What is an allergy?
An allergy is an abnormally high immune reaction to certain stimuli. Lots of people believe they have a food allergy or intolerance and seek allergy testing to identify which foods to avoid. People who have atopic conditions such as eczema, asthma or rhinitis (such as hay fever) are more likely to suffer from food allergies.
Food allergies can either be immediate-type reactions linked to the antibody IgE, or more delayed, non-IgE mediated reactions, usually involving gut symptoms. Food allergies are more common in children than adults as children often outgrow their allergy.
Diagnosing food allergy
Diagnosis starts with an allergy focused clinical history to identify all relevant symptoms and whether there are signs of immediate or delayed food allergies. Suspected immediate IgE mediated reactions are confirmed by skin prick testing or specific IgE allergy tests to the suspected foods, interpreted by a specialist in food allergy.
The importance of having appropriate competencies to interpret the tests is highlighted in the RCPCH food allergy care pathway
There are currently no validated tests to diagnose delayed, non-IgE mediated food allergy, often incorrectly termed as food intolerance. The only common form of food intolerance (does not involve the immune system) seen in pre-school children is secondary lactose intolerance, due to loss of/ insufficient lactase. See my article on the differences between lactose intolerance and cow’s milk allergy. Adults are more likely to suffer from a range of food intolerances, where they have a level of food that they can tolerate, above which they suffer with gut symptoms, as may occur in irritable bowel syndrome (IBS).
Diagnosis of delayed food allergy is achieved by eliminating the suspected allergens in foods for between 2-6 weeks to see if the symptoms get better, and then re-introducing them to see if the symptoms come back. If they do, this confirms the diagnosis. See the NICE food allergy in children guidelines and Milk Allergy in Primary care (MAP) guideline
There are no other validated methods for allergy testing. The NICE food allergy guidance states that some complementary or alternative health practitioners offer food allergy tests. These include tests such as applied kinesiology, hair analysis, vega tests, serum-specific IgG antibody tests, live blood analysis and cytotoxicity testing, but there is no evidence to suggest that they can reliably diagnose food allergy.
Dubious tests for food allergy/ intolerance:
- Applied Kinesiology (muscle testing)
The test gets the person to hold the suspected food, and muscle strength is then measured by applying pressure to the extended arm. It is believed that muscles in the body are sensitive to anything that is harmful, such as food allergens, and so become weakened. In young children, the parent may be used as an intermediary. Correction of imbalances in the body may involve crystals or acupuncture/ acupressure and can result in a long list of ‘food intolerances’.
Kinesiologists are not qualified to diagnose or treat any medical condition, which includes allergies, yet worringly some practising kinesiologists state that their treatment can help with allergies, intolerances, reactions to foods, pollens, chemicals, anxiety, panic attacks, fears, phobias, stress, emotional issues, pain and sleep.
2. Vega testing (electrodermal test)
Vega testing is sometimes just referred to as food intolerance testing. The equipment used is a galvanometer, often referred to as a Vega machine, which measures electric currents to look at the body’s resistance to food allergens. The patient holds a cylinder in one hand while a small sensor is placed on the surface of the skin on either the fingers or toes, and the electric current is measured. Increased resistance to the current apparently indicates allergy to the food. The value on the galvanometer however is caused by the amount of contact and pressure applied by the technician.
A full food test involves around 100 different foods and will often results in a list of at least 20 different foods to avoid. Worryingly, the technician will usually provide nutritional information and guidance on eliminating these foods and possibly re-introducing them again. This is a role for a dietitian and exclusion of major food groups such as dairy, wheat and soy can result in nutritional deficiencies. An allergy focused clinical history may not be taken, in which case they would be unaware of whether they are dealing with IgE mediated allergies that carry a risk of life-threatening reactions. Re-introduction in such cases could potentially be fatal.
3. Hair analysis
A few strands of hair are tested for their mineral content. It is believed that if a harmful food is eaten, it will show up in the hair’s mineral makeup. Hair grows slowly (approximately 1cm per month) however, so hair does not reflect the current condition of the body.
A wide range of suggested food intolerances usually result, which can include major food groups such as dairy. A list of deficiencies to various nutrients are also provided, including things for which there are no recommended intake levels, such as omega-3 fatty acids (DHA, EPA), glutamine, vanadium etc and therefore no way of identifying whether there is actually a deficiency.
4. IgG/ IgG4 testing
This test involves a blood test to check for the antibody IgG, which is created by the body to fight certain allergenic foods. However, unlike IgE antibodies which are responsible for allergies, IgG is found in both allergic and non-allergic people. The production of IgG antibodies is thought to be a normal response to eating food, and often its presence reflects the fact that the food has been eaten recently. IgG has been shown to increase during successful research studies looking at food immunotherapy (regular introduction of small amounts of the food the person is allergic to, to try to get them to stop reacting to it).
