AS A retired biology lecturer, I would like to comment on Mr Sanderson’s letter on meat eating (Oxford Mail, December 29).

I don’t think that he has got it quite right.

While it is true that eating large amounts of red meat does increase the risk of bowel cancer, there is little or no evidence that eating a wide range of meat and meat products in moderation is harmful.

It is also worth noting that mankind, with few exceptions, has always had some meat in the diet since we first evolved.

This explains why human dentition is that of an omnivore with relatively large incisors.

Most animals which are true vegetarians have teeth adapted for finely grinding and chewing vegetation, such as cows and sheep, and lack incisors.

Furthermore our digestive systems have not evolved to be able to break down cellulose, which means that the energy we can derive from most vegetable material is limited.

One way or another, true vegetarians can use cellulases, enzymes which break down cellulose to simple sugars which can be used to provide energy.

Finally, if you look at the remaining hunter gatherer groups which still exist, such as the Kalahari bushmen, then they exploit a huge range of insects, animals, wild bird eggs, fruit, roots and tubers – whatever is in season.

They are true omnivores who’s diet historically had been the same for thousands of years, and were living in sustainable harmony with their environment.

All the indicators point to early humans being hunter gatherers.

The moral from this, in my view, is that we should eat sensibly, and that does mean lots of fruit and vegetables, and be quite comfortable eating a wide range of meat and meat products, fish and dairy products, as long as we do so in moderation at all times.

BOB JOHNSTON, Vale of White Horse district councillor, Kennington Road, Kennington