Lycopene Supplements Put to the Test

High doses of lycopene—the red pigment in tomatoes—were put to the test to see if it could prevent precancerous prostate lesions from turning into full-blown cancer.

Back in 1980s, the Adventist Health Study found “strong protective relationships” against prostate cancer with increasing consumption of legumes, citrus, dried fruit, nuts, and tomatoes. In the 1990s, a Harvard study focused attention on tomatoes, which appeared to be “especially beneficial regarding prostate cancer risk.” Researchers suspected it might be the red pigment in tomatoes called lycopene, which has greater antioxidant power than some of the other pigments, such as the orange beta-carotene pigment in carrots and cantaloupes. Lycopene dramatically kills off prostate cancer cells in a petri dish, even down at the levels you might expect in your bloodstream after just eating some tomatoes. So, not surprisingly, the Heinz ketchup company, along with manufacturers of lycopene supplements, petitioned the FDA to allow them to print health claims on their products.

As I discuss in my video Lycopene Supplements vs. Prostate Cancer, they were essentially denied. The FDA said the evidence was “very limited and preliminary” and didn’t allow any endorsements for ketchup or supplements. By that time, further population studies had cast doubt on the lycopene theory. Consumers of high dietary intakes of lycopene didn’t seem to have lower cancer rates after all, but who has high dietary intakes of lycopene? Those who eat the most pizza. So, maybe it’s no surprise there are mixed results. What we needed was to put lycopene to the test.

It started with a case study of a 62-year-old man with terminal prostate cancer. Both surgery and chemotherapy had failed. He had metastases all over that had spread to the bone and was sent to hospice to die. So, he took it upon himself to initiate “phytotherapy”—plant-based therapy. Every day, he took the amount of lycopene found in a quarter cup of tomato sauce or a tablespoon of tomato paste. His PSA, a measure of tumor bulk, started out at 365, dropped to 140 the next month, and then down to just 8 the month after that. His metastases started disappearing, and, “at last followup he was asymptomatic”—living happily ever after.

When lycopene was given at a higher dose in pill form, however, it didn’t seem to work. A 2013 review of all such lycopene supplement trials failed to support the initial “optimism.” In fact, the researchers were just happy that the lycopene pills didn’t end up causing more cancer, like beta-carotene pills did. Then came 2014. 

Researchers in Italy had been giving the largest doses they could have of lycopene, selenium, and isolated green tea compounds to men with precancerous prostate lesions, hoping they could prevent full-blown cancer. But, in 2014, the expanded results of a similar trial were published, in which selenium and vitamin E supplements resulted in more cancer. Yikes! So, the researchers in Italy stopped their trial and broke the code to unblind the results. And indeed, those taking high doses of lycopene, green tea catechins, and selenium appeared to get more cancer than those who just got sugar pills.

“The potential implications are dramatic,” said the lead researcher, “given the current massive worldwide use of such compounds as alleged preventive supplementations in prostate and other cancers.” What went wrong? 

 Well, after the beta-carotene pill debacle, researchers measured cellular damage at different natural and unnatural doses of beta-carotene, as you can see at 3:32 in my video. At dietary doses, beta-carotene suppressed cellular damage, but at supplemental doses, which are higher, it not only appeared to stop working, but it caused more damage. The same with lycopene. “Both lycopene and [beta]-carotene only afforded protection against DNA damage…at relatively low concentrations”—at the kinds of levels one might see in people eating lots of tomatoes or sweet potatoes. That is, “levels [that] are comparable with those seen in the plasma [blood] of individuals who consume a carotenoid-rich diet.” However, at the kind of blood concentrations that one might get taking pills, “the ability to protect the cells against such oxidative [free radical] damage was rapidly lost” and, indeed, the presence of high levels of beta-carotene and lycopene may actually serve to increase the extent of DNA damage. It’s no wonder high dose lycopene pills didn’t work.

