Green bean

Green beans can be offered once your baby is about 6 months old and ready for solids. They are also called string beans.

Green beans belong to a large family of legumes. The tender pod is eaten before the little seeds inside swell and ripen in the sun and water. Bush, pole and wax beans are relatives. All of them come from the common bean, which is native to Central and South America.

They contain plenty of water, fiber and folate. They contain vitamins B6, C and K. They also give a little iron, magnesium, lutein, zeaxanthin and various antioxidants. Together they help gut bacteria, hydration, the brain, iron uptake, immune defense, clotting, blood cells and eyesight.

At 6 months cook the beans whole and uncut. A whole pod can be safer than pre-cut pieces at this age and is easier for the baby to hold. As the baby chews, the gums squash the pod and make it less round. Small cut pieces are likelier to be swallowed whole. To lower the risk further, flatten the cooked pod with the back of a fork.

For fine motor practice, raw green beans can act as a spoon for scooping a purée such as hummus. The baby will not eat the raw bean, because biting through it takes a strong jaw and, in most babies, teeth. But it is great for learning to scoop.

At 12 months cut the cooked beans into bite-sized pieces. They also suit fork practice. After 18 months keep serving bite-sized pieces by hand or with a fork, but shorten the cooking time so your child gets used to chewing firmer food. You can also serve whole beans with a dip.

On nitrates: You can serve nitrate-containing vegetables such as green beans as part of a varied diet. Excess nitrate can affect the oxygen level in the blood. Babies learning to self-feed do not eat much solid food. In a balanced diet the benefit of these vegetables outweighs the unlikely risk of overconsumption. To limit exposure, skip untested well water and be careful with purées. Do not keep homemade purées of higher-nitrate vegetables for more than 24 hours. Do not give commercial purées that were not eaten within 24 hours of opening.

Green beans can be firm. Cut small, they match the size and shape of the windpipe at this early age. These traits raise the choking risk.

If the small beans inside worry you, chewing the pod squashes them flat and lowers the risk. You can lower it further by flattening the cooked pod with the back of a fork. Stay within arm's reach during meals.

Green bean allergy is rare, though not unheard of. Introduce it like any new food: a little at first, and watch how your baby responds.