GASTRIC ACID protects against mad cow disease

Beef and acid reducers – a combination we might have to be more careful about in the future. Photo: Rune Petter Ness

A reduced stomach-acid level means less protection against prion diseases.

By Lisa Olstad

Prion is the name given to those tiny, much-dreaded particles which constitute the infectious agent in BSE (Bovine Spongiform Encephalopathy), also known as mad cow disease, scrapie and Creutzfeldt-Jacob disease. Many of the prion’s secrets have not been revealed yet. However, what we do know is that the normal defence mechanisms of the body – the antibodies and the white blood cells – are helpless when the prions attack.
But now medical research has come up with new and sensational information: Mice that are given antacids, or acid-reducing drugs, are more easily infected with prion diseases than are mice with normal gastric acid.
Might not this also be valid for us two-legged creatures?
“We can certainly not reject that possibility,” say Professor Helge Waldum and Research Fellow Tom Chr. Martinsen at NTNU. They are the first researchers in the world to have studied the effect gastric acid has on prion diseases.

Clear results
Waldum has conducted research on gastric acid for twenty years. He knows a lot about its ability to fight infectious agents such as viruses and bacteria – and one day he asked himself whether it was possible that gastric acid might also reduce prion infections.
The fact is that prions are able to withstand an attack of acid quite effectively. But gastric acid also contains active enzymes. It is, generally speaking, a remarkable bodily fluid, according to Waldum. That is, so long as one doesn’t tamper too much with its acid level.
Waldum and Martinsen gave acid reducers to a group of laboratory mice, and they let members of another group keep their normal gastric acid. At the same time they gave the animals one portion of fodder which was infected with scrapie. Some of the animals received high prion concentrations, others were given low ones.
And then they waited.
Six months later the first symptoms appeared: trembling, limpness, falling over – symptoms which were confirmed by microscopic examination of the brain tissues. The tendency was clear:
• There was no significant difference between those mice which had been given the highest dosages of prions. Almost every single one of them fell ill, whether they had received acid reducers or not.
• But the difference became evident among those mice which had received the lower prion dosages. With these mice, the disease occurred most frequently among those that had received acid reducers. And in the group that had received the very lowest dosages of prions, the disease occurred only among those that had been given acid reducers. All the mice with normal gastric acid had resisted the prion attack and remained healthy.

Use antacids with caution
Antacids top the list of the most frequently used medications in the world. About 10 per cent of the Norwegian population use prescription antacids on a regular basis. Is it time we start thinking about lowering our consumption?
Waldum and Martinsen do believe that there is every reason to take these finds seriously:
“As yet we do not know enough about prion diseases. We don’t know what percentage of prions end up in our digestive system when we eat contaminated meat, and we don’t know how much of it gastric acid can successfully resist. We don’t know how violent a level of prion attack the body can withstand. But we do know for sure that as far as mice are concerned, gastric acid has an important function. If people really want to be on the safe side, they should be more cautious about reducing the gastric acid, especially when they are eating meat.”

Contact: Helge Waldum
Department of Clinical and Molecular Medicine, NTNU
Tel: +47 73 86 85 41
Email: Helge.Waldum@medisin.ntnu.no

Gemini Facts

• Prions are tiny, infectious particles that probably consist of proteins only. They are insignificantly influenced by chemical disinfectants and sterilization agents, by radiation or by heat.

• Prion diseases occur when prions are absorbed in the intestines and attack the central nervous system. The symptoms are mental confusion and involuntary movements. The brain becomes sponge-like. The incubation period is very long – and the outcome is lethal.

• Human beings can be infected by eating meat from sick animals. In England alone more than a hundred people have died from Creutzfeldt-Jacob disease. No one knows how many are already infected.