Fighting Autism Brain Inflammation with Food

One food may be able to combat all four purported causal factors of autism: synaptic dysfunction, oxidative stress, mitochondrial dysfunction, and neuroinflammation.

In a keynote address at an autism conference, Harvard neurologist Martha Herbert said, “I think we need to conduct research as if we know this is an emergency.” Already, up to 1.5 percent of American children have autism, and it appears to be on the rise. What about fever’s dramatic effect? “Dramatic relief of autistic behavior by infectious fever continues to tantalize parents and practitioners” and, indeed, from a research standpoint, “what could be more revealing than a common event that virtually ‘normalizes’ autistic behavior for a time?” But, “[t]here’s so much going on during fever.…Where to begin?

Once it became understood that one cause of autism may reside in the synapses—the “soul of the brain,” the nerve-to-nerve junctions where information is transmitted—attention turned to heat shock proteins, which are released by the brain when you have a fever. They can improve synaptic transmission and, thus, may be capable of improving long-range brain connectivity, which is depressed in autism. A compound, sulforaphane, upregulates those heat shock proteins, so you could potentially get the benefits without the fever. Which drug company makes it? What do I ask for at the pharmacy? You don’t. As I discuss in my video Fighting Autism Brain Inflammation with Food, you just need to check out the produce section at your local market.

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

But, as you can see at 1:57 in my video, 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, there is “a long history of studies showing that ASD [autism] is associated with oxidative stress and diminished antioxidant capacity.” Nrf2 levels are cut nearly in half, which is what triggers our body’s antioxidant response. Nrf2? What is that? It’s “considered to be a master regulator” of our body’s response to environmental stressors. If only there were a way to boost Nrf2 with foods. Well, there is.

Sulforaphane just so happens to be perhaps “the most potent naturally occurring inducer” of Nrf2 on the planet. 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.

There’s also the mitochondrial dysfunction. Children with autism are more likely to suffer from dysfunctional mitochondria, the little powerplants within our cells where metabolism takes place. If only there were some food that could improve mitochondrial function. And, there is: “A diet rich in cruciferous vegetables effectively retunes our metabolism by…restoring metabolic homeostasis,” or metabolic balance. Power plants for our cellular powerplants.

As you can see at 3:58 in my video, not only can sulforaphane boost the gene expression of heat shock proteins as much as sixfold within six hours, but it can also 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.

Can we just try giving these kids some broccoli already?

Before we do, there’s one final factor. Neuroinflammation—brain inflammation—is 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, you’ll find up to 200 times the levels of inflammatory mediators, such as 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. If overexpressed, as in autism, it can lead to chronic or excessive inflammation. If only there were a food…

Really? Broccoli does that, too? Yes! In fact, the major anti-inflammatory mechanism for sulforaphane is inhibiting NF-kappa-beta.

That completes the picture. Give broccoli to someone with autism, 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 counters all four purported causal factors of autism. That’s one of the differences between foods and drugs. Drugs tend to have single effects. But, autism spectrum disorder is multifactorial, so it’s no wonder there are no drugs that work. But “strategies using multi-functional phytochemicals” such as 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 cover in my video Best Foods for Autism. You can also check: Flashback Friday: The Best Foods for Fighting Autism and Brain Inflammation.

Dramatic relief of autistic behavior during a fever? If you missed it, check out my last video, Fever Benefits for Autism in a Food.


For more on autism, see:

What else can broccoli’s magic do?

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:

Combating Air Pollution Effects with Food

There is a food that offers the best of both worlds—significantly improving our ability to detox carcinogens like diesel fumes and decreasing inflammation in our airways—all while improving our respiratory defenses against infections.

Outdoor air pollution may be the ninth leading cause of death and disability in the world, responsible for millions of deaths from lung cancer, emphysema, heart disease, stroke, and respiratory infection. In the United States, living in a polluted city was associated with 16, 27, and 28 percent increases in total, cardiovascular, and lung cancer deaths, compared to living in a city with cleaner air. As well, living in a city with polluted air may lead to up to a 75 percent increase in the risk of a heart attack. “Additionally, the possibility of dying in a traffic jam is two and a half times greater in a polluted city.” No one wants to be living in a traffic jam, but it’s better than dying in one.

In addition to causing deaths, air pollution is also the cause of a number of health problems. It may not only exacerbate asthma but also increase the risk of developing asthma in the first place. These pollutants may trigger liver disease and even increase the risk of diabetes. Indeed, “even when atmospheric pollutants are within legally established limits, they can be harmful to health.” So, what can we do about it?

