DR TOBY MURCOTT looks at the scientific research behind pollen blockers and other alternative hay fever remedies

HayMax This ointment works by blocking the pollen from entering the nose, its maker claims. The theory is: no pollen, no hay fever.

Any evidence? A single clinical trial of pollen blockers has found them effective at reducing hay fever. A similar effect has been reported for Vaseline. Pollen blockers coat the sensitive lining of the lower nose, preventing pollen from reaching it. It will not stop pollen reaching the eyes, but the nose has a far larger surface area than the eyes, making it a bigger target for pollen. £6.95 for a 5ml pot from www.haymax.biz; 01525 406600

Pycnogenol (pine bark extract) In hay fever sufferers, the immune system reacts to pollen by releasing histamine, the hormone that causes the swelling and itchiness of the nose and eyes, and the sneezing. It’s claimed that pycnogenol, an extract from the bark of the French maritime pine, lessens these symptoms by reducing the effect of histamine. Adults should take one to three 30mg capsules daily.

Any evidence? Pycnogenol contains a number of biologically active chemicals. It has been shown to have antiinflammatory properties in animal studies so it is possible that it might relieve hay fever symptoms but there are no studies looking at this directly. £10.79 for 30 capsules from www.hollandandbarret. co.uk ; 0870 6066605 Linpharma Butterbur Petasin Butterbur Petasin is a herbaceous plant that grows in marshy areas in Europe, North Africa and Asia. The active ingredients are petasites found in the root of the butterbur plant. They are said to have antiinflammatory properties that help to combat hay fever symptoms. Not suitable for children under 12, or women who are pregnant or breast-feeding.

Any evidence? A Swiss study, published in the BMJ in 2002, claimed that butterbur was as effective as cetirizine, a common pharmaceutical antihistamine. This prompted a debate in the journal questioning the study’s design and conclusions. A later study of 330 people from the same researchers concluded that butterbur was better than a placebo (dummy pill), but a study of 35 patients in Scotland found it no better than a placebo. £19.95 for 50 capsules from www.yourhealthfoodstore.co.uk

Bioforce Luffa Complex Tablets This remedy brings together seven tropical herbs, including sponge cucumber and khella, and is said to alleviate symptoms. Available as tablets, a tincture to be taken with water, or a nasal spray. Not suitable for children under 2.

Any evidence? Of the many ingredients, only sponge cucumber ( Luffa operculata) and thryallis (Galphimia glauca) have been studied as treatments for hay fever. There is some evidence from one trial that a homoeopathic spray containing these ingredients, and others, might be effective. £7.40 for 120 tablets from www.bioforce.co.uk, 0845 6085858

New Era Combination H This homoeopathic remedy contains 12 minerals, including common salt, to alleviate the symptoms. The tablets are based on lactose, to which some people are sensitive.

Any evidence? There is a little evidence from clinical trials that homoeopathy might be effective for relieving the symptoms of hay fever, but that evidence is weak and hotly debated. £4.49 for 450 tablets from www.hollandandbarret.co.uk; 0870 6066605

Nettles Nettle leaf is believed to contain active compounds that inhibit the body’s production of inflammatory chemicals called prostaglandins. These may help sufferers.

Any evidence? There are no specific studies, but there is research that suggests nettles might have an effect on the body’s defence mechanism and reduce the production of chemicals involved in an allergic response, including prostaglandins. £10.95 for 100 400mg capsules from Cotswold Nettle Leaf, www.homeherbs.co.uk

MyAirZone air purifier This device, about the size of a mobile phone, can be worn around the neck, clipped to a shirt, or placed on a desk. The makers claim it will strip the air around users of allergens, including pollen, by emitting charged particles that bind to airborne particles and cause them to fall to the ground. They say it will remove pollen in a room of up to 16sq m (172sq ft).

Any evidence? Air ionisers have been shown to reduce the amount of dust and pollen in the air. There is also some research that suggests that ionisers can reduce asthma symptoms, but it is not clear whether this is because it removes pollen from the air or some other mechanism. But the efficacy of battery-powered devices has not been researched independently. £99.99 from www.healthy-house.co.uk; 0845 4505950

Dr Toby Murcott is a former BBC science correspondent

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