Hormones in Meat
Public concern over the safety of South African meat and meat products which might contain hormones has increased, particularly since the use of hormones in meat production is not permitted in Europe (EU). Some of the health problems being raised are low sperm counts in men, boys developing breasts and early onset of puberty in girls.
The fact is, for decades in South Africa, almost all abattoir meat has been produced with the aid of hormones, and it is known to be a completely safe practice.
Bovines (cattle, etc) normally produce their own sex and other hormones and over thousands of years, humans have eaten meat and have suffered no ill effects. Difficult farming conditions in South Africa mean that it is necessary to use all possible methods to maximise the efficiency of our agricultural industry, in conditions that are safe for both humans and animals.
What Are Hormones?
Hormones are chemical substances with very specific effects. Some hormones, like the sex hormones, have secondary, more general effects, such as promoting growth (or producing soft female skin texture).
Hormones In Food
These chemical substances that produce human hormonal activity are widespread in common foods. These substances from vegetable sources are called phytohormones from the Greek phyto meaning vegetable.
The following table shows the sex hormone contents of a selection of foods in micrograms (µg) per 500 g food, from the highest to the lowest.
(As a comparison: birth-control pills contain between 30 to 350 µg hormone per unit, which means we can say that about 30 µg is the minimum dose for causing any changes or having any physiological effects on the human body.)
|Soybean oil||1000 µg/500g|
|Cabbage (raw)||12 µg/500g|
|Ice cream||3 µg/500g|
|Beer made from hops||0.078 µg/500g|
|Beef from steers – implanted cattle||0.007µg/500g|
|Beef from steers – non implanted cattle||0.005 µg/500g|
So we can see that a pint of beer (or a helping of peas or ice cream!) will provide more sex hormones than a 500g steak, but none are enough to produce any physiological effect whatsoever.
Looking at it another way, a person would have to eat about 4.28 tons of beef or 15g of soybean oil every day, to consume enough hormone to have any effect on the human body.
The Use Of Hormones In Meat Production
There are four anabolic steroids (hormones) commonly used in promoting the growth of animals:
- estradiol and progesterone, which are the naturally occurring hormones;
- zeranol and trenbalone, which are the synthetics.
When used as recommended, these hormones are extremely safe for both the animal and the final consumer and residues are really negligible.
In the meat industry, hormones are used only for a short period while the animal is being fattened on a “feedlot”. In feedlots, for example a 10-month-old steer or heifer of 200 kg receives an ear implant. After about 100 days of feeding, the animal has grown to 400 kg when it is ready for slaughter. The most common hormone ear implants contain zeranol or a mixture of trenbalone and estradiol. Both implants promote improved conversion of feed into muscle by up to 20% and also ensures that South African abattoir meat has a low fat content. The implant can have a maximum active life of about 70 days.
Without the use of hormones bovines require about three years to achieve slaughter weight, whereas in South Africa the aim is to slaughter animals at 18 to 24 months old for improved farming efficiency.
In most cases South African Legislation has set the allowed limits lower than those required internationally. The Farm Feeds, Fertilizers, Agricultural Remedies and Stock Remedies Act 36 of 1947 and its regulations follows the international norms of Codex Alimentarius Commission, World Health Organisation (WHO), Food and Agriculture Organisation (FAO) and the Joint Expert Committee for Food Additives (JECFA).
The great advantage in South Africa is that the use of hormones in red meat production is permitted and controlled by the Department of Agriculture, which means that products and usage levels are known and residues can be monitored. (In Europe, at present, all hormone usage is illegal, so the usage there is unknown and possibly unmonitored!)
The South African legal limit for trenbalone in bovine carcasses is 0.01 ppm (parts per million) in liver and 0.002 ppm in muscle, which is well below the levels regarded as safe by JEFCA, and the Unite Nations WHO and FAO. These limits are also well below the “no observable effect” limits that have been determined so far.
In the present climate of concern for human and animal welfare, people do have concerns over farming practices and rightly so. However, the South African food scientists and the authorities have had these same concerns for a long time. The public can rest assured that legislation is in place to ensure our meat products are safe for consumption, and that if research throws doubt on any current practice, the appropriate action will be taken to ensure human and animal welfare, both in the long and short term.
Risks Are Reviewed In The UK
A Meat Hormone Working Group was set up on 04 December 2002, by the MAFF Veterinary Products Committee (VPC) to review the latest evidence on whether there could be a risk to human health from hormone residues in bovine meat and meat products.
The outcome of this investigation was that “The scientific evidence does not indicate that the use of hormones in farming presents a risk to public health”.
“Human Safety of Hormone Implants Used to Promote Growth in Cattle”. 2000. by Dr. ME Doyle, University of Wisconsin. USA.
“Use of Growth Promoters in Future Production: One point of view”, by S.L. Boyles of the Ohio State University, USA., in 46th International Congress of Meat Science & Technology, Buenos Aeries, Argentina. 2000.
Reviewed and updated by Dr B Cole (2016).