New review explains how overconsumption of fructose, a common additive in sweetened foods and beverages, can contribute to diseases CREDIT Chinese Medical Journal

In today’s fast-paced world, the dependence on the widely available “fast” foods and beverages has risen. These foods are typically low in fiber and essential nutrients, and often consist of high amounts of added sugar. This shift in dietary trends, accompanied by a sedentary lifestyle, has been attributed to the rise in various metabolic disorders like diabetes, fatty liver disease, and heart disease. The concerning thing about sugar is that the more you eat it, the more you crave it—leading to a vicious cycle of excessive sugar consumption and poor health.

So what exactly is this added sugar and why is it so bad for us? To understand this, let us first understand the basics. Refined sugar (or “sucrose”) is structurally composed of two simple forms of sugars called “glucose” and “fructose.” Although these simple sugars are structurally similar to each other, they are metabolized via different pathways in the body. And while excessive fructose intake (even within “normal” ranges, to some extent) has been shown to be harmful for us, the underlying mechanisms behind fructose metabolism and their potential role in metabolic disorders have not been fully understood so far.

Researchers from China, thus, sought to understand the fate of dietary fructose in the body and pathways regulating its metabolism, in a comprehensive review published in Chinese Medical Journal. Explaining the clinical implications of their study, Prof. Weiping J. Zhang, corresponding author of the study, says, “Our review provides a comprehensive update on the progress on molecular and cellular aspects of fructose metabolism and their role in the development of metabolic diseases. These findings can aid the development of new diagnostic, preventative, and therapeutic strategies for metabolic diseases.”

The researchers begin by explaining that most of the fructose that we ingest is absorbed by cells lining the intestine. Protein transporters called GLUT5 and GLUT2, expressed by intestinal cells, facilitate this absorption, with GLUT5 showing the highest affinity to fructose. Interestingly, these receptors are regulated in response to fructose levels, and thus, GLUT5 deficiency can result in fructose malabsorption and intestinal dysfunction. In fact, studies in mice have shown that deletion of GLUT5 can cause intestinal problems like gas and fluid accumulation. This is why, GLUT5 is a potential drug candidate for certain fructose-induced diseases.

Now when fructose enters circulation, its levels in the blood (albeit much lower than glucose) are kept at bay by the kidney and liver, both crucial metabolic hubs in our body. In these organs, fructose is redirected for glucose production, via a process called “gluconeogenesis.” However, this reaction requires the breakdown of a molecule called “ATP” (the main source of energy in cells). Thus, an excessive intake of fructose can lead to ATP depletion in cells, which activates another pathway involved in uric acid metabolism—leading to an accumulation of uric acid in the blood and joints and increasing the risk of developing “gout” (a condition causing severe joint pain). The researchers further explain that fructose consumption can also trigger an increase in cholesterol levels and abdominal fat, increasing the risk of heart disorders.

Next, the study talks about gene-level changes that regulate fructose metabolism. A protein called “ChREBP” is a crucial regulator of genes involved in the absorption, transport, and degradation of sugars. Animal studies in ChREBP-deficient mice now suggest that ChREBP is essential for fructose absorption and clearance. The molecular mechanisms regulating ChREBP activation in response to fructose stimulation, however, remain less understood. Prof. Zhang explains, “Obtaining a better understanding of the biochemical regulatory mechanism of ChREBP pathway can definitely provide new clues into the regulation of fructose metabolism and its metabolic effects. Future advances in this field will benefit our efforts to achieve better cardiometabolic health and inform clinical recommendations on the dietary intake of sugar.”

Overall, these findings shed light on how an increase in fructose consumption can lead to an imbalance in various metabolic pathways in our body and subsequently cause various diseases.

Indeed, what we eat plays a huge role in our overall health!

Give your body the best chance at fighting off illness by boosting natural immunity every day, all year.

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It racks up nearly half a billion Google search results a week? Yet 1 in 4 Brits have no idea what ‘natural Immunity’ means. So says a new report^[1] by The Fruit Juice Science Centre – Brits Wrecking Their Immune Health Thanks To COVID-19 Stress – Why we all need to love our immune health, naturally, inside out. And nearly half of us are not aware that maintaining a healthy immune system year-round is the key to good health. In fact, 20% say good immune health is only needed during the winter!

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Touching on natural immunity, Dr Gill Jenkins defines this 2021 buzzword as “living our life in a way that keeps our immune system healthy, before we add in other protections, such as vaccination or handwashing”.

“Your immune system is working 12 months of the year, 24/7. Luckily there are things you can do every day to maintain a strong immune system,” reveals Dr Gill Jenkins, who adds that nutrients including vitamin C and folate are essential for the immune system to work normally.

