Tuesday, April 24, 2007

Omega-3s


A recent news article about the importance of omega-3 fatty acids caught my attention.

A type of omega-3 fatty acid may slow the growth of two brain lesions that are hallmarks of Alzheimer's disease, UC Irvine scientists have discovered. The finding suggests that diets rich in docosahexaenoic acid (DHA) can help prevent the development of Alzheimer's disease later in life.

This news is not surprising since the brain is an astonishing 60 percent fat, of which half is docosahexaeonic acid or DHA. DHA is found only in fish. The reason that I was struck by this finding is because my father died of Alzheimer's (or senile dementia) and so did his two brothers. (They tend to call all forms of old age forgetfulness Alzheimer's now.) All three were in their eighties when they died. Their father, my grandfather, also had some kind of dementia in old age. But the interesting thing is that he came from Newfoundland where his father and grandfather going back three more generations were all fishermen. They settled in an outport on Conception Bay called Bull Cove. (Bull Cove is abandoned now and the photo shows how it looked to my cousin when she made a trip there in the 90s.) They lived for and by cod. They ate fish daily I'm sure. And when they weren't eating fish, they were eating berries which are abundant on the island—blueberries and partridge berries in particular—and full of antioxidants.

My siblings and cousins have asked me if I have found any evidence of the disease being hereditary in my genealogy research, but before my grandfather, there is no record of it. Records from Newfoundland are scanty, of course, and my great-grandfather died of pneumonia at sea at the young age of 32 years. We don't know what he might have died of had he lived into old age. Life was hard in Newfoundland, and still is. The progenitor of the family, who came to Newfoundland from England, died at 77 after "after a long and painful illness, which he bore with resignation to the Divine." Whatever it was, it doesn't sound like Alzheimer's.

After reading the above Science Daily article I thought that perhaps it was all the fish that they ate that might have protected my Newfoundland ancestors from the disease. Omega-3 fatty acids which are anti-inflammatory need to be balanced with omega-6 fatty acids. Our modern American diet is way too high in omega-6s due to grain and seed oils like corn, safflower, etc. and due to the fact that our beef is grain- and corn-fed and not grass-fed. The ideal ratio between these two fats would be 1 to 1 but even the USDA recommends a ratio of 6s to 3s of 10 to 1 and most Americans get a much higher ratio than that, as much as 30 to 1 according to some sources.

If DHA is important at the end of life it is equally, if not vitally, important at the beginning of life. 50 percent of the calories in breast milk come from fat which is essential to the baby's growth and development. In particular, the DHA in the milk promotes brain and eye development. A pregnant woman or nursing mother would do well to keep her own supply up by eating plenty of fish. But now women are warned not to eat certain fish because of the mercury found in fish, especially tuna, shark, and swordfish. This has had the unfortunate result that some women may not eat any fish at all.

Luckily, there is a remedy: fish oil capsules and good old-fashioned cod liver oil. These oils have no mercury in them. Small fish like herring and mackerel are safe, too. Although they contain mercury, there is a huge difference between the amount found in them and the amount found in the larger fishes. There are also some fish that are farmed and therefore herbivorous like trout and tilapia that would be good choices if you are worried about mercury.

I myself take cod liver oil daily (1 teaspoon) plus one fish oil capsule. That way I don't get too much vitamin A or D. The cod liver oil is lemon-flavored and doesn't taste at all like the stuff my mother forced on me when I was young. (But thanks, Mom.) And I feel like I am continuing in the tradition of my ancestors.

1 comment:

  1. That's very interesting, especially in light of this recent EOS article, Emergence of Complex Societies After Sea Level Stabilized.

    You can download the article here: http://www.agu.org/pubs/eos/eo0715.shtml

    ReplyDelete