Monday, 12 August 2013

tuberculosis and the importance of meat

This weekend I listened to the BBC Radio 4 programme Any Questions?. Benjamin Zephaniah was one of the guests. He is a vegan and had some interesting things to say on the question of diet. This was prompted by a question about lab-cultured burgers.

Benjamin seemed very up to date on the subject of how much protein people need and the importance of meat. The other contributors continue to believe the old-fashioned idea that people need large amounts of protein and that the only easy way to get that is through eating meat.

I was especially perturbed by what was said by Hugh Pennington, Emeritus Professor of Microbiology at Aberdeen University.

I believe that the biggest factor in getting rid of tuberculosis in this country ... has been that people can buy cheap chicken. And chicken is the big big protein source. Herbert Hoover ran an election campaign ... on 'a chicken in every pot' but it was successful. Now you may not like the way the chickens are grown but it is very cheap very good protein, and that has saved lots and lots of lives. And white meat from chicken is good for you. Beef is a bit of a luxury. So that's where I stand. Chicken, eggs, milk and that sort of stuff.

It is true that when people are trying to recover from tuberculosis, or many diseases, that they should eat good quality protein. But, as it says on this site under the heading High quality proteins to repair the damaged tissue
  • The best and easily digestible proteins are from egg whites and milk. About 2 eggs and 3 glasses of milk are required in a day.
  • Other good sources of protein are chicken, fish, meat, cheese, nuts and seeds, pulses.
So it looks like vegetarians can very easily get the protein that they need to recover from tuberculosis. They can have egg whites and milk. Or cheese, nuts, seeds and pulses. It also looks as if vegans can easily get the protein they need too. They can have nuts, seeds and pulses. So I really don't know why Professor Pennington is going on about chicken.

Another guest on the programme, Matthew Sinclair said It's hard to get the full mixed proteins you need without meat. This is simply not true. This belief stems from the time when scientists overestimated the amount of protein that people need. Now the scientific recommendations for the amount of protein that people need is much lower. I know that plant proteins tend to be slightly deficient in one or more of the amino acids, but when you have protein from different plants - such as grains and pulses - they make up for each other's deficiencies. That's not so important anyway now that we know people's protein requirements are more modest.

The other thing that Matthew Sinclair said I didn't like is what the audience member who asked the question also said. They said that scientists have done wonders in breeding crops to benefit mankind, so isn't it wonderful that now they are turning their attention to proteins. As if proteins only come from animals. Farm animals do not create proteins, they can only take protein from plants and very inefficiently re-organize them into their tissues. Soya and other pulses are the cheap proteins. It's about time people realized that, because if they don't we're never going to be able to feed the world.

People should not worry about whether they are getting enough protein. In Britain people, even poor people, get about one and a half times as much protein as they need. Even if they are recovering from an illness, such as TB, they wouldn't need to have more. Although, if they want to be on the safe side, they could have eggs and milk. If they want to worry about getting enough of any nutrients, it would make more sense if they worried about getting more vitamin D.

Vitamin D has been linked to TB, among other things, and it seems if you take more vitamin D then you are less likely to get TB or more likely to recover from it. It's difficult to get enough vitamin D from food sources or from sunlight, so I would take a vitamin D tablet. Not chicken. Eggs have got some vitamin D. Oily fish do too. So if you eat oily fish you get protein, omega-3 (another nutrient we could do with more of) and some vitamin D. Cod liver oil has omega-3 and some vitamin D.

The irony is that chickens are fed on animal feed that often contains anchovies. Anchovies are being overfished. This Guardian article is very interesting.

Betrand noted that despite accounting for the biggest stock in the world, anchovies are seldom used for human food, crushed instead into a fine flour to make animal feed for fowl, pigs and farm-raised fish.

If people fed less anchovies to animals like chickens and ate them themselves they would have cheaper protein, they would have more long-chain omega-3 and they would have more vitamin D. There would be less TB in the world. When anchovies are fed to chickens about half of the protein is lost, and nearly all of the omega-3 and vitamin D. It's not so bad if it is egg production and not meat.

Anchovies in the supermarket are expensive, but there should be a way of getting anchovies to people all over the world cheaply. You might say that people don't want to eat anchovies, but if instead of 'a chicken in every pot' for Americans we tried to get cheap protein in the form of soya and sustainably fished anchovies to everyone that would be a much better way of feeding the world.

Soya in the form of tofu and tempeh has a bland flavour but miso is delicious. Anchovies could combine quite well with miso, even in the form of anchovy flour, to make a tasty soup or stock. There may be other ways to use anchovies.