When my daughter was very small, I used to put my mouth over her belly button and make noises with air pressure to make her laugh. She always did. But now that she is more than two years old, she plays with her own belly button – a few times a day – putting her hands under her clothing and rubbing it (apparently) for self-stimulation. Is this normal? I feel guilty for giving her the idea in the first place. I worry that this could result in an infection if her hands are not clean and whether some psychological damage could result. Should I get her to stop this, and if so, how?
I.M., Tel Aviv

Prof. Eitan Kerem, chairman of pediatrics at Hadassah University Medical Centers in Jerusalem, replies:

This behavior is very normal for a child of your daughter’s age. And it has no connection to your having blown air into her navel as a game, so don’t feel guilty. During normal development, children start exploring their body.

They are most obsessed with their mouth, hair, navel and ear lobes, and they may also be seen stimulating their external genitals. Up to one third of the children of this age group may be seen doing this self-stimulating act.

Playing with the navel is even less of an issue than self-stimulating the genitals. It is impossible to stop a baby from self stimulating the parts of the body, and it is wrong to do so.

Since it is part of normal development, parents have to accept this. If your child’s development is normal and her social and communication skills are appropriate for her age, you do not need to do anything. Just ignore it and it will go away. Only if she develops an infection from scratching the area should something be done to treat the infection, but this is rare.

I suffer from low thyroid function and am on supplements of thyroxine. I was never told by my endocrinologist to abstain from eating soy products, but I have since learned that soy interferes with the absorption of thyroxine. Is this correct? As I am not a meat eater, I eat and drink a lot of soy.

I also heard that as I suffer from a fibroid in my uterus, I should abstain from drinking soy milk as it contains estrogen and thus will encourage the growth of the fibroid even more. I have in the past suffered from pains from the fibroid, but when I stopped drinking soy milk, I noticed that the pain stopped.

I wonder how many people are unaware of the side effects of soy products and why doctors do not warn us about this.

E.N., Givat Shmuel

Olga Raz, chief clinical nutritionist at Tel Aviv Sourasky Medical Center, comments:
Soy falls into a category of foods known as goitrogens, together with all kinds of cabbage and other vegetables and grains, that promote formation of goiter, which is an enlarged thyroid. Soy has long been thought to interfere with the body’s ability to absorb synthetic thyroid hormone. However, there is no evidence that people who have hypothyroidism should avoid soy completely. All you need to do is to wait four hours after taking thyroid medication before consuming any products that contain soy.

As for hormonal functions, there is controversy as well, as genistein – which is found in soy – has the structure of estrogen and is thought to affect hormonal functions in both genders, so if you feel better by not eating soy, that is OK.

Avocado oil is being marketed today with claims that it is the most nutritious of all. But it is no less expensive than olive oil. Does avocado oil offer anything more than canola oil, which is beneficial but much cheaper than the two?

Dorit Adler, chief clinical nutritionist at Hadassah University Medical Center in Jerusalem’s Ein Kerem, replies:
My view of avocado oil is positive, just as it is on avocados in general, because it and olive oil are made in a similar way. But it is too early and would be an error to speak of avocado oil as better than olive oil, because many long-term large studies will need to be published in leading peer-reviewed medical journals. Avocado oil should be part of the basic foods that protect the body, along with other components of the Mediterranean diet, but it does not replace any other vegetable.

Each oil has a different composition of fatty acids. Avocado oil is generally similar to olive oil, but in terms of nutrition is more complicated.

There are many different nutrients in avocado, such as antioxidants, which are different from those in olives. Therefore avocado oil can be included in the group of protective foods and oils.

Olga Raz adds:
In principle, the fatty acid components of avocado oil are very similar to those in olive oil. It might be that avocado oil has more beneficial phytochemicals, but I have not seen any reference to that in the medical literature.

The material sent by the company that makes the oil is not impressive and not clear.

Rx for Readers welcomes queries from readers about medical problems. Experts will answer those we find most interesting. Write Rx for Readers, The Jerusalem Post, POB 81, Jerusalem 91000, fax your question to Judy Siegel- Itzkovich at (02) 538-9527, or e-mail it to jsiegel@jpost.com, giving your initials, age and place of residence.

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