Paper after paper have described all the terrible things air pollution can do to us, but “most…failed to mention public policy. Therefore, while science is making great strides in demonstrating the harmful effects of atmospheric pollution on human health, public authorities are not using these data” to reduce emissions, as such measures might inconvenience the population “and, therefore, might not be politically acceptable.” We need better vehicle inspections, efficient public transport, bus lanes, bicycle lanes, and even urban tolls to help clean up the air, but, while we’re waiting for all of that, is there anything we can do to protect ourselves?

As I discuss in my video Best Food to Counter the Effects of Air Pollution, our body naturally has detoxifying enzymes, not only in our liver, but also lining our airways. Studies show that people born with less effective detox enzymes have an exaggerated allergic response to diesel exhaust, suggesting that these enzymes actively combat the inflammation caused by pollutants in the air. A significant part of the population has these substandard forms of the enzyme, but, either way, what can we do to boost the activity of whichever detoxification enzymes we do have?

One of my previous videos Prolonged Liver Function Enhancement from Broccoli investigated how broccoli can dramatically boost the activity of the detox enzymes in our liver, but what about our lungs? Researchers fed some smokers a large stalk of broccoli every day for ten days to see if it would affect the level of inflammation within their bodies. Why smokers? Smoking is so inflammatory that you can have elevated C-reactive protein (CRP) levels for up to 30 years after quitting, and that inflammation can start almost immediately after you start smoking, so it’s critical to never start in the first place. If you do, though, you can cut your level of that inflammation biomarker CRP nearly in half after just ten days eating a lot of broccoli. Broccoli appears to cut inflammation in nonsmokers as well, which may explain in part why eating more than two cups of broccoli, cabbage, cauliflower, kale, or other cruciferous veggies a day is associated with a 20 percent reduced risk of dying, compared to eating a third of a cup a day or less, as you can see at 3:41 in my video.

What about air pollution? We know that the cruciferous compound “is the most potent known inducer” of our detox enzymes, so most of the research has been on its ability to fight cancer. But, for the first time, researchers tried to see if it could combat the pro-inflammatory impact of pollutants, such as diesel exhaust. They put some human lung lining cells in a petri dish, and, as you can see at 4:11 in my video, the number of detox enzymes produced after dripping on some broccoli goodness skyrocketed. Yes, but we don’t inhale broccoli or snort it. We eat it. Can it still get into our lungs and help? Yes. After two days of broccoli sprout consumption, researchers took some cells out of the subjects’ noses and found up to 100 times more detox enzyme expression compared to eating a non-cruciferous vegetable, alfalfa sprouts. If only we could squirt some diesel exhaust up people’s noses. That’s just what some UCLA researchers did, at an amount equal to daily rush hour exposure on a Los Angeles freeway. Within six hours, the number of inflammatory cells in their nose shot up and continued to rise. But, in the group who had been getting a broccoli sprout extract, the inflammation went down and stayed down, as you can see at 4:58 in my video

Since the dose in those studies is equivalent to the consumption of one or two cups of broccoli, their study “demonstrates the potential preventive and therapeutic potential of broccoli or broccoli sprouts,” but if broccoli is so powerful at suppressing this inflammatory immune response, might it interfere with normal immune function? After all, the battle with viruses like influenza can happen in the nose. So what happens when some flu viruses are dripped into the nostrils of broccoli-sprout eaters compared with people consuming non-cruciferous alfalfa sprouts? After eating broccoli sprouts, we get the best of both worlds—less inflammation and an improved immune response. As you can see at 5:55 in my video, after eating alfalfa sprouts, there is a viral spike in their nose. After eating a package of broccoli sprouts every day, however, our body is able to keep the virus in check, potentially offering “a safe, low-cost strategy for reducing influenza risk among smokers and other at risk populations.”

So, better immune function, yet less inflammation, potentially reducing the impact of pollution on allergic disease and asthma, at least for an “enthusiastic broccoli consumer.” But what about cancer and detoxifying air pollutants throughout the rest of our body? We didn’t know, until now. Off to China, where “levels of outdoor air pollution…are among the highest in the world.” By day one, those getting broccoli sprouts were able to get rid of 60 percent more benzene from their bodies. “The key finding…was the observed rapid and highly durable elevation of the detoxification of… a known human carcinogen.” Now, this was using broccoli sprouts, which are highly concentrated, equivalent to about five cups of broccoli a day, so we don’t know how well more modest doses would work. But if they do, eating broccoli could “provide a frugal means to attenuate…the long-term health risks” of air pollution. More on air pollution here.

I’ve been reading about the terrible effects of air pollution for a long time and I am thrilled there’s something we can do other than uprooting our families and moving out to the countryside.


