21 janeiro, 2008

O uso de antioxidantes na prevenção da doença



Os antioxidantes têm sido promovidos como terapêutica preventiva em diversas situações. Dados epidemiológicos têm, de facto, mostrado uma forte relação inversa entre a ingestão de antioxidantes, ou alimentos ricos nesses nutrientes e o risco de cancro e doença cardiovascular isquémica.
A avaliação da terapia com antioxidantes em humanos tem geralmente dado resultados desanimadores. Até à data, os resultados publicados de ensaios aleatórios e controlados de suplementos com antioxidantes não têm proporcionado uma clara evidência de efeito benéfico.
Resultados de grandes ensaios multicêntricos mostraram que os suplementos antioxidantes nem sempre foram eficazes para reduzir a incidência de cancro ou problemas cardiovasculares,
particularmente em doentes de alto risco.
Não têm confirmado o efeito benéfico potencial, e alguns deles têm mesmo sugerido efeitos negativos para a saúde.
Alguns autores argúem que a falha na demonstração do benefício com os antioxidantes é devida a dose inadequada, à duração do tratamento ou ao tipo de antioxidantes.
Os resultados positivos dos ensaios observacionais podem sugerir que os antioxidantes sejam marcadores para outro factor que proporcione benefício. Em geral, os melhores
resultados dos antioxidantes foram observados em estudos epidemiológicos com derivados da dieta. Não se sabe se esses efeitos benéficos podem ser especificamente atribuídos
aos antioxidantes identificados nesses alimentos; podem ser necessários os variados nutrientes encontrados nos alimentos ricos em antioxidantes, que actuariam sinergicamente,
proporcionando os efeitos protectores.
A quantidade de antioxidantes nos suplementos pode ser tão elevada, comparada com a dieta, que leva a um efeito tóxico.
No desenho dos estudos será importante considerar os estilos de vida. Na interpretação de estudos prospectivos de coortes, os enviesamentos são inerentes à selecção de participantes;
por exemplo, as pessoas que consomem grandes quantidades de frutos e vegetais tendem a ter um estilo de vida saudável. Os resultados positivos dos estudos observacionais poderiam estar relacionados com este estilo de vida.
Os estudos observacionais realizam-se na população geral, enquanto muitos ensaios são efectuados em doentes de alto risco. É possível que, pela idade e características ligadas
ao risco, esses indivíduos sejam menos susceptíveis à redução dos problemas cardiovasculares.
Tendo em conta o aumento da mortalidade com altas doses de betacaroteno e recentemente com a vitamina E, o uso de suplementos com doses altas deve ser desaconselhado até existir evidência de eficácia, documentada por ensaios clínicos bem concebidos. Devem ser considerados todos os riscos possíveis dos suplementos, especialmente no doente crónico.
O papel exacto dos suplementos com antioxidantes na prevenção da doença não está estabelecido. Os antioxidantes não devem ser utilizados por rotina numa população
com uma alimentação variada.
Assim sendo, as actuais recomendações indicam que a estratégia mais segura e eficaz na prevenção e tratamento de doenças associadas às lesões oxidativas continua a ser a manutenção de uma dieta variada, rica em frutos e vegetais, ricos em nutrientes antioxidantes e outros fitoquímicos.
O farmacêutico recomendará uma dieta equilibrada e estilos de vida saudáveis com exercício moderado, sobriedade no consumo de álcool e evitando o tabaco.

Aurora Simón (Conclusão de um estudo publicado no Boletim do CIM - 2005)

