and processed carbs can lower HDL over time.
- Don't smoke: Smoking is one of the most significant factors that suppresses HDL levels3.
The takeaway
Exercise supports mental health through multiple pathways, and this study suggests HDL cholesterol may be one of them. This study serves as a good reminder that movement benefits your body and brain in multiple, interconnected ways.