Friday Favorites: Benefits of Nutritional Yeast for Cancer

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.

In an article entitled “The Treatment of Inoperable Cancer”, it was noted that “200 years ago, it was observed that a certain number of malignant growths disappeared after an attack of [a type of strep infection]”—and that was 200 years before 1901, when this was published. A disproportionate number of cases of spontaneous tumor regressions have followed various infections. The thought is that an infection may kind of so rile up the immune system, the cancer may get caught in the cross-fire—a phenomenon that may have inspired healers dating back to the ancient Egyptians, thousands of years ago.

But, you don’t know until you put it to test—though it wasn’t formally studied until the 1800s, when doctors started intentionally infecting cancer patients. The most famous proponent was William Coley, the so-called “Father of Immunotherapy,” at what would eventually become Memorial Sloan Kettering. He “was convinced that having a severe infection could cause cancer to regress.” So, with “a great deal of courage,” he started injecting cancer patients. The problem, of course, is that causing infections is quite dangerous, and “two of his patients died.” However, their tumors did shrink!

If only there was a way we could boost the immune system without killing people. Well, that’s the theory behind therapeutic cancer vaccines—one of which has been in practice for decades: squirting a weakened bovine tuberculosis bacteria into the bladders of patients with bladder cancer, to make the immune system attack; boosting long-term survival up to 36%.

Okay, but is there something we can eat that can boost immune function? In my videos on countering stress-induced immune suppression and preventing common childhood infections, I reviewed evidence about a type of fiber in baker’s, brewer’s, and nutritional yeast, called “beta-glucans…[which] are considered immunomodulatory compounds suggested to enhance the defense against infections” and, potentially, cancer.

Beta-glucans themselves do not appear to have a direct cytotoxic effect in terms of killing cancer cells, but may boost anti-tumor immunity by activating our immune cells. For example, if you take freshly excised tumors of breast cancer patients, and let loose natural killer cells upon them, they can kill off a small percentage of the tumor cells. But, first prime them in vitro with some yeast beta-glucans, and they become five times more effective at killing cancer cells. What if you just eat it, though?

When twenty-three women with metastatic breast cancer were given just a 16^th of a teaspoon of nutritional yeast worth of beta-glucans, they experienced a 50% increase in the number of monocyte white blood cells in their bloodstream (which are part of our natural defenses), as well as a significant increase in their activation. But, it was just a two-week study. The clinical significance of this finding is unclear. What we want to know is if they actually live longer.

The only English-language, randomized, double-blind, placebo-controlled trial of breast cancer patients and beta-glucans was more of a wound-healing study, where they found that the women taking beta-glucans healed so much faster after surgery that the tubes could be removed from their chests and armpits—in some cases, days earlier. This was the first clinical study to demonstrate improved wound healing using oral beta-glucans. The other two—showing benefits for pediatric burns and leg ulcers—were performed using topical beta-glucan preparations: putting it on the skin directly, something that did not appear to reverse precancerous skin lesions better than placebo. But, that’s because the placebo cream worked so well, too. “Both groups showed a…significant reduction.” They speculated that “[s]ince each patient…acted as their own control,” putting the beta-glucan cream on one arm, and the placebo cream on the other, that the application of beta-glucans on one arm may have been absorbed into the system, and helped on the other arm, given that systematic effects have been noted following topical administration.

But, what effect might oral beta-glucans have on the progression of internal cancers? Yeah, oral yeast beta-glucans can cause dramatic tumor shrinkage—in mice, but there appears to be only one human study published in English. Twenty patients with advanced cancer on chemo were given a beta-glucan supplement in an open label, uncontrolled trial. “Sixty percent of the patients [supposedly] reported a sense of well-being while taking the [beta]-glucan, and asked to remain on the treatment…after the completion of the study.” But, that just sounds like classic placebo effect. Same thing with reporting being less tired, but this is interesting: “one patient with lymphoma and [enlarged lymph nodes in the neck] who delayed his standard chemotherapy for 4 weeks during the study…noted a marked reduction in the size of the nodes while taking the [supplement] alone.” So, this, you know, one kind of anecdotal case is interesting, especially since there are no side effects, but not exactly revolutionary.

In Japan, there have been more than 20 randomized, controlled trials on the use of beta-glucans as an adjunct cancer treatment, which evidently show an enhancement of chemo or radiation therapy, resulting in “a positive effect on the survival and quality of life…” For example, there was evidently a study on taking a yeast beta-glucan supplement to help “cancer relapse after surgery. There were no relapses in the treated group compared to [about one in five] in the control group.” Even more intriguing, yeast beta-glucans for inoperable cancer patients—end-stage cancer, since only about one in 20 patients made it three months. And by six months, they were all dead, “whereas in the treated group, [most] survived for more than 3 months”—not one in 20, but most, “and 43% were still alive after 6 months.”

