Many of us enjoy a sweet drink now and then, especially on a warm summer’s day or when a sugar craving hits. Most of us are quite aware that these should be enjoyed only on occasion. These drinks are often higher in refined sugars and linked to several health issues, including obesity, and type 2 diabetes.
During pregnancy, a high intake of added sugar has also been associated with a range of adverse outcomes, such as excessive weight gain, gestational diabetes, and an increased risk of premature delivery. In an effort to reduce sugar intake, many people (including pregnant women) are turning to diet drinks (or artificially sweetened beverages). These often contain artificial or non-nutritive sweeteners. These sweeteners, like aspartame, sucralose, and saccharin, provide sweetness without adding significant calories. They are much sweeter than sucrose (commonly known as table sugar) and therefore can elicit the same sweet taste with almost no caloric value. In recent years they have been added to all kinds of foods and beverages, and studies suggest that around 1 in 3 pregnant women now consume them regularly. Whilst some of these sweeteners are approved as safe during pregnancy by regulatory bodies, it’s worth asking, does ‘safe’ necessarily mean ‘ideal’?
Let’s have a look at what the research says!
Possible Impacts on Birth Outcomes
Researchers have attempted to investigate the potential link between consumption of artificial sweeteners, and the impacts on birth outcomes. One study found that daily consumption of artificial sweeteners during pregnancy was associated with an 18% increased risk of premature delivery (1). There are several explanations for why this occurs. Firstly, many artificial sweeteners aren’t properly digested by the body. Instead, they pass through the gut and can disrupt the balance of gut bacteria. Our microbiome is a diverse ecosystem of bacteria and other organisms that exist in our body, specifically the gut. Certain microbiome compositions have been shown to play a role in metabolic dysfunction. Research has shown that babies who are born to mothers who consume these artificially sweetened drinks during pregnancy showed an altered gut microbiome. Changes have been observed in bacteria species which are involved in metabolism.
For babies, the first year of life is a critical period for immune development and metabolic health. Disruption of the gut microbiome during this period may lead to long term health consequences. This is especially important to consider in light of increasing childhood obesity rates. Additionally, some studies performed on animals have shown that this disruption on the microbiome can lead to inflammation and changes in blood sugar control, which could affect the health of the placenta and increase the risk of delivering early. They also found that artificial sweeteners may slightly increase birth weight and raise the chances of having a larger than average baby (5). This might be because some sweeteners can trick the body into absorbing more sugar and releasing more insulin, even though they don’t contain calories themselves. Over time, this could lead to higher blood sugar levels, which can affect baby’s growth. Another interesting point is that artificial sweeteners don’t seem to affect our hunger hormones, which means they might not help with appetite control. This could lead to eating more overall, which may influence baby’s size at birth.
Long-Term Impacts on Birth Outcomes
Consuming too much sugar during pregnancy can affect a baby’s development in utero, disrupting the normal development of their metabolic system, which can go onto increase risk of chronic disease development. It may also shape their feeding habits and metabolism to favour storing adipose tissue (fat tissue). Interestingly, children exposed to high sugar levels before birth might develop a stronger preference for sweet tastes, and some research even suggests this could lead to sugar addiction.
When researchers compared sugar-sweetened drinks with artificially sweetened ones, they found that both carried similar risks. Only those that drank water showed a lower risk for these issues. Additionally, animal studies have shown that prenatal exposure to artificial sweeteners can lead to a stronger preference for sweet foods and metabolic changes like higher blood sugar and insulin resistance later in life. It is important to note that these findings have not been directly proven in humans.
Research on how artificial sweetener intake during pregnancy affects childhood outcomes in humans is still limited, but some studies raise concerns. For example, one study found that women who consumed artificial sweeteners daily had double the risk of having an overweight child by age 1. Another showed that children whose mother’s consumed artificial sweeteners were more likely to be overweight by age 7. This is in line with previous research that supported water intake, as those that consumed more water had a lower risk of having a higher body mass index (BMI) (3)(4)
Autism and Aspartame
The link between aspartame, a popular sweetener found in many diet drinks, and autism is one that has been a contentious topic in recent years. It is argued that aspartame breaks down into potentially harmful compounds in the body, which could affect neurodevelopment. Some animal studies have shown links between aspartame and neurological conditions, however human studies have not conclusively confirmed this.
