Red meat: A diet of value or health hazard?

Meat of adult mammals, such as beef, mutton, and horse, has consumption based largely on availability, price and tradition.

Meat of adult mammals, such as beef, mutton, and horse, has consumption based largely on availability, price and tradition.

Its production is a very compound action depending not only on demand (which is usually based on price and income) but on many other social and economic influences.

In Rwanda, meat seems to be taking either sides of influence if we compare the way people enjoy brochettes. However, considering the social and economic level of an individual, meat is taken in high esteem in most African communities.

The common types include beef, pork, lamb and veal, plus sausage, ham, bacon and cold cuts. Meat has prestige value; it is often regarded as the central food round which meals are planned.

And various types of meat are sometimes made the basis of festive and celebratory occasions. And in the scientific point of view, it is regarded as a food of high nutritive value.

However, Vegetarians assert that meat in short supply can be a measure of the nutritional quality of the diet as a whole.

They consider a typical diet to be heavily dependent on one type of cereal or root crop, meat, even in small amounts, complements the staple food.

It provides a relatively rich source of well absorbed iron and also improves the absorption of iron from other foods, its amino acid composition complements that of many plant foods, and it is a concentrated source of B vitamins, including vitamin B12 which is absent from plant foods.

Red meat as a source of food value

According to the World Health Organisation report, meat as a human source of protein requirements is estimated to be 55 gm per day for adult male man and 45 g for female.

These amounts refer to protein of what is termed “good quality” and highly digestible, otherwise the amount ingested must be increased proportionately to compensate for lower quality and lower digestibility.

The quality of a protein is considered as a measure of its ability to satisfy human requirements for the amino acids. All proteins, both dietary and tissue proteins, consist of two groups of amino acids.

Those that must be ingested ready-made i.e. are essential in the diet, and those that can be synthesised in the body in adequate amounts from the essential amino acids.

The qualities of dietary protein are measured in various ways but basically it is the ratio of the available amino acids in the food or diet compared with needs.

Meat and meat products are a source of vitamins and minerals. They are important sources of all the B-complex vitamins including thiamin, riboflavin, niacin, biotin, vitamins B6 and B12, pantothenic acid and folacin.

The last two are especially abundant in liver which, together with certain other organs is rich in vitamin A and supplies appreciable amounts of vitamins D, E and K.

Meat is also an excellent source of minerals such as iron, copper, zinc and manganese. Manganese plays an important role in the prevention of zinc deficiency, and particularly of iron deficiency which is widespread.

The amount of iron absorbed from the diet depends on a variety of factors including its chemical form, the simultaneous presence of other food ingredients that can enhance or inhibit absorption, and various physiological factors of the individual including his/her iron status.

Overall, in setting Recommended Daily Intakes of nutrients the proportion of iron absorbed from a mixed diet is usually taken as 10%. Half of the iron in meat is present as haeme iron (in haemoglobin).

This is well absorbed, about 15-35 percent, a figure that can be contrasted with other forms of iron, such as that from plant foods, at 1-10 percent.

Not only is the iron of meat well absorbed but it enhances the absorption of iron from other sources e.g. the addition of meat to a legume or cereal diet can double the amount of iron absorbed.

So they contribute significantly to the prevention of anaemia, which is so widespread in developing countries. Meat is the richest source of zinc in the diet and supplies one third to one half of the total zinc intake of meat-eaters. It is present in all tissues of the body and is a component of more than fifty enzymes.

Health concerns associated with consumption of meat

Despite all the nutritional values associated with the consumption of meat, Dr. Jules Kabahizi of Rwanda’s Health Foundation believes red meat is more hazardous than beneficial to our health.

It is estimated that after an average of almost five years, people who ate the most red meat and processed meat had a 35 percent greater risk of developing colorectal cancer than those who ate the least amounts.

He says that unless if ate in appropriate quantities, but too much consumption of it causes coronary or Ischaemic heart disease (cardiovascular diseases).

The major cause of death in some parts of the developed world is coronary heart disease and saturated fatty acids as dietary risk factor.

It is because about a quarter of the saturated fatty acids in the diet is supplied by meat fat and the consumption of meat itself has come under fire.

Dr. Kabahizi explains that the first stage of disease development is a narrowing of the coronary arteries by deposition of a complex fatty mixture on the walls a process termed atherosclerosis.

And then the lethal stage is the formation of a blood clot that blocks the narrowed artery thrombosis. Although thrombosis is not deadly, the reduced blood flow to the heart muscle deprives it of oxygen and can lead to extensive damage referred to as myocardial infarction.

In blood, there are three types of lipoproteins (protein-lipid complexes). These include low density lipoproteins, which its 46 percent of the molecule is cholesterol, high density lipoproteins with 20 percent as cholesterol and very low density lipoproteins with 8 percent cholesterol.

The high levels of total blood cholesterol are associated with the incidence of heart disease and high intakes of saturated fatty acids elevate blood cholesterol levels. This defines the association of saturated fatty acids and coronary heart disease. This now means that low density lipoproteins are dangerous yet high density lipoproteins are protective.

Dr. Kabahizi therefore urges people to reduce the intake of saturated fatty acids as compared with unsaturated fatty acids and so reduce blood levels of low density lipoproteins. But merely choosing lean red meats and reduced fat processed meats does not appear to remove the cancer risk.

Other risk factors identified include a family history of the disease, smoking, and lack of exercise, various types of stress and certain disease states together with a number of dietary factors. The high saturated fat content is the major contributor to heart disease. His call supports and extends the results of several previous studies about red meat.

The cancer risk actually rises with fairly small amounts of these foods. Eating more than red meat and processed meat per day puts at risk. However, for consumers who want to apply these findings to best protect their health, questions remain about specific food choices.