There’s a protein in your brain that protects you from Alzheimer’s disease.
It’s called brain-derived neurotrophic factor (BDNF), and it promotes the survival of neurons in the brain.
Here’s the latest research that is establishing the importance of this natural protective protein—including seven simple, practical ways to boost your levels.
A NATURAL MEMORY PROTECTOR…EVEN IF YOU GET ALZHEIMER’S DISEASE
While there is growing evidence in both animals and humans that BDNF plays a key role in the brain’s ability to repair itself from dementia, until now the evidence has been largely indirect. Low blood levels of BDNF in people, for example, are statistically associated with an increased risk for Alzheimer’s. But blood levels don’t always track well with brain levels.
A new study is more definitive. Researchers at Rush University Medical Center in Chicago studied the cognitive function of 535 older men and women—some with Alzheimer’s and some not—for an average of six years, and, when they died, autopsied their brains. Results: The amount of BDNF proteins in their brains was directly related to the documented rate of cognitive decline that those men and women experienced in the years before they died. Findings…
• Study participants with the most BDNF protein (top 10%) in their brains had 50% slower cognitive decline than those with the least (lowest 10%).
• Even among those with Alzheimer’s disease, higher levels of BDNF were associated with less severe cognitive effects.
Even this new study doesn’t prove that BDNF protects against Alzheimer’s, but it strengthens the case considerably. The good news is that there are straightforward ways to boost your levels.
7 WAYS TO BOOST BDNF
The research on how to boost BDNF levels in the brain isn’t quite as definitive. After all, scientists can’t exactly put people on treadmills and then look inside their brains. But studies in animals and humans point to some very practical healthy habits that can boost BDNF. Here’s what we know…
1. Exercise—moderately and frequently. Several studies have found that exercise increases blood levels of BDNF. The good news is that regular moderate- and even low-intensity exercise appears to be effective. In one study of healthy men and women (55 to 80 years old), moderate-intensity walking for just 40 minutes increased blood BDNF and maintained cognitive performance—with the oldest people seeing the biggest boost—more than stretch/toning exercises did for the control group. Another study found that over a six-month period, regular low-intensity exercise (less than an hour of stretching with rubber tubing three times a week) led to increased BDNF levels in people who were previously inactive compared with participants who continued to be inactive.
2. Eat less. Animals on a calorically restricted diet have higher brain levels of BDNF compared with those that are allowed to eat as much as they want. While there are no comparable studies in people, there is evidence that avoiding overeating is beneficial. In a study of older adults (70 to 92 years old), those who consumed the most calories (more than 2,143 daily) had almost twice the risk for mild cognitive impairment as adults who consumed the least (fewer than 1,525 daily calories). (Want to break the overeating habit? Try this using this five-point hunger scale.)
3. Eat better. Animal studies find that a diet that’s very high in fat and sugar leads to lower brain BDNF. But carefully conducted clinical studies report that when it comes to preventing Alzheimer’s, the quality of dietary fat is particularly important. The Mediterranean diet, which is low in sugar but includes plenty of healthy fats (olive oil, fatty fish, nuts), is protective, for example. So is the MIND diet, which is also low in sugar but high in healthy fats. Researchers believe that boosting BDNF may be a key way that these diets protect the brain—and they will be testing that hypothesis in an upcoming clinical trial.
4. Consider intermittent fasting. It’s not for everyone, but eating just 500 or 600 nutritious calories on one or two days a week, while eating a normal amount on the other days, may boost BDNF. The theory: Skipping meals stresses your neurons, and your body boosts BDNF to buttress neurons while you’re undernourished. Several animal studies show that fasting increases BDNF. In one study, rats fed every other day for six months had nearly five times more BDNF than rats fed every day. Human studies that involve fasting are not easy to come by, but one small study of people who didn’t eat at all during daylight hours showed increased blood BDNF. (To learn more about safe intermittent fasting, see Bottom Line’s article The Eat-What-You-Want Diet.)
5. Get spicy. Curcumin, a major component of the spice turmeric that’s found in curries, appears to protect the brain—possibly by boosting BDNF. In India, people who consume the most curry have the lowest risk for Alzheimer’s. In mice, curcumin protects against brain damage caused by an animal version of Alzheimer’s, and a lab-made form of curcumin has been shown to boost BDNF in mice. Clearly we need to learn more, but we already know that turmeric’s curcumin is powerfully anti-inflammatory—with other proven benefits. “It’s effective at lowering cholesterol and reducing osteoarthritis pain,” says naturopathic physician Andrew Rubman, ND, Health Insider’s medical contributing editor. “It reduces aches and pains and inflammation throughout the body.” Since curcumin is only about 2% of turmeric, you’ll have to eat a lot of curry to get much curcumin—but fortunately curcumin supplements have a good safety profile. If you want to supplement, Dr. Rubman recommends taking 500 mg of a curcumin extract three or four times a day.
6. Stay social. Animal studies have shown that social isolation, compared with communal living, leads to reduced BDNF in the brain. One study in older humans also showed that social support is linked to increased blood levels of BDNF.
7. Catch rays. BDNF levels are higher in the spring and summer months than they are in fall and winter, according to a study of more than 2,800 men and women, with a direct relationship between the number of hours of sunshine per day and higher BDNF. Whether it’s vitamin D (which, of course, is higher when you get sun exposure) that elevates BDNF isn’t clear—one human study found that daily supplementation with 2,000 IU of vitamin D, a modest amount, didn’t increase BDNF. So get some sun—in moderation, of course.
There is clearly much more we need to learn about BDNF, and there is already research toward creating a drug that boosts it. But you already have the power to create more of this protective natural brain compound yourself—every day.