We consider it quite a feat to escape
winter without a single cold. However, research is beginning to indicate that a healthy
diet may help strengthen the immune system and give your body the best chance of fighting
colds.
To date, the only specific cold treatments available from your doctor or pharmacist are
designed to deal with symptoms such as sore throats, runny or stuffy noses, coughing,
sneezing and sleeplessness. Very little advice is given on diet for the simple reason that
there is little research-based evidence to suggest that what you eat has much effect once
the virus has taken hold.
One possible exception to this rule is increasing intakes of vitamin C.
Although not yet conclusive, the indications are that giving people large quantities of
this nutrient the moment that cold symptoms appear may be of some benefit. It has been
found that for some people, taking between 500 -1000mg of vitamin C a day could help
to lessen the severity and possibly the duration of a cold. Researchers feel that these
effects could be due to the vitamin C in the blood boosting interferon levels thus helping
to protect cells from viral attack.
Vitamin C intakes can be increased through foods and drinks such as citrus fruits and
juices, kiwi fruit, sweet potatoes, peppers, blackcurrants, green leafy vegetables and
exotic fruits, such as guava, or certain foods fortified with vitamin C. Supplements of
vitamin C may also be considered.
Other work indicates that prevention could well be better than cure. When elderly
people in long-term care were given a multi-micronutrient supplement including 20mg of
zinc, 100µg of selenium, 15mg of vitamin E and 6mg of beta carotene, scientists
discovered that they caught fewer respiratory infections. It is possible that diets
supplying good and regular amounts of these vitamins and minerals could help to protect
the population at large.
It is not just vitamins and minerals that are potentially important infection fighters.
Herbalists have long promoted the benefits of garlic for its antiviral effects; a property
that could be due to a natural constituent it supplies. Extracts from Echinacea, (the
purple cornflower), as drops or capsules are also valued for their antiviral effects.
Just as certain nutrients seem to help strengthen the immune system, stress appears to
deplete some vitamins and minerals. Combining a healthy varied diet containing a lot of
fruits and vegetables with a good balance of exercise and sleep would seem to be a good
strategy to start this winter’s battle against the common cold.
References
Paul Knipschild: Systemic Reviews: Vitamin C and the common cold. BMJ; 309:719-21, 1994
. Carr AB et al: Vitamin C and the common cold: Using identical twins as controls. Med J
Aust 2:411-12, 1981. Gerber WF et al: Effect of ascorbic acid, sodium salicylate, and
caffeine on the serum interferon level in response to viral infection. Pharmacology 13
(3): 228-33, 1975. Mary Ann Johnson et al: Micronutrient Supplementation and Infection in
Institutionalized Elders, Nutr Re, vol. 55, No. 11, 400 – 404. Berdanier CD: The many
faces of stress, Nutr. Today 22 (2): 12, 1987. Ross AC: Vitamin A and protective immunity,
Nutr Today 27 (4):18, 1992
Foods Supplying Vitamin C, Vitamin E, Beta Carotene, Zinc and Selenium
| Nutrient | Foods To Eat |
| Vitamin C | Citrus fruits, kiwi, guava, peppers, blackcurrants, strawberries |
| Vitamin E | Almonds, hazelnuts, sunflower seeds, sweet potatoes, sunflower oil, wheat germ and wheat germ oil, avocado pears |
| Beta carotene | Carrots, sweet potatoes, pumpkin, guava, mangoes, apricots, red peppers tomatoes, dark green vegetables |
| Zinc | Shellfish, red meat, wheat germ, whole grain cereals like wholemeal bread and whole grain breakfast cereals |
| Selenium | Brazil nuts, sunflower seeds, mussels, tuna canned in oil, haddock, kidneys |
