Turmeric

In a study of dementia patients, on alternating months they applied a lavender-scented oil to the participants’ faces and an unscented oil to their feet, and then the reverse. So everyone got the oil treatment and the attention during the massage. If inhaling lavender really had a benefit, you’d expect participants to do better with lavender on their faces. But that was not the case, so lavender does not seem to help. Most aromatherapy studies in dementia were similarly unsuccessful, though there was one remarkable exception, which I discuss in more detail at see.nf/lemonbalm.

Since then, two studies have been published that attempted to replicate the remarkable results I describe in that video. The first found a 38-percent reduction in agitation and aggression, a 50-percent reduction in depression and dysphoria (the opposite of euphoria), and a marked improvement in overall neuropsychiatric symptoms. However, pretty much the same thing happened in the unscented control group. In other words, even just a minute or two of touch and social interaction can make a big difference, but the lemon balm did not appear to provide any special benefit. The second study offered no clarity. Lemon balm seemed to reduce agitated behavior in participants without dementia, but not in those with dementia, whereas lavender apparently had the opposite effect and improved the behavior of participants with dementia, but not that of participants without dementia. Clearly, more research is needed here, especially given the safety and simplicity of aromatherapy interventions. It’s just: Who is going to fund such studies—the balm industry?

Turmeric

In see.nf/turmericdementia I report on a remarkable case series in which the condition of three Alzheimer’s patients improved sensationally after treatment with turmeric. The researchers concluded that this was the first demonstration of turmeric as an “effective and safe drug” for the treatment of Alzheimer’s. Of course, turmeric is not a drug, but simply a spice you can pick up cheaply in any supermarket. The scientists gave study participants about a quarter teaspoon a day, which comes out to a value of a few cents.

In see.nf/curcumind I provide an overview of the state of the research. Ultimately, curcumin supplementation may confer a small cognitive benefit in older people without dementia, but two randomized placebo-controlled double-blind trials of curcumin in Alzheimer’s patients both showed no benefit. Why didn’t the scientists achieve the same dramatic results with curcumin supplementation that were described in the case reports of individuals treated with turmeric? Maybe it was just pure chance at work. Or perhaps turmeric as a whole is more than the sum of its parts. Curcumin is only one of hundreds of phytonutrients in it. In response, some scientists proposed producing a mixture of components that “represents turmeric with its medicinal value better than curcumin alone.” But why artificially stir together something that Mother Nature has already packed into turmeric? Because you can’t patent a normal spice—and if you can’t patent it, how are you going to charge more than just a few cents for it?

Saffron

Even if there are startling stories about healing with turmeric, saffron provides the best data for spice interventions in Alzheimer’s. Three double-blind studies (detailed in see.nf/saffron) are promising. In people without dementia, however, saffron does not appear to improve cognitive performance.

The three studies were funded by public, noncommercial grants—so neither by supplement manufacturers nor by spice producers. They were conducted in Iran, however, which produces about 90 percent of the world’s saffron harvest. Promoting saffron consumption may therefore be in the national interest, which reminds me of the New Zealand government sponsoring research on kiwis, the fruit. But who else is going to fund studies on a simple spice?

Each saffron blossom produces only a few threads, and you need 50 000 blossoms to produce a pound of the spice. You could fill an entire soccer field with those blossoms. No wonder saffron is the most expensive spice in the world and retails for about 200 US dollars per ounce (approx. 28 g). But you don’t need much of it. In the memory studies, only 0.125 grams per day were used, about four small pinches of 15 threads each. As a side effect, mood can brighten, since eleven randomized trials found that saffron works significantly better than placebo overall for mild to moderate depression, at a dose of only a pinch a day (30 mg). Daily doses of up to 1.5 grams (50 pinches) are considered safe. (Saffron is usually sold in 1- to 2-gram packages.) Taking 5 or more grams per day can lead to severe reactions; 12 to 20 grams per day is already an overdose that can be fatal.

Vitamin D

Starting in 2019, vitamins such as vitamin D replaced Ginkgo biloba as the most common component of dietary supplements for “brain health.” Observational studies found that the cognitive abilities of people with lower vitamin D levels worsen over time and that these people are more likely to develop dementia. But it’s not just the sunshine vitamin alone; many other factors play into it. For example, people with lower levels tend to be less physically active, smoke, and be obese, and each of these factors affects the brain independently of the others. Randomized controlled trials found that vitamin D can improve cognitive performance in sick rats and mice. But does that apply to us?

An intervention study that found no effects of vitamin D in young adults was published in 2011, but it wasn’t until 2018 that a study was conducted in older people with mild cognitive impairment. The randomized placebo-controlled double-blind trial showed that 400 IU of vitamin D daily for twelve months significantly improved cognitive function compared to placebo. The following year, a similar study was published, but with 800 IU per day for people with full-blown Alzheimer’s, with the same result. It is not clear what the best dosage is. An ambitious study in which overweight older women with low blood vitamin D levels were given 600 IU, 2000 IU, or 4000 IU daily for a year found that those on 2000 IU daily performed better on learning and memory tests than those on only 600 IU, while those on 4000 IU performed worse on one measure (reaction time). Other studies in relatively healthy adults that compared 2000 IU with 800 IU and 4000 IU with 400 IU, however, found no clear difference in overall cognitive performance.