A Half Teaspoon of Dried Rosemary May Improve Cognitive Function

In Hamlet, Act 4, Scene 5, Ophelia notes that rosemary is for remembrance, an idea that goes back at least a few thousand years to the ancient Greeks, who claimed that rosemary “comforts the brain…sharpens understanding, restores lost memory, awakens the mind…” After all, “plants can be considered as chemical factories that manufacture all sorts of compounds that could have neuroprotective benefits”. So, let’s cut down on processed foods and eat a lot of phytonutrient-rich whole plant foods, including, perhaps, a variety of herbs. Even the smell of certain herbs may affect how our brain works. Unfortunately, as I discuss in my video Benefits of Rosemary for Brain Function, I’ve found much of the aromatherapy literature scientifically unsatisfying. There are studies offering subjective impressions, for example, but while sniffing an herbal sachet is indeed “easy, inexpensive, and safe,” is it effective? The researchers didn’t even compare test scores.

However, even when there was a control group, such as one study where researchers had people perform a battery of tests in a room that smelled like rosemary, lavender, or nothing, and even when the researchers did compare test results, the lavender appeared to slow down the subjects and impair their performance, whereas the rosemary group seemed to do better. Perhaps that was just because of the mood effects, though, as I show at 1:36 in my video. Maybe the rosemary group did better simply because the aroma pepped them up in some way—and not necessarily in a good way, as perhaps the rosemary was somehow overstimulating in some circumstances?

Now, there have been studies that measured people’s brain waves and were able to correlate the EEG findings with the changes in mood and performance, as well as associate them with objective changes in stress hormone levels, as you can see at 2:05 in my video, but is that all simply because pleasant smells improve people’s moods? For instance, if you created a synthetic rosemary fragrance with a bunch of chemicals that had nothing to do with the rosemary plant, would it have the same effect? We didn’t know…until now.

Aromatic herbs do have volatile compounds that theoretically could enter the blood stream by way of the lining of the nose or lungs and then potentially cross into the brain and have direct effects. A 2012 study was the first to put it to the test. Researchers had people do math in a cubicle infused with rosemary aroma. The subjects got that same boost in performance, but for the first time, the researchers showed that their improvement correlated with the amount of a rosemary compound that made it into their bloodstream just from being in the same room. So, not only did this show that it gets absorbed, but that such natural aromatic plant compounds may have a direct effect on changes in brain function.

If that’s what just smelling it can do, what about eating rosemary? We have studies on alertness, cognition, and reduced stress hormone levels inhaling rosemary. “However, there were no clinical studies on cognitive performance following ingestion of rosemary”…until now. Older adults, average age of 75, were given two cups of tomato juice, with either nothing, a half teaspoon of powdered rosemary, which is what one might use in a typical recipe, a full teaspoon, two teaspoons, more than a tablespoon of rosemary powder, or placebo pills to go even further to eliminate any placebo effects.

“Speed of memory is a potentially useful predictor of cognitive function during aging,” and, as you can see at 4:08 in my video, researchers found that the lowest dose had a beneficial effect, accelerating the subjects’ processing speed, but the highest dose impaired their processing speed, perhaps because the half-teaspoon dose improved alertness, while the four-teaspoon dose decreased alertness. So, “rosemary powder at the dose nearest normal culinary consumption demonstrated positive effects on speed of memory…” The implicit take-home message is more isn’t necessarily better. Don’t take high-dose herbal supplements, extracts, or tinctures—just cooking with spices is sufficient. A conclusion, no doubt, pleasing to the spice company that sponsored the study. No side effects were reported, but that doesn’t mean you can eat the whole rosemary bush. In one study, an unlucky guy swallowed a rosemary twig that punctured through the stomach into his liver, causing an abscess from which two cups of pus and a two-inch twig were removed. So, explore herbs and spices in your cooking. Branch out—just leave the branches out.

That twig is like a plant-based equivalent of Migrating Fish Bones!

Interested in more on aromatherapy? See:

For more on spicing up your life, check out:

And, learn more about improving cognition and preventing age-related cognitive decline in:

In health,

Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:


What to Take for Menstrual Cramps

In my video Ginger for Migraines, I described how ginger works as well as the leading “drug” in the treatment of migraines, “one of the most common causes of pain syndromes,” affecting as much as 12 percent of the population. Twelve percent is “common”?

How about menstrual cramps, which plague up to 90 percent of younger women? You can tell this study was written by a guy because he emphasizes the absenteeism and all the “lost productivity” for our nation. Menstrual cramps also just really hurt.

Can ginger help? As I discuss in my video Benefits of Ginger for Menstrual Cramps, women took a quarter teaspoon of ground ginger powder three times a day during the first three days of menstruation, and pain dropped from seven on a scale of one to ten down to a five, whereas there was no significant change in the placebo group, as you can see at 0:56 in my video. Most women in the placebo group said their symptoms stayed the same, whereas those unknowingly in the ginger group said they felt much better.

A subsequent study found that even just an eighth of a teaspoon three times a day appeared to work just as well, dropping pain from an eight to a six and, in the second month, down to a three. The “alleviation of menstrual pain was more remarkable during the second month of the intervention,” and study participants had only been taking the ginger for four days, not the whole month, suggesting it might work even better if women use ginger every period. 

