Tag Archives: seafood

Seafood Consumption May Protect Against Alzheimers Dementia

…according to an article at the Journal of the American Medical Association. The study involved Chicago-area residents who had provided information about their eating habits. After death, their brains were biopsied, looking for typical pathological findings of Alzheimers Disease.

fresh salmon and lobsters

Rich sources of omega-3 fatty acids include salmon, sardines, herring, trout, and mackerel

Participants who ate seafood at least once a week had fewer Alzheimers lesions in their brains, but only if they were carriers of a particular gene the predisposes to Alzheimers. The gene is called apolipoprotein E or APOE ε4.

You’ve heard that seafood may be contaminated with mercury, right? The seafood eaters in this study indeed had higher brain levels of mercury, but it didn’t cause any visible brain damage.

The Mediterranean diet, relatively rich in seafood, has long been linked to a lower risk of dementia.

A weakness of the study is that the researchers didn’t report results of clinical testing for dementia in these participants before they died. You can have microscopic evidence of Alzheimers disease on a biopsy, yet no clinically diagnosis of dementia.

Steve Parker, M.D.

Steve Parker MD, Advanced Mediterranean Diet

Two diet books in one

Which Fish Provide Maximum Health Benefit and Least Mercury?

Salmon is a good choice

Salmon is a good choice

The Environmental Working Group has a fresh article reviewing the risk of mercury poisoning from seafood consumption. I’m not familiar with EWG. I’m trying not to hold it against them that Dr. Mark Hyman is on the board of directors.

Anyway, the EWG has some advice for you if you worry about mercury toxicity from fish. I try to stay up to date on the issue since I’m convinced that consumption of cold-water fatty fish twice a week is good for your health, in general. If the mercury doesn’t kill you.

Here are some quotes from the EWG article:

…EWG has compiled a list of “moderate mercury” species that would pose a mercury risk for pregnant woman and children who eat fish regularly. This list is more comprehensive than the 2004 EPA/FDA advisory, which warned that women of childbearing age and young children, who are most susceptible to the damage done by mercury, should eat only six ounces a week of albacore tuna and should avoid four other high-mercury species – swordfish, tilefish, king mackerel and shark.

EWG rightly points out that much of the “seafood” consumed in the U.S. really doesn’t provide much of the healthful omega-3 fatty acids.

Among popular seafood species, salmon stands out as an excellent choice.  Four to eight ounces of salmon weekly, depending on the species, can provide 100 percent of the recommended amount of omega-3s. Some types of farmed salmon present significant environmental health concerns. EWG recommends that people choose wild salmon instead.

EWG’s analysis highlights several other affordable and sustainably produced species, including anchovies, sardines, farmed trout, and mussels.  Just four to eight ounces of these species weekly would meet recommended omega-3 requirements for pregnant women and people with heart disease.

***

Americans eat more than 400 million pounds of canned imported tuna because it is affordable and can be stored for a long time. Canned tuna is the second most popular seafood in the U.S., after shrimp.  An average American eats an average of 2.5 pounds of tuna every year (NOAA 2012).  Albacore tuna, also called “white” tuna, contains significant amounts of omega-3s, but tests indicate that it also contains significant amounts of mercury. “Light” tuna is usually skipjack tuna but can also contain yellowfin tuna. Skipjack and yellowfin have lower mercury levels than albacore, but fewer omega-3s.

As Jim Gaffigan asked, “Has anyone even bothered to ask why the tuna are eating mercury?”

In 30 years of practicing medicine, including 12 years right on the Gulf Coast, I’ve never seen a case of mercury toxicity. Maybe I’ve missed it. Maybe it’s quite rare.

Read the whole enchilada.

Steve Parker, M.D.

h/t Conner Middelmann-Whitney