19 janeiro, 2008

Sulfato de Glucosamina mais eficaz e seguro no tratamento da artrose


As diferenças entre o sulfato e o cloridrato de glucosamina estão patentes nos critérios de análise dos estudos realizados. O sulfato tem uma farmacocinética conhecida, um mecanismo de acção definido e tem vindo a demonstrar, de uma forma consistente, eficácia no tratamento da artrose e no alívio da dor. O benefício do sulfato de glucosamina no tratamento da artrose do joelho, enquanto medicamento de prescrição médica, está demonstrado em estudos de longa duração que comprovam não só o seu efeito modificador da doença como também de alívio da dor, o principal sintoma referido pelos doentes.Lucio Rovati, chefe do Departamento Clínico e de Investigação do grupo Rotta Research explicou, durante o Congresso Mundial de Osteoartrose que decorreu em Praga, qual a diferença entre a o sulfato de glucosamina, de prescrição médica na Europa e o cloridrato de glucosamina, suplemento nutricional nos EUA. Segundo o especialista, “embora similares, não falamos da mesma substância. O sulfato de glucosamina está testado, registado e foi submetido a rigorosos estudos de qualidade. O seu mecanismo de acção está perfeitamente claro e, por isso, podemos garantir o seu efeito benéfico no tratamento da artrose”, disse o investigador. Por isso, “as substâncias não devem ser confundidas e os seus efeitos devem ser analisados em separado”, diz o investigador, sublinhando que também os critérios de análise dos resultados dos estudos devem ser revistos. A biblioteca Cochrane revive e analisou recentemente todos os estudos realizados com esta substância e “concluiu que o sulfato de glucosamina original tem efeitos benéficos na diminuição dos sintomas e na modificação da estrutura articular, o que significa que é melhor que qualquer outra substância utilizada para o mesmo efeito”, explicou Lúcio Rovati. O investigador acrescenta ainda que “existem estudos realizados com o cloridrato de glucosamina mas que se revelaram no mínimo controversos, pois não é sabido como a substância é absorvida, qual a sua bio-equivalência ou qualidade”. Tratam-se, portanto, de produtos diferentes com funções distintas. “Nas doses em que é administrado, o sulfato de glucosamina desactiva vários genes responsáveis pela doença, inflamação, sintomas e destruição da articulação. Ou seja, bloqueia especificamente, as moléculas que destroem a cartilagem e a expressão da enzima que regula a inflamação”, explica o investigador. Desta forma, “o fármaco tem também um efeito sobre a inflamação, embora não directo, porque embora não bloqueie a actividade da enzima, limita a sua expressão”, concluiu Lucio Rovati.

Em, FARMACIA.COM.PT

Ten tips for improving posture and ergonomics





Introduction to posture and back support

Over time, poor posture may be caused by habits from everyday activities such as sitting in office chairs, looking at the computer, driving, standing for long periods of time, or even sleeping. Poor posture can easily become second nature, causing or aggravating episodes of back pain and damaging spinal structures. Fortunately, the main factors affecting posture and ergonomics are completely within one’s ability to control and are not difficult to change.

The following guidelines suggest several ways to improve posture and ergonomics, especially for people who work sitting in an office chair for most of the day.

Know the warning signs of back pain caused by poor ergonomics and posture. 
Back pain may be the result of poor ergonomics and posture if the back pain is worse at certain times of day or week (such as after a long day of sitting in an office chair in front of a computer, but not during the weekends); pain that starts in the neck and moves downwards into the upper back, lower back and extremities; pain that goes away after switching positions while sitting or standing; sudden back pain that is experienced with a new job, a new office chair, or a new car; and/or back pain that comes and goes for months.

Get up and move. 
As muscles tire, slouching, slumping, and other poor postures become more likely; this in turn puts extra pressure on the neck and back. In order to maintain a relaxed yet supported posture, change positions frequently. One way is to take a break from sitting in an office chair every half hour for two minutes in order to stretch, stand, or walk.

Keep the body in alignment while sitting in an office chair and while standing. Distribute body weight evenly to the front, back, and sides of the feet while standing. While sitting in an office chair, take advantage of the chair’s features. Sit up straight and align the ears, shoulders, and hips in one vertical line. Any single position, even a good one, will be tiring. Leaning forward with a straight back can alternate with sitting back, using the back support of the office chair to ease the work of back muscles. Also be aware of and avoid unbalanced postures such as crossing legs unevenly while sitting, leaning to one side, hunching the shoulders forward or tilting the head.

Use posture-friendly props and ergonomic office chairs when sitting.
Supportive ergonomic “props” can help to take the strain and load off of the spine. Ergonomic office chairs or chairs with an adjustable back support can be used at work. Footrests, portable lumbar back supports, or even a towel or small pillow can be used while sitting in an office chair and while driving. Using purses, bags, and backpacks that are designed to minimize back strain can also influence good posture. Proper corrective eyewear, positioning computer screens to your natural, resting eye position can also help to avoid leaning or straining the neck with the head tilted forward.

