Eating Onions During Pregnancy: Safety and Benefits

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Written by Gina Wagg BA, Dip.

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Many pregnant women find that onions make them feel nauseous, not to mention it being difficult to cut them without crying! However, onions are still a popular craving for some women.

Onions – whether cooked or raw – are perfectly safe during pregnancy, and may even have many benefits. However, general food safety and hygiene still applies when handling onions. Some dishes containing onions may also need to be checked further for pregnancy-safe ingredients.

With so many different kinds of onions out there, they all have their own nutritional breakdowns and benefits. I’ll walk you through how to safely enjoy everything from green onions to sour cream dip during pregnancy!

Types of Onion and Pregnancy-Safety

Onion is a pretty broad term, so I’ll walk you through the most common kinds of onion and how pregnancy-safe they are:

Green onion, which is also known as scallions or spring onions, are safe during pregnancy. One product to be aware of are diced green onions in pre-prepared salads (or pre-diced onion in bags) as these can easily be contaminated with listeria, e. Coli and other pathogens. The safest thing to do is to wash, cut and cook green onions at home. If you’re buying pre-cut onions, it’s best to wash them first –read our salad article to see why.

Red onions or white onions may make you cry while cutting them, but they are also safe to eat fresh, raw or cooked during pregnancy. Onions have a long shelf life, but err on the side of caution and toss out any with visible damage, sprouting or bruising. 

Pickled onions and pickled foods in general are very common pregnancy cravings and thankfully are safe during pregnancy as long as you consume them by the expiry date. However, be aware that acidic foods like pickled onions can aggravate heartburn, which is already fairly common in pregnancy (source: Current Medicinal Chemistry).

The high vinegar and salt content in pickled onions can be worrisome as it’s easy to overconsume sodium, which should be limited to 2,400 mg per day. Overconsumption of sodium can cause high blood pressure (source: National Library of Medicine). If you’ve been asked to cut down on salt in your diet – be aware of this when eating pickled onions.

Sage and Onion Stuffing is made from sage, onion, breadcrumbs and eggs, so the safety concern during pregnancy is for this dish is about raw eggs. Sage and onion stuffing that is cooked in the oven at 165°F/75°C is safe to go, whether it has been cooked alone or inside a chicken or turkey. For more on stuffing, see this article.

Onion dips such as sour cream and onion or french onion dips are safe during pregnancy if they are made from pasteurized ingredients. The bases of these dips, like mayonnaise, are usually pasteurized. In fact, mayonnaise, sauces and dips containing eggs for sale in the US are pasteurized (source: FDA) as are all cheese and dairy products. 

Onion seeds have been rumored to cause miscarriage but there are no scientific studies to back up this claim. Bear in mind that nigella seeds are often called black onion seeds but they are not related to onions at all!

different types of onions in a basket

Can I Eat Raw Onion When Pregnant?

There is an urban myth that raw leftover onions are “poisonous” and are a “magnet for bacteria” but this has been debunked (source: NOA).

The reality is that onions are actually anti-bacterial and studies have shown that they can fight bacteria such as E. coli – but pregnant women should still practice food safety (source: Journal of Food and Drug Analysis).

Generally, raw sealed onions are good for up to seven days in the fridge. However, pregnant women need to be extra careful when it comes to leftovers as vegetables such as onions are as susceptible as any other veggie to contamination from salmonella or E. coli (source: CDC). 

Fresh cut raw onions are safe during pregnancy but leftovers should be consumed well before the seven-day mark during pregnancy. 

Bear in mind that the Center for Disease Control and Prevention (CDC) linked most kinds of foodborne illness to raw vegetables such as pre-cut salads.

Pre-cut onions or raw onions in a salad should be washed thoroughly before consumption, even if the label says pre-washed. Buying premade coleslaw with onions from a deli is also something to skip during pregnancy as it may be contaminated with listeria bacteria. You can read more about coleslaw safety here.

Instead, you can make your own coleslaw with pasteurized mayonnaise and freshly cut and washed onions and cabbage. 

Learn more about how to wash pre-cut onions and salads in our article on washing fruits and veggies during pregnancy.

Benefits of Onions During Pregnancy

Onions are considered one of your 5-a-day and are loaded with nutritional benefits, vitamins, and minerals. This makes onions a great addition to meals during pregnancy. 

