Our ageing rate varies - Can we know anything about it?
You may have heard about biological age before. It is the idea that your chronological age, shown on your driver’s license, for example, does not reflect your physiological age. You may naturally come to this conclusion by observing your group of friends. The exact same time has passed for everybody, with radically different consequences. One of your best friends from high school may seem blessed with endless energy and youthful skin. Scientists succeeded in quantifying this common assumption by studying different biomarkers and developing algorithmic models to determine what age reflects you the most. Today, we would like to dive deeper into a promising one: glycans. What are they, and how can they help you to know more about your ageing process?
Glycans are crucial for the immune system
Glycans are sugar-chain structures attached to protein and lipids. They’re present on all cells and look like trees made of mini-blocks of sugars, such as mannose, galactose, glucose and sialic acid. The shapes of these blocks can teach us a lot about their conditions and how they interact with the attached proteins. This is a crucial achievement as they are essential for the cells to be healthy and function properly.
We can learn plenty about our immune system by looking at the glycans on Immunoglobulin G (IgG), the most abundant antibody in our blood. IgGs help the body to defend against infection from bacteria and viruses. Glycans switch them to determine whether they’re in proinflammation mode or anti-inflammation mode. A normal immune response means that IgGs are balanced between these two functions. A lot of proinflammatory IgGs favour the development of auto-immune diseases. Too many anti-inflammatory IgG would weaken our immune system.
Hence, the glycans on IgG are amazing biomarkers for inflammaging, one of the hallmarks of ageing. The older you get, the more prone you are to chronic inflammation that can deteriorate your immune system. We can then determine your ageing rate and biological age by measuring your inflammatory index.
Glycans evolve with ageing
Ageing challenges this precious balance. Glycans on IgGs are one of the ways to balance low-grade inflammation. With ageing, glycans on IgGs tend to be more proinflammatory, whereas young glycans suppress low-grade chronic inflammations. Losing this regulation makes us more prone to cardiovascular diseases and other deteriorations.
Just as we don’t age the same way, glycans do not age similarly. There are three main reasons behind the change in glycans:
- 20% are due to the passage of time. The “mini-trees” lose sialic acid and galactose blocks as they age. As a result, they go from an anti-inflammatory function to a proinflammatory stage. This imbalance negatively affects the immune system.
- 40% are due to genetics. Our genome carries an ample panel of information, including our glycan composition. Studies have linked ethnicity and a different pace of ageing by studying glycosylation.
- 40% are due to lifestyle. Glycans are highly reactive to lifestyle choices such as stress, exercise and diet.
Sadly, we cannot change the course of natural ageing and genetics. However, we can most definitely change our lifestyle.
With ageing, hormones fluctuate. We also notice that women in menopause are more prone to inflammatory diseases like diabetes, dementia or cardiovascular diseases. Interestingly, the profile of the IgG glycans in women hitting menopause also becomes exponentially more proinflammatory, especially compared to their male counterparts. A study on young women with chemically induced menopause revealed that the ones receiving oestrogen supplementation had their IgG glycans balanced again between pro and anti-inflammatory mediators.
Men also face hormonal imbalance with ageing: andropause. Unlike women, their transition is more steady and less abrupt. Accordingly, they don’t experience this sudden upsurge in their glycan age and inflammatory symptoms.
Evolution could not have developed humans to live for so long after reproduction. Our bodies could not have been designed to function for so long without high levels of hormones such as oestrogen or testosterone. Consequently, dysfunctions appear with ageing, such as an imbalance in the IgG glycans, provoking inflammatory diseases.
Modify your lifestyle
Many studies correlate the environment to glycans, such as diet and medical interventions. They offer us leads for lifestyle changes that could potentially lower your biological age and improve your immune system. The following examples review the current scientific literature and should not constitute medical advice. Always seek the guidance of your doctor or other qualified health professional with any questions regarding your health or medical condition.
Your microbiota is one of the first doors to external elements, such as dust, microbes or germs. In consequence, it is considerably connected to your immune system. It is one of the explanations why auto-immune diseases are frequently linked to the gut and the stomach. Taking care of your microbiota can lower your biological age and optimise your glycans. You can start by eating a variety of vegetables, nuts and fruits. It will help your immune system understand its surroundings and make better inflammatory response choices.
Intermittent fasting is a diet in which you do not restrict what you eat but when you eat. The most common is the 16:8, which means you fast for sixteen hours and eat in an eight-hour window. Studies in mice show several potential benefits, including increased microbial diversity and reduced inflammation.
A sedentary lifestyle coupled with a rich diet can lead to obesity. The accumulation of excessive fat stimulates the release of inflammatory mediators and reduces the production of anti-inflammatory hormones such as adiponectin. Researchers have proven that extensive weight loss benefits people in an overweight situation. It reduces glycan age by altering the glycans on IgG. Subjects have been exposed to low-calorie diets and bariatric interventions to lower their weight. In both cases, the profile of their glycans changed for the better, and their biological age decreased. We can presume that body fat loss stimulated cytokines, which enhanced the immune system. Cytokines are small proteins that trigger the immune system to react. They can be anti-inflammatory and proinflammatory, and their balance is essential in defending against pathogens.
Scientific studies have highlighted the benefits of exercising on the body and mind. You might not be surprised to learn that exercising also has anti-inflammatory benefits on your IgG glycans. Intensive exercises like high-intensity interval training (HIIT) and sprint training under proper recovery are great for your immune system. But simply walking more and being more active overall helps your anti-inflammatory glycans. Balance is also crucial in exercising. Scientists have linked overtraining with higher biological age, proinflammatory glycans and dysregulated immune system. Often, overtraining is more a matter of improper recovery than too much exercising. Do not forget to rest, eat and sleep enough while exercising for a prolonged time. Especially if your goals are to lose weight, caloric restriction and intensive exercise can accelerate overtraining and, consequently, inflammations.
The mind-body connection is extremely powerful. Your exposure to stress can onset actual diseases and accelerate ageing. Indeed, the neuroendocrine system may become unbalanced when exposed to intense stress or prolonged stressful situations. As a result, it can create a chain reaction of molecular mechanisms that can trigger chronic inflammations and diseases. Your nervous system causes specific cells to release hormones into the blood that can deteriorate your organism. Scientists have underlined changes in protein glycosylation in patients with post-traumatic experiences. As a result, it lowered their biological age. You must limit your exposure to stress in your daily life for better ageing. Our modern lifestyle can be challenging, but incremental changes can go a long way. Getting the right amount of sleep may help lower those stress hormones. Having a regular sleep schedule, limiting your exposure to bright lights at night and avoiding caffeine in the second half of the day can help optimise your sleep. Creating a meditation routine has also been proven to help face stressful situations while lowering resting heart rate and blood pressure and improving sleep quality.
Glycans are an essential element in your cells and immune system functioning. We can learn a lot by analysing their shapes, such as your biological age, ageing rate and immune system condition. By pairing this information with your lifestyle, you may be able to shape a healthy routine that works for you. Let’s keep in mind that no universal lifestyle changes work for everyone. The effects vary from one individual to another. The advantage of implementing those changes while measuring your glycan’s conditions is having fast feedback on the results to build the longevity strategy that suits you best.
"Intense Physical Exercise Induces an Anti-inflammatory Change in IgG N-Glycosylation Profile" - Frontiers in Physiology. [Online] Available at: Frontiers
"Mucin-derived O-glycans supplemented to diet mitigate diverse microbiota perturbations" - Nature Microbiology. [Online] Available at: Nature Microbiology
"Extensive weight loss reduces glycan age by altering IgG N-glycosylation" - PubMed. [Online] Available at: PubMed
"N-glycosylation profiling of plasma provides evidence for accelerated physiological aging in post-traumatic stress disorder" - Translational Psychiatry. [Online] Available at: Translational Psychiatry
"Interactions between sleep, stress, and metabolism: From physiological to pathological conditions" - PubMed. [Online] Available at: PubMed
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"The Role of Sleep Hygiene in Promoting Public Health: A Review of Empirical Evidence" - National Center for Biotechnology Information. [Online] Available at: NCBI
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"Obesity and inflammation: the linking mechanism and the complications" - National Center for Biotechnology Information. [Online] Available at: NCBI
"Circulating cytokines as determinants of weight loss-induced improvements in insulin sensitivity" - National Center for Biotechnology Information. [Online] Available at: NCBI
"Menopause: an evolutionary perspective" - PubMed. [Online] Available at: PubMed