Cocoa powder and eye blood vessel damage in lab and mouse studies
What it found
In cells and mice, cocoa powder reduced signals tied to new blood vessel growth and helped protect the retina from damage.
The work was done in human cells in dishes and in mice, not in people.
What they found
Animal and lab studies
HIF-1alpha protein in cells
In human endothelial cells, cocoa powder reduced the buildup of HIF-1alpha protein caused by low oxygen, without changing its mRNA levels. It also lowered the mRNA for VEGFA, EPO, and GLUT1.
Endothelial migration and tube formation
In lab tests, cocoa powder reduced VEGF-A-induced migration and tube formation by human endothelial cells. Wound closure fell from about 80% to about 55% at 0.1 micrograms per milliliter and to about 40% at 1.0 micrograms per milliliter.
Corneal blood vessel growth in mice
In mice with alkali-burned corneas, oral cocoa powder reduced the area covered by new blood vessels. Coverage fell from about 65% in untreated injured mice to about 38% at 50 mg/kg and about 22% at 200 mg/kg.
Inflammatory and fibrosis markers in mice
In injured corneal tissue from mice, cocoa powder lowered mRNA and protein levels of markers linked to blood vessel growth, inflammation, and scarring. At 200 mg/kg, MMP2 and MMP9 fell by about 50%, VEGF by more than 60%, and alpha-SMA and Ninj1 by more than 55%.
Retinal structure in mice
In mice with MNU-induced retinal degeneration, cocoa powder helped preserve the outer nuclear layer and rhodopsin signal. Outer nuclear layer thickness went from about 40% of control in untreated mice to about 65% and 80% at 50 and 200 mg/kg.
Glial activation in mouse retinas
MNU increased GFAP, a marker of glial activation, about three-fold in mouse retinas. Cocoa powder reduced it by about 35% at 50 mg/kg and about 60% at 200 mg/kg.
What the authors conclude
“These findings suggest that CP functions as a dietary modulator of pathological angiogenesis and degenerative remodeling and may provide complementary benefit in ocular neovascular and retinal degenerative conditions.”
Also in their conclusions
- They say cocoa powder acts as a dietary modulator of pathological angiogenesis and degenerative remodeling.
- They suggest it may provide complementary benefit in ocular neovascular and retinal degenerative conditions.
- They call for further studies to clarify the specific bioactive components and mechanisms and to evaluate their translational applicability.
How it was done
The authors wanted to see whether cocoa powder affects the molecular pathways behind blood vessel growth and tissue breakdown in eye conditions such as corneal neovascularization and age-related macular degeneration. They note that current eye injections for these conditions are burdensome and do not fully stop disease progression.
They tested cocoa powder on human umbilical vein endothelial cells in the lab and gave it by mouth to mice with alkali-burned corneas or MNU-induced retinal degeneration. Mice received 50 or 100 mg/kg once daily for 7 days, and the authors measured blood vessel growth, inflammatory markers, and retinal structure.
What it can’t tell you
- These were lab and mouse studies, so they cannot show what happens in people.
- The cocoa powder used was Dutch-processed, so the results may not apply to other types of cocoa.
- The authors note that the effects should not be attributed solely to flavanols.
Who paid
- Funding
- Funded by National Research Foundation of Korea (from the PubMed record).
- Conflicts
- The authors declare no conflicts of interest. Yeo Jin Sa and Kyu Ha Lee are employees of Nexpharm Korea Co., Ltd. The company had no role in the design of the study, collection, analysis, or interpretation of the data, the writing of the manuscript, or the decision to publish the results.
- Authors work at
- Sungkyunkwan University, Republic of Korea
The paper
- Title
- Cocoa Powder Modulates HIF-1α Stability and Inhibits Ocular Angiogenic and Degenerative Pathology
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Hwang SJ, Park I, Sa YJ, Lee KH, Kim CS, Lee HJ (2026). Cocoa Powder Modulates HIF-1α Stability and Inhibits Ocular Angiogenic and Degenerative Pathology. Nutrients. doi:10.3390/nu18071150Free full textPubMed 41978200DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error