A recent review published in the journal Nutrients has examined how cocoa flavanols found in dark chocolate may affect risk factors for cardiovascular disease and metabolic dysfunction-associated steatotic liver disease (MASLD). The authors evaluated current clinical evidence on whether dark chocolate could play a role in managing these health risks.
Cardiovascular disease remains the leading cause of death worldwide, while MASLD affects over 30% of adults globally. Both conditions share common risk factors such as oxidative stress, chronic inflammation, dyslipidemia, obesity, insulin resistance, and hypertension. These risk factors are linked to higher chances of heart attacks, strokes, and progression of fatty liver disease.
While medications like resmetirom have been approved for some patients with noncirrhotic MASH, most MASLD management still relies mainly on lifestyle changes. Many people are interested in low-cost dietary approaches that could support standard treatments.
The review notes that dark chocolate with high cocoa content is considered a functional dietary component rather than a primary therapy. The bioactive compounds in cocoa-rich dark chocolate—including flavanols like epicatechin and catechin—have antioxidant and anti-inflammatory properties. These substances can neutralize reactive oxygen species and reduce oxidative stress, which is important in both heart and liver diseases.
Processing methods such as fermentation and roasting affect the concentration of flavanols in chocolate. Dark chocolate with at least 70% cocoa content is considered more biologically active than milk or white chocolate.
Studies have shown that moderate intake of dark chocolate may increase antioxidant enzyme activity and inhibit inflammatory mediators such as TNF-α and IL-6. Cocoa compounds also suppress signaling pathways involved in inflammation. These molecular effects are significant because chronic inflammation is associated with obesity, fatty liver disease, hypertension, and cardiovascular disease.
Clinical trials suggest that consuming moderate amounts of dark chocolate can lower levels of low-density lipoprotein cholesterol (LDL) and triglycerides while raising high-density lipoprotein cholesterol (HDL). There is mixed evidence about its effect on blood sugar control; some studies report modest improvements in post-meal glucose levels and insulin sensitivity. However, excess consumption increases calorie, sugar, and fat intake, which may offset any benefits.
Flavanols may also help lower blood pressure by increasing nitric oxide production and suppressing angiotensin-converting enzyme activity. Some randomized trials have found improved vascular function after eating dark chocolate. However, results are inconsistent among people with advanced heart disease or those taking multiple medications.
For MASLD, small trials indicate that dark chocolate can reduce markers of oxidative stress and liver cell injury. While these findings suggest possible protective effects along the gut-liver-heart axis, current evidence does not support using chocolate as a treatment or prevention strategy for MASLD or fibrosis progression due to limitations such as short study durations and small sample sizes.
Most available studies are short-term (2-12 weeks), involve few participants, use varying doses of flavanols, and face challenges related to blinding due to the sensory qualities of chocolate. The benefits seem stronger for individuals without advanced cardiovascular disease or diabetes compared to those already taking medication for these conditions.
No large-scale or long-term randomized controlled trials have demonstrated reductions in major clinical outcomes like heart attacks or progression of liver fibrosis from consuming dark chocolate.
The review concludes that "moderate consumption of cocoa-rich dark chocolate may beneficially influence oxidative stress, inflammation, lipid metabolism, endothelial function, and selected markers of metabolic dysfunction-associated steatotic liver disease." However, these effects relate mainly to early-stage risk modulation based on surrogate biomarkers rather than established treatment for existing diseases.
The authors state: "Large, long-duration randomized controlled studies using standardized flavanol formulations are required before definitive clinical recommendations can be made. Dark chocolate may be incorporated into an otherwise healthy dietary pattern but should not be considered a substitute therapy."
