Dr John Briffa: Fighting back

The distinct downturn in the temperature that comes at this time of year inevitably signals an upsurge in the numbers of individuals going down with colds. On any given day, during the cold season, nigh on a million people in the UK will be blighted by the common cold, and each of us can expect to endure some 200 such infections during a lifetime.

Yet, despite our best efforts, the cold virus appears to have remained immune to medical advances made in the last century; we are regularly reminded that while men take rockets to the moon, doctors and scientists have been unable to find a cure for this most ubiquitous of infections. However, contrary to popular opinion, science does show that the common cold is susceptible to treatment in the form of specific vitamins, minerals and herbs. There is, indeed, good evidence to suggest that natural remedies for winter infections are not to be sniffed at.

Our susceptibility to infection is essentially dictated by the efficiency of our immune system - the part of the body responsible for repelling unwanted organisms, including the virus responsible for the cold. One natural agent renowned for its immune-strengthening and anti-viral actions is vitamin C. Loading up on vitamin C-rich foods such as citrus and kiwi fruits in winter may help to keep infections at bay.

However, a more aggressive approach is likely to work better if an infection is threatening. Studies suggest that 1.5 to 4g of vitamin C, taken in divided doses during the day at the onset of a cold, reduces the duration of the infection by about a third. My experience is that a heavier-handed approach is often even more effective. Taking 1 to 2g of vitamin C every two waking hours until a day or two after symptoms disappear seems to stop most colds in their tracks.

Another useful nutrient for combating the common cold is zinc. One study found that sucking a zinc lozenge every two waking hours reduced the average duration of colds by seven days compared to placebo. The precise form of the zinc in the lozenge is important - it should be zinc gluconate. One downside of zinc gluconate lozenges is that they taste pretty dreadful, though this relatively minor inconvenience seems to be heavily outweighed by the benefits in terms of cold relief.

Another infection-fighter often used in natural medicine is Echinacea. This herb has proven immune-stimulating activity, and one study found that taking it reduced the duration of a cold by half. Tinctures (alcoholic extracts) of Echinacea are available in health-food stores. I recommend taking 20 drops of tincture every two hours at the first signs of infection for two days, followed by 20 drops three times a day for up to 10 days.

While vitamin C, zinc lozenges or Echinacea all seem to have infection-fighting capacity, I find taking two or three of these natural agents at the same time tends to work best. With a combined approach, don't be surprised if you find the common cold turns out not to be so common after all.

Nutrition news

Fish such as salmon, mackerel and sardines, and seafood such as mussels, crab and oysters are rich in omega-3 fats. These oils have been linked with protection from heart disease. However, new research suggests that omega-3 fats might help protect against dementia, too.

Apart from helping to maintain a healthy circulation, these healthy oils are believed to be important for normal functioning of the brain. There is also evidence that omega-3 fats may help regenerate brain cells and protect them from damage. In the BMJ study, researchers looked at the association between fish and seafood consumption and the risk of developing dementia later in life. Eating fish or seafood at least once a week was found to be associated with risk reduction in dementia of about a third.

Some of these apparent benefits seemed related to the fact that fish and seafood consumers tend to be better educated. However, even taking this into account, it appears that getting a decent quota of fish and seafood in the diet may help preserve our mental faculties as we age.

Dear John

Ever since I was a child I have suffered from little spots on my upper arms that make my skin feel like sandpaper. No amount of scrubbing or moisturising seems to shift them. Is there anything that could make them go?
Ms T B, by email

Permanent goose bumps are referred to by dermatologists as follicular hyperkeratosis. In practice this condition appears to be caused by a nutritional deficiency, specifically in vitamin A. Other signs that might suggest a vitamin A deficiency include night blindness and increased susceptibility to infection.

I have found that supplementing with vitamin A usually resolves follicular hyperkeratosis in time. Large doses are usually required in the short term. I recommend you take 50,000 IU of vitamin A per day for three months. Take this in combination with vitamin E at a dose of 800 IU per day, as this boosts the effect of vitamin A in the body.

After three months, reduce the dose to about 15,000 to 25,000 IU of vitamin A and 400 IU of vitamin E per day. While these doses are safe, high doses of vitamin A supplementation have been linked with an increased risk of birth defects. If you are pregnant or planning pregnancy, don't take more than 10,000 IU of vitamin A per day in supplement form.

· If you have any issues you would like Dr Briffa to address in this column, please email him on john.briffa@observer.co.uk. Please note that Dr Briffa cannot enter into any correspondence.

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