One medium onion (approximately 170 grams) contains 64 calories and 20% of the recommended daily amount of Vitamin C, 10% of your Vitamin B6 requirements, 7% of the RDA of folate, 7% potassium, and 10% manganese. (source: Nutrition Data).

Scallions or spring onions are also a rich source of vitamins and minerals. 100 grams of scallions contains 259% of the RDA of vitamin K, 16% folate, 20% vitamin A and 31% vitamin C (source: Nutrition Data). 

Folate, also known as vitamin B9, is an integral part of your diet during pregnancy. This vitamin has been associated with helping to prevent birth defects such as spina bifida and to help prevent complications such as preeclampsia (source: Plos One).

Folate, or folic acid in supplemented form, also helps to create red blood cells which are responsible for carrying oxygen around the body, this is why anemia can sometimes be caused by folate deficiency. 

Onions are also a good source of fiber and prebiotics, which are great for digestion (and beneficial during pregnancy as constipation is common) Prebiotics can help to reduce inflammation, improve digestion and can help improve gut health overall (source: World Journal of Gastroenterology). 

Many women develop gestational diabetes during pregnancy and some studies have shown a link between onions and better blood sugar control. Several animal studies showed that onions helped to better control blood sugar levels and similar results have been seen in human studies too.

42 people with type 2 diabetes lowered their fasting blood sugar levels by 40 mg/dl four hours after consuming 100 grams of red onion. While those who had type 1 diabetes had lowered their blood sugar levels by 89 mg/dl (source: Environmental Health Insights

Osteoporosis during pregnancy and while breastfeeding is rare but not impossible. Some studies have shown that onions can help to decrease bone loss and even boost bone density (source: JMBR).

Overall, onions are a healthy and nutritious food to eat when you’re pregnant!

freshly cut red onion on a wooden cutting board

I’m Pregnant – Why Are Onions Making me Nauseous?

Many women report feeling nauseous after eating, tasting or even smelling onions during pregnancy when they never experienced this before. 

Pregnancy can alter your sense of taste and smell which can be due to hormonal changes so, with onions having a particularly strong scent it’s no surprise that many pregnant women can’t stand them.

An aversion to foods such as onions can also be due to cultural factors but there are also theories that expecting mothers become averse to foods as an adaptive response to disease vulnerability to try to protect their growing baby (source: Journal of Food and Nutrition Research). However, the science behind cravings is still vague.

That said, clean, freshly cut onions are generally safe during pregnancy and it’s most likely a case of your changing hormones making onions taste or smell different than usual, and it’s nothing to worry about.

A Note on the “Pregnant Onion Plant” or Flower

The pregnant onion plant, also known as a false sea onion of a sea onion and is a type of bulbous plant that sprouts light green flowers. It is native to South Africa but is not an uncommon house plant in other parts of the world, and thrives outdoors in hot states like California. 

All parts of the pregnant onion plant are poisonous and the sap can cause skin irritation. While in nature, animals such as baboons might eat the bulbs of pregnant onion plants, it is toxic to humans – whether you’re pregnant or not – and many animals too.

Consumption of parts of the pregnant onion plant may cause heart, liver, or kidney failure whether you’re pregnant or not (source: Victorian Resources Online).

This plant is not related to edible onions which are from the Allium family and is instead from the Asparagaceae family (source: Kew Science).

If you have a pregnant onion house plant in your home be careful not to consume any of it, and wash your hands thoroughly if you touch it. 

The Onion Pregnancy Test Myth

Onions are linked to old, “natural” pregnancy tests but there is not a whole lot of science behind them that still stands today. 

The ancient Egyptians used to have women insert an onion (or any bulbous vegetable) into their bodies overnight. If your breath smelled like onions the next morning then this meant you were not pregnant, but if it didn’t smell like onions it meant you were!

This was based on the idea that the uterus was “open” when you’re not pregnant so the stench would travel up the body through to the mouth like a wind tunnel but if the uterus is “closed” during pregnancy so the smell would not travel to the mouth. 

It goes without saying that this has no scientific or anatomical proof that this is an accurate pregnancy test. You shouldn’t be putting onions ‘down there’, as it may cause a number of unpleasant side effects, including bacterial infections. There are much easier ways to take a pregnancy test – so if you’re in any doubt, speak to your doctor.