For more on cruciferocity, see my videos Lung Cancer Metastases and Broccoli and Breast Cancer Survival Vegetable.

There’s a secret to maximizing broccoli’s benefits. See Flashback Friday:Second Strategy to Cooking Broccoli.

For more on Cooking Greens: How to Cook Greens and Best Way to Cook Vegetables.

What about broccoli sprout pills? See Broccoli: Sprouts vs. Supplements.

Speaking of respiratory inflammation, what about dietary approaches to asthma? Learn more:

There are sources of indoor pollution, too. See Throw Household Products Off the Scent.

There is one way what we eat can directly impact air pollution, beyond just personal protection. Check out Flashback Friday: Diet and Climate Change: Cooking Up a Storm.

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:

We Have Specific Fruit and Vegetable Receptors

According to a recent survey, the number of Americans adults who say they are eating ‘pretty much whatever they want’ is at an all-time high,” which unfortunately includes “too few fruits and vegetables,” as well as “too little variety.” Half of all fruit servings are taken up by just six foods: orange juice, bananas, apple juice, apples, grapes, and watermelons. Only five foods—iceberg lettuce, frozen potatoes, fresh potatoes, potato chips, and canned tomatoes—make up half of all vegetable servings. We’re not only eating too few fruits and veggies. We’re also missing out on the healthiest fruits, which are berries, and the healthiest vegetables, which are dark green leafies. The fruit and vegetable palette for our palate is sadly lacking.

Why does dietary diversity matter? As I discuss in my video Specific Receptors for Specific Fruits and Vegetables, different foods may affect different problems. Cabbage, cauliflower, broccoli, and Brussels sprouts are associated with lower risk of colon cancer in the middle and right side of our body, whereas risk of colon cancer further down on the left side of our body appears to be better lowered by carrots, pumpkins, and apples. So, “different F/V [fruits and vegetables] may confer different risks for cancer” of different parts of even the same organ.

Variety is the spice of life—and may prolong it. “Independent from quantity of consumption, variety in fruit and vegetable consumption may decrease lung cancer risk,” meaning if two people eat the same number of fruits and vegetables, the one eating a greater variety may be at lower risk.

It’s not just cancer risk. In a study of thousands of men and women, a greater quantity of vegetables and a greater variety may independently be beneficial for reducing the risk of type 2 diabetes. Even after removing the effects of quantity, “each different additional two item per week increase in variety of F&V [fruit and vegetable] intake was associated with an 8% reduction in the incidence of T2D [type 2 diabetes].” Why? Well, it “may be attributable to individual or combined effects of the many different bioactive phytochemicals contained in F&V. Thus, consumption of a wide variety of F&V will increase the likelihood of consuming” more of them.

“All the vegetables may offer protection…against chronic diseases,” but “[e]ach vegetable group contains a unique combination and amount of these [phytonutrients], which distinguishes them from other groups and vegetables within their own group.” Indeed, because “each vegetable contains a unique combination of phytonutriceuticals (vitamins, minerals, dietary fiber and phytochemicals), a great diversity of vegetables should be eaten…to get all the health benefits.”

Does it matter, though, if we get alpha-carotene or beta-carotene? Isn’t an antioxidant an antioxidant? No. “It has been shown that phytochemicals bind to specific receptors and proteins” in our bodies. For example, our body appears to have a green tea receptor—that is, a receptor for EGCG, which is a key component of green tea. There are binding proteins for the phytonutrients in grapes, onions, and capers. In my video The Broccoli Receptor: Our First Line of Defense, I talk about the broccoli receptor, for instance. Recently, a cell surface receptor was identified for a nutrient concentrated in apple peels. Importantly, these target proteins are considered indispensable for these plants foods to do what they do, but they can only do it if we actually eat them.

Just like it’s better to eat a whole orange than simply take a vitamin C pill, because, otherwise, we’d miss out on all the other wonderful things in oranges that aren’t in the pill, by just eating an apple, we’re also missing out on all the wonderful things in oranges. When it comes to the unique phytonutrient profile of each fruit and vegetable, it truly is like comparing apples to oranges.


This is one of the reasons I developed my Daily Dozen checklist of foods to incorporate into one’s routine. Download the free iPhone and Android apps, and be sure to watch my video Dr. Greger’s Daily Dozen Checklist.

I discuss how produce variety—not just quality and quantity—may be important in Apples and Oranges: Dietary Diversity and Garden Variety Anti-Inflammation, so I hope you’ll check them out. You can also learn more about why combining certain foods together may be more beneficial than eating them separately in Food Synergy.

In health,
Michael Greger, M.D.

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