Food

Spinach

A leafy green rich in nitrates, folate, lutein, and iron; improves blood pressure and arterial stiffness and provides pigments for vision.

In practice

Frequent servings, raw or lightly cooked to preserve nitrates and folate.

Precautions

Safe. Because of its oxalate content, moderate it if you have calcium oxalate kidney stones.

Effect by goal · level of evidence

Hypertension

reduces Moderate clinical trial (A)

In healthy adults, a diet with spinach (a rich source of nitrates) improved arterial stiffness and blood pressure versus a low-nitrate control (randomized trial).

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Eye health

improves Low-moderate cohort (AA)

Its lutein and zeaxanthin accumulate in the macula and are associated with a lower risk of age-related macular degeneration.

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In depth

⏱ 2 min read

Spinach is one of the largest dietary sources of inorganic nitrate, which the body converts into nitric oxide (a vasodilator), in addition to folate, lutein, zeaxanthin, vitamin K, magnesium and iron. That profile explains its effects on blood pressure, vascular function, physical performance and eye health.

Nitrates, pressure and performance

Nitrate from leafy greens is converted into nitric oxide, which relaxes blood vessels and improves blood pressure and arterial stiffness. That same mechanism improves exercise efficiency, which is why nitrate-rich vegetables are used in sports nutrition.

Lutein and vision

The lutein and zeaxanthin in spinach are deposited in the macula of the eye and filter blue light; a higher intake is associated with a lower risk of macular degeneration and cataracts.

References

Jovanovski, E. et al. (2015). Effect of spinach, a high dietary nitrate source, on arterial stiffness and related hemodynamic measures: a randomized, controlled trial in healthy adults. Clin Nutr Res 4(3), 160-167. doi:10.7762/cnr.2015.4.3.160

Information, not medical advice. Scientific evidence reflects the quality of the studies.