Full Transcript Introduction to NutritionFacts and LDL Cholesterol 0:00 Doesn't it seem like when it comes to nutrition, there are more opinions than 0:04 facts to go around? Every day we hear new [music] theories 0:08 about diets and supplements and best foods to eat. Well, my role is to take 0:13 the mystery out of good nutrition and look at the science. Welcome to the 0:18 NutritionFacts podcast. I'm your host, Dr. [music] Michael Greger. 0:22 Today we take a deep dive on lowering cholesterol, LDL cholesterol, through 0:26 diet, um 0:28 which was turned down [music] into a book that 0:32 came out last October, I believe. And we start with a story from our former 0:37 senior research scientist, Dr. Christine Dennis. 0:41 Of the top 10 take-home messages for the primary prevention of cardiovascular 0:45 disease, take-home number nine is that 0:47 cholesterol-lowering statin drugs are considered the first-choice drug 0:50 treatment for preventing heart disease in those with sufficiently elevated LDL 0:54 cholesterol. Though side effects, like muscle pain or 0:58 weakness, may impact up to a quarter of users. Regardless whether you and your 1:02 doctor decide to start drugs, the number one take-home message is that the most 1:06 important way to prevent heart disease, the number one killer of men and women, 1:11 is to promote a healthy lifestyle throughout life. Enter the portfolio 1:15 diet for the maximal reduction of LDL cholesterol. There are three main added 1:19 factors in our diet that raise LDL cholesterol: trans fat, saturated fat, 1:24 and dietary cholesterol. Therefore, the tolerable upper intake 1:28 levels of these three factors are essentially zero, since any intake above 1:32 zero increases LDL cholesterol concentration and therefore increases
What the Portfolio Diet Includes 1:36 risk of coronary heart disease. So, trans fat, saturated fat, and 1:40 cholesterol intake should be as low as possible. 1:43 That means cutting back as much as possible on meat, dairy, eggs, and junk. 1:49 And since partially hydrogenated oils must be removed from the US food supply 1:52 by law, all these other uses have been banned. 1:56 So, animal products are now the leading source of trans fat in the US diet, as 2:00 well. Those eating a Western diet have 2:03 circulating LDL levels around 120 mg per deciliter. 2:07 No surprise then, those eating plant-based tend to have lower LDL, with 2:12 lower levels the longer they have been eating a whole foods plant-based diet. 2:15 As low as 70. But even though that's an excellent 2:19 number compared to most people, there really isn't a safe cutoff. When 2:23 it comes to LDL, the lower the longer the better, even if you're at low risk. 2:29 That's where the portfolio diet can come in. By eating a healthy plant-based 2:33 diet, you've already subtracted all the major foods that increase your 2:36 cholesterol. The portfolio diet is a plant-based diet 2:40 with a bonus, a portfolio of foods. Four food types you can add to your diet to 2:46 pull cholesterol out of your system. The food components include 1 and 1/2 oz 2:51 of nuts a day, good sources of plant protein, in other words, legumes like 2:55 soy, other beans, split peas, chickpeas, or lentils, 2:59 lots of food with viscous fiber. That's the kind of slimy fiber found in oats, 3:02 okra, eggplant, barley, and ground flax seeds. And finally, 2 g a day of plant 3:07 sterols from fortified foods or supplements. 3:09 Dr. Greger's going to take a deep dive into phytosterols, but first, let's just 3:13 see what this diet can do. The portfolio diet was tested head-to-head against 3:16 statin treatment plus a very low saturated fat diet in a 4-week 3:20 randomized controlled trial among people with high cholesterol. 3:23 And incredibly, those in the portfolio diet group had nearly a 30% drop in LDL 3:28 cholesterol, similar to the 33% drop observed in the statins plus low 3:33 saturated fat group. Simply by emphasizing the addition of 3:37 four dietary components that are each likely to contribute 4 to 7% to overall 3:43 cholesterol reduction, you have a diet that reduces LDL 3:46 cholesterol with drug-like potency. In a systematic review and meta-analysis
Portfolio Diet Results and Sample Foods 3:52 of controlled trials of the portfolio diet, we still see consistent LDL 3:56 lowering benefits, about a 17% drop above and beyond the currently 4:00 recommended relatively strict National Cholesterol Education Program Step Two 4:04 diet, along with lowering of systemic 4:07 inflammation and an estimated 13% decrease in 10-year heart disease risk. 4:13 And these results weren't even in individuals who all actually went on a 4:16 portfolio diet. They were merely told to eat that way. 4:20 Even just two educational sessions over 6 months telling people to adopt it can 4:24 have a significant effect. I mentioned the four food components, but what does 4:28 a sample menu look like? Nuts for snacks, soy foods and beans for plant 4:32 protein, oats, barley, okra, eggplant, Metamucil, 4:35 and oranges for soluble fiber. They were using plant sterol fortified margarine, 4:40 like Benecol and Promise Active, formerly known as Take Control. 