Food as Medicine

Both conventional and complementary systems of medicine acknowledge the vital link between diet and the prevention of illness. Conventional doctors stress the importance of eating a balanced diet in order to prevent disease; nutrition-based complementary therapies such as nutritional therapy and naturopathy use food not only in a preventative way, but also as medicine to tackle disease actively.

Complementary medicine practitioners base their therapies on the naturopathic philosophy that, given the right conditions, the body is a self-healing organism. They use diet to help enhance this self-healing capacity. Therapists believe that most illnesses can be prevented, alleviated, and sometimes even cured with a diet that is tailored to individual needs. When examining a patient, the therapist looks for signs of nutritional deficiency, allergies, food intolerances, poor digestion, toxic overload; and any problems with the balance of intestinal flora, the bacteria that protect the gut lining. Dietary therapies may be effective in the prevention and treatment of many illnesses from colds and constipation to diabetes, heart disease and cancer.


Colds and influenza are caused by viral infections and are highly contagious. People who are run down, stressed or depressed may be particularly susceptible to colds and influenza.

Dietary therapy

A balanced diet that includes plenty of fresh fruit and vegetables helps to strengthen the immune system and resist infection. Once a cold has taken hold, the individual should drink plenty of fluids – at least six to eight glasses a day – in order to combat dehydration and keep mucus moving; include diluted vegetable juices, soups and herbal teas. A hot drink made with freshly squeezed lemon juice and a teaspoon of honey can be comforting. The lemon is an excellent source of vitamin C and the honey helps to soothe a sore throat. Nutritional therapists recommend that an individual reduces his intake of dairy products during a cold as these foods are believed to be mucus-forming. Some nutritionists also recommend limiting sugar intake (including fruit sugars), because they believe that glucose (blood sugar) competes with vitamin C in the body. This can result in a reduction in the function of white blood cells which impairs the functioning of the immune system. Sugar also provides empty calories which are processed using the body’s nutrients; this saps the body of nutrients rather than supplying it with energy.

Chicken soup is an old-fashioned cold remedy. It contains an amino acid called cystine that resembles a drug doctors prescribe for respiratory infections because it thins out mucus in the lungs. Chicken soup is also comforting and easily digested.

Garlic and onions are used as nasal decongestants in herbal medicine and may help to relieve cold symptoms. Garlic has antiviral and antibacterial properties; it can either be added to cooking or taken in supplement form.

There has been a long debate over the virtues of vitamin C as a cure for the common cold. In 1970, US biochemist and Nobel prize winner Linus Pauling wrote a revolutionary book called Vitamin C and the Common Cold, in which he claimed that large doses could decrease the severity of a cold. More recent US research reviewed 38 studies on the use of vitamin C – 37 of these indicated that vitamin C users suffered fewer colds; their colds were of a shorter duration; and their symptoms were less severe. Research into large doses of vitamin C has generally shown a beneficial effect on the immune system (seek expert advice about dosages). Good food sources of vitamin C include broccoli, watercress, peppers, kiwi fruit, strawberries and citrus fruit.

Vitamin A is another important protector against infection; cod liver oil is a rich source of this vitamin, and a traditional preventative for infections (seek expert advice about appropriate dosages). Food sources include liver (although this should be avoided during pregnancy), sweet potatoes, full-fat dairy products, eggs, squash, watercress, mangoes and apricots.

The British Common Cold Research Unit, during its 40-year search for a cure, reported that the mineral, when taken in large quantities as a lozenge, may help to shorten the duration of a cold (seek expert advice about appropriate dosages). Merely eating zinc-rich foods does not have the same effect. Zinc may be included in some over-the-counter remedies for colds.


Regular daily bowel movements are important for the health of the digestive system; they reduce the risk of large-bowel disease, particularly cancer of the colon. Constipation – irregular bowel movements and the difficult passage of stools – is usually caused by insufficient fibre in the diet. It can also be caused by the over-consumption of drugs such as painkillers, iron supplements and laxatives.

Dietary therapy

A diet high in both soluble and insoluble fibre, found naturally in whole grains, fruit and vegetables, helps the formation of soft stools that can be passed both easily and quickly from the body. Insoluble fibre acts like a sponge, absorbing large quantities of water, adding bulk to waste matter, and hurrying it through the system. Constipation sufferers can benefit from increasing their intake of insoluble fibre, found in whole-grain varieties of starchy foods such as wholemeal bread and brown rice, muesli, and dried fruit such as prunes and figs.

Although bran is an excellent source of insoluble fibre, health experts no longer recommend sprinkling raw bran over food because it reduces the absorption of essential minerals and can be too harsh on the bowel – even causing irritable bowel syndrome. Soluble fibre dissolves in water to form a gel that helps to keep the stools soft; it also has the effect of ‘slow-releasing’ the carbohydrates digested, providing a more sustained supply of energy. Foods that are high in soluble fibre include fruit and vegetables, oats, pulses, nuts and seeds.

The introduction of more fibre to the diet should always be gradual. It is not uncommon to experience symptoms such as bloating and flatulence while the body takes time to adjust. It is important to drink plenty of water – at least two litres (3-½ pints) a day, preferably between meals. In addition to dietary measures, regular physical activity helps to stimulate bowel movements.