artery function Archives - Amazing Health Advances

Flavonoid Benefits from Apple Peels

The AHA! Team — Tue, 23 Jul 2024 08:28:19 +0000

Michael Greger M.D. FACLM via Nutrition Facts – Peeled apples are pitted head-to-head against unpeeled apples (and spinach) in a test of artery function. Regularly eating apples may contribute to a lower risk of dying prematurely. “Moderate apple consumption,” meaning one or two apples a week, “was associated with a 20% lower risk of all-cause mortality”—that is, dying from all causes put together—“whereas those who ate an apple a day had a 35% lower risk of all-cause mortality compared with women with low apple consumption.” You’ll often hear me talking about a lower or higher risk of mortality, but what does that mean? Isn’t the risk of dying 100 percent for everyone, eventually? As you can see in my graph below and at 0:40 in my video Friday Favorites: For Flavonoid Benefits, Don’t Peel Apples, I present some survival curves to help you visualize these concepts. For example, if you follow thousands of older women over time, nearly half succumb over a period of 15 years, but that half includes those who rarely, if ever, ate apples—less than 20 apples a year. Those who ate one small apple or about a quarter of a large apple a day survived even longer Instead, those averaging more like half a small apple a day lived longer; over the same time period, closer to 40 percent or so of them died. And those who ate one small apple or about a quarter of a large apple a day survived even longer. Why is that the case? It seems to be less the apple of one’s eye than the apple of one’s arteries. Even a fraction of an apple a day is associated with 24 percent lower odds of having severe major artery calcifications, a marker of vascular disease. You may think that’s an obvious benefit since apples are fruits and fruits are healthy, but the effect was not found for pears, oranges, or bananas. Both of these studies were done on women, but a similar effect (with apples and onions) was found for men. We think it’s because of the flavonoids, naturally occurring phytonutrients concentrated in apples. As you can see below and at 2:02 in my video, they’re thought to improve artery function and lower blood pressure, leading to improvements in blood flow throughout the body and brain, thereby decreasing the risk of heart disease and strokes. You don’t know, though, until you put it to the test. When I first saw a paper on testing flavonoid-rich apples, I assumed they had selectively bred or genetically engineered a special apple. But, no. The high-flavonoid apple was just an apple with its peel, compared to the low-flavonoid apple, which was the exact same apple with its peel removed. After eating the apples, flavonoid levels in the bloodstream shot up over the next three hours in the unpeeled apple group, compared to the peeled group, as you can see below, and at 2:36 in my video. This coincided with significantly improved artery function in the unpeeled apple group compared to the peeled one. The researchers concluded that “the lower risk of CVD [cardiovascular disease] with higher apple consumption is most likely due to the high concentration of ﬂavonoids in the skin which improve endothelial [arterial] function”—though, it could be anything in the peel. All we know is that apple peels are particularly good for us, improving artery function and lowering blood pressure. Even compared to spinach? As you can see in the graph below and at 3:14 in my video, if you give someone about three-quarters of a cup of cooked spinach, their blood pressure drops within two to three hours. If you instead eat an apple with some extra peel thrown in, you get a similar effect. The researchers concluded that apples and spinach almost immediately improve artery function and lower blood pressure. Researchers concluded that apples and spinach almost immediately improve artery function and lower blood pressure What’s nice about these results is that we’re talking about whole foods, not some supplement or extract. So, easily, “this could be translated into a natural and low-cost method of reducing the cardiovascular risk profile of the general population.” For more about apples, see the topic page and check out the related videos below. What about dried apples? See Dried Apples vs. Cholesterol. What about apple cider vinegar? Check out Flashback Friday: Does Apple Cider Vinegar Help with Weight Loss?. And what about apples going head-to-head with açai berries? See The Antioxidant Effects of Açai vs. Apples. Key Takeaways Women eating one apple a day had a 35 percent lower risk of dying from all causes (compared with women with low apple consumption) and a 20 percent lower risk after eating one or two apples a week. Women consuming even a fraction of a single apple a day had 24 percent lower odds of having severe major artery calcifications, a marker of vascular disease. This effect was not found for pears, oranges, or bananas. A similar effect was found for men eating apples and onions. It’s thought that the flavonoids, naturally occurring phytonutrients in apples, improve artery function and lower blood pressure, thereby decreasing heart disease and stroke risks. When testing flavonoid-rich apples, researchers compared the effects of eating apples with their peels on versus removed. Eating unpeeled apples resulted in higher flavonoid levels in the bloodstream and significantly improved artery function, compared to eating apples without their skins. Consuming spinach, like apples with their peels, almost immediately improves artery function and lowers blood pressure. To read the original article click here.

