Tomato Sauce Put to the Test for Prostate Cancer

What happened when cancer patients were given three quarters of a cup of canned tomato sauce every day for three weeks?

“Occasionally…positive things happen in the field of cancer prevention science to popular, good-tasting foods.” Cruciferous vegetables like broccoli are wonderful, but they may be “a hard food for the public to swallow.” By contrast, who doesn’t like tomatoes?

As I’ve discussed previously, studies using high-dose supplements of lycopene, the antioxidant red pigment in tomatoes thought to be the active anti-cancer ingredient, failed over and over again to prevent or treat cancer. In fact, it may even end up promoting cancer, since lycopene may actually act as a pro-oxidant at the high levels one can get with supplements. But, lycopene in supplement form doesn’t appear to be effective at lower doses either. “There is a strong inverse [protective] correlation between the intake of fruit and vegetables and the incidence of certain cancers.” However, when we supplement with only a single compound isolated in pill form, we may upset the healthy, natural balance of antioxidants.

It does seem to be quite the human hubris to think we can reproduce the beneficial effects of consuming entire fruits and vegetables by giving supplements of a single phytochemical, which would normally interact with thousands of other compounds in the natural matrix Mother Nature intended. “In addition to lycopene, [other] known carotenoids in tomatoes and tomato-based products include β-carotene, γ-carotene, ζ-carotene, phytofluene, and phytoene, all of which…have been found to accumulate in human prostate tissue.” There are also numerous non-carotenoid compounds in tomatoes that may have anti-cancer activity, not to mention all of the compounds we have yet to even characterize.

It’s not about finding the one magic bullet, though. As one study title reads, “The anti-cancer effects of carotenoids and other phytonutrients resides in their combined activity.” For example, as you can see at 1:52 in my video Tomato Sauce vs. Prostate Cancer, at the low concentrations of the tomato compounds phytoene, phytofluene, and lycopene that are found in most people who eat normal amounts of tomatoes, there’s very little effect on cancer cell growth in vitro when used separately. But, when they are combined together, a non-effective dose of phytoene and phytofluene plus a non-effective dose of lycopene somehow become effective, significantly suppressing prostate cancer cell growth. The same synergy can be seen across foods. Curcumin, the yellow pigment in turmeric and curry powder, tomato extracts, and the vitamin E found in nuts and seeds do little individually to inhibit pro-growth signaling of prostate cancer cells—less than 10 percent—but all three together suppress growth signaling about 70 percent. The whole is greater than the sum of its parts.

So, instead of giving cancer patients lycopene pills, what if we give them some tomato sauce? Researchers gave 32 patients with localized prostate cancer three quarters of a cup of canned tomato sauce every day for three weeks before their scheduled radical prostatectomy. In their bloodstream, PSA levels dropped by 17.5 percent. PSA, prostate-specific antigen, is a protein produced by prostate gland cells, and elevated blood PSA levels are routinely used to monitor the success of cancer treatment. “It was surprising to find that the 3-week, tomato sauce-based dietary intervention” could decrease PSA concentrations in men with prostate cancer. As well, free radical damage of the DNA in their white blood cells dropped by 21 percent. Imagine how antioxidant-poor their diet must have been beforehand if less than one cup of tomato sauce a day could reduce DNA damage by more than a fifth! 

What did they find in their prostates, though? Human prostate tissue is thought to be “particularly vulnerable to oxidative DNA damage by free radicals, which are thought to play a critical role in all stages of carcinogenesis,” that is, of cancer formation. This may be for a number of reasons, including fewer DNA repair enzymes. Well, the researchers had tissue samples taken from biopsies before the tomato sauce regimen started, as well as tissue samples from surgeries after three weeks of tomato sauce, and resected tissues from tomato sauce-supplemented patients had 28 percent less free radical damage than expected. I show a graph of the DNA damage in the prostate before the tomato sauce and after just 20 days of sauce at 4:18 in my video. You can see the drop yourself. What’s interesting is there was no association between the level of lycopene in the prostate and the protective effects. Tomatoes contain a whole bunch of things, some of which may be even more powerful than lycopene.

Regardless, in contrast to the lycopene supplements alone, the whole food intervention seemed to help. To see if lycopene plays any role at all, one would have to test a lycopene-free tomato—in other words, a yellow tomato. So, what if you compared red tomatoes to yellow tomatoes, which have all the non-lycopene tomato compounds, to straight lycopene in a pill? Researchers fed people red tomato paste, yellow tomato paste, lycopene pills, or placebo pills, and then dripped their blood onto prostate cancer cells growing in a petri dish. As you can see at 5:18 in my video, the red tomato serum—the blood from those who ate red tomato paste—significantly decreased the prostate cancer cell’s expression of a growth-promoting gene called cyclin D1, compared to those not eating anything. This downregulation of the gene by the red tomato consumption “may contribute to lower prostate cancer risk by limiting cell proliferation.” The red tomato seemed to work better than the yellow tomato, so maybe the lycopene helped—but not in pill form. This gene “was not regulated” by the lycopene pill serum, indicating that it may be something else. And, lycopene alone significantly upregulated procarcinogenic genes. “Therefore, it can be stated that tomato consumption may be preferable to pure lycopene…”

So, what’s the best way? A spouse wrote to the editor of the Harvard Men’s Health Watch, saying their husband wants to have pizza for his prostate but they don’t think it’s a healthy food. The doctor replied with the suggestion of a “cheese-free pizza (with broccoli instead of pepperoni, please)” or just some “tomato juice.”