One study (2) examined whether drinking artificially sweetened beverages or consuming aspartame during pregnancy or breastfeeding was linked to autism in children. The researchers found that boys with autism were more than three times as likely to have been exposed to diet drinks or aspartame early in life, compared to boys without autism. Interestingly, this link was only seen in boys, not girls. There was no clear connection found in girls, however that could have happened for a number of reasons.
It is important to note that just because there is a relationship between artificial sweeteners and autism, doesn’t necessarily mean that it is the cause. So, while we cannot conclusively say that these sweeteners may impact neurodevelopment, we can note that they may play some role. In this instance, pregnant women should be cautious about including these as part of a normal diet until more data comes out regarding their effects.
Potential Link to Allergies
There is also some early research suggesting a possible link between artificial sweetener use during pregnancy and a higher risk of allergies in children. While the evidence isn’t strong enough to say for certain, it is worth exploring. One study found that having artificially sweetened soft drinks every day was associated with an increased risk of their child developing asthma and allergic rhinitis (6). Interestingly, this association was not found with sugar sweetened beverages.
So, Are Diet Drinks Safe During Pregnancy?
The current evidence shows that there may be a link between artificial sweeteners during pregnancy and undesirable health outcomes for both mum and the baby. This includes an altered gut microbiome, increased birth weight, premature delivery, childhood obesity and poor long term eating habits, as well as a potential increased risk of allergies. It is important to note that the evidence is still emerging, so we cannot draw strong conclusions, especially since much of this research is based on animal studies.
That being said, just because the guidelines say consumption of artificial sweeteners are ‘safe’ doesn’t always mean they are ‘ideal’. When a product is deemed ‘safe’, it typically means it is not immediately harmful to consume at normal levels, however this doesn’t necessarily take into account the impacts on long term health outcomes. Science is a constantly evolving field and guidelines and recommendations often lag behind the research. Given the potential for long lasting impacts on a baby’s health, and particularly the microbiome, it may be wise to be approach this topic with caution. Until we know more about the impacts of these drinks, especially during pregnancy, it may be sensible to limit intake of these drinks during pregnancy.
Are all sweeteners harmful in pregnancy?
Another factor to consider, is the type of artificial sweetener that has been studied in regards to adverse health outcomes. Sweeteners usually fall into two major categories: nutritive and non nutritive sweeteners. Artificial or non-nutritive sweeteners are often used instead of sugar. They give foods and drinks a sweet taste without adding kilojoules (calories). You’ll find them in many supermarket products, from ‘tabletop’ sweeteners you can add to tea, coffee, cereal or fruit, to items like soft drinks, cordials, jellies, yoghurt, ice-cream, chewing gum, lollies, cakes and desserts. These products are usually labelled ‘diet,’ ‘low joule’ or ‘sugar-free.’ Nutritive sweeteners are made from various types of carbohydrates. Foods and drinks with these sweeteners are sometimes labelled as ‘carbohydrate modified’ or ‘lower carb/low sugar’. They add sweetness and usually provide fewer kilojoules (calories) than regular sugar but they are not energy-free.
The frequency at which you consume products with sweeteners would impact how ‘high risk’ it is to have in pregnancy. A classic situation of “the dosage makes the poison”.
What Can I Drink Instead?
If you’re looking to cut back on sweet drinks during pregnancy, there are plenty of alternatives to try. Some of my favourite examples include:
- Naturally flavoured water using fresh fruit, cucumber, or mint
- Sparkling water with a splash of juice or a squeeze of lemon or orange
- Homemade iced teas made from cold herbal infusions
- Hot tea from herbal varieties like peppermint tea or ginger tea
- Milk, or milk alternatives, with a teaspoon of cacao
- Homemade smoothies made with fruit, yoghurt, oats and milk
- Water!!
Listen to your body, stay hydrated, and focus on a nourishing, overall varied diet – this is what will have the biggest impact on you and your baby’s health.
