Can sugar make you feel sad?

Qualified Life Coach
Ask Marianna

04 December 2018

How does sugar affect you mentally?

In recent years, the issue of refined sugar has been gradually seeping into the public consciousness as it is often associated with major health issues such as obesity and diabetes and even other problems such as poor sleep, skin conditions like acne and poor immunity. However, while the physical symptoms of sugar are well-known and researched, how sugar can impact your mood and mental health isn’t as well documented. 

The good news is that it looks as though this is finally changing as more studies are being conducted around the issue and, unsurprisingly, it looks as though refined sugar has a lot to answer for! One study that is gaining a lot of attention was published in the Scientific Reports Journal last year. 

This long-term study tracked the diets and medical conditions of over 8000 people over the course of 22 years. It found that men who consumed approximately 67g or more of sugar a day were 23% more likely to be diagnosed with depression or anxiety compared to men who consumed 40g or less. Interestingly, at the beginning of the study none of the participants were being treated for mental illness!1 

Of course this study only identifies the correlation; it doesn’t appear to attempt to explain why it exists in the first place. However, it does appear to fit in nicely with other studies conducted around similar issues, so below I’m going to list just a couple of ways that refined sugar could be impacting your mood. 

Refined sugar can suppress BDNF: You’re probably wondering what on earth BDNF actually is and I don’t blame you. BDNF, or Brain-derived Neurotrophic Factor for those in the know, is actually a protein and it plays a really important role in your cognitive health, helping to stimulate the production of new brain cells. It allows you to learn faster, improves your memory and can even slow down the ageing process.

Impressive, but when it comes to your mood BDNF works to protect your brain cells in times of stress and keeps your neural pathways nice and flexible. However, high rates of refined sugar have been associated with suppressing this protein and studies have shown that those diagnosed with depression and other mental health conditions often present lower levels of BDNF.3  

Refined sugar is often pro-inflammatory: Inflammation is becoming a major buzzword these days and for good reason! While a small amount of inflammation can be a good thing, too much can have a negative impact for almost every area of your health, including your mental wellbeing. Unfortunately, refined sugar can be pro-inflammatory as it elevates your blood glucose levels. Once these are raised, it can increase your production of inflammatory cytokines, C-reactive proteins and harmful molecules like AGEs. 

This can be problematic for your mood as high levels of C-reactive proteins have been associated with increased risk of psychological distress which could be why low-grade inflammation is often linked to depression.4 It’s also thought that inflammation could affect how tryptophan, an essential amino acid, is utilised, directing it towards the production of chemicals like quinolinate, which can promote feelings of anxiety.5 

Refined sugar upsets your blood glucose levels: This is hardly surprising information but refined sugar can be disastrous for your blood sugar levels, causing you to experience rapid highs followed by exhausting lows. As I’ve mentioned, these fluctuations can promote inflammation but they also wreak havoc on your energy levels and sometimes even induce emotions such as anxiety, irritability and fatigue. It’s also worth mentioning that it isn’t just your mood impacted by your blood glucose levels – your sleep patterns can also suffer which can leave you more vulnerable to negative emotions. 

Refined sugar depletes your nutritional stores: When your body breaks down carbohydrates like sugar, a number of vitamins and minerals are involved in the process. In the case of complex carbohydrates, this system works as they provide additional nutrients to supplement the ones being utilised in the digestion process but this isn’t true for sugar. Refined sugar has very little nutritional value which means it actually depletes your stores of nutrients such as B vitamins, vitamin C, vitamin D, magnesium and chromium. This in turn can influence your mood as these nutrients – particularly certain B vitamins, vitamin D and magnesium – are crucial for your mood and energy levels! 

Refined sugar does have physical symptoms: Okay, so far we’ve established that refined sugar can directly impact your mood and cognitive function but it’s also important to highlight that the physical consequences of a high sugar diet can also affect your mental wellbeing. If you’re continually plagued by problems like acne, poor immune function, flagging energy levels and a bigger waistline then you’re not exactly going to be in a positive frame of mind. Your confidence could be impacted and you may find that you suffer from low self-esteem which can sometimes be a recipe for low mood and anxiety. 

Are there any healthy sugars?

Sugar has definitely earned a bad reputation in the last few decades but it would be wrong to completely jettison all forms of sugar from your diet. After all, sugar can act as a source of energy for your brain and your body so you actually do need it in small amounts. What really matters is where you’re sourcing this sugar from – ideally, you should be able to get all the sugar your body needs from natural sources such as fruit and vegetables. 