Why eat tomato sauce when you can just take lycopene supplements? See my video Lycopene Supplements vs. Prostate Cancer.

Are there any foods we should avoid? Check out, for example, Prostate Cancer Survival: The A/V Ratio and How Our Gut Bacteria Can Use Eggs to Accelerate Cancer.


We may be able to prevent cancer and even reverse the progression of cancer with diet. See: 

It isn’t always easy to get guys to change, though. See Changing a Man’s Diet After a Prostate Cancer Diagnosis.

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:

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:

Presumed Safety of Probiotics Questioned

In certain medical conditions, probiotic supplements may actually make things worse.

If you’ve ever made sauerkraut at home, you know you don’t have to add any kind of starter bacteria to get it to ferment, because the lactic acid-producing bacteria are already present on the cabbage leaves themselves out in the field. This suggests that raw fruits and vegetables may not only be a source of prebiotics—that is, fiber—but also a source of “novel” probiotics. 

As I discuss in my video Culture Shock: Questioning the Efficacy and Safety of Probiotics, researchers have since worked on characterizing these bacterial communities and found two interesting results. First, “the communities on each produce type were significantly distinct from one another.” Indeed, the tree fruits harbor different bacteria than veggies on the ground, and grapes and mushrooms seem to be off in their own little world. So, if these bugs do indeed turn out to be good for us, this would underscore the importance of eating not just a greater quantity but also a greater variety of fruits and veggies every day. And, second, the researchers found that there were “significant differences in [microbial] community composition between conventional and organic” produce. “This highlights the potential for differences in the microbiota [or bacteria] between conventionally and organically farmed produce items to impact human health”—but we don’t know in what direction. They certainly found different bacteria on organic versus conventional produce, but we don’t know enough about fruit and veggie bugs to make a determination as to which bacterial communities are healthier.

What about probiotic supplements? I’ve talked before about their potential benefits in my videos Preventing and Treating Diarrhea with Probiotics and Gut Feelings: Probiotics and Mental Health, but there appears to be publication bias in the scientific literature about probiotics. This is something we see a lot with drug companies, where the sponsor, such as the supplement company paying for its own probiotic research, may not report negative results. It won’t publish it, as if the study never happened. In that case then, doctors just see the positive studies.  

As you can see at 2:00 in my Culture Shock: Questioning the Efficacy and Safety of Probiotics video, using fancy statistical techniques, researchers estimated that as many as 20 unflattering studies “with smaller or deleterious results” were simply MIA. They just weren’t published. What’s more, even in the studies that were published, even when the authors were directly sponsored by a yogurt company, for example, “very commonly conflicts of interest are not reported…”

There’s also been concerns about safety. A review for the government’s Agency for Healthcare Research and Quality concluded that there’s “a lack of assessment and systematic reporting of adverse events in probiotic intervention studies,” so while “the available evidence in RCTs [randomized controlled trials] does not indicate an increased risk [for the general public]…the current literature is not well equipped to answer questions on the safety of probiotic interventions with confidence.”

Let’s talk about the study that freaked people out a bit. Acute pancreatitis, sudden inflammation of the pancreas, is on the rise and can become life-threatening in some cases, as bacteria break through our gut barrier and infect our internal organs. Antibiotics don’t seem to work, so how about probiotics? They seemed to work on rats. If you cause inflammation by cutting the rats open and “mechanically damaging” their pancreas, not only do probiotics show “strong evidence for efficacy,” but there were “no indications for harmful effects…” So, half the people with pancreatitis got probiotics, and the other half got sugar pills. As you can see at 3:37 in my video, the mortality rates shot up in the probiotics group compared to placebo within ten days. More than twice as many people died on the probiotics. Thus, probiotics for acute pancreatitis probably aren’t a good idea, and, even further, probiotics “can no longer be considered to be harmless”…

The researchers were criticized for not cautioning patients about the risk before they signed up for the study. (The study subjects were told probiotics had a long history of safe use with no known side effects.) In response to the criticism, the researchers replied that there were no known side effects—until their study.

At the start of this blog, I alluded to my Preventing the Common Cold with Probiotics? video.


Perhaps it would be safer and more effective to focus on fostering the growth of good bacteria by feeding them prebiotics (fiber and resistant starch). Learn more:

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: