With more and more of the aging population affected by Alzheimer’s disease, and clinical trials for new medications often providing underwhelming results, a new study in The American Journal of Geriatric Psychiatry may be especially promising. It finds that taking a daily dose of curcumin, the compound in turmeric root that gives curry its yellow color, may not only prevent memory problems from worsening over time, but may actually improve them. Most noteworthy, these changes occurred not only in the participants’ cognitive capacities, but also in their brain cells.
Led by UCLA’s Gary Small, the team worked with a randomized sample of 40 people, ages 50 through 90. These people took a twice-daily 90-mg curcumin supplement or placebo for 18 months. The curcumin supplements were a preparation that have greater bioavailability than usual. In other words, the curcumin was readily absorbed and used by the body. The participants all had mild memory problems, but didn’t have Alzheimer’s disease or other forms of dementia. At the study’s outset, they took tests of memory and cognition and filled out questionnaires to measure mood and depression. They underwent brain scans so the team could look at deposition of “brain gunk”—amyloid-beta plaques and tau “tangles,” the two hallmarks of Alzheimer’s.
Every six months over the study’s 18 month period, the team tested the participants for memory, cognition, and mood; they also scanned their brains. (The study was double-blind. Even the researchers did not know what supplement was assigned to the participants until the conclusion of the study.)
It turned out, the memory function of those who’d taken curcumin improved by 28% on average over the 18 months. In contrast, the control group’s scores rose slightly (possibly because they got more familiar with the tests) and then declined. The depression scores of those taking curcumin also improved; the control group’s didn’t change. Interestingly, brain scans revealed significantly less amyloid and tau accumulation in two brain regions of the participants taking curcumin. These regions were the amygdala and hypothalamus, which control anxiety, memory, decision-making, and emotion.
The main side-effects in the current study were abdominal pain and nausea.
The Possible Therapeutic Effects of Curcumin
Earlier studies did not clearly demonstrate the therapeutic effects of curcumin. Which is why this new study is exciting, since it’s a true clinical study. Researchers have long observed that some groups of people in India have lower incidence of Alzheimer’s disease. Perhaps, this is due, in part, to the higher intake of turmeric.
Past studies have hinted at curcumin’s antidepressant and anti-anxiety effects, while others have illustrated its potential role in preserving brain function as we age. Curcumin’s antioxidant and anti-inflammatory effects are thought to underlie its neurological effects: It’s been shown to disrupt the formation of, and even help break down, the amyloid plaques that build up in the brains of Alzheimer’s patients. Still, other researchers don’t believe it has much of an effect, or that curcumin is the right component of turmeric to focus on. “Exactly how curcumin exerts its effects is not certain, but it may be due to its ability to reduce brain inﬂammation, which has been linked to both Alzheimer’s disease and major depression,” said Small in a statement. The team next plans to study whether the supplement may be effective in treating people with major depression rather than memory problems.
The study’s main limitation is that it was quite small. It’s participants were also generally healthy, educated, and motivated to complete the long trial. So whether or not the results are applicable to the general population is a little unclear; follow-up studies will need to take this into account. It’s not clear whether eating curry every once in a while would do any good—probably not. But studies have hinted that eating it quite regularly is linked to better cognition with age, and again, populations for whom it’s a regular part of the diet do appear to have reduced risk of Alzheimer’s. More work must be done before the optimal dose for various individuals or groups can be determined. In the meantime, if you love curry, eat it fairly often. The new study suggests that you’d probably do well to continue.