What about the duration of pain? As you can see at 1:52 in my video, a quarter teaspoon of ground ginger powder three times a day not only dropped the severity of pain from about a seven down to a five but also decreased the duration of total hours in pain from 19 hours down to about 15 hours, indicating that three quarters of a teaspoon of ginger powder a day for three days is a safe and effective way to produce pain relief in college students with painful menstrual cramps, compared to placebo, capsules filled instead with powdered toast. But women don’t take breadcrumbs for their cramps. How does ginger compare with ibuprofen? An eighth of a teaspoon of ginger powder four times a day for three days versus 400 milligrams of Motrin were put to the test, and the ginger worked just as well as the drug of choice, as you can see at 2:40 in my video.

If you do take the drug, though, I was surprised to learn that it may be better to take drugs like ibuprofen and naproxen on an empty stomach because that may speed up the pain relief and help keep people from taking higher doses.

I’ve touched on this effect before in Ginger for Nausea, Menstrual Cramps, and Irritable Bowel Syndrome. What else can this amazing plant do? See, for example:

What else can really help with cramps, PMS, and cyclical breast pain? Check out:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:

The Foods With the Highest Aspirin Content

The results of a recent aspirin meta-analyses suggesting a reduction of cancer mortality by about one-third in subjects taking daily low-dose aspirin “can justly be called astounding.” Yet the protection from “Western” cancers enjoyed by those eating more traditional plant-centered diets, such as the Japanese, “is even more dramatic.” I examine this in my video Plants with Aspirin Aspirations.

Before the Westernization of their diets, animal products made up only about 5 percent or less of the Japanese diet. At 0:37 in my video, you can see the difference in cancer mortality of U.S. men and women compared with Japanese men and women. “[A]ge-adjusted death rates from cancers of the colon, prostate, breast, and ovary were on the order of 5–10-fold lower in Japan than in the US at that time; mortality from pancreatic cancer, leukemias, and lymphomas was 3–4-fold lower in Japan. But this phenomenon was by no means isolated to Japan; Western cancers were likewise comparatively rare in other societies where “people ate plant-based diets.”

“The cancer protection afforded by lifelong consumption of a plant-based diet, in conjunction with leanness and insulin sensitivity (which tend to be promoted by low-fat plant-based diets)…may be very substantial indeed.” Therefore, a “lifestyle protocol for minimizing cancer risk” may include a whole-food plant-based diet.

If part of this cancer protection arises out of the aspirin phytonutrients in plants, are there any plants in particular that are packed with salicylates? Though salicylic acid, the main active ingredient in aspirin, is “ubiquitously present in fruits and vegetables,” the highest concentrations are found in herbs and spices.

Red chili powder, paprika, and turmeric contain a lot of salicylates, but cumin is about 1 percent aspirin by weight. Eating a teaspoon of cumin is like taking a baby aspirin. (See the table at 1:54 in my video for details on other herbs and spices, and their salicylate content.) “Consequently, populations that incorporate substantial amounts of spices in foods may have markedly higher daily intakes of salicylates. Indeed, it has been suggested that the low incidence of colorectal cancer among Indian populations may be ascribed in part to high exposure to dietary salicylates throughout life from spice consumption.”

“The population of rural India, with an incidence of colorectal cancer which is one of the lowest in the world, has a diet that could be extremely rich in salicylic acid. It contains substantial amounts of fruits, vegetables, and cereals flavored with large quantities of herbs and spices.” Some have proposed it’s the curcumin in the spice turmeric (which I discuss in detail in my video Turmeric Curcumin and Colon Cancer), but it may be the salicylic acid in cumin—and the spicier the better.

A spicy vegetable vindaloo may have four times the salicylates of a milder Madras-style veggie dish. As you can see from the chart at 2:55 in my video, after just one meal, we get an aspirin spike in our bloodstream like we just took an aspirin. So, eating flavor-filled vegetarian meals, with herbs and spices, may be more chemoprotective—that is, more protective against cancer—than regular, blander vegetarian meals.

We may also want to eat organic produce. “Because salicylic acid is a defense hormone of plants, the concentration…is increased when plants become stressed,” like when they are bitten by bugs (unlike pesticide-laden plants). Indeed, soups made from organic vegetables were found to have nearly six times more salicylic acid than soups prepared from conventionally grown ingredients.

We should also choose whole foods. Whole-grain breads, which are high in salicylic acid, contain about 100 times more phytochemicals than white bread: 800 phytochemicals compared to 8.

“Interest in the potential beneficial effects of dietary salicylates has arisen, in part, because of the extensive literature on the disease-preventative effects of Aspirin™. However, it should not be forgotten that plant products found to contain salicylic acid are generally rich sources of other phenolic acids…[and many] also have a marked anti-inflammatory and redox-related bioactivity [that is, antioxidant activity] in mammalian cells. Their potential protective effects should not be overlooked. In this context, the importance of dietary salicylic acid should not perhaps be over emphasised…Indeed, some believe that ‘salicylic acid deficiency’ has important public health implications and that it should be classed as an essential vitamin, namely ‘Vitamin S’.”

What they’re saying is that we should all eat a lot of plants.

If you missed the first two videos in this series, see Should We All Take Aspirin to Prevent Heart Disease? and Should We All Take Aspirin to Prevent Cancer?.

The drug-like anti-inflammatory power of certain plant foods may make them a risky proposition during pregnancy. See Caution: Anti-Inflammatory Foods in the Third Trimester.

Herbs and spices not only have some of the most anti-inflammatory properties, but they also are well-rounded protectants. See:

In health,
Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations: