I’m often asked my opinion about a diet or a disease is. Who cares what my or anyone else’s opinion is? All we should care about is what the science says. What does the best available balance of evidence published in the peer-reviewed medical literature have to say right now?
Welcome to the NutritionFacts Podcast – I’m your host Dr. Michael Greger.
Our story today is about an alternative approach to some of the health problems that bother us. And we start with the unusual powers – of garden variety lettuce.
There is a perception that time spent asleep is time wasted, but it is widely recognized that inadequate sleep is associated with multiple acute and chronic conditions and results in the increased risk of death and disease. Force people to go one week with only six hours of sleep a night, and you can change expression of more than 700 genes. The most dire effect may be endothelial dysfunction. The endothelium is the thin layer of cells that covers the internal surface of blood vessels and is responsible for allowing our arteries to relax and dilate back open properly. Randomize people for about a week to get five rather than seven hours of sleep, and just that two-hour difference a night resulted in a signiﬁcant impairment in artery function.
Okay, but what do these numbers mean. How bad is a week of 5-hour nights? Sleep deprivation is no joke. The magnitude of impairment is similar to that reported in people who smoke, have diabetes, or have coronary artery disease. No wonder people who sleep less than seven hours a night may experience a 12 percent to 35 percent increased risk of premature death, compared to those who get a full seven hours. Yet a significant portion of the population may routinely get less than that. Sufﬁciently long, restful sleep sessions each night are said to be an indisputable cornerstone of good health. Okay, so what can we do about it?
Those who have sleep apnea, a common consequence of obesity that interferes with sleep, benefit from the use of CPAP machines while they’re losing the weight to treat the underlying cause, hopefully. But what if apnea isn’t your problem? What if you just have trouble falling asleep or staying asleep? Any natural dietary remedies?
I already have videos on using kiwifruit to fight insomnia and tart cherries, too. Are there any vegetables that might help? Lactuca sativa is a plant that has traditionally been used in the treatment of insomnia. What is this exotic-sounding leafy vegetable? Lettuce! Evidently, lettuce extracts have been used from the time of the Roman Empire as agents with sedative and sleep-inducing properties. Lettuce actually does have a hypnotic substance in it called lactucin, which is what makes lettuce taste a little bitter. But you don’t know if it actually works, until you put it to the test. And it works!…in toads. But it also works, in rodents. Sleep in both mice and rats is enhanced by romaine lettuce. They used romaine, since it has a higher lactucin content compared to other lettuces.
Okay, but does it actually work in people? About 10 years ago, a study was published in which insomnia sufferers were randomized to receive lettuce seed oil, oil extracted from lettuce seeds. Within a week, about 70 percent of those in the lettuce seed oil group said their insomnia very much or much improved, compared to just 20 percent in the placebo control group. The researchers conclude that lettuce seed oil was found to be a useful, safe sleeping aid in geriatric patients suffering from sleeping difficulties. They chose to study older individuals because insomnia affects surprisingly approximately 20 to 40 percent of older adults, at least a few nights a month.
You think that’s bad. Sleep disturbances can plague as many as nearly 8 out of 10 women during pregnancy. Of course, there are lots of different sleeping pills, but they may endanger the fetus or mother. For example, doctors frequently prescribe Ambien for pregnant women who have trouble sleeping, but Ambien use is associated with a wide range of adverse pregnancy outcomes, like low birthweight babies, premature birth, and Caesarean section. And the use of valium during pregnancy has been linked to birth defects, including limb deﬁciencies. There has to be a better way. What about trying lettuce?
