December 2012

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Antibiotic resistance is as big a problem as global warming

According to the Chief Medical Officer, Dame Sally Davies, “Antibiotics are losing their effectiveness at a rate that is alarming and irreversible - similar to global warming.” The situation has become so worrying that the Health Protection Agency and the Royal College of General Practitioners have now produced a leaflet for GPs to give to patients, to explain why they have not been prescribed antibiotics.

Prescriptions for antibiotics have increased by 10 per cent in the last five years and one third of people in the UK have taken them in the last 12 months. The unnecessary use of antibiotics has led to bacteria adapting and finding ways to survive the effects of these drugs, so that they no longer work. Experts are particularly concerned about antibiotic resistance in strains of Escherichia coli, which cause urinary tract infections and Pneumococcus, responsible for a type of pneumonia.The leaflet explains how long common illnesses, like colds and sore throats, usually last, what you can do to ease the symptoms and danger signs that mean you need to see a doctor. What it fails to tell people, however, is how they can strengthen their immune systems in order to avoid these minor infections in the first place. See our ‘How to’ section below to find out how you can support your immune system this winter.

What’s up? Discover Britain at its wintery best

The winter issue of Optimum Nutrition magazine features an article on ‘‘green exercise’, a term given to the practice of engaging in physical activity in a green space or natural environment. Research suggests that contact with green spaces and nature improves psychological health by reducing stress levels and enhancing mood and self-esteem. Although the days are colder at this time of year, there is still plenty of opportunity to keep active in the great outdoors. The Festival of Winter Walks, which was set up by Britain’s walking charity Ramblers, aims to encourage people to do more walking. During the festival, which runs annually over the Christmas and New Year period (between 22 December and 6 January), there will be hundreds of woodland walks taking place across England, Scotland and Wales. All are free, fun and open to everyone, and are chosen and led by Ramblers volunteers. For more information or to search for walks in your area visit

Grapefruit – drug interactions: a possible cause for concern

A paper published in the Canadian Medical Association Journal1 raises concerns over the increasing number of prescription drugs that have the potential to interact with grapefruit and cause adverse health effects, and the apparent lack of knowledge about these interactions in the general healthcare community.

The review, which was conducted by the research group that first discovered the interaction between grapefruit and certain medications over 20 years ago, explains that there are currently over 85 drugs that are either known or predicted to interact with grapefruit to a certain degree. However, the most alarming trend is the rise in the number of medications that have the potential to cause serious adverse effects in more recent years (an increase from 17 to 43 between 2008 and 2012). This represents, on average, an increase of more than six drugs per year, and is due to the introduction of new chemicals and formulations. All of these drugs have similar characteristics: they are all orally administered; they all have a low absolute bioavailability; and they are all required to be metabolized by the enzyme cytochrome P4503A4 (CYP3A4).
All forms of grapefruit (freshly squeezed juice, frozen concentrate and whole fruit), as well as some related citrus fruits (Seville oranges, often used in marmalades, limes and pomelos), have the potential to impair and irreversibly inhibit the activity of CYP3A4 in the gastrointestinal tract.

This interaction is due to a group of chemicals in grapefruit called furanocoumarins.
For patients taking prescription medication, it is important to always read the patient information leaflet that comes with it, and to speak with your general practitioner if you have any concerns. It is also essential for GPs, as well as nutritional therapists and dieticians who frequently make dietary recommendations, to be fully aware of the potential interactions between pharmaceutical drugs and foods/nutrients. 

Fruit and vegetable intake linked to improved immune function in older people

Ageing is associated with dysregulation of the immune system and an increased risk of infection. As fruit and vegetable intake tends to be low in older populations, it is possible that increasing their consumption of fruits and vegetables may have beneficial effects on their immune status.

This was the hypothesis examined in a recent study published in the American Journal of Clinical Nutrition2. Researchers compared the effect of increasing fruit and vegetable intake to the recommended five portions per day for 16 weeks with a low fruit and vegetable diet (two portions or less) on measures of immune function in 83 older people aged 65 to 85 years. At 12 weeks, all participants received a tetanus vaccine and a pneumococcal vaccine, and their antibody response to the vaccination was examined at week 16. Results showed an improved response to the pneumococcus vaccination, but not to the tetanus vaccination, in individuals who consumed five portions of fruit and vegetables per day compared with those who consumed only two portions. The authors conclude that this finding links an achievable dietary goal with potentially enhanced protective immunity.

‘How to’ support your immune system this winter

At this time of year, it is impossible to avoid each and every person showing signs of a cough or cold; however, there are some things we can do to help keep healthy this winter:
• Practice good hygiene. Frequent and thorough hand washing is particularly important, especially if you have been around somebody who is sick, or are a regular commuter on public transport.
• Eat a healthy diet. Aim to include a rainbow of fruits and vegetables – this will help us get the nutrients that are required for optimal immune function, such as vitamins A, C, E, B vitamins, zinc, magnesium and selenium. Try and avoid junk foods, highly processed foods, excess sugar and trans fats.
• Optimise your vitamin D status. This vitamin plays a supportive role in immune function. Many of us do not get enough vitamin D during the winter months due to the lack of direct sunlight on our skin. It is may therefore be wise to take a vitamin D supplement during winter.
• Get at least eight hours’ sleep a night. A lack of sleep is thought to impair the immune system and the body's capacity to fight off the viruses that cause colds and flu
• Balance your gut flora. In our winter 2011 issue of Optimum Nutrition, clinical nutritionist Mina Dean explained the role of our gut bacteria in modulating our immune response. Probiotics may help to stimulate the immune system and reduce allergic reactions. To read the full article click here.
• Exercise. Regular and moderate exercise can help support immune function. Research has shown that people who work out regularly tend to have fewer colds than those who don’t, and they also experience milder symptoms if they do fall ill.
• Use herbs, such as astragalus, echinacea, garlic, green tea, turmeric and ginger.
• Manage stress. Although research suggests that short-term stress can have immune benefits, long-term, chronic stress can suppress the immune response. Yoga, meditation, tai chi and exercise can all be helpful stress-busters.


1. Bailey DG, Dresser G, Arnold JMO (2012). Grapefruit-medication interactions: Forbidden fruit or avoidable consequences? Canadian Med Ass J Nov 26 (Online ahead of print).
2. Gibson A, Edgar JD, Neville CE, Gilchrist SECM, McKinley MC, Patterson CC, Young IS, Woodside JV (2012) Effect of fruit and vegetable consumption on immune function in older people: a randomized controlled trial. Am J Clin Nutr; 96:1429-1436.

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