Should You Be Eating Soya?

Soya is one of the few plant‑based foods to contain all nine essential amino acids, making it both a complete protein and one of the highest plant‑based sources of protein available. A dietary staple across Asia for thousands of years, it has long held a reputation for being the go-to protein source for those following a vegan diet. But in recent years, questions have been raised around the safety and environmental impact of soya, leading some to avoid it altogether. In this short article, I’ll be separating fact from fiction to help you to make an informed choice.

Nutritional Benefits

First of all, let’s get to grips with the different forms of soya on the market. Whole soya beans are not only full of protein, they’re also a great source of calcium, iron, potassium, and fibre. Buying them in bulk is a cost-effective way to boost your diet, and you can use these versatile beans for anything from soups and stews to crunchy roasted snacks. Gently processing soya beans transforms them into tofu and soya milk which, thanks to its impressive protein content, is one of the closest plant‑based alternatives to cow’s milk, and can easily be substituted in most recipes.

Like all beans and legumes, soya naturally contains small amounts of phytates and lectins, phytochemicals that can affect digestion and mineral absorption when consumed in large amounts. These are simply part of the plant’s defence system, and their levels can be greatly reduced through soaking, pressure cooking, sprouting, or fermentation.

When soya is fermented, the nutrient profile becomes even more impressive, producing a wealth of enzymes and beneficial bacteria, which further aid our digestion. Traditional foods such as tempeh and miso are now readily available in most supermarkets – just be sure to keep them in the fridge and to avoid cooking at high temperatures, as this can reduce levels of enzymes and bacteria. You can now even buy fermented soya milk, which is creamier and easier to digest than typical non‑fermented varieties.

As with meat and dairy products, you can find wholefood sources of soya beans and you can find ultra-processed forms (UPFs). Ultra-processing a food — whether it’s soya nuggets or chicken nuggets — can not only strip away beneficial nutrients, but also alter how the body digests and absorbs them. As with any diet, if you choose to include UPFs, they’re best kept as an occasional treat.

While tofu, tempeh, and miso are convenient and nutritious options, it’s always best to use in moderation and to include a variety of plant proteins in your diet to maximise nutrient intake, and of course for a broader range of flavours and textures. Beans, lentils, chickpeas, peas, quinoa, nuts, and seeds each offer their own unique nutrient profile.

Environmental Concerns 

But what of the environmental impact of soya? While concerns about deforestation are valid, it’s important to put this into context: almost 80% of global soya crops are grown to feed animals in industrial farming, not for direct human consumption (WWF, 2022)¹. This reliance on huge amounts of feed crops, along with the land, water, and energy required to house and manage the animals, multiplies emissions further. Eating soya directly — through tofu, tempeh and soya milk — helps reduce your carbon footprint. Additionally, opting for organic soya supports sustainable farming, protects biodiversity, and reduces pesticide use.

Health Considerations

Another common concern about soya relates to hormones, and there’s a lot of misinformation on this subject. Soya contains phytoestrogens, such as isoflavones — plant compounds structurally similar to human oestrogen, but much weaker. Research shows that these compounds can help support healthy hormone balance in both women and men (Messina et al., 2022)², and they’re even used in some health supplements for this purpose. For most people, moderate amounts of organic whole or fermented soya are not only safe but beneficial.

It is true, however, that certain health conditions — such as untreated hypothyroidism — may warrant reduced intake. And while studies have repeatedly found that those who regularly consume soya and isoflavones tend to have lower rates of certain cancers (Fan et al., 2022)³, there is still insufficient data for people living with or after cancer. If unsure, always seek guidance from a medical professional.

Soya is a complete, versatile, and nutrient-rich plant protein that makes it easy to eat well while supporting a more sustainable and compassionate food system. By choosing whole, organic, and fermented forms, you can nourish your body, help protect the planet, and make positive choices for animal welfare.

Here are some easy ways to healthfully include soya in your diet:

• Tempeh mince: Lightly steam tempeh for about 10 minutes to soften its flavour, then grate or crumble it. This will give you the ideal wholefood protein source you can use anywhere you’d usually use mince.
• Miso stock: Choose unpasteurised miso (to be stored in the fridge) as an unprocessed alternative to stock cubes or bouillon. Stir it in at the end of cooking to preserve nutrients and friendly bacteria.
• Umami glaze: Mix 1 tbsp miso with 1 tbsp maple syrup, 1 tsp sesame oil and a squeeze of lime and use as an umami glaze for tofu or roasted vegetables.
• Tofu scramble: Crumble tofu with turmeric, tamari, nutritional yeast and a pinch of black salt to create a simple tofu scramble that can be used in place of scrambled eggs.