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Issue 100
Nerves, Eyes, Bones and Bacteria
HEALTHY BONES
Bones are made of a matrix of water, protein fibres and mineral salts. Bone tissue has many channels for blood vessels delivering nutrients and oxygen to
nourish and make new cells. Bones containing bone marrow have more blood vessels. Bone mass is greater in men than women. Bones stop growing in
length at about 16-18 years but, bone density continues to increase until about the age of 30 years, then it begins to decline. Good circulation is important to healthy bones(3). Fractures may occur when bone is stressed or suffers a hard blow. If an abscess infects the bone, the resulting inflammation may interfere
with the blood supply, leading to part of the bone dying(4).
Osteoporosis
Osteoporosis is defined as progressive deterioration of bone mass and tissue, leading to an increase in bone fragility. More than one third of adult women in the UK will suffer one or more osteoporotic fractures in their lifetime. In men, the risk is about half that of women. Decrease in bone mineral density, caused among other factors by calcium and vitamin D deficiency, is the most common cause of fractures.
There is evidence that food supplement formulas containing calcium and vitamin D may help prevent the onset of osteoporosis and bone fractures in the ageing
population(5). If levels of calcium in the diet are causing concern, a supplement specially formulated for bone health or a calcium supplement together with a
multinutrient may be considered to help safeguard dietary intake.
PROBIOTICS(6)
Probiotic bacteria are micro-organisms that have the specific property of transforming sugars almost exclusively into lactic acid. They are abundant in nature, where probiotic bacteria such as lactobacillus plantarum are found in and on plants. The most natural way of obtaining good bacteria is through food, however, the processing and preparation of food can be detrimental to the lactic bacteria found in fresh foods. Production of cheese, yogurt, cultured buttermilk, kefir, sauerkraut and other fermented foods relies on lactic bacteria. Lactic bacteria are essential for human survival. They are normally present on the skin, in the digestive tract and the vaginal mucosa, where they fulfil numerous functions including protection of tissues against the action of harmful microbes, therefore having a beneficial role in general health. The most dramatic changes in the intestinal bacteria happen between birth and weaning, then again in the later stages of life. In between, the microbial population of the dominant bacteria remains relatively stable and prevents potentially pathogenic bacteria from sticking to the intestinal wall by creating a 'barrier effect'. The balance of bacteria in the digestive tract remains fragile and susceptible to lifestyle changes such as stress, diet, antibiotics or other medicines. An imbalance can result in various disorders including bloating, intestinal pains, nutritional deficiencies and constipation.
Diarrhoea is an example of the 'barrier effect' being disrupted by the pathogenic bacterium Clostridium difficile. The intestinal wall is the primary site of action for probiotics where they interact with immune cells. The intestinal immune system is important in two ways for health. Firstly, to suppress the immune response against foreign proteins from bacteria or food found in the digestive tract. This helps prevent oversensitivity to food and minimises chronic digestive tract inflammation such as Crohn's disease. Secondly, to promote protective immune responses against pathogenic bacteria, the synthesis of antibodies is a key component of protective immunity in the gut.
In later years (around fifty and over) it is particularly important to maintain the levels of bifidobacterium in the colon because the body does not produce them
to the same extent as during infancy. It is recommended that we consume at least 3 grams of fructo-oligosaccharides a day to help provide the correct background to maintain friendly bacteria levels. They are found in many foods including bananas, most vegetables, wheat, onions and garlic.
EYES
Most people take the health of their eyes for granted. Regular eye tests help determine the health of the eyes as well as how the sight may have changed.
Good advice could include avoiding smoky atmospheres and to protect the eyes from direct sunlight. Eyes need a continuous supply of nutrients. Light-sensitive nerve cells on the retina convert images into electrical impulses that are carried by the optic nerve to the brain. The brain controls both eyes so that they work in
conjunction with each other, aligning themselves onto an object so that a clear image is formed on each of the retina(4). Eyes are susceptible to cellular damage caused by free radicals and other by-products of oxygen metabolism. This damage is known as oxidative stress and has been implicated in many disease processes, especially age related disorders. The retina is particularly susceptible to oxidative stress because of its high consumption of oxygen, its high proportion of polyunsaturated fatty acids and its exposure to visible light. The antioxidant vitamins A, C and E protect cells against oxidative stress(7).
NERVES
Nerves are governed by two systems - autonomic and central. The autonomic nervous system controls things the body does 'automatically' like digestion,
temperature regulation and heart rate. The central nervous system consists of the brain and spinal cord linked to a network of nerve fibres which carry messages from body tissues and organs back to the brain. The central nervous system turns thoughts into actions; for example stirring a cup of tea. The central
nervous system is the one we are most aware of. Although nerves may easily be damaged by viruses, compression, injury or surgery, the cells have a limited
ability to repair themselves if good nutrition is present(8). |
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