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Are Avocados Associated with Greater Risk or Reduced Risk of Cancer?

AHA Publisher — Tue, 25 May 2021 07:00:58 +0000

Michael Greger M.D. FACLM via Nutrition Facts – Avocado consumption can improve artery function, but what effect might guacamole have on cancer risk? In my last video about avocados, The Effects of Avocados and Red Wine on Meal-Induced Inflammation, I described their anti-inflammatory effects and cholesterol- and triglyceride-lowering effects, but what about the Are Avocados Good for You? video I did years ago about the chromosome-damaging effects in a petri dish? That goes back to 1975, when a pesticide naturally produced by the avocado tree was discovered, thought to explain why lactating livestock suffer mammary gland damage after nibbling on the leaves. The toxin, named persin, was also found to be damaging to the heart, which is why you should never feed avocado to your pet birds. But, if persin attacks mammary cells in animals, might it attack breast cancer cells in humans? As you can see at 0:52 in my video Are Avocados Healthy?, it did seem to have the same kind of cellular cytoskeleton-clumping effect in vitro that chemotherapy can have, demonstrating potent cell growth stopping and killing effects of the novel plant toxin among various lines of human breast cancer cells. So, researchers are thinking about how it might one day be used as chemo itself, but I’m thinking, Holy guacamole, Batman! Please tell me it doesn’t have toxic effects on normal cells, too. We got an answer in 2010 with an evaluation of the genotoxicity—the toxicity to our chromosomes—of avocado extracts on human white blood cells in a petri dish. As you can see at 1:35 in my video, normally, less than 10 percent of our dividing cells have any chromosome abnormalities, but if you drip some avocado fruit extracts on them, up to half come out defective in some way. The researchers concluded that there’s something in avocado fruit that “can potentially induce significant genomic instability and some genetic damage in human lymphocytes in vitro,” that is, in white blood cells in a petri dish. If the same effect occurs in actual people, it could, for example, result in transforming cells into cancer. That is a big if, though. These were blood cells. You don’t inject guacamole into the vein. For something to get into our bloodstream, it first has to survive our stomach acid, get absorbed through our intestines, and then sneak past our liver’s detoxification enzymes. And indeed, persin may be affected, changed by acidic conditions. So, given all the differences between what happens in a petri dish and inside a person, it’s essential to carry out further studies “before making a final remark on the genotoxicity.” Sounds reasonable, but what do you do before these studies come out? I was concerned enough that I provisionally moved avocados from being a don’t-hold-back green-light food to a moderate-your-intake yellow-light food to err on the side of caution until we knew more. Even if persin were utterly destroyed by stomach acid, what about oral cancer? As you can see at 3:01 in my video, avocado extracts at high enough concentrations can harm the growth of the kinds of cells that line our mouths. This was in a petri dish, though, where the avocado is coming in direct contact with the cells—but that’s also kind of what happens in your mouth when you eat it. However, it harms oral cancer cells even more. At 3:32 in my video, you can see a bunch of oral cancer cells. In the first image, the mitochondria, the power plants of the cells fueling cancer growth, are seen in red. In the second image, you can see they’ve been extinguished by the avocado extract—no more red-colored mitochondria. Since it does this more to cancerous cells than normal cells, the researchers conclude that avocados may end up preventing cancer. What about the esophagus, which lies between the mouth and the stomach? Researchers similarly found that an avocado fruit extract appeared to inhibit cancer cell growth more than normal cell growth when it came to both colon cancer cells and esophageal cancer cells, as you can see at 3:53 in my video. But, rather than comparing the effects to normal colon and esophagus cells, they compared them to a type of blood cell, which, again, is of limited relevance in a petri dish study of something you eat. A study I found to be pretty exciting looked at p-cresol, which is a “uremic toxin” and may also be toxic to the liver. “Found to be associated with autism,” it comes from eating high-protein diets, whereas if you eat a more plant-based diet, which is the only source of prebiotics like fiber and resistant starch, your levels go down. See, fermentation of carbohydrates in the colon, like fiber, is considered beneficial, whereas fermentation of protein, which is called putrefaction, is considered detrimental. So, if you switch people to a high-protein diet, within days, the excess protein putrefying in their gut leads to an increase in ammonia as well as p-cresol—in fact, a doubling of levels within a week. But, might phytonutrient-rich plant foods, like apples, cranberries, grapes, or avocados, protect the cells lining our colon “from the deleterious effects of p-cresol…in terms of cell viability, mitochondrial function, and epithelial integrity,” meaning protection against gut leakiness? At 5:12 in my video, I show the data on barrier function integrity. You can see that it is damaged by p-cresol, but rescued by all the cranberry, avocado, grape, and apple extracts. Mitochondrial function, however, was only improved by the cranberries and avocados, which also were the only ones that appeared to prevent the deleterious effect of p-cresol on colon cell viability. The bottom line, though, is that avocados appear to have beneficial effects on colon lining cells. Okay, but enough of these in vitro studies, already. Yes, an avocado extract can inhibitcancer cell growth in a petri dish, but unless you’re doing some unspeakable things to that avocado—like guacamole with benefits—there’s no way that avocado is going to come in direct contact with your prostate cells. So, what does this study mean? This is why I was so excited to see the first study to actually look for a link between avocado consumption and prostate cancer. Actual human beings eating avocados! So, do avocado eaters have more cancer risk or less cancer risk? Men who ate the most avocado, more than about a third of an avocado a day, had reduced risk of prostate cancer—in fact, less than half the odds. So, with the data on improved artery function, lower cholesterol, and, if anything, an association with decreased cancer risk, I’d suggest moving avocados back up with the other green-light foods. To read the original article click here. For more articles from Dr. Greger click here.

