Benefits
Blood pressure (cocoa flavanol studies, not cocoa butter)
A Cochrane review of 35 randomized trials in 1,804 people found a drop of about 2 mmHg in blood pressure in short-term studies (moderate-quality evidence), and a 1-month trial in 100 healthy adults found better flow-mediated dilation. The large COSMOS trial did not significantly reduce total cardiovascular events (P = 0.11). These studies used cocoa flavanol products, not goCOCOA.
Memory and cognition
COSMOS-Mind, a 3-year randomized trial in 2,262 older adults, found cocoa extract (500 mg/day flavanols) had no effect on global cognition (P = 0.28). The only positive memory study cited was small (37 adults aged 50 to 69 completed it): over 3 months, high cocoa flavanol intake improved dentate gyrus function on brain imaging and a related memory test. Mars helped fund it. Neither study tested goCOCOA.
Physical performance in older adults
In a COSMOS substudy of 603 older adults followed for 2 years, cocoa extract with 500 mg a day of flavanols did not change grip strength, walking speed, balance, chair stands or a combined physical performance score compared with placebo. A review of 13 cocoa flavanol exercise studies found that short-term intake gave athletes no performance boost. One small 30-day trial did report a gain in aerobic fitness.
Blood sugar and metabolism
No study cited here measured insulin or blood sugar directly. In COSMOS, 18,381 older adults without diabetes who took cocoa extract (500 mg flavanols a day) for a median 3.5 years developed type 2 diabetes at the same rate as those on placebo (hazard ratio 1.04, P = 0.58). Laboratory ideas about insulin signaling remain untested in people taking goCOCOA.
Aerobic fitness (peak oxygen uptake)
Generic cocoa flavanols, not goCOCOA itself, were tested in 68 healthy adults aged 55 to 79: 500 mg twice a day or a matched control for 30 days. Peak oxygen uptake rose by about 190 ml per minute (confidence interval 1 to 371, so the gain may be small) and peak exercise capacity by about 9.6 watts; control did not change. It is one small trial. A 2-year COSMOS substudy at 500 mg a day found no change in grip strength or walking speed.
Mechanism of action
eNOS activation and nitric oxide production
Cocoa flavanols such as epicatechin are thought to increase nitric oxide production in the lining of blood vessels, which widens them. This is the leading proposed explanation for the small blood pressure changes seen in cocoa flavanol trials. goCOCOA is a cocoa butter powder with no published flavanol content, so whether it supplies a meaningful amount is unknown.
Clinical trials
Randomized, double-blind, placebo-controlled trial of cocoa extract (500 mg/day cocoa flavanols including 80 mg epicatechin) versus placebo in 21,442 older US adults, with a median follow-up of 3.6 years. Main goal: total cardiovascular events. (Sesso et al. 2022, Am J Clin Nutr)
21,442 US adults (women 65 and older, men 60 and older). Median follow-up 3.6 years.
Total cardiovascular events, the main goal, were not significantly reduced (hazard ratio 0.90, 95% confidence interval 0.78 to 1.02, P = 0.11). Heart attack, stroke, artery-opening procedures and death from any cause did not differ significantly. Among several secondary outcomes, cardiovascular death was 27% lower (hazard ratio 0.73, 0.54 to 0.98). An analysis limited to people who kept taking the capsules showed fewer total events (hazard ratio 0.85), but that kind of analysis is less reliable than the main comparison. The capsules were cocoa extract, not goCOCOA.