Phytochemicals may be “guardians of our health,” but the safety of consuming concentrated extracts is unknown. “The protective benefits of a phytochemical-rich diet are best obtained from frequent consumption of fruits, vegetables, and whole grain products”—by whole plant foods. The food industry has different ideas, though. Soon, there may be phytochemical-fortified bacon, martinis, and ice cream, says an article in the journal Food Technology. If they can find just the right mix of plant compounds, it “is not inconceivable that foods that once contributed to illness and disease may be reconstructed…to offer significant health benefits.”

So what are the Best Supplements for Prostate Cancer? Watch the video to find out!


More on natural treatments for prostate cancer in:

Instead of tomato-compound supplements, what if we just fed some cancer patients some tomato sauce? That’s the subject of my video Tomato Sauce vs. Prostate Cancer

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:

Açaí vs. Wild Blueberries for Artery Function

“Plant-based diets…have been found to reduce the risk of cardiovascular disease” and some of our other leading causes of death and disability. “Studies have shown that the longest living and least dementia-prone populations subsist on plant-based diets.” So why focus on açaí berries, just one plant, for brain health and performance?

Well, “foods rich in polyphenols…improve brain health,” and açaí berries contain lots of polyphenols and antioxidants, so perhaps that’s why they could be beneficial. If you’re only looking at polyphenols, though, there are more than a dozen foods that contain more per serving, like black elderberry, regular fruits like plums, flaxseeds, dark chocolate, and even just a cup of coffee.

As you can see at 1:02 in my video The Benefits of Açaí vs. Blueberries for Artery Function, in terms of antioxidants, açaí berries may have ten times more antioxidant content than more typical fruits, like peaches and papayas, and five times more antioxidants than strawberries. But blackberries, for instance, appear to have even more antioxidants than açaí berries and are cheaper and more widely available.

Açaí berries don’t just have potential brain benefits, however. Might they also protect the lungs against harm induced by cigarette smoke? You may remember the study where the addition of açaí berries to cigarettes protected against emphysema—in smoking mice, that is. That’s not very helpful. There is a long list of impressive-looking benefits until you dig a little deeper. For example, I was excited to see a “[r]eduction of coronary disease risk due to the vasodilation effect” of açaí berries, but then I pulled the study and found they were talking about a vasodilator effect…in the mesenteric vascular bed of rats. There hadn’t been any studies on açaí berries and artery function in humans until a study published in 2016.

Researchers gave overweight men either a smoothie containing about two-thirds of a cup of frozen açaí pulp and half a banana or an artificially colored placebo smoothie containing the banana but no açaí. As you can see at 2:26 in my video, within two hours of consumption of their smoothie, the açaí group had a significant improvement in artery function that lasted for at least six hours, a one or two point bump that is clinically significant. In fact, those walking around with just one point higher tend to go on to suffer 13 percent fewer cardiovascular events like fatal heart attacks.

As I show at 2:52 in my video, you can get the same effect from wild blueberries, though: about a one-and-a-half-point bump in artery function two hours after blueberry consumption. This effect peaks then plateaus at about one and a half cups of blueberries, with two and a half cups and three and a half cups showing no further benefits.

What about cooked blueberries? As you can see at 3:12 in my video, if you baked the blueberries into a bun, like a blueberry muffin, you get the same dramatic improvement in artery function.

Cocoa can do it, too. As shown at 3:30 in my video, after having one tablespoon of cocoa, you gain about one point, and two tablespoons gives you a whopping four points or so, which is double what you get with açaí berries.

One and a quarter cups’ worth of multicolored grapes also give a nice boost in artery function, but enough to counter an “acute endothelial insult,” a sudden attack on the vulnerable inner layer of our arteries? Researchers gave participants a “McDonald’s sausage egg breakfast sandwich and two hash browns.” They weren’t messing around! As you can see at 3:56 in my video, without the grapes, artery function was cut nearly in half within an hour, and the arteries stayed stiffened and crippled three hours later. But when they ate that McMuffin with all those grapes, the harmful effect was blunted.

Eat a meal with hamburger meat, and artery function drops. But if you eat that same meal with some spices, including a teaspoon and a half of turmeric, artery function actually improves.

