I agree, the article did a poor job of elucidating leafy greens role in enhancing memory. Allow me to suggest a more plausible mechanism of action for this effect:

Leafy greens contain more magnesium than other sources due to its presens in the cholorphyll structure. The glycolytic cycle also requires magnesium for enzymes [0], so one might expect the memory enhancement effect to be more likely the result of additional glucose avalibility [1]. Additionally, alcohol consumption can cause a magnesium deficiency by diuretic effect - disrupting the glycolytic cycle and resulting in poor memory retention when deficiency occurs.

Although soluable magnesium supplements work in the same way, I'm currently testing agricultural methods of increasing Mg2+ levels in leafy greens.

[0] https://www.ncbi.nlm.nih.gov/pubmed/2931560 [1] https://www.sciencedirect.com/science/article/pii/S014976341... [2] https://www.ncbi.nlm.nih.gov/pubmed/7836619