A half-teaspoon a day of brewer’s yeast is put to the test in a randomized, double-blind, controlled clinical trial.
In 1854, a case report was published in the precursor of the British Medical Journal suggesting two to three tablespoons of brewer’s yeast every day could cure diabetes within six weeks. It took another hundred and fifty years before it was finally put to the test in a randomized, double-blind, controlled clinical trial. Researchers investigated the effect of about a daily half teaspoon of brewer’s yeast for three months. What happened? A significant drop in fasting blood sugars and hemoglobin A1c, as well as an improvement in insulin sensitivity, as you can see below and at 0:33 in my video Flashback Friday: Benefits of Brewer’s Yeast for Diabetes. What do these numbers mean?
Hemoglobin A1c is a measure of how high your blood sugars have been over time. A measured value under 6 percent means you’ve had normal blood sugars, between 6 and 6.5 percent means you have pre-diabetes, and anything higher than 6.5 percent means you are diabetic. You can have well-controlled diabetes or way out-of-control diabetes, but a hemoglobin A1c above 6.5 percent is considered diabetic.
In the study, the placebo group started out around 9 and stayed around 9, but the brewer’s yeast group dropped from 9 to 8. So, the placebo group was stuck up around 9 percent, but the yeast group dropped down to 8 percent. The yeast group wasn’t cured, but in three months’ time, they were able to achieve significantly better diabetic control by eating just a half teaspoon of brewer’s yeast each day, which would cost about four cents a day!
What about a half teaspoon for just seven weeks? As you can see below and at 1:52 in my video, subjects were once again given a half teaspoon of brewer’s yeast a day. They started out with an A1c level of 8. The placebo appeared to help a bit, but the yeast helped even more, with A1c levels dropping from 8 down to an almost nondiabetic 6.6. That’s amazing! How could it be? The drug industry has been trying for decades to discover the so-called glucose tolerance factor in yeast, but no shareholder is going to be happy with a therapy you can buy for only four cents a day.
We know that whatever it is in yeast that’s causing the drop contains the trace mineral chromium. Can you just give chromium supplements on their own? No, giving straight chromium does not appear to be particularly effective. Might the special fiber in yeast, the beta-glucans, play a role?
Supplementation with the amount of beta-glucan found in 2 to 3 daily teaspoons of brewer’s yeast did result in a slimmer waist and a drop in blood pressure within six weeks, as you can see below and at 2:47 in my video. The study participants trimmed about an inch off their waist, despite making no significant changes to their caloric intake. Blood pressures were significantly reduced as well, an effect also seen with whole brewer’s yeast. Just a half teaspoon of brewer’s yeast a day led to a significant drop in high blood pressure, which, incidentally, is a key contributor to the cardiovascular and kidney complications of diabetes.
The British Medical Journal published a report in 1854 that suggested two to three daily tablespoons of brewer’s yeast could cure diabetes in six weeks.
Hemoglobin A1c measures blood sugars over time, and a value below 6 percent indicates normal blood sugars, 6 to 6.5 percent signals pre-diabetes, and more than 6.5 percent means you’re diabetic.
Researchers investigated the claim 150 years later and found that a daily half teaspoon of brewer’s yeast for three months resulted in improved insulin sensitivity and a significant drop in fasting blood sugars and hemoglobin A1c. The placebo group’s A1c started and stayed around 9 percent, but the brewer’s yeast group dropped from 9 to 8 percent, achieving significantly better diabetic control.
When subjects got a daily half teaspoon of brewer’s yeast for just seven weeks, their A1c levels dropped from 8 to 6.6 percent, which is nearly nondiabetic.
The component in yeast that causes the drop contains chromium, a trace mineral, but giving chromium supplements doesn’t seem to be effective.
Beta-glucan is a special fiber in yeast, and supplementation with the amount in two to three daily teaspoons of brewer’s yeast resulted in a slimmer waist and lowered blood pressure within six weeks, despite no significant changes to their caloric intake.
For more on the pros and cons of baker’s, brewer’s, and nutritional yeasts, check out these videos:
Preserving Immune Function in Athletes with Nutritional Yeast
Flashback Friday: Best Food to Prevent Common Childhood Infections
Flashback Friday: Best Food to Counter Stress-Induced Immune Suppression
Benefits of Nutritional Yeast for Cancer
Flashback Friday: Best Food for Hay Fever (Seasonal Allergies)
Flashback Friday: Does Nutritional Yeast Trigger Crohn’s Disease?
Flashback Friday: Is Candida Syndrome Real?
Is Nutritional Yeast Healthy for Everyone?
What if you changed your whole diet? See How Not to Die from Diabetes and How Not to Die from High Blood Pressure.
Michael Greger, M.D.
PS: If you haven’t yet, you can subscribe to my free videos here and watch my live presentations:
2019: Evidence-Based Weight Loss
2016: How Not to Die: The Role of Diet in Preventing, Arresting, and Reversing Our Top 15 Killers
2015: Food as Medicine: Preventing and Treating the Most Dreaded Diseases with Diet
2014: From Table to Able: Combating Disabling Diseases with Food
2013: More Than an Apple a Day