I’ve read that soya milk increases the risk of breast cancer. Should I avoid it?

Soya milk and soya products, such as yoghurts, tofu and tempeh soyabean cake, contain plant chemicals known as isoflavones. These “super nutrients” are said to have “oestrogen-like” effects in our bodies. Given that the risk of breast cancer has been linked to a higher level of oestrogen, it is logical to assume that soya may increase the danger.

However, studies in humans have found no effect from soya isoflavones on either breast tissue density or breast cell proliferation, both of which are markers for increased breast cancer risk.

Among women who have had breast cancer, the Shanghai Breast Cancer Survival Study, which included 5,000 women six months after diagnosis, showed that those who ate about 15g of soya protein a day had a 33 per cent lower risk of dying from breast cancer or relapsing compared with women who ate the least soya protein (6.6g per day).

Given that research on both pre and post-menopausal women who ate significant amounts of soya-based foods has found no significant effect on oestrogen levels in the body, it is likely that whatever good things soya does for our general health, it is independent of hormone levels.All of this said, if you have any concerns, it is best to speak to your GP or a breast cancer expert about your individual situation.

Japanese women seem to have fabulous-looking skin well into old age. Is this to do with eating foods such as soya beans and tofu?

Their great-looking skin is probably partly down to genetics and a lot down to avoiding too much exposure to the sun.

However, a pilot study carried out at the Federal University of Sao Paulo in Brazil on 30 post-menopausal women has indicated that soya isoflavones taken in supplement form over a six-month period appeared to improve skin elasticity in 75 per cent of women and to increase collagen (the protein in skin that gives it bounce and a youthful plump appearance) in more than 85 per cent of women.

Studies on levels of soya consumption in Asia suggest that intakes of 15g-25g of soya protein daily are not unusual. You can get this by having two to three servings of soya foods a day such as 250ml of soya milk (this could be on cereal or as a latte or cappuccino), a 125g pot of soya yoghurt and a 100g portion of tofu in a stir-fry or a smoothie.

It is just possible that this kind of regular intake may play a role in anti-ageing for our skin, but I would not dispense with the suncream and sunhat too soon.

I love edamame beans and roasted soya “nuts”. Are they good for you?

Edamame bean is the name used for young whole soya beans. They can be served in their green husk or pre-husked.

You can expect a typical bowl of unhusked edamame beans that you eat with your fingers (pushing the beans out of the husk with your teeth) to give you 100 calories and around 5g of fat per 80g serving. This makes a really healthy, filling starter to nibble on.

Husked edamame beans (Bird’s Eye produces a frozen version; they are great for adding to vegetarian stir-fries or just using as a side vegetable) have 150 calories and 6g of fat per 100g.

Soya “nuts” have been roasted in oil, and a 100g serving of these snacks has 400 calories and 19g of fat. This is still better than peanuts with 602 calories and 53g of fat for the same weight but, clearly, soya nuts are not a low-calorie option. If they are salted, you can also expect nearly 1g of salt, a sixth of your daily maximum.

There seems to be controversy over whether soya can really help to lower cholesterol. What are the facts?

In the UK, Japan and the US, manufacturers of foods such as soya milk are allowed to add a health claim to their packaging stating that soya protein can help to lower cholesterol.

Although some studies appear to question this, most research does still support the claim, indicating that intakes of 15g-40g of soya protein a day can lower “bad” cholesterol by 6 per cent.

An even more powerful cholesterol-lowering effect can be achieved by following a low-fat diet that includes three portions of soya-based foods daily plus porridge oats, pulses (such as red kidney and butter beans), two servings of foods containing plant sterols such as Benecol or Flora Proactive yoghurts and a handful of almonds.

This style of eating, known as the portfolio diet, has been proven to reduce bad cholesterol by more than 30 per cent, which is comparable to cholesterol- lowering statin drugs.

If you have a nutrition question, e-mail amanda.ursell@thetimes.co.uk

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