• Increase awareness of posture and ergonomics in everyday settings.
Being aware of posture and ergonomics at work, at home, and at play is a vital step towards instilling good posture and ergonomic techniques. This includes making conscious connections between episodes of back pain and specific situations where poor posture or ergonomics may be the root cause of the pain.

Use exercise to help prevent injury and promote good posture. 
Regular exercise such as walking, swimming, or bicycling will help the body stay aerobically conditioned, while specific strengthening exercises will help the muscles surrounding the back to stay strong. These benefits of exercise promote good posture, which will, in turn, further help to condition muscles and prevent injury. There are also specific exercises that will help maintain good posture. In particular, a balance of trunk strength with back muscles about 30% stronger than abdominal muscles is essential to help support the upper body and maintain good posture.

Wear supportive footwear when standing. 
Avoid regularly wearing high-heeled shoes, which can affect the body’s center of gravity and change the alignment of the entire body, negatively affecting back support and posture. When standing for long periods of time, placing a rubber mat on the floor can improve comfort.

Remember good posture and ergonomics when in motion. 
Walking, lifting heavy materials, holding a telephone, and typing are all moving activities that require attention to ergonomics and posture. It is important to maintain good posture even while moving to avoid injury. Back injuries are especially common while twisting and/or lifting and often occur because of awkward movement and control of the upper body weight alone.

Create ergonomic physical environments and workspaces, such as for sitting in an office chair at a computer. 
It does require a small investment of time to personalize the workspace, home, and car, but the payoff will be well worth it. Undue strain will be placed on the structures of the spine unless the office chair, desk, keyboard, and computer screen, etc. are correctly positioned (e.g. see Reducing back pain while sitting in office chairs).

Avoid overprotecting posture.
Remember that it is important to maintain an overall relaxed posture to avoid restricting movements by clenching muscles and adopting an unnatural, stiff posture. For individuals who already have some back pain, it is a natural tendency to try to limit movements to avoid the potential pain associated with movement. However, unless there is a fracture or other serious problem, the structures in the spine are designed for movement and any limitation in motion over a long period of time creates more pain and a downward cycle of less motion and more pain, etc



Por Spine Health

Choosing the right ergonomic office chair


Working in an office typically involves spending a great deal of time sitting—a position that adds stress to the structures in the spine. Therefore, to avoid developing or compounding back problems, it's important to have an ergonomic office chair that supports the lower back and promotes good posture.

What kind of ergonomic office chair is best?

There are many types of ergonomic chairs available for use in the office. No one type is necessarily the best, but there are some things that are very important to look for in a good ergonomic office chair. These things will allow the individual user to make the chair work well for his or her specific needs.
This article will examine the traditional office chair, as well as alternatives that can be used as an office chair that may be preferable for some people with back problems.

What features should a good ergonomic office chair possess?

In first considering the "conventional" style of office chair, there are a number of things an ergonomic chair should have, including:

Seat height. Seat height should be easily adjustable. A pneumatic adjustment lever is the easiest way to do this. A seat height that ranges from about 16 to 21 inches off the floor should work for most people. This allows the user to have his or her feet flat on the floor, with thighs horizontal and arms even with the height of the desk.

Seat width and depth. The seat should have enough width and depth to support any user comfortably. Usually 17-20 inches wide is the standard. The depth (from front to back of the seat) needs to be enough so that the user can sit with his or her back against the backrest of the ergonomic office chair while leaving approximately 2 to 4 inches between the back of the knees and the seat of the chair. The forward or backward tilt of the seat should be adjustable.
Lumbar support. Lower back support in an ergonomic office chair is very important. The lumbar spine has an inward curve, and sitting for long periods without support for this curve tends to lead to slouching (which flattens the natural curve) and strains the structures in the lower spine. An ergonomic chair should have a lumbar adjustment (both height and depth) so each user can get the proper fit to support the inward curve of the lower back.

Backrest. The backrest of an ergonomic office chair should be 12 to 19 inches wide. If the backrest is separate from the seat, it should be adjustable in height and angle. It should be able to support the natural curve of the spine, again with special attention paid to proper support of the lumbar region. If the office chair has the seat and backrest together as one piece, the backrest should be adjustable in forward and back angles, with a locking mechanism to secure it from going too far backward once the user has determined the appropriate angle.

