A new study in the journal Neurology found that eating foods packed with omega-3 fatty acids could lower blood levels of beta-amyloid, a protein that contributes to Alzheimer’s disease and cognitive dysfunction.
The study focused on 1,219 people over 65 with no signs of Alzheimer’s. Researchers looked at their diets about a year before they tested blood levels of beta-amyloid in these participants.
Now, here’s the thing. You can measure beta-amyloid levels in your blood, but not your brain. However, the amount in your blood to a certain level correlates with your brain levels. So researchers felt confident using blood levels to measure beta-amyloid.
They also measured 10 nutrients, including vitamins C, D, and E, as well as omega-3 and omega-6 levels.
Researchers learned the more omega-3 fatty acids these people got, the lower their blood beta-amyloid levels. In fact, people who got one gram of omega 3s a day had 20 – 30% lower beta-amyloid levels.
These results stayed the same even after researchers adjusted for age and other demographics as well as the amount of the APOE gene (a risk factor for Alzheimer’s disease) that person had.
“Determining through further research whether omega-3 fatty acids or other nutrients relate to spinal fluid or brain beta-amyloid levels or levels of other Alzheimer’s disease related proteins can strengthen our confidence on beneficial effects of parts of our diet in preventing dementia,” said study author Dr. Nikolaos Scarmeas.
I discuss omega 3s so much because amazing new studies like this one always appear that confirm their numerous benefits. I can’t think of anyone, in fact, who couldn’t benefit from omega 3s.
Your best food source to get them is from wild-caught fish like salmon and tuna. A four-ounce piece of salmon, in fact, packs nearly 2/3 of your daily value for omega 3s.
But what about mercury levels? You can’t mention sushi or fresh fish these days, after all, without someone asking this question.
Here’s the deal. Fish offers way too many nutrients to completely eliminate it from your diet because of mercury levels.
That small piece of salmon I mentioned earlier, for instance, contains a whopping 1,000 IUs of vitamin D. You would probably have to supplement to get those therapeutic amounts otherwise. (Which isn’t a bad idea, by the way.)
Salmon also provides over 100% of your daily value (DV) for vitamin B12 and amino acid tryptophan. Plus you get almost 31 grams of high-quality protein.
Now, here’s why I don’t stress out so much about mercury in fish. Selenium, a mineral prevalent in fish, chelates (or binds) mercury. That piece of salmon provides over 61% of your DV for selenium, and other fish have similar amounts.
Selenium could explain why some people eat fish many times every week and show no signs of mercury toxicity.
I have several other suggestions for people concerned about mercury. For one, skip bigger fish like swordfish and shark that are higher in this toxic metal.
On the other hand, lower-mercury seafood choices include salmon, sardines, shrimp, and tilapia. Opt for these more often.
Mercury levels in tuna depend on what kind you get. Aalbacore tuna, for instance, has more mercury than canned light tuna. And tuna steaks, though higher in omega 3s than other tuna, also contain more mercury.
Yes, keeping up with mercury levels can get confusing. I recommend you visit EWG.org to learn more about the most up-to-date safe fish sources.
Of course, mercury doesn’t just exist in fish. Dental amalgams, for instance, contain about 50% mercury. Talk to your dentist about non-mercury fillings.
Here’s a source of mercury you might not consider: high-fructose corn syrup (HFCS).
In addition to all the other metabolic havoc this sweetener creates, a study in the journal Environmental Health found that half the HFCS-added foods researchers tested contain mercury. That’s because factories that produce HFCS often use outdated mercury-cell technology. As if you needed another reason to avoid HFCS!
If you love sushi or otherwise cutting out fish isn’t an option – and I think you should eat it at least several times a week – I recommend eating it with plenty of vegetables.
Besides their numerous other benefits, vegetables (especially sulfurous ones like broccoli and cabbage) provide your liver the nutrients to effectively detoxify so you have less risk of mercury toxicity.
If you’re still concerned about mercury levels in fish, you can always take a good fish oil instead.
My favorite is Barleans Fresh Catch Fish Oil, a pharmaceutical-grade fish oil harvested from deep-sea, cold water, small-bodied Peruvian anchovy that’s guaranteed free of mercury and other dangerous metals.