IgG testing usually results in a long list of food ‘intolerances’ which are likely to reflect the foods most commonly eaten, and hence would also have the most detrimental nutritional impact if advised to be excluded from the diet.
5. Live Blood Analysis
Live Blood Analysis, also known as live cell microscopy or nutritional blood analysis involves taking a drop of blood from the fingertip, placing it on a glass plate under a microscope and viewing it using dark field microscopy on a video screen. The practitioner will diagnose amongst other things acid in the blood if red blood cells stack up (rouleaux formation), which actually occurs when the blood starts to dry out, clump together or clot against the glass. Splinters or debris on the glass slides which haven’t been cleaned thoroughly may be reported as being uric acid crystals, cholesterol plaques or parasites.
Holistic practitioners include alternative medicine providers such as bogus nutritionists, herbologists, naturopaths and chiropractors who are highly likely to have no qualifications in haematology. Those undertaking Live Blood Analysis claim it provides information about the state of the immune system, lack of oxygen in the blood, possible vitamin and mineral deficiencies, pH and mineral imbalance, amount of toxicity, presence of fungus and yeast, and some even claim it can spot cancer and other degenerative immune system diseases.
They may state that adopting the Blood Type Diet can help you avoid the foods that you are intolerant and allergic to, as well as helping you achieve optimum health, eliminate digestive problems and help you lose unwanted weight for good. However, there are no credible scientific studies to support these claims
6. Cytotoxicity testing
In this test, a test tube of blood is obtained from the client and centrifuged to separate the white blood cells. These are mixed with plasma and sterile water and applied to a large number of microscope slides, each coated with a dried food extract. They are then examined under a microscope at intervals over a two hour period to see if the cells have changed shape or disintegrated, which are supposedly signs of allergy to that food.
The practitioner may point out that your T cells are not shaped like a T (which is normal), or there are bacteria in your blood (which in fact are the platelets important in clotting). A personalised diet program will then be provided, usually including the need to avoid certain foods, purchase vitamins and minerals and / or some special drops for treatment.
Changes to the appearance of cells upon exposure to allergens however, cannot be viewed with a microscope and studies have shown that cytotoxic tests do not correlate with food allergies in individuals.
Who should you trust to diagnose food allergies?
- Allergy specialists, with competencies in accordance with the RCPCH food allergy care pathway
- Allergy Dietitians
Blog author: Dr Lisa Waddell, BSc (Hons) Nutr, RD, Ph, MBDA
Specialist paediatric allergy dietitian, Food Allergy Nottingham Service (FANS)
As a Freelance and Research Dietitian I am always eager to not only give sound nutrition advice but to back it up with science. Nutrition is the people’s topic; wherever you go you will hear people giving their ‘expert opinion’ on what has caused the obesity epidemic or why their aunt can’t tolerate wheat or dairy. We need food and drink to survive and given we are all in control of what we eat and drink and make our own food choices every day, we can’t be blamed for feeling like an expert when it comes to nutrition.
But what makes those food choices right? As Dietitians we learn why and how food and drink affects our bodies and our health, and we use this knowledge to try to help others to become healthier through changing their diet and lifestyle.
After a few years practicing in the NHS, I decided to not only find the science behind the nutrition facts but to try to make my own contribution as well. I am now carrying out human research trials looking at appetite regulation and obesity management. We are trying to find the effects of specific types of foods or diets on how hungry we feel, how much weight we gain or lose, and how our body composition changes because of those foods/diets. I am specifically interested in fish oils and high protein diets.
By delving deeper into the science, finding the reasons why certain foods harm or help us, I can enrich my knowledge and better advise my clients who come to see me in clinic.
Blog contributor: Claire Pettitt
September is here, the traditional month to celebrate the British harvest festival. Whilst agriculture may not be the financial mainstay of the economy it used to be, and food production and processing has changed significantly over recent decades, it remains a prime month for hedgerows busting with edible goodness and farmers harvesting their crops. From beetroot to butternut squash and rocket to raspberries, September is the month!
So for those of us trying to reach 5-a-day, this month offers us loads of choice, and opportunity to try new things. If you’re stuck for ideas check out http://www.bbc.co.uk/food/seasons a month-by-month guide to which foods are in season, including different fruits and vegetables. There are also some recipes to show you how to cook them.
