Flashback Friday: The Best Foods for Fighting Autism and Brain Inflammation

Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.

Harvard neurologist Martha Herbert, in a keynote address at an autism conference, said “we need to conduct research as if we know this is an emergency.” Already, up to one and a half percent of American children have autism, and it appears to be on the rise. Well, what about fever’s dramatic effect? This “dramatic relief of autistic behavior [during a fever] continues to tantalize parents and practitioners.” From a research standpoint, “what could be more revealing than a common event that virtually ‘normalizes’ autistic behavior for a time?” “There’s so much going on during fever,” though; where do you even begin?

Well, once it became understood that one cause of autism may reside in the synapses—the so-called “soul of the brain,” the nerve-to-nerve junctions where information is transmitted—attention turned to HSPs, heat shock proteins, released by the brain when you have a fever, that can improve synaptic transmission, and thus, may be “capable of improving long-range [brain] connectivity which is depressed in [autism].” ASD stands for autism spectrum disorder. And, there’s this compound, sulforaphane, that “upregulates” those heat shock proteins. So, you could potentially get the benefits without the fever. What drug company makes it? What do I ask for at the pharmacy? Nope, wrong aisle.

Sulforaphane is not made in chemical plant; it’s made by a plant. Sulforaphane is made by broccoli, kale, cabbage, collards, and cauliflower—in other words, cruciferous vegetables. So, maybe if we give some broccoli to those with autism, it will make things better by boosting the heat shock proteins.

But, synaptic dysfunction is not the only contributing cause of autism. There’s also oxidative stress. “The brain is particularly vulnerable to oxidative stress” because lots of free radicals are forged in the brain, which has few “antioxidant defense capacities.” And, indeed, “[t]here is a long history of studies showing that [autism] is associated with oxidative stress and diminished antioxidant capacity.” Nrf2 levels cut nearly in half, which is what triggers our body’s “antioxidant response.” If only there was a way we could boost Nrf2 with foods—boom, there it is! Sulforaphane just so happens to be perhaps “the most potent natural…inducer…of Nrf2” on the planet.

What’s this Nrf2 thing again? It’s “considered to be a master regulator of” our body’s response to environmental stressors. Under any kind of stress—oxidative stress, inflammatory stress—Nrf2 triggers our “antioxidant response elements,” activating all sorts of cell-protective genes that balance out and detoxify the free radicals, and facilitate protein and DNA repair.

So, maybe if we give some broccoli to those with autism, it will also make things better by triggering Nrf2, which activates those antioxidant response elements. And then, there’s the mitochondrial dysfunction. “[C]hildren with autism [are] more likely to” suffer from dysfunctional mitochondria, the little power plants within our cells where metabolism takes place. If only there was some food that could improve mitochondrial function. And, there is. “A diet rich in cruciferous vegetables effectively retunes our metabolism by…restoring metabolic [balance].” Power plants for our cellular power plants.

Not only can sulforaphane boost the gene expression of heat shock proteins as much as six-fold within six hours, it can double the mass of mitochondria in human cells growing in a petri dish. So, maybe if we give some broccoli to those with autism, it will also make things better by relieving some of that mitochondrial dysfunction that is creating even more free radicals. Okay. So, can we try giving some kids some broccoli already? First, one final factor: neuroinflammation—brain inflammation, another causal factor in autism. If, at autopsy, you look at brain tissue of those with autism, you can see inflammation throughout the white matter.  And, if you do a spinal tap, up to 200 times the levels of inflammatory mediators, like interferon, bathing their brains. 

What’s causing all that inflammation? Well, the master regulator of the inflammatory cascade is a protein called NF-kappa-beta, which induces inflammation and, if overexpressed, like in autism, can lead to “chronic or excessive inflammation.” If only there was a food. Wait—broccoli does that, too? In fact, it’s the major anti-inflammatory mechanism for sulforaphane, inhibiting NF-kappa-beta.

Well, then; that completes the picture. Give someone with autism broccoli, and heat shock proteins are released to boost synaptic transmission, Nrf2 is activated to wipe out the free radicals, mitochondrial function is restored, and we suppress the inflammation triggered by NF-kappa-beta. One food to counter all four purported causal factors. That’s one of the differences between foods and drugs. Drugs tend to have single effects. But, autism spectrum disorder, ASD, “is multi-factorial”—no wonder there’s no drugs that work. But, “strategies using multi-functional phytochemicals [like sulforaphane] or even [better] the [whole] plants [themselves],…are highly attractive”—in theory. But, you don’t know, until you put it to the test, which I promise we’ll cover, next.

