Doesn’t it seem like when it comes to nutrition there are more opinions than facts to go around? Every day we hear new theories about diets, and supplements, and the best foods to eat. My role is to take the mystery out of good nutrition, and look at the science. Welcome to the Nutrition Facts Podcast. I’m your host Dr. Michael Greger. And I’m here to bring you an evidence-based approach to the best way to live a healthier longer life.
Osteoarthritis is our most common form of joint disease, affecting more than 30 million Americans. What can we do about it? In our first story, we look at the first clinical study on the effects of berries on arthritis.
How might berries improve human health, healthy aging, and quality of life? Maybe, due to their anti-inflammatory effects, since inflammation can be an underlying contributing factor in the “development, progression, and complication” of a number of chronic diseases. Higher intake of anthocyanins, the brightly-colored pigments in berries, has been associated with anti-inflammatory effects, which may be “a key component” underlying the associated reduction in chronic disease risk. But these are all just associations. You can’t prove cause and effect until you put it to the test.
A double-blind, randomized, placebo-controlled trial found that blueberry smoothies could turn off inflammation genes. (This is measuring the expression of pro-inflammatory genes in white blood cells taken from individuals before and after six weeks of drinking placebo smoothies with no blueberries.) They got worse over time. Six weeks later, more inflammatory chemicals pouring out, whereas the blueberry group started out about the same at week zero, but six weeks of daily blueberries and, the expression of inflammatory genes went down.
“In addition to attenuating inflammation,” they demonstrate that “blueberry consumption was able to significantly decrease the levels of free radicals” in their bloodstream: no change in the placebo group, but after six weeks of blueberry smoothies, the amount of free radicals in their blood was extinguished by half. Okay, but does all that antioxidant and anti-inflammatory power actually translate into clinical benefits? For example, what is the effect of blueberry consumption on recovery after excessive weight lifting-induced muscle damage?
A randomized crossover study: a blueberry smoothie or antioxidant-matched placebo smoothie five and 10 hours prior to, and then 12 and 36 hours after, exercise-induced muscle damage. The smoothies were about a cup and a half of frozen strawberries, a banana, and apple juice, or without the berries, but dextrose and vitamin C added to match it for calories and antioxidant power. Even so, the blueberries worked better at mopping up free radicals. Yeah, but what we care about is the recovery of muscle strength, so you can jump right back into training. Same drop in peak torque 12 hours later, but a day later, significantly faster restoration of peak muscle strength, demonstrating that the ingestion of blueberries can accelerate recovery — something that may be especially relevant to athletes who compete over successive days.
That’s all well and good, but what about using berries to treat inflammatory diseases like arthritis? Yes, they may have protective effects against arthritis in a rat — significantly reducing “paw volume”— how swollen their paw gets when you inject it with some inflammatory irritant. But there had never been any human arthritis berry studies, until now.
Remember that amazing study where strawberries alone could reverse the progression of precancerous lesions? The strawberries were dramatically downregulating pro-inflammatory genes. Give strawberries to diabetics for six weeks, and not only does their diabetes get better, their C-reactive protein levels, a marker of systemic inflammation, drops 18%. Even just a single meal can help. Have people eat a largely unhealthy breakfast, and the level of inflammatory markers goes up over the next six hours, but less so if you added just five large strawberries to the meal.
So, can “strawberries improve pain and inflammation” in confirmed knee osteoarthritis? No fair that the title ruined the suspense, but yes, osteoarthritis patients randomized to get like a pint and a half of strawberries a day for 12 weeks and yeah, certain inflammatory markers plummeted on the strawberries. But did they actually feel any better? Significant reductions in constant pain, intermittent pain, and total pain. The “first clinical study on the effects of berries” on human arthritis, and found that a “simple dietary intervention, the addition of berries to one’s diet, may have a significant impact on pain, inflammation, and overall quality of life in obese adults with osteoarthritis.”
In our next story we discover how a quarter-to a half-teaspoon a day of powdered ginger can be as pain-relieving as ibuprofen, without the risk of damage to the intestinal lining.
If ginger is so effective against migraines, and the pain of menstrual cramps, what about osteoarthritis—an all-too-common disorder that produces “chronic pain and disability?” The first major study, published in 2000, showed no benefit over placebo. But, the study only lasted three weeks.
The next, in 2001, lasted longer—six weeks—and was, by the end, indeed able to show significantly better results than placebo. But, the placebo did so well, reducing pain from like sixties on a scale of 1 to 100, down to like forties, that bringing pain down that extra little bit into the thirties was not especially clinically significant. And so, an editorial in the official journal of the American College of Rheumatology concluded that ginger “should not be recommended for treatment of arthritis because of the limited efficacy.”
But, since that time, there’s been a few other trials that showed more impressive results such that ginger is now considered indeed “able to reduce pain and disability in osteoarthritis.”
But, how well, compared to other treatments? “Since osteoarthritis is a chronic disease,” it’s especially important to weigh the risks versus benefit of treatment, and the commonly used anti-inflammatory drugs can carry “serious cardio-vascular and gastro-intestinal risks.”
For example, if you stick cameras down people with osteoarthritis on drugs like ibuprofen, nearly half were found to have major injuries to the lining of their small intestines—seven out of sixteen. Now, you can reduce that risk by taking an additional drug to counteract the side effects of the first drug. Ibuprofen-type drugs reduce our stomach lining’s ability to protect itself from the stomach acid; so, by blocking acid production with another drug, one can reduce the risk.
