FOR many people who don’t have a background in biology, it is difficult to fathom this business of hormones and their function in the body.

The key is to understand that hormones are “messengers” to the cells in the body and, as such, act as regulators for many bodily functions. For example, the thyroid makes and secretes two hormones, thyroxine (T4) and thyronine (T3), which affect the metabolism of almost every cell in the body.

Pharmaceutical companies have been able to replicate and replace hormones found in the body with great success to produce synthetic hormones. These are exact copies of the molecules that the thyroid and ovaries make.

Synthetic hormones are used to treat various medical conditions when a patient is experiencing adverse side effects from the ageing process.

Synthetic hormones come in many forms; the most common form is a mixture of urine from a pregnant mare and progestin. Progestin is a form of progesterone, a hormone that plays a role in the menstrual cycle and pregnancy. Progestin is used in combination with another hormone called aestrogen in birth control pills. These versions of hormones have done wonders for those who are going through peri-menopause, menopause, or who are post-menopausal.

While hormones are a necessary part of the body’s functioning mechanism, the presence of synthetic hormones in food has the potential to disrupt the physiological function of the endocrine systems. The endocrine system is the collection of glands that produce hormones who regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep and mood, among other things.

Studies have found that synthetic hormones put women who take hormone replacement therapy at a 41 per cent higher risk for stroke, 29 per cent higher risk for heart attack, and a 26 per cent higher risk for breast cancer. Additionally, the risk for blood clots forming in the legs and lungs doubled in women who took synthetic hormones. These studies have also shown that long-term use of synthetic hormones led to a 60 per cent to 85 per cent higher risk for breast cancer and breast tumours.

Synthetic hormones are also known to contaminate fresh produce. These hormones find their way into our food through a number of avenues including waste water, which may contain human sewage; industrial site drainage; toxic waste; and petroleum waste products or by-products.

The reuse of waste water for irrigation of agricultural land is a well-established practice that introduces many contaminants into our environment and crops, including pharmaceuticals, hormones and personal care products. The increasing use of raw or processed sewage to grow conventional food has created the conditions for overgrowth of pathogenic (even deadly) bacteria.

It is estimated that 90 per cent of the global waste water being used in agriculture today is untreated, meaning that it contains hundreds, if not thousands of potential biological and chemical toxicants that may ultimately end up in your food and body. These toxicants may include dangerous hormones.

Even when sewage is pretreated in order to remove chemicals, foreign materials, and microorganisms, up to 93 per cent of highly concentrated active drug compounds still remain, including hormones and hormone metabolites that remain biologically active.

Synthetic hormones in milk

Natural growth hormones are essential in young animals and humans alike, for healthy growth and development. However, the controversy lies in synthetic hormones that are approved for use to enhance the growth rate of cattle, poultry and other animals.

These hormones are also used to increase milk production and may find their way into our food supply in more ways than one.

Hormones are present in most animal products, including beef and poultry. They are injected directly into the animals or added to their feed to enhance the amount of eggs, dairy and meat produced. The steroid hormones oestrogen, progesterone and testosterone are also given to cattle and other animals to promote growth and development.

Synthetic varieties may also be given to cattle to increase milk production, bone growth, and meat production. Since this growth hormone is found in humans, it was assumed to be safe if it was sourced from foods such as meat and dairy. However, it may be linked to an increase in certain types of cancers, including that of the prostate, breast and colon cancers.

While many factors, including genes, smoking, and fat intake, may contribute to these cancers, it’s very likely that at least part of that risk is related to consumption of synthetic hormones.

Dr Wendy-Gaye Thomas, MD is group technical manager, Technological Solutions Limited, a Jamaican food technology company. E-mail her at wendy.thomas@tsltech.com