Now evidently, it’s not clear how patients were divvied up into treatment vs. control groups. If they weren’t randomly assigned, they may have inadvertently cherry-picked healthier patients for the treatment group, which could explain the results. Now, I’ve looked for this study everywhere so I could get it translated, but even the National Library of Medicine couldn’t find it. If anyone out there can, though, I’ll do a follow-up video. But, the amount of beta-glucan they used is what you’d find in a single pinch of nutritional yeast, which would cost less than a penny. And the only side effect would be tastier popcorn. So, why not give it a try?

Please consider volunteering to help out on the site.

• Cooper A. The Treatment of Inoperable Cancer. London Medical Press and Circular, Volume 123.
• Hoption cann SA, Van netten JP, Van netten C. Dr William Coley and tumour regression: a place in history or in the future. Postgrad Med J. 2003;79(938):672-80.
• Bickels J, Kollender Y, Merinsky O, Meller I. Coley's toxin: historical perspective. Isr Med Assoc J. 2002;4(6):471-2.
• Mccarthy EF. The toxins of William B. Coley and the treatment of bone and soft-tissue sarcomas. Iowa Orthop J. 2006;26:154-8.
• Brandau S, Suttmann H. Thirty years of BCG immunotherapy for non-muscle invasive bladder cancer: a success story with room for improvement. Biomed Pharmacother. 2007;61(6):299-305.
• Herr H W, Schwalb DM, Zhang ZF, Sogani PC, Fair WR, Whitmore Jr WF, Oettgen HF. Intravesical bacillus Calmette-Guérin therapy prevents tumor progression and death from superficial bladder cancer: ten-year follow-up of a prospective randomized trial. JCO.1995.13.6.1404 Journal of Clinical Oncology 13, no. 6 (June 1995) 1404-8.
• Guo C, Manjili MH, Subjeck JR, Sarkar D, Fisher PB, Wang XY. Therapeutic cancer vaccines: past, present, and future. Adv Cancer Res. 2013;119:421-75.
• Samuelsen AB, Schrezenmeir J, Knutsen SH. Effects of orally administered yeast-derived beta-glucans: a review. Mol Nutr Food Res. 2014;58(1):183-93.
• Chan GC, Chan WK, Sze DM. The effects of beta-glucan on human immune and cancer cells. J Hematol Oncol. 2009;2:25.
• Vetvicka V, Thornton BP, Wieman TJ, Ross GD. Targeting of natural killer cells to mammary carcinoma via naturally occurring tumor cell-bound iC3b and beta-glucan-primed CR3 (CD11b/CD18). J Immunol. 1997;159(2):599-605.
• Demir G, Klein HO, Mandel-molinas N, Tuzuner N. Beta glucan induces proliferation and activation of monocytes in peripheral blood of patients with advanced breast cancer. Int Immunopharmacol. 2007;7(1):113-6.
• Yenidogan E, Akgul GG, Gulcelik MA, Dinc S, Colakoglu MK, Kayaoglu HA. Effect of β-glucan on drain fluid and amount of drainage following modified radical mastectomy. Adv Ther. 2014;31(1):130-9.
• Delatte SJ, Evans J, Hebra A, Adamson W, Othersen HB, Tagge EP. Effectiveness of beta-glucan collagen for treatment of partial-thickness burns in children. J Pediatr Surg. 2001;36(1):113-8.
• Medeiros SD, Cordeiro SL, Cavalcanti JE, et al. Effects of purified Saccharomyces cerevisiae (1→3)-β-glucan on venous ulcer healing. Int J Mol Sci. 2012;13(7):8142-58.
• Tong DW, Barnetson RS. Beta-1,3-D-glucan gel in the treatment of solar keratoses. Australas J Dermatol. 1996;37(3):137-8.
• Mo L, Chen Y, Li W, et al. Anti-tumor effects of (1→3)-β-d-glucan from Saccharomyces cerevisiae in S180 tumor-bearing mice. Int J Biol Macromol. 2017;95:385-392.
• Weitberg AB. A phase I/II trial of beta-(1,3)/(1,6) D-glucan in the treatment of patients with advanced malignancies receiving chemotherapy. J Exp Clin Cancer Res. 2008;27:40.
• Kim SY, Song HJ, Lee YY, Cho KH, Roh YK. Biomedical issues of dietary fiber beta-glucan. J Korean Med Sci. 2006;21(5):781-9.

Image credit: Alex Ex via Wikimedia. Image has been modified.

Motion graphics by Avocado Video