What about orange juice? Four cups a day of commercial orange juice from concentrate for four weeks showed no change in artery function. What about freshly squeezed orange juice? Still nothing. That’s one of the reasons berries, not citrus, are the healthiest fruits.

For a beverage that can improve your artery function, try green tea. Two cups of green tea gives you that same effect we saw with cocoa, gaining nearly four points within just 30 minutes. And, as you can see at 5:05 in my video, that same crazy effect is also seen with black tea, with twice as powerful an effect as the açaí berries.

So, why all the focus on just that one plant? Why açaí berries? Well, the real reason may be because the author owns a patent on an açaí-based dietary supplement.


How do the antioxidant effects of açaí berries compare to applesauce? See The Antioxidant Effects of Açaí vs. Apples.

What about the effects of other foods on artery function? Coronary artery disease is, after all, our leading cause of death for men and women. See:

What else can blueberries do? 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:

Topical Green Tea for Acne and Fungal Infections

Which plant should we use for which skin disease? That’s the topic of my video Natural Treatment for Acne and Fungal Infections. Thousands of studies have been published to date about the health effects of green tea, but it wasn’t until fairly recently that researchers began to look at the possibility of using green tea for the prevention and treatment of infections. Patents have been taken out on the antibacterial, antifungal, and antiviral properties of tea. Let’s review some of the evidence.

In terms of fungal infections, green tea compounds have demonstrated “potent antifungal activity” against the primary cause of athlete’s foot, fungal nail infections, jock itch, and ringworm—comparable, in some cases, to powerful antifungal drugs like fluconazole. This was shown in a petri dish, though. How about a green tea footbath for athlete’s foot fungus between the toes? Evidently, tea leaves were once used as a folk remedy for the fungus, so why not put it to the test? Indeed, a once-a-day, 15-minute dilute green tea footbath led to a significant improvement in symptoms compared to controls.

Green tea baths also appeared to help with fungus-associated atopic dermatitis, though there was no control group in that study, and a full-strength green tea may help clear candida yeast from poorly cleaned dentures. What about the bacteria that cause plaque and gingivitis? Even a 2% green tea mouthwash was found to be effective. Yes, you should be able to control plaque just with proper brushing and flossing—with an emphasis on “proper.” Most people don’t brush for the recommended four minutes a day, so a dilute green tea mouthwash may help.

In terms of plaque bacteria-killing ability, green tea was beaten out by a “garlic with lime mouth rinse,” but I think I’ll just stick to green tea, especially when green tea appears to not only kill plaque bugs directly but also boost the antibacterial capacity of saliva after you drink it.

What about green tea for acne? Six weeks of a 2% green tea lotion cut the number of pimples by more than half and significantly reduced the severity, as you can see at 2:48 in my video, making it a cheap, effective treatment for acne.

Impetigo is another bacterial skin infection that can affect the face, but a tea ointment can affect an 80 percent cure rate, on par with antibiotics given topically or orally.

What about bladder infections? We know a certain concentration of green tea compounds can kill the type of E. coli that causes urinary tract infections. The question then becomes how much tea do you have to drink to achieve those concentrations in your bladder? Not much, it turns out. Just one cup of tea might have an effect, but you may need to space out multiple cups over the day because it gets cleared out of your system within about eight hours, as you can see at 3:45 in my video.

So, where do we stand now? The test tube data look promising, but there has yet to be a single study to put it to the test. At this point, green tea should just be used as an adjunct therapy for bladder infections. But, with emerging multidrug-resistant organisms, green tea certainly holds potential.

Wait a moment. If green tea is so good at killing bacteria, might we be killing the good bacteria in our gut when we drink it? No. That’s what’s so amazing. “It has also been shown that green tea has no effect over intestinal flora, which is a great advantage against other bactericidal [bacteria-killing] agents.” But that may not actually be true. Drinking green tea may actually boost the levels of our good bacteria by acting as a prebiotic, thereby improving the colon environment, so it may actually have some effect on our gut flora after all, but it appears to be all good.


Drinking tea with meals may impair iron absorption, so it’s better to drink it between meals. For more on green tea, one of my favorite beverages, along with water and hibiscus tea, see:

For more on acne, 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: