Spinach may cause Alzheimer's disease in at-risk people, research suggests. 

研究表明，菠菜也许会使高危人群患上阿兹海默症（老年痴呆症）。

The salad leaf's iron-rich content may damage the brain similar to how the compound causes metal to rust, according to the researchers. 

People with high levels of iron alongside the protein amyloid, which has previously been associated with Alzheimer's, are more likely to experience rapid cognitive decline, a study found. 

Those with high amyloid but low iron levels are less at-risk of the disease, the research adds. 

Removing such 'rust' from the brain could prevent or delay the degenerative condition, the researchers add.