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Improve Artery Function by Lowering Your Sodium-to-Potassium Ratio

AHA Publisher — Fri, 21 Aug 2020 07:00:01 +0000

Michael Greger M.D. FACLM via Nutrition Facts – The potassium content in greens is one of two ways they can improve artery function within minutes of consumption. More than a thousand years ago, for the treatment of hypertension, an ancient Persian medical text advised lifestyle interventions, such as avoiding meat and pastries, and recommended eating spinach. A thousand years later, researchers discovered that a single meal containing spinach could indeed reduce blood pressure, thanks to its nitrate content. All green leafy vegetables are packed with nitrate, which our body can use to create nitric oxide that improves the flexibility and function of our arteries. This may be why eating our greens may be one of the most powerful things we can do to reduce our chronic disease risk. As you can see at 0:54 in my video Lowering Our Sodium-to-Potassium Ratio to Reduce Stroke Risk, just switching from low-nitrate vegetables to high-nitrate vegetables for a week can lower blood pressure by about 4 points, and the higher the blood pressure people started out with, the greater benefit they got. Four points might not sound like a lot, but even a 2-point drop in blood pressure could prevent more than 10,000 fatal strokes every year in the United States. Potassium-rich foods may also act via a similar mechanism. If we get even just the minimum recommended daily intake of potassium, we might prevent 150,000 strokes every year. Why? Potassium appears to increase the release of nitric oxide. One week of eating two bananas and a large baked potato every day significantly improved arterial function. Even a single high-potassium meal, containing the equivalent of two to three bananas’ worth of potassium, can improve the function of our arteries, whereas a high-sodium meal—that is, a meal with the amount of salt most people eat—can impairarterial function within 30 minutes. While potassium increases nitric oxide release, sodium reduces nitric oxide release. So, the health of our arteries may be determined by our sodium-to-potassium ratio. As you can see at 2:30 in my video, after two bacon slices’ worth of sodium, our arteries take a significant hit within 30 minutes. However, if you add three bananas’ worth of potassium, you can counteract the effects of the sodium. As I show at 2:48 in my video, when we evolved, we were eating ten times more potassium than sodium. Now, the ratio is reversed, as we consume more sodium than potassium. These kinds of studies “provide additional evidence that increases in dietary potassium should be encouraged,” but what does that mean? We should eat more beans, sweet potatoes, and leafy greens, the latter of which is like giving you a double whammy, as they are high in potassium and nitrates. The recommendation from a thousand years ago to eat spinach is pretty impressive, though bloodletting and abstaining from sex were also encouraged, so we should probably take ancient wisdom with a grain of salt—but our meals should be added-salt free. This article has been modified. To read the original article click here. For more articles from Dr. Greger click here.

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