Case study – Allergies

The health benefits of a diet rich in vegetables and fruit are well publicised. Conditions that benefit from consumption of a variety of these natural occurring produce include:

• Decreased risk of heart disease [2];
• Lowered blood pressure [3];
• Lowered cholesterol [6];
• Lowered risk of stroke [5];
• Lowered risk of age related degenerative eye conditions [4];
• Digestive irregularities [1].

It is perhaps for this reason that many people opt for a vegetarian diet. However, in some cases a vegetarian diet may not be to your benefit.

Peter is a 14-year old adolescent who has adopted a vegetarian diet by choice. He chose this because he suffers from digestive upsets, which include daily diarrhoea, stomach cramps and discomfort. Unlike most teenagers he has always had a varied diet, which included at least 5 portions of fruit and vegetable per day. He has already substituted cows dairy for organic goat and soya products. He did not display any other signs of nutrient deficiencies such as acne, eczema or frequent illnesses.

Peter completed a food intolerance test, which highlighted the following foods as triggers:
Lentils, soya bean, peas, haricot beans, kidney beans, wheat, corn, rice, eggs, all dairy, trout, tuna, salmon, cod and all nuts except walnuts.

You will notice that he is intolerant to all vegetable protein except walnuts and seeds. It is therefore no surprise that his presenting symptoms did not abate when he changed his food intake to that which is generally accepted as a healthy alternative. Of all the grains he can only tolerate barley, oats, rye, quinoa, buckwheat and millet.

The above combinations make eating convenience foods almost impossible. Gluten free products contain corn, rice or soya flour, none of which is suitable for Peter. This makes a bowl of cornflakes or rice krispies with either soya/rice/almond/goat or cow’s milk for breakfast most unsuitable for this young lad.

After much discussion it was agreed that a vegetarian diet is not suitable for this young man at the moment and changes were suggested. Peter understands that an intolerance is not a classic allergy and that the current state of affairs is short term. We are combining his food intake with specific, therapeutic supplementation so that his gut can heal. This will enable him to re-introduce certain foods at some point in the future.

This interesting case study highlights the uniqueness of individuals and emphasises that what may be a healthy option for some, may very well exacerbate symptoms in others.


1. Lembo A, Camilleri M. Chronic constipation. N Engl J Med. 2003; 349:1360–68.
2. HC, Joshipura KJ, Jiang R, et al. Fruit and vegetable intake and risk of major chronic disease. J Natl Cancer Inst. 2004; 96:1577–84.
3. Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med. 1997; 336:1117–24.
4. Sommerburg O, Keunen JE, Bird AC, van Kuijk FJ. Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes. Br J Ophthalmol. 1998; 82:907–10.
5. He FJ, Nowson CA, MacGregor GA. Fruit and vegetable consumption and stroke: meta-analysis of cohort studies. Lancet. 2006; 367:320–26.(2)Hung
6. Appel LJ, Sacks FM, Carey VJ, et al. Effects of protein, monounsaturated fat, and carbohydrate intake on blood pressure and serum lipids: results of the OmniHeart randomized trial. JAMA. 2005; 294:2455–64.