As an added bonus, food which is in season is often cheaper as it doesn’t have be grown in greenhouses or flown round the world – better for the environment too! There are also opportunities to make the most of nature’s abundance – blackberries and elderberries being two of the most commonly occurring in Suburbia. Just remember – if you’re not sure what you’re foraging, check before you eat! And make sure you wash your findings too. You might also want to consider Pick-Your-Own farms for a nettle-free experience, or planting your own.
by Mariëtte Abrahams MBA RD founder of Pomegranate Nutrition Consulting Ltd
The increased interest in disease prevention and Wellness around the world, has also led to the peaked interest in the emerging field of Nutrigenomics, otherwise known as personalised nutrition. Personalized Nutrition looks at our individual genetic make-up and our response to foods. This area is one of the fastest growing science areas at present with huge investment for research made by the food industry. The aim of the field is to identify specific variations within our genetic make-up that influences how we metabolise and absorb nutrients which play a role in our health and hopefully prevent the onset of chronic illnesses or lifestyle diseases such as Obesity, Diabetes and Cardiovascular disease.
Whilst in practice it would still mean that healthy eating practices apply such as; eating wholegrains, fruit, vegetables and lean meats, in the future, we may be able to more accurately predict individual requirements and responses such as requirement for omega-3 fats and phytonutrients (for example)
In addition, the development of functional foods, or foods with a health benefit will be developed according to the genetic needs of a particular population group. If you have not noticed it in the news, “Super Broccoli” is already available in selected shops.
So looking into the future, what could your personalised lifestyle look like?
- A choice of Genotype specific foods to optimise your health
- Tailored specific Nutrient recommendations
- Targeted nutritional and natural supplements
- Genotype-specific exercise prescription and programme
- Regular family dietary lifestyle coaching to consider each family member´s individual needs
- Personalised Health tracking, Biomarker measurement, personalised health alarms such as the UV damage band and without a doubt…..
- Wellness treatments on prescription
It is by no means a complete solution to the global epidemic problem of lifestyle diseases, but hopefully it will contribute to the dietary and lifestyle choices of many. As with so many things in our lives being connected, synced and personalised, soon our food too will join our list of absolute must have´s to express our individual preference.
For more information on personalised nutrition visit
Are you dreaming of a Mediterranean holiday that feels a little out of your reach? Bring a touch of the med to your home life this summer with these sizzling nutrition tips!
Liven up your lunch
Warmer weather is often associated with eating more salad but if all you’re crunching through at lunch is a bowl of green leaves you’re likely to feel hungrier later in the day and reach for something less virtuous to see you through a sugar low.
Balance your salad with some protein – experiment with different pulses such as chickpeas or puy lentils or cheeses such as feta or halloumi. Drizzle with olive oil and lemon juice for a healthy, zesty dressing. Remember although olive oil is high in heart healthy monounsaturates it is still oil so if you’re concerned about calories, watch how liberally you drizzle!
Include wholegrain goodness
It can often be tempting to avoid these foods for fear of bloating and sluggishness in the afternoon. However in reality cutting carbohydrates out at meal times leaves you prone to lethargy, dips in your blood sugar and cravings for high sugar energy fixes.
Carbohydrates also provide wholegrains – the benefits of consuming the whole grain are continuing to emerge but so far include supporting the maintenance of a healthy weight and a reduced risk of bowel cancer and type 2 diabetes. At least 3 good reasons to add wholegrain pasta, quinoa or wholemeal pita bread to your meal for the perfect balance.
Add some colour to your day
Blackberries, blueberries, raspberries, redcurrants, tomatoes, strawberries, cherries, rhubarb and radishes are all in season now and are a great addition to your diet – create a colourful looking fruit bowl for your desktop, brighten up a salad or treat yourself to a rhubarb crumble or strawberry pancake for pudding.
Catch of the day
Oily fish are a valuable source of omega 3’s and in particular boost your protection against heart disease and stroke. There is also some evidence suggesting that they may help with brain function – perhaps useful to get you through a long afternoon meeting!
Tinned sardines make a convenient addition to a lunchtime summer salad or sandwich but if you’re worried your colleagues might not appreciate it, go for a salmon or trout steak for supper once a week instead, to get your healthy quota!
Guest Blogger Laura Clark
As a Registered Dietitian I have always been pleased to contribute to various programmes on radio. Over the years this has been to local radio, national and specialist stations.
I feel it is important that I give credible information about nutrition and diet. With this in mind I have talked about all sorts of items over my phone from various locations (including the side of the road), as the editors tend to want an immediate response to something about food in the news!
Since Easter I have been pleased to be involved in doing a regular slot on the BBC Radio Northampton Kitchen Garden Show, which goes out on a Sunday morning from 9-11am.
