Category: Main EN

  • Normal aging of the skin

    How does the skin age?

    The skin is a barrier between our body and the outside world, protecting us from aggressors, retaining water and controlling our temperature. The skin has three layers: the epidermis, the dermis and the subcutaneous tissue.

    As the skin ages, these three components undergo changes. Some changes are obvious: wrinkles appear and elasticity decreases. Indeed, our skin cells are no longer as efficient, the fibres (collagen and elastin) that give structure and elasticity to our skin are less numerous, melanomas fill up with melanin creating dark spots… The causes are numerous: internal, such as genetics, cell metabolism and hormonal changes (e.g. at menopause), but also external, including sun exposure (UV), pollution, chemicals, oxidative stress, regular sugar consumption, smoking, skin care, UV for example promotes the destruction of extracellular matrix fibres (collagen, hyaluronic acid) and damages mitochondria (part of the cell responsible for reducing oxidative stress, cell survival and energy production).

    What about hair and nails?

    Our hair and nails also age. Their growth, structure and colour change. In the hair, the fibres in the roots are weaker, the melanocytes responsible for colour function less well, and the follicle cells decrease in hair production. The nails are more fragile, thin and discoloured, the morphology of the nail plate (which grows the nail) changes and their lipid content varies with age.

    This is a normal process, as the cells degenerate progressively, but oxidative stress and the environment (care, pollution, sun…) have a long-term effect.

    What can be done to maintain beauty?

    As the famous quote goes “You never get a second chance to make a first impression”, so every day is important in the quest for healthy ageing in general and skin ageing in particular.

    We can act to avoid external factors that can have a negative effect on our appearance, because prevention is our ally: a healthy lifestyle can limit the harmful effects of this oxidative stress, notably through physical exercise, a low-stress environment (which also has a positive effect on cardiovascular disease, the immune system and neuropsychiatric functions), appropriate sun exposure, good sleep and a healthy diet including plenty of plants.

    Disclaimer of liability:
    The information published on www.swiss-alp-health.ch does not claim to be complete and is not a substitute for individual medical advice or treatment. It cannot be used as an independent diagnosis or to select, apply, modify or discontinue treatment of a disease. In case of health problems, it is recommended to consult a doctor. Any access to www.swiss-alp-health.ch and its contents is at the user’s own risk.

  • The functioning of brain and eyes

    Parts and functions of the brain

    The brain works like a big computer. It processes the information it receives through the 5 senses, and sends back messages, conscious and unconscious, to the body. However, the functions of the brain go much further with the ability to think, make decisions and feel emotions.
    The size of the human brain can be estimated at two clenched fists and its weight is around 1.5 kg. On the outside, it looks a bit like a big walnut, with folds and crevices. Brain tissue is made up of about 100 billion neurons and a trillion cells that support and nourish the tissue (glial cells).

    The brain is made up of different parts: the brain, the cerebellum and the brain stem. The brain, for the most part, is made up of the cerebral cortex (divided into 2 hemispheres, right and left, which themselves can be divided into lobes) as well as the thalamus, hypothalamus, amygdala, hippocampus… Then, moving closer to the spinal column, we find the other parts : cerebellum (at the back) and the brain stem (composed of the midbrain, the pons, and the medulla), and finally, we reach the spinal cord.

    Each part has its own functions: movement coordination, spatial orientation, problem solving and planning, emotions, decoding of sensory information, attention, language, memory, appetite or sleep control, reflexes and reward mechanisms, control of unconscious activities such as blood glucose levels, hormone production, respiratory or cardiac rhythm…1,2

    Différents parts of the brain

    Neurons and information transmission 

    A neuron is a cell composed of a “body” (like all cells, with a nucleus containing DNA and organelles for the synthesis of proteins and energy), small receptor “arms” called dendrites and a long transmitter “arm” called an axon. A neuron will pick up different types of information or stimuli and transport them as an electrical signal (the myelin around the axon allows rapid transport). On arrival, the electrical signal allows the release of neurotransmitters (chemical molecules). These will end up in a small space between 2 neurons, called a synapse, and then bind to the next neuron. If there are enough neurotransmitters that bind to the receptors of the 2nd neuron, the activation threshold will be exceeded and an electrical signal will be created and propagate to the end of this neuron, releasing neurotransmitters in a new synapse, etc. There are also inhibitory neurotransmitters (e.g. GABA), which aim to prevent activation of the 2nd neuron. Finally, specific neurotransmitters allow the transmission of specific information (dopamine – for motivation/reward system, decision of movements, serotonin -stability, inhibition-, acetylcholine -muscle contraction, memory-, noradrenaline -regulation of metabolism, attention, learning- … ).3,4,5

    How does vision work ?

    How do our eyes and brain work together to transform light into an image? Light rays enter the eye through the cornea, the transparent layer on the outside of the eye, and then pass through the pupil in the centre of the iris. The iris has the ability to enlarge and shrink, depending on the amount of light entering the eye. The light rays then pass through the natural crystalline lens of the eye, which shortens or lengthens to focus the light rays correctly on a specific point on the retina. The retina captures all the light rays thanks to two types of cells: the rods are sensitive to the intensity of the light, and the cones are used to see colours (they are activated by green, red or blue). The cells that are activated send an electrical signal towards the optic nerve. The signals coming from each eye meet at the optic chiasm and then divide again according to the visual field (the left part of the image – coming from both eyes – goes to the right hemisphere of the brain and vice versa). These optical fibres then go to the back of the brain, in the visual cortex part of the occipital lobe, where the information will be decoded.6, 7,8

    Differents parts of the eye

    Aging of the brain

    As we age, the brain changes at all levels. The morphology is different: the volume decreases (from -5% per decade after 40 years old, especially in the prefrontal cortex which regulates reasoning, and part of the personality and emotions), the vascularisation changes, irrigating certain areas less, etc. Modifications are also found at the level of cells (slower transmission of information -demyelination-), synapses (changes/loss of connections) and molecules (reduced secretion of neurotransmitters and hormones). 

    Fortunately, the brain remains plastic and some losses can slow down or even improve with time and training. Certain factors such as regular exercise, healthy nutrition and a limited alcohol intake, seem to be beneficial in keeping the brain functional. Thus, according to article “Dietary and Lifestyle Guidelines for the Prevention of Alzheimer’s Disease,”11 published in 2014 in the scientific journal Neurobiology of Aging: “Vegetables, legumes (beans, peas and lentils), fruits and whole grains should replace meats and dairy products as a basic part of the diet”.

    This article is intended to summarize the basics of how a part of the human body works, but in no way replaces medical diagnosis and treatment.

    Disclaimer of liability:
    The information published on www.swiss-alp-health.ch does not claim to be complete and is not a substitute for individual medical advice or treatment. It cannot be used as an independent diagnosis or to select, apply, modify or discontinue treatment of a disease. In case of health problems, it is recommended to consult a doctor. Access to www.swiss-alp-health.ch and its contents is at the user’s own risk.

    1. Anatomie du cerveau et du système nerveux – Fédération pour la Recherche sur le Cerveau (FRC). https://www.frcneurodon.org/comprendre-le-cerveau/a-la-decouverte-du-cerveau/anatomie-du-cerveau-et-du-systeme-nerveux/.
    2. How does the brain work? – InformedHealth.org – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK279302/.
    3. How do neurons work? – Queensland Brain Institute – University of Queensland. https://qbi.uq.edu.au/brain-basics/brain/brain-physiology/how-do-neurons-work.
    4. How does a neuron work? https://www.wingsforlife.com/en/latest/how-does-a-neuron-work-562/.
    5. Comprendre le cerveau et son fonctionnement – Institut du Cerveau. https://icm-institute.org/fr/actualite/comprendre-le-cerveau-et-son-fonctionnement/.
    6. How the Human Eye Works | Cornea Layers/Role | Light Rays. https://www.nkcf.org/about-keratoconus/how-the-human-eye-works/.
    7. How Does Vision Work? – Video & Lesson Transcript | Study.com. https://study.com/academy/lesson/how-does-vision-work.html.
    8. Bâtonnets et cônes | Ask A Biologist. https://askabiologist.asu.edu/batonnets-et-cones.
    9. Peters, R. Ageing and the brain. Postgraduate Medical Journal vol. 82 84–88 (2006).
    10. What happens to the brain as we age? https://www.medicalnewstoday.com/articles/319185#Recent-discoveries-in-brain-aging.
    11. Barnard, N. D. et al. Dietary and lifestyle guidelines for the prevention of Alzheimer’s disease. Neurobiology of Aging vol. 35 S74–S78 (2014).

  • What is oxidative stress?

    Oxidation, how does it work?