You may remember my series of videos about the engine-of-aging enzyme, TOR. Well, kids with autism tend to have higher TOR activity in their bodies, and this “hyperactive…TOR…signaling” may actually play a role in causing autism, making TOR a potential target to treat autism—or even theoretically reverse it, if we could target downstream TOR signaling, like between TOR and S6K1. Well, that’s actually one of the ways broccoli compounds kill off prostate cancer cells—by inhibiting the “signal transduction between…TOR and S6K1.” Breast cancer too; sulforaphane is “a potent inhibitor” of breast cancer cells, because “it targets downstream elements of the [TOR] pathway.”

So, if we gave broccoli to those with autism, if it blocks TOR, maybe it would block some of the synaptic dysfunction that contributes to the features of autism. And, that’s in addition to blocking autism pathways four other ways: “oxidative stress and lower antioxidant capacity, [the] mitochondrial dysfunction,” the brain inflammation. And, not just in a petri dish: “sulforaphane can cross the blood-brain-barrier.” You eat broccoli, and sulforaphane “quickly reach[es your brain] to exert its protective effects”—in theory, but you don’t know, until you put it to the test.

But now, you can understand why such a study could attract researchers from leading institutions: Harvard, Hopkins, and get published in one of our most prestigious journals: PNAS (the Proceedings of the National Academy of Sciences). But what did they find? Well, first, what did they do? A “placebo-controlled, double-blind, randomized trial, young men (aged 13–27) with moderate to severe [autism] received…sulforaphane…from broccoli sprout[s], or [an] indistinguishable [sugar pill].” They “were dosed according to body weight.” Those under 100 pounds got about a tablespoon of broccoli sprouts worth of sulforaphane a day, which is about a cup’s worth of broccoli. Between 100 and 200 pounds got about two cups of broccoli’s worth, or two tablespoons of fresh broccoli sprouts, and the big boys got three cups’ worth a day, or a little under a quarter-cup of broccoli sprouts. Why didn’t they just use actual broccoli, or actual sprouts? Because then you couldn’t have a blinded study; the patients, doctors, and parents would know who’s getting the special treatment and who’s not, and that could introduce bias just through the placebo effect. So, instead, no one knew, until the end, who got the sulforaphane, and who just got nothing in a pill.

They chose dietary sulforaphane because of its “capacity to reverse” oxidation, dysfunction, and inflammation. Yeah, but, when put to the test, did it actually work? Well, the placebo didn’t. Give people with autism nothing, and nothing much happens. But, effectively, secretly sneak them some broccoli, and “substantial…improvement…in [behavior], social interaction,…and verbal communication.” But, it all disappeared once the broccoli stopped.

Let me show you what it looks like. This is the ABC score, the “Aberrant Behaviour Checklist,” which includes things like repetitive behaviors. In the placebo group, no big change, which is what you’d expect. But the abnormal behaviors plunged in the sulforaphane group—the group that got the sulforaphane found in about five cents’ worth of broccoli sprouts a day. But, the study ended on week 18, and a month later, things were heading back to where they started.

Similar findings for a “Social Responsiveness Scale”—significant improvements until the treatment was stopped, and then caught right back up to how poorly those in the placebo group continued to function. And, these weren’t just scores on a page. “The substantial improvements…were conspicuous;” the doctors could see them; their parents and caregivers could see the improvements. No drug has ever been shown to have these kinds of effects. And, look, these were young men, starting at age 13. One could imagine it working as well, or even better, for younger children, because their brains are still developing.

And look, what’s the downside? “Broccoli sprouts are widely consumed…all over the world…without any reports of adverse effects.” Now, remember, we’re talking about whole foods, not broccoli or sulforaphane supplements. Remember, I did videos about them. Broccoli sprouts work; commercial broccoli sprout supplements hardly at all. Broccoli has sulforaphane—florets more than the stems. 

Broccoli sprouts have like ten times more, but broccoli pills, powders, and supplements have little or none. So, broccoli and cruciferous vegetables for all kids—autism or not—and hey, maybe pregnant women as well, for potential “prenatal prevention” of autism in the first place.

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Image credit: National Human Genome Research Institute (NHGRI). Image has been modified.

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