Seat material. The material on the seat and back of the ergonomic office chair should have enough padding to be comfortable to sit on for extended periods of time. Having a cloth fabric that breathes is preferable to a harder surface.

Armrests. Armrests should be adjustable. They should allow the user's arms to rest comfortably and shoulders to be relaxed. The elbows and lower arms should rest lightly, and the forearm should not be on the armrest while typing.

Swivel. Any conventional style or ergonomic office chair should easily rotate so the user can reach different areas of his or her desk without straining.

By: Rodney K. Lefler, DC

Is your job aging you? Computer users be aware...


If your job entails sitting for long periods while using the computer, you are at risk for developing actual physical changes to your spine and poor posture, serious pain in your back, neck, and legs, and other possibly permanent health problems. The damage starts as early as in your 20s and 30s, with some symptoms showing up immediately while others continue to progress over time.
The back problems don’t discriminate much among career choices: media buyers, web designers, lawyers, researchers, etc., all are at risk. The criteria are simple. If you sit in an office chair and work at a computer for most of your day, then you have a potential back problem in the making.
The set of back problems for computer users is technically referred to as “non-accidental injury” and results from a combination of factors, including poor body mechanics (aka bad posture), prolonged inactivity, repetitive motions (doing same thing over and over), and fatigue – just plain being worn out and tired (continual late nights or all-nighters, anyone?). This type of injury can lead to some very noticeable physical signs that your job/office chair/computer is prematurely aging you, such as:
-Hunched posture
-Upper back pain
-Neck strain
-Lower back pain
-Sciatica
-Carpal tunnel syndrome

What to do? Short of changing jobs, standing and moving around throughout the day, and going back to pen and paper, the office chair and computer are likely to remain a part of any office job you choose. The key is to start making proactive changes now, while you’re still in your 20s-30s-40s, to slow or reverse longer-term back problems that are already in progress.

Six ways to turn back the clock on computer-related back issues:

1. Just move. Your body can only tolerate one position for about 20 minutes at a pop, 30 minutes max. Not only will you experience discomfort, over time the soft tissues in your back (muscles, ligaments, tendons) slowly lose their elasticity, causing unnatural postures, stress in the back and then pain. So, remind yourself that a prolonged static posture is the enemy! Change positions often. Stand, stretch, take a short (or long) walk. Learn the Reverse Arch Stretch Exercise that can be done right in your office chair and literally takes just a few seconds to do.
2. Avoid hunching. Often computer users will sit at the front of their office chair and hunch forward to see the computer screen. This is exactly the WRONG way to use your chair. You actually want to sit back in your chair and have your computer screen at the right height so you don’t have to bend your neck. With a regular tennis ball, you can train yourself to sit back in your chair while sitting and working at the computer. Try the tennis ball technique for 30 days and see if you can “retrain” your posture.
3. Choose a good office chair. The key with your office chair is that it has the flexibility to adjust to your body and work needs in order to support your low back and create good posture. It doesn’t have to be expensive and it doesn’t have to have “ergonomic” in the description. What you do need to look for in a good office chair are the following:
-Adjustable seat height
-Enough seat width and depth
-Lumbar adjustment
-Adjustable back rest
-Padded seat material
-Adjustable arm rests
-Swivel

4. Set up a back-friendly office. There are some tried-and-true guidelines for setting up your office chair and workstation to make them right for your unique work needs. First, you should determine the proper height of your desk, and then you can adjust your office chair according to your unique physical proportions.

5. Use exercise as the ultimate weapon against back problems. Really important for maintaining good posture as you age is having strong back and abdominal muscles – your core body muscles - to hold your trunk up and in proper alignment. Specific abdominal and back strengthening exercises are needed to build and maintain these core muscles. General aerobic and muscle fitness from walking, swimming, biking, pilates, dancing – whatever kind of movement you prefer – is an absolute must to get your blood circulating after a day of sitting in front of the computer, and frankly as smart prevention against back problems for anyone. As daunting as it seems, getting in some regular back-healthy exercise is in fact doable.

6. Consult your Osteopath. This kind of dysfunctions are an everyday plate for Osteopathy Therapists. Osteopathy techniques can restore the normal joint mobility, eliminate contracted muscles, induce normal neuromuscular function, alleviate pain and advise you wisely.

Posted by: Sylvia in Spine Health