But, ginger can actually improve stomach lining protection. So, ginger, at the kinds of doses used to treat osteoarthritis, a quarter to a half-teaspoon a day, can be considered not just neutral on the stomach, but beneficial. So, it can be as pain-relieving as ibuprofen, but without the risk of stomach ulcers.
Okay. But, this sounded a little nutty to me—topical ginger treatment, as in externally applying a ginger-soaked cloth or patch to the affected joint. It was a controlled study—compress versus patch—both showing remarkable and lasting pain relief for osteoarthritis sufferers.
But, what’s missing? Right, a control group—there was no placebo patch. I don’t care if “ginger has been applied externally to painful joints for a thousand years.” The placebo effect has been shown to be remarkably effective in osteoarthritis to provide pain relief. So, until there’s a controlled study on topical ginger, I’m not going to believe it. But there wasn’t such a study, until twenty men stuck ginger slices onto their scrotum.
Men with inflamed testicles applied six to ten paper-thin slices of ginger over the affected testes. And, evidently, the ginger group healed nearly three times faster. Unfortunately, the original source is in Chinese; so, I can’t get further details, as is the only other controlled study on topical ginger I could find. This evidently translates to “evaluation of point plaster therapy with ginger powder in preventing nausea and vomiting during chemotherapy.”
We know ginger powder, taken orally, can be “a miracle against chemo-induced vomiting;” what about stuffing it into your belly button? The external application of ginger powder to the so-called “point of Shenque,” which is the navel, while the control group got potato powder into their belly button. And, lo and behold, the ginger group evidently had significantly less nausea and vomiting.
Unfortunately, only the abstract is in English; so, I can’t tell how they effectively blinded the patients to the treatment. I mean, presumably, it would be easy to tell whether or not you were in the ginger or placebo group just by the smell. But, maybe they controlled for that. Until we know more, I would suggest those who want to try ginger use it in their stomach, rather than on their stomach.
Finally today we have a randomized controlled study of the benefits of topical cabbage leaves for osteoarthritis. And no, I am not making that up.
In a section of the British Medical Journal called Minerva, where they compile interesting little snippets, they published a picture of a woman who they found had taped a cabbage leaf to her knee. She said that this was the only measure that provided relief from the symptoms of her osteoarthritis. Some doctors responded with bemusement; others were “like, duh”—amazed to see the photograph, not because “a cabbage leaf was used, but that this was considered newsworthy.” The doctor disclosed she may be a little biased, though, as she admits to being a cabbage leaf user herself.
“There is nothing new about this ancient remedy,” wrote another reader, “used to help reduce all kinds of painful swelling.” “Freshly washed cabbage leaves are known in European folk medicine as the poor man’s poultice.” “So there is nothing freakish or stupid about” putting cabbage leaves on your knees! Okay. I didn’t realize it was such a touchy topic.
Of course, we’ll never really know if it actually works. There’s never been a randomized controlled trial of “topical cabbage leaves for osteoarthritis,” and there never will be…until now:
“Efficacy of Cabbage Leaf Wraps in the Treatment of Symptomatic Osteoarthritis of the Knee: A Randomized Controlled Trial.” Wait, how did this study even get funded? A family foundation just stepped forward and paid for it. I love that. In fact, it’s the former president and first lady of Germany’s foundation. After all, “osteoarthritis of the knee is one of the most common chronic diseases among older adults.” So, let’s “test the effects of cabbage leaf wraps.” Why not?
Patients with confirmed osteoarthritis of the knees were randomly assigned to four weeks of treatment with a cabbage leaf on their knees every day, or a topical pain gel containing an anti-inflammatory drug, or neither. Even better would have been a fourth group applying like iceberg lettuce leaves, but I’ll take what I can get.
Here’s a graph of pain intensity over the 28-day experiment. Here’s how the drug worked: not much better than doing nothing. But, the cabbage worked better. Overall, the study “found that a 4-week application of cabbage leaves was more effective than usual care with respect to pain, functional disability, and quality of life. It was, however, not in the final analysis superior to a 4-week application of topical medication.” But, hey, cabbage leaves are safe, “can be used in the longer term.” So, why not give them a try?
It also wouldn’t hurt if you ate some as well, as cabbage may have internal anti-inflammatory potential as well. The anti-inflammatory effects may explain the health benefits of cabbage family vegetables. Not just potent anti-inflammatory effects in petri dishes, but in people. Ten days of broccoli consumption in smokers cut CRP levels 40%! Okay, but what about for arthritis?
In vitro, sulforaphane, the magic cabbage chemical, “protects cartilage from destruction,” suggesting that a high-cabbage or broccoli family vegetable diet “may be a useful measure either to prevent or to slow the progression of osteoarthritis.” But, even if sulforaphane can protect cartilage cells in a petri dish, how do we even know the compound makes it into the joint when we eat it? I mean, no one’s ever done a study where you like have people eat broccoli, and then stick a needle in their knee joint to check. No one, that is… until now.
And, sulforaphane was indeed detected in the synovial fluid of 40 patients with osteoarthritis “following broccoli consumption,” followed by significant epigenetic changes of gene expression within the joint. The next step is to see if it can actually improve the disease.
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