The lettuce seed oil study had a number of limitations. For example, it was only single-blind––meaning the researchers knew who was on the lettuce supplements and who was on placebo, which could have introduced some bias. But the researchers essentially said, “Give us a break. Big pharma has billions to spend on research. No one wants to fund studies on lettuce.” Finally, we got a double-blind, placebo-controlled study, but this time on a whole food, not just some lettuce seed extract. Yeah, but how do you come up with a placebo lettuce? How are you going hide who gets lettuce and who doesn’t? Well you can’t fit a head of lettuce into a capsule, but you can fit whole lettuce seeds. And here we go, a double-blind randomized placebo-controlled trial on lettuce seeds for pregnancy-related insomnia. A hundred pregnant women with insomnia were randomized to receive capsules containing either a quarter teaspoon of ground lettuce seeds or a placebo for two weeks, and those on the lettuce seeds saw a significant improvement in a sleep quality index score compared to placebo, with no reported side eﬀects.
In our final story today – we look at how cranberries and pumpkin seeds can help with an enlarged prostate.
More than 50 percent of men in their 50s and 70 percent or more of men in their 60s suffer from benign prostatic hypertrophy or BPH––otherwise known as enlarged prostate. This can result in burdensome lower urinary tract symptoms, such as having to get up frequently at night to pee. Current medical treatments are clinically effective, but their efficacy is compromised by side effects and low compliance rates. Symptoms include sexual dysfunction, high-grade prostate cancer, and depression. No wonder there’s poor compliance. And when medication treatment fails, surgical procedures are considered, such as transurethral resection of the prostate. There has got to be a better way.
Population studies suggest that low intake of animal protein and high intake of fruits and vegetables may be protective, but not just cutting down on any animal protein. Eggs and poultry seem to be the worst, along with refined grains, but no association was found for red meat or dairy. Population studies aside, are there any foods that have been put to the test? There have been more than 30 randomized controlled trials on the herb saw palmetto. And it’s been found to be…totally useless.
Evidently, cranberries were used by Native Americans to treat urinary ailments, but you don’t know, until you put ‘em to the test. Now, when they say dried cranberries, they’re not talking about those sugary oily “craisins,” but rather just straight, whole cranberry powder. And significant improvements were seen in BPH symptoms, quality of life, and all urination parameters for just about a teaspoon a day of powdered cranberries.
So, we know a teaspoon works, but what about a third of a teaspoon, or a sixth of a teaspoon? They also helped. The results from that one teaspoon of powdered cranberries from the last study would equate to this. Now, this study used a supplement, because it was funded by the company, but the supplement is just straight cranberry powder. So, you might as well buy it in bulk for much cheaper, and just add it to a smoothie or something.
What about a berry that’s a little tastier, like drinking purple grape juice? No benefit whatsoever.
In a previous video, I talked about the use of flax seeds, which may have a therapeutic efficacy comparable to that of commonly used drugs, with only good side effects. Okay, so what about other seeds? Pumpkin seeds have evidently been used in folk medicine as a remedy for prostate disorders for centuries, and in a petri dish, they can cut the growth of BPH prostate cells in half. Scientists have also injected pumpkin seed extracts into rabbits. But what about people?
Pumpkin seed oil appears to help with prostate issues. When pitted head-to-head against the drug Prazosin, it seemed to work as well as the pill. The same when it was head-to-head against the drug Terazosin. What they didn’t have, though, was a placebo group. It would have been nice to see how well the pumpkin seed oil supplement did against placebo. And hey, in an ideal world, I’d love to see another group actually just given whole pumpkin seeds themselves. And, boom—there it is. More than a thousand men were randomized to either a pumpkin seed extract, a placebo, or just about a tablespoon a day of plain pumpkin seeds.
The study was funded by the drug company that made the supplement, but the supplement flopped; it was no better than placebo. But the pumpkin seeds themselves worked. The supplement appeared to reduce symptoms, but not better than placebo. However, just the plain old seeds did. So, it wasn’t just some compound extracted from the oil. And, in fact, we’ve since learned that even an oil-free extract seemed to work. Bottom line, the researchers concluded, is that pumpkin seed could be recommended for BPH patients with mild-to-moderate symptoms. This conclusion was echoed by the European equivalent of the FDA. Pumpkin seeds can be used for the relief of lower urinary tract symptoms related to an enlarged prostate after more serious conditions have been excluded by a medical doctor.
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