On the programme is a gardening expert plus local culinary contributor and while I often try to follow the theme have talked about various items including-
- Raw milk
- Fruit and vegetables
To find out more visit:
A recent article in the Journal of Family Health Care highlights the continuing concern about the rise of Vitamin D deficiency in the under 5’s and describes the key issues about why rickets is on the rise for the first time in several generations.
Current government advice in the UK states that all children from 6 months to 5 years be given supplementary Vitamin A, C and D, unless they are receiving more than 500ml of infant formula a day. However, a recent report found that toddler’s diets contain only a quarter of their daily vitamin D with many parents and healthcare professionals including health visitors being unaware of the recommendation around vitamin supplementation.
Children at particular risk of vitamin D deficiency are those who aren’t exposed to sufficient sunlight- our main source of vitamin D. These include those living in northern parts of the UK, children who cover their skins for cultural or religious reasons, children using sun block in summer, children whose mothers were low in vitamin D during pregnancy and children with darker skins. Justified concern from parents over cancer risk and sunlight has also contributed to the problem. Unfortunately there are few dietary sources of vitamin D; oily fish, eggs and fortified cereals being the main ones, making vitamin supplements even more vital.
The solutions presented included the need for clear advice about getting a certain amount of sun; a centrally funded public health initiative to raise awareness; widespread fortification of breakfast cereals and giving higher dose vitamins to pregnant women, an initiative currently being done in France.
Get in touch and let us know what you think about any of the issues discussed in this article.
National Childhood Obesity Week is marked between 5th and 11th July this year. It has been frequently reported that childhood obesity is on the increase. Parents may well be familiar with the National Child Measurement Programme (NCMP) which takes height and weight of children in Reception and Year 6, and the media often relays to us the latest in the ongoing debate as to whether the fast food industry, supermarkets, schools, parents, poor celebrity role models, or urbanisation is responsible for the increase.
Whilst that debate rumbles on, there are some things that we can do for the health and wellbeing of our children, encouraging a healthy diet at home and making physical activity fun and part of everyday life. Here are just a few websites to help you and your family on your way to becoming fitter and healthier.
- The Change4Life website has loads of recipe ideas, healthy eating tips and ways to be more physically active, especially over the summer holidays. http://www.nhs.uk/Change4Life/Pages/change-for-life.aspx
- This NHS tool will calculate whether your child is overweight – you just need their current height and weight, and date of birth. http://www.nhs.uk/Tools/Pages/Healthyweightcalculator.aspx
For older children and teenagers:
- This website is for teens and provides common sense advice and support for teens worried about their weight. http://teenweightwise.com/
- The British Heart Foundation contains activities for older children to learn more about being healthy. http://www.bhf.org.uk/cbhf/
Approximately a third of the most common cancers in the UK could be prevented by people eating a healthy diet, drinking less alcohol, being physically active and maintaining a healthy weight.
The World Cancer Research Fund has produced 10 Recommendations for Cancer Prevention on how you can reduce your cancer risk.
1. Be as lean as possible without becoming underweight.
2. Avoid sugary drinks. Limit consumption of energy-dense foods (particularly processed foods high in added sugar, or low in fibre, or high in fat).
3. Limit consumption of red meats (such as beef, pork and lamb) and avoid processed meats.
4. Be active for at least 30 minutes every day.
5. Eat more of a variety of vegetables, fruits, wholegrains, and pulses such as beans.
6. If consumed at all, limit alcoholic drinks to two for men and one for women a day.
7. Limit consumption of salty foods and foods processed with salt (sodium).
8. Don’t use supplements to protect against cancer
And for special populations only;
9. It is best for mothers to breastfeed exclusively for up to six months and then add other liquids and foods.
10. After treatment, cancer survivors should follow the Recommendations for Cancer Prevention.
If you are looking for a freelance dietitian go to www.freelancedietitians.org
It’s that time of the year when everyone’s digging out the barbeque and making the most of the warm sunny days. But according to NHS choices food poisoning cases double over the summer months, caused mainly by undercooked meat and cross contamination (where germs like E.coli, salmonella and campylobacter pass from raw meat onto cooked food).
Although most cases are usually mild, for more vulnerable groups like children and older people this can be very serious even fatal. So follow these simple steps to keep your family and friends healthy this summer.
- Defrost all meat and poultry thoroughly before cooking
- Check your coals are hot enough- they should be glowing red with a powdery grey surface before you start
- Turn the meat regularly, and move it around the barbeque to cook it evenly
- Check the meat is piping hot in the centre and that there is no pink meat visible
- Avoid cross contamination by always washing hands after touching raw meat
- Use separate utensils, plates and containers for cooked and raw meat
- Keep raw meat and cooked meat separate on the barbeque
Why not try barbequed sweetcorn or barbequed peach (in foil) to count towards your 5ADAY