There are good reasons why many vegans and vegetarians swear by soy. It’s versatile, packed with protein and other nutrients, plus, it makes a tasty meat alternative.
Although soy is lauded for its many benefits, it comes with a few negatives, too. Let’s take a look.
- Soy is a legume. But, unlike many other legumes, it’s an excellent source of plant protein.
- Soy is naturally cholesterol-free and low in saturated fat, making it a healthy, plant-based alternative to meat.
- Soy can boost your fibre intake, which helps to sustain a healthy colon.
- Soy contains Omega-3 fatty acids, which help to lower the risk of cardiovascular diseases.
- It’s chock-full of B vitamins, Vitamin D, calcium, iron, zinc and antioxidants.
- It provides an excellent dose of polyunsaturated fat, which has heart-health benefits
- It‘s an ingredient in many readymade convenience foods. These include soy milk, tofu, soy sauce and tempeh.
- It may help alleviate symptoms of menopause. Menopause occurs when a woman has her last menstrual period. Hormone therapy is often used to relieve the symptoms of menopause and to counteract the drop in oestrogen. This comes with some health risks, so many women look for alternatives to manage their menopause symptoms. One of these alternatives is soy, which contains chemical compounds called isoflavones. These have some oestrogen-raising effects.
It affects your thyroid
Soy has excessive levels of goitrogens – compounds that hamper your thyroid’s ability to use iodine properly. This may cause hypothyroid problems, which means that your whole metabolism slows down. Hypothyroidism may also cause low energy levels, make you feel cold all the time, and make you vulnerable to disease. Be aware that vegetables like cauliflower, broccoli and cabbage (in excessive quantities) can also disrupt your thyroid.
It disrupts your hormones
Although soy may help with managing menopause as it raises oestrogen levels, it can cause problems. Isoflavones disrupt the reproductive systems of people who aren’t menopausal. Excess soy could temporarily stop the menstrual cycle in women. In men, it could cause an imbalance of testosterone, resulting in fat accumulation around the waist, a low libido, and a loss of energy and stamina.
Parents with young children should take care when choosing baby formulas as many contain substantial doses of soya. A baby’s hormones need to be balanced for them to develop properly and for their sexual characteristics to develop. For example, too much oestrogen can result in underdeveloped testicles and problems during puberty. Speak to your child’s doctor if you’re concerned.
It makes digesting protein difficult
Protease is an enzyme that breaks down proteins. Soy contains protease inhibitors (trypsin inhibitors), which block the action of protease. When proteins aren’t broken down, they can’t be absorbed and used for important functions, such as repairing and building tissues.
The bottom line
According to dietician Kathy McManus, natural soy products like tofu and edamame are valuable sources of protein and other minerals. So, it’s okay to eat these whole soy foods in moderation, a few times a week. However, try to avoid soy isoflavone supplements and foods made with soy protein isolate, including protein powders and nutrition bars. These put you at greater risk for the possible side-effects of soy intake than the whole-food soy options.