“Both of these can be found in orange juice with one 150 ml glass of pure orange juice providing 84% of Vitamin C – the Nutrient Reference Value (NRV) — the dietary target set for the UK and Europe.”

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And whilst it’s safe to say that the state of our immune system has never been more important, the past 12 months has left 75% of Brits stressed and anxious. Unfortunately, this stress can wreak havoc on our immune health.

Nearly half of those who experience stress most days said they gained weight gain in the past year, with 34% turning to takeaways and ready meals as a stress relief. Plus, research by The Fruit Juice Science Centre reveals that a quarter of respondents admit to drinking more alcohol now than before lockdown, and moving less, as research published by UCL⁹ says that 40% of Brits reported less exercise in the most recent lockdown compared with the first one.

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So, with our natural immunity taking a knock, here’s what we can do to provide our body with the support it needs…

#1. Get a vitamin C hit by drinking a daily glass of pure orange juice

It’s such an easy daily habit, yet according to the UK’s National Diet and Nutrition Survey (NDNS), adults typically drink just 2 servings of fruit juice a week, while children and teens only have 3 to 4 servings a week. Ensuring a daily glass of 150ml of orange juice doesn’t just deliver vitamin C and folate, it also provides potassium, needed for normal blood pressure. Plus, 100% fruit juice is a bioavailable source of nutrients and polyphenols – antioxidant-packed substances naturally found in many plant foods.

Hesperidin is the hero polyphenol found in 100% pure orange juice, although 80% of people say they haven’t even heard of it.

Dr Nisa Aslam explains that commercially squeezed orange juice contains three times more hesperidin than you can find in juice squeezed at home, offering more of its antibacterial and antiviral benefits. “There is also now emerging evidence claiming that hesperidin ‘may be a novel substance in the fight against coronaviruses.” Yet another reason to get your daily dose of orange juice.

#2. Practice stress management

Only 14% of people have attempted to de-stress or lower their levels of anxiety in a bid to improve their immune system, according to the research by the Fruit Juice Science Centre.

Simply devoting time to diaphragmatic breathing can help lower stress levels. Dr Gill Jenkins recommends Boxed Breathing. Breathe in through your nose for a count of four, keeping the air in your lungs for a count of four, exhale for a count of four, then hold the air out and keep your lungs empty for a count of four

Taking time away from digital devices will also help as nearly three-quarters of those who feel stressed and anxious most days are spending more time watching TV and films and scrolling through social media than before lockdown. Dr Nisa Aslam adds that a daily 20-minute walk in nature, as well as interacting with loved ones also help to relieve stress.

#3. Take time to exercise

One study found that moderate and vigorous-intensity exercise bouts of 30-60 minutes improved immune defence activity and metabolic health^[2]. “Aim to get your heart rate up and break sweat a few times a week. The rush of feel-good endorphins works wonders at improving a negative mood and lowering stress levels,” says Dr Gill Jenkins, who recommends brisk walking, running, cycling and resistance training as good options.

#4. Focus on nutrition

Whilst pure orange juice is a wise addition to your day-to-day diet, there are other foods too providing nutritional essentials for natural immunity. Dr Gill Jenkins recommends vitamin D from oily fish, eggs and fortified foods.

“This should be topped up daily with a vitamin D supplement containing at least 10ug, as per advice from the Department of Health and Social Care. As vitamin D is primarily made when sunlight hits our skin, the UK’s darker months and even cloudy days in summer don’t provide sufficient sunlight to safeguard optimal blood levels.”

Dr Gill Jenkins also suggests folate rich foods including kale Brussels sprouts, broccoli, chickpeas and kidney beans and fortified breakfast cereals. “Omega-3 fatty acids, found in oily fish, nuts and seeds are also important for natural immunity as are polyphenols, prebiotics and probiotics, which all help with our gut health. Around 70-80% of our immune cells are found in the wall of the gut and the gut microbiota and immune system are mutually dependent as each influences the other. “Feed your good bacteria with fruits and vegetables and their juices, fermented foods like kefir and kombucha, garlic, onions and fibrous foods.

#5. Crack the sleep code

Despite the NHS advising adults to get six to nine hours of sleep a night, 43% of those who reported feeling stressed most days in the Fruit Juice Science Centre poll, get less than six hours of shut eye a night. Ensure optimum rest by sticking to consistent sleep/wake routine and winding down before bed. Remove yourself from digital devices to avoid alertness caused by blue light, and try various ‘calming’ activities such as meditation, a hot bath and/or reading.

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^[1] UK Wrecking Their Immune Health Thanks To COVID-19 Stress – Why we all need to love our immune health, naturally, inside out; Summerpring 2021

^[2] https://www.sciencedirect.com/science/article/pii/S2095254618301005 – ‘The compelling link between physical activity and the body’s defence system’