Explore what science says about DHA and folic acid for brain health—and who most benefits from taking them.
Explore what science says about DHA and folic acid for brain health—and who most benefits from taking them.
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Wait a minute...what did I come into this room for again? Oh, right—it had something to do with supplements and memory. Stick around for some new research on vitamin supplements for cognitive health and who might get the most benefit from taking them.
Hello and welcome back to the Nutrition Diva podcast, a show where we dig through all the nutrition headlines, memes, and trends to ferret out the ones that are a) true and b) can actually make a positive difference in your health. I’m your host, Monica Reinagel and I appreciate that you chose to spend a few minutes of your day with me.
Many of you listening are, like me, starting to enjoy the wisdom and equanimity that comes with age. Just kidding–we’re all freaking about about our thinning hair, achy knees, and sagging skin. As Bette Davis wisely noted: Aging is not for sissies!
But, all kidding aside, while the visible signs of aging can be annoying, it’s the invisible signs of aging that often cause the most worry—those occasional lapses in memory or concentration. The idea of losing our cognitive ability as we age is uniquely disturbing. It’s not just the inconvenience of a forgotten detail; it’s the fear that this could signal the beginning of something more serious, like mild cognitive impairment—or even dementia.
That’s why diets, programs, and supplements that promise to preserve or even boost our brain health are so appealing. But do they deliver? And, for whom?
Today, I want to unpack a recent study looking at the effects of nutritional supplements on cognitive function. This research was conducted in China and it focused on older adults who were already exhibiting signs of mild cognitive impairment. That means they may have been experiencing some noticeable changes in their memory or thinking skills, but not to the extent that it was significantly interfering with their daily lives. (Yet.)
Participants were divided into four groups. One group took 400 mcg a day of folic acid. Another took 800mg of DHA. (Just to refresh your memory, DHA is one of the two main fatty acids found in fish oil; the other is EPA. While EPA is known for its heart health benefits, DHA is particularly important to brain health.) The third group in this study took both folic acid and DHA, and the last group received a placebo. They took these supplements for six months, during which their cognitive performance was evaluated.
And the results were promising, although there were some caveats. All three of the supplement groups showed improvements in various measures of cognitive performance—such as memory and problem-solving skills. Those taking the combined supplements showed the greatest improvements, and those taking DHA alone showed the least. But, the gains didn’t last. When the supplements were discontinued, cognitive performance started to decline again.
Now there’s an obvious solution: keep taking the supplements. These are not extremely high dosages of these nutrients, it’s not a terribly expensive regimen, and there are few side effects or risks to worry about. But before we jump to any conclusions about how these findings might apply to us, there is some important context.
As I said, this study was done in China, where about 20% of older adults are deficient in folate. This is not the case in the United States or Canada, where folic acid fortification programs ensure that most people get enough from their diets. Similarly, DHA intake is strikingly low in this population.
We know from other studies that low folate and DHA levels are strongly associated with cognitive decline. And addressing these deficiencies with supplements could very well lead to measurable improvements in cognitive function. The question is: Would taking these supplements provide any benefit for someone who is not deficient in folate and/or DHA? Maybe not.
In fact, meta-analyses show that taking folic acid only improves cognitive health in places where they don’t have mandatory folic acid fortification. And this illustrates an important but often overlooked point about vitamin supplementation: the people who benefit the most are often those who start out with a deficiency. If you’re already getting enough of these nutrients from your diet, supplementation might not make much difference.
And you can get too much of a good thing–particularly with folic acid. The recommended upper limit for folic acid is 1,000 mcg a day. And that includes the amount you’re getting from fortified foods as well as supplements. The typical U.S. adult gets 100 to 300 mcg of folic acid from fortified foods like cereal, bread, or pasta. So, an 800 mcg supplement could easily take you over the recommended limit.
Consuming more than the recommended upper limit of folic acid can mask a vitamin B12 deficiency–which older people are at increased risk of. And, as I discussed in a previous episode, some studies have linked excessive folic acid intake (from supplements) to an increased risk of colon cancer, particularly in individuals who have a history of precancerous polyps.
Fortunately, none of these concerns apply to folate, which is the form of the nutrient that you get from foods as opposed to supplements. For me, the takeaway here is that ensuring adequate folate and DHA intake through our diets is a smart move—and not just for cognitive health. So let’s talk about how we might do that.
Folate is found in dark leafy greens like spinach, kale, and Swiss chard, as well as in legumes such as lentils, black beans, and chickpeas. If you want to bump up your folate, find more ways to cook with spinach. Saute it and add to eggs for an easy frittata. You can stir a few handfuls of raw spinach into hot pasta or grains–the heat will wilt it on contact. Top your salads with a liberal scoop of chickpeas. If you enjoy avocados, you’re in luck—they’re a good source of folate and can be spread on toast, blended into dips, or sliced onto salads. And if you don’t already have a favorite lentil soup recipe, it’s time to find one. (I’ll include a link to my favorite one in the show notes.)
DHA, on the other hand, is found in fatty fish like salmon, mackerel, sardines, trout, and herring. Just one serving of salmon (about 3 ounces) can provide well over the recommended daily amount of DHA. To work more DHA into your diet, try replacing a meat-based dinner once or twice a week with a fish-based option. A simple salmon fillet baked with olive oil and herbs, or a quick sardine toast with whole-grain bread, can be delicious and brain-boosting. For those who don’t eat fish, algae-based DHA supplements provide a plant-based alternative. You may also find plant-based milks fortified with DHA.
So, what’s the bottom line for today? While supplements like folic acid and DHA may improve cognitive function in those with deficiencies, it’s not clear that they would provide the same benefit for those who are not deficient in those nutrients. I think the best (and more appetizing) approach is to focus on getting these essential nutrients through your diet. Not only are foods like leafy greens, lentils, avocados, and fatty fish rich in folate and DHA, but they also provide a wealth of other nutrients that support overall health—and they’re delicious!
If you have a question you'd like me to answer, you can email me at nutrition@quickanddirtytips.com You can also leave me a message at 443-961-6206
Nutrition Diva is a Quick and Dirty Tips podcast. Our team includes Brannan Goetschius, Nathan Semes, Davina Tomlin, Holly Hutchings, and Morgan Christianson.and Nathaniel Hoopes.
That's all for this episode. Thanks for listening! I'll see you next week.