The problem is that, more and more, sugar is creeping into our diets in other forms – namely refined sugar which is present in foods such as ice cream, chocolate and cakes, but also in less suspicious foods. According to the World Health Organisation, added or refined sugar should account for around 5% of your total energy intake.6 This amounts to roughly no more than 6 teaspoons a day, however here in the UK, we’re consuming around double this amount!

What foods have added sugar?

So, if you’re trying to reduce your sugar intake it’s important you don’t just focus on the obvious culprits. That’s why I’m going to identify a few surprising foods that sugar can lurk in!

  • White Bread – When people think of sugar they often forget that it can linger in processed forms of carbohydrates and white bread is a primary example. Unlike wholemeal bread which still contains a decent amount of fibre and B vitamins, white bread has been stripped of these nutrients and just one slice can contain as much as 3g of sugar!7 
  • Cereal – Cereal is generally perceived as a healthy food but it very much depends on the type of cereal you are eating. Coco Pops, Lucky Charms and Frosted Shreddies probably seem like obvious choices when it comes towards having a high sugar content, but even healthy options such as granola can be rich in sugar which is why it’s really important to read the label! 
  • Tomato ketchup – Tomato sauce is an extremely popular condiment here in the UK, often accompanying chips or a bacon roll. However, this red sauce is concealing a nefarious sugar content – Heinz Tomato Sauce, for example, contains around 22g of sugar for every 100g!8 That’s why it might be worth investing in a ketchup that has a lower salt and sugar content – Dr Wills’ Tomato Ketchup, for example, doesn’t contain any artificial ingredients or added sugar or, alternatively, you could try making your own!
  • Nut butters – Nut butters are considered to be quite a trendy, healthy food with many people now adding them to smoothies or serving them with slices of apple or banana. Once again though, quality does matter as some nut butters can be surprisingly rich in sugar. Ideally, the shorter the ingredients list, the better!
  • Frozen meals: We’re all guilty of relying on frozen foods when we’re in a hurry. They’re a cheap, quick option and since most of them are savoury, we don’t normally think about their sugar content. Often, frozen foods are preserved using starch which, once it enters your digestive tract, can be converted into sugar. Fresh is still best I’m afraid, which is why I often recommend cooking batches of meals at home so you’ve got plenty of options for the week ahead! 
  • Coffee – Salted caramel latte anyone? Speciality coffees are all the rage and, while there’s nothing wrong with having them as a weekly treat, if your daily routine involves popping along to Starbucks or Costa for a cappuccino or a mocha latte, then your blood glucose levels are going to suffer. Our Nutritionist Emma talks a little more about coffee in her blog ‘Coffee habit? 7 reasons why it could be hindering your weight-loss efforts!’ which I highly recommend you read if you’re looking to kick that Starbucks habit 
  • Water – Water? Really? Well, yes and no. Plain old tap water or bottled water is unlikely to affect your blood glucose levels but, if you’re partial to fruity waters or carbonated water then it’s a different story. Not only do these types of drinks contain plenty of sweeteners and artificial flavours, they tend to be rich in sugar so it might still be best to stick to the stuff that comes out of your tap!

How can I improve my low mood?

It’s all very well discussing how your sugar intake can affect your mental wellbeing but if you’re struggling to deal with low mood, then you may need to look beyond simply amending your diet. There are a variety of factors to consider here but the good news is that we are here to help. Here at A.Vogel Talks Low Moodwe offer plenty of information on not only the symptoms of low mood, but also how you can tackle the issue by making small changes to not just your diet, but your lifestyle and outlook too. 

However, if you are going through a turbulent period and feel a bit down, you could try our St John’s Hyperiforce Tablets for an extra little lift. Prepared using the St John’s Wort herb, this remedy can help to soothe mild symptoms of anxiety and low mood, enabling you to cope with your feelings rather than being overcome by them. It’s important to bear in mind though, that this remedy can be contraindicated with a variety of medications so always read the product information leaflet first!

Finally, if you really are struggling to cope with low moods and anxiety, it’s important that you speak to someone, be it a loved one, family member or a friend. Although our remedies can help with mild symptoms, they are not to be treated as an alternative to antidepressants so, if you are worried about how you’re feeling, never be afraid to confide  in your doctor. 









A.Vogel Hyperiforce St John's Wort Tablets used to relieve the symptoms of slightly low mood and mild anxiety, 60 tablets

60 tablets

£ 11.99

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For low mood and anxiety. Made from freshly harvested herbs.
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Here’s what I recommend

As the A. Vogel Mood advisor, I recommend St. John’s wort made from freshly harvested Hypericum, to help with feelings of low mood.

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