    Oxidation is a chemical reaction that takes place in the presence of oxygen. You can see it when you cut an apple: once cut, the apple tends to turn brown because one of its enzymes reacts with oxygen and transforms a molecule (called phenol) into another molecule (called quinone) which will decompose into a brown pigment. The addition of lemon juice will slow down this browning because it contains vitamin C, a strong antioxidant, which will reduce the quantity of quinones and thus prevent the brown pigment from appearing.

    It is the same balance between oxidation and anti-oxidation that takes place in each of our cells. Of course, we need oxygen to live and each of our cells uses it in many processes. During some of these reactions, for example when ATP cell energy is produced, free radicals (ROS – reactive oxygen species) are formed. Their presence – in small quantities – is normal, and they have certain functions such as communication between cells, the synthesis of cellular components or as a weapon of the immune system against pathogens. At the same time, ROS are constantly detoxified by certain antioxidant enzymes or by other mechanisms, to become harmless products, such as water H2O.1,2 An oxidative balance is reached, and normally works very well! Except that this is not always the case…

    It’s all a question of balance… Otherwise, it’s oxidative stress!

    Oxidative stress is a phenomenon caused by an imbalance between the production and accumulation of free radicals (ROS) in cells and tissues, and our body’s ability to detoxify these reactive products.1

    While the presence of ROS created by our cellular metabolism is normal, certain environmental factors, such as UV rays, ionizing radiation, pollutants, heavy metals, tobacco, alcohol, certain drugs and chemicals, contribute to a significant increase in the production of ROS. This large amount of ROS cannot be fully detoxified by our antioxidant defences, and this imbalance leads to cell and tissue damage. This is called oxidative stress.

    To counteract this, there are also exogenous antioxidants which can react with ROS to render it harmless, prevent its production or activate antioxidant enzymes.1,2  Vitamins B2, C, E, selenium, copper, manganese, zinc and polyphenols in olive oil help protect cells from oxidative stress.

    Why is oxidative stress negative?

    When there is too much ROS in relation to our antioxidant defences, the membranes of our cells and our proteins, lipids, DNA etc. will be “attacked” and damaged.1 Changes in the DNA of a cell lead to a deregulation of its functions and “behaviour”, which will impact the tissue in which it is located. 

    Aging can be defined as “the progressive loss of function of our tissues”, and the repetition of damage due to excess ROS can therefore accelerate it. Thus, over time, if oxidative stress is not reabsorbed, damage accumulates, tissues are no longer able to maintain their homeostasis and become dysregulated.1 Moreover, with age, antioxidant defences are reduced, making us more sensitive to excess ROS.4

    Fortunately, it is never too late to get involved in reducing oxidative stress in our bodies. The generation of exogenous ROS can be minimised by avoiding exposure to radiation, pollutants, heavy metals, tobacco and alcohol, certain drugs and chemicals.

    Beneficial physical activity

    Moderate and regular aerobic physical activity (long, low-intensity aerobic exercise using oxygen in the muscles) is also important to limit the accumulation of oxidative stress because it stimulates antioxidant defences, especially in the muscles. It is also essential for maintaining good health in general. However, high-intensity physical activity will increase oxidative stress in our bodies.4

    Disclaimer of liability:
    The information published on www.swiss-alp-health.ch does not claim to be complete and is not a substitute for individual medical advice or treatment. It cannot be used as an independent diagnosis or to select, apply, modify or discontinue treatment of a disease. In case of health problems, it is recommended to consult a doctor. Access to www.swiss-alp-health.ch and its contents is at the user’s own risk.

    1. Pizzino, G. et al. Oxidative Stress: Harms and Benefits for Human Health. Oxidative Medicine and Cellular Longevity vol. 2017 (2017).
    2. Burton, G. J. & Jauniaux, E. Oxidative stress. Best Practice and Research: Clinical Obstetrics and Gynaecology vol. 25 287–299 (2011).
    3. Birben, E., Sahiner, U. M., Sackesen, C., Erzurum, S. & Kalayci, O. Oxidative stress and antioxidant defense. World Allergy Organization Journal vol. 5 9–19 (2012).
    4. Liguori, I. et al. Oxidative stress, aging, and diseases. Clinical Interventions in Aging vol. 13 757–772 (2018).
    5. Salim, S. Oxidative stress and the central nervous system. Journal of Pharmacology and Experimental Therapeutics vol. 360 201–205 (2017).
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