My granddaughter, Bella, is bilingual. Her mom is Brazilian and her dad is a Wisconsin boy, through and through. She is a mixture of both.

Bella is 2. When she talks to us, she expects us to understand everything she says. But you know 2-year-olds. They pronounce things their way, which doesn’t always translate into words the way we know them.

When it’s all English, it’s easy. But when it’s a choice between English or Portuguese, it’s more complicated -- for us, that is. So when we don’t understand something, often it’s because it’s in the other language, the one unfamiliar to us. Bella looks at us and repeats it in English -- slowly and loudly, as if we just can’t hear her. She doesn’t know we don’t understand, she just thinks we can’t hear (or maybe she thinks were just plain dumb).

Now, here are the questions my wife, Penny, and I wondered about: Can the mind keep track of both languages? If so, how does it do it? And does it affect other learning?

New research published in the Proceedings of the National Academy of Sciences, a most prestigious journal, shows children can easily manage the use of two languages. By 20 months, bilingual babies already know something about the differences between the two languages -- words and grammar. They already can figure out the complexities. They implicitly know, for example, that the word “dog” in Portuguese is “cachorro” -- and they can use it differently with different people.

To determine this, researchers studied 24 French-English bilingual babies in Canada. Showing them pictures and asking them to point, they mixed up questions with words in both languages, using English, French and a blend of the two. They also mixed up the sentence structure each time.

What they found was that these new language learners were able to successfully answer the questions by pointing to the correct pictures regardless of whether they were asked in pure French, pure English or a mix of both. But they also found there was a “processing” cost. When the languages switched, the babies’ pupils dilated, a sign of concentration in both children and adults. The babies had to work harder to get the right answer.

But it wasn’t the same for both languages. If the kids in the study were growing up in a predominantly English-speaking house, they had to concentrate a bit when the French words came out. And if they were in a predominantly French-speaking house, they had to concentrate a bit more when the English words came out. All very interesting stuff reminding me, as the daddy of four -- kids are always smarter than you think.

Breastfeeding update: New research published in the Journal Neurology shows another reason for women to breastfeed their babies for at least 15 months -- doing so means you’re less likely to get multiple sclerosis. Add this to the other benefits of breastfeeding -- less ovarian cancer, less breast cancer, less risk of getting diabetes and less chance of dying prematurely from a heart attack -- and it makes breastfeeding a no-brainer.

The study looked at nearly 400 women who had developed MS, comparing them to women who had not, and found that breastfeeding made it 50 percent less likely for a woman to get this dreaded disease. You may wonder why breastfeeding would play a role in a woman getting MS. Some experts say sex hormones have an effect, while others think it’s just the lack of ovulation while breastfeeding. In fact, we don’t know.

A few things to note: The moms involved in the study were not breastfeeding exclusively for 15 months; as their child got older, they breastfed as additional nutrition and nurturing along with other foods. And this was not a cause-and-effect study, but just an association.

My spin: Still, if you put these associations together, you can understand why breast is best. Any woman who is able to breastfeed should try her most to do so. It’s good for mom just like it’s good for baby. Stay well.

This column provides general health information and is not specific advice intended for particular individual(s). It is not a professional medical opinion or diagnosis. Always consult your personal health care provider about concerns. No ongoing relationship of any sort (including but not limited to any form of professional relationship) is implied or offered by Dr. Paster to people submitting questions.