4:45 Yes, they have added plant sterols, but they're also chock-full of salt, 4:49 saturated fat, and artificial flavors. I mean, if you're going to use some sort 4:54 of spread, this would be better than non-sterol fortified margarine or 4:57 butter, but seems like a strange way to prevent 4:59 heart disease. Plant sterols are naturally concentrated 5:03 in sesame seeds and wheat germ, and also found in a variety of grains and 5:06 legumes. To get that recommended 2 or 3 g a day 5:10 though, you may have to take plant sterol supplements. 5:14 In fact, should we all be doing that? That's what Dr. Greger will tackle next, 5:19 and then see if there's any other cholesterol-lowering supplements that 5:21 might be worth taking. Finally, what about all the other foods 5:25 that lower cholesterol? What about expanding our portfolio to 5:29 make some kind of portfolio plus diet with as many different 5:33 cholesterol-lowering foods and herbs and spices as we can? 5:36 Again, not as a replacement for drugs, but as a way to drive our LDL as low as 5:42 possible with our fridge and pantry in addition to anything we might have in 5:47 our medicine cabinet. Did you know that even if we eat little
How Phytosterols Block Cholesterol Absorption 5:51 or no cholesterol, phytosterols can block the reabsorption of the excess 5:56 cholesterol our liver dumps into our intestines? 5:59 Here's our next story. The dietary guidelines cite the National 6:03 Academies in recommending that dietary cholesterol consumption be as low as 6:08 possible. While eggs are the most concentrated 6:11 source of cholesterol gram for gram, the greatest contribution to the American 6:15 diet is meat, including poultry and fish. 6:18 But even if our cholesterol intake is zero, our liver dumps excess cholesterol 6:24 into our digestive tract through the bile, 6:27 expecting there to be about a hundred grams of fiber in there every day to 6:32 trap and flush it out of the body. But when people are getting five to ten 6:38 times less fiber than nature intended, much of that cholesterol gets reabsorbed 6:43 and can circulate back through our system. That's why one of the components 6:48 of the cholesterol-lowering portfolio diet are foods like oatmeal that are 6:52 high in sticky fiber that traps cholesterol. But the diet also includes 6:57 phytosterols, plant sterols. It's almost identical, and the receptor in the 7:04 lining of our intestines can't tell the difference. So, the phytosterols compete 7:09 with cholesterol to squeeze in through this receptor. So, if there's lots of 7:13 phytosterols in the gut, some of the cholesterol can't get in or back in and 7:18 ends up in the toilet instead of our bloodstream. 7:22 With more and more phytosterol consumption, more and more cholesterol 7:25 is being flushed out of the body. Now, even if you eat a strictly 7:30 plant-based diet without any dietary cholesterol, you'd still be getting rid 7:35 of more cholesterol by eating more phytosterol. 7:39 Unfortunately, like fiber intake, plant sterol intake is way down in modern 7:44 diets. We probably evolved getting about a thousand milligrams a day, but these 7:48 days, we may only be getting about 300 mg a day, though those eating more plant 7:53 foods may be getting twice that. Little bits are found throughout the 7:57 plant kingdom in vegetables, grains, legumes, and fruits, but the highest 8:01 whole food sources tend to be nuts and seeds. Phytosterols may help explain the 8:06 cholesterol-lowering effects of nuts, but nuts are already a part of the 8:10 portfolio diet. Why add phytosterols, too? 8:14 Well, people may only be getting a few hundred milligrams a day from nuts. 8:19 It turns out there's a continuous dose-response relationship between 8:23 phytosterol intake and LDL cholesterol lowering. Yeah, going from very few 8:28 plant foods to lots of plant foods can draw more cholesterol out of the body, 8:32 but 2 g a day can draw [clears throat] out even more, and that translates into 8:37 lower LDL cholesterol in the blood. So, a really healthy diet is worth me drop 8:42 our LDL by about 6%, but 2 or 3 g a day can drop our LDL more like 10%, and that 8:49 alone could reduce our risk of heart disease by about 10% over a decade or 8:53 20% over a lifetime. That's why we see heart health 8:57 guidelines recommending the use of phytosterols as a supplementary strategy
Phytosterol Benefits, Limits, and Safety 9:02 alongside lifestyle modifications to decrease blood cholesterol levels. 9:07 Okay, so phytosterols are effective, but are they safe? I'll address that 9:13 next. 9:17 Despite the vast literature on phytosterols lowering blood cholesterol 9:20 levels, there's to date no study investigating the ultimate proof of 9:24 efficacy, the lowering of the incidence of coronary heart disease. 9:29 Uh this is probably the strongest argument against them. There are no 9:32 studies with hard endpoints to confirm that the drop in LDL cholesterol from 9:37 plant sterols translates to a drop in heart attacks. 9:41 The reason is that even if people start out with a 10-year cardiovascular 9:45 disease risk of 10%, you'd have to randomize about 30,000 people to 9:50 phytosterols for a decade to detect such an effect. And at a more reasonable 9:54 10-year risk of 5%, you might have to enroll more than 300,000. 10:00 Now, one could argue that the cholesterol-lowering is all we need to 10:03 know, since basically lowering LDL cholesterol by any means appears to 10:07 lower cardiovascular risk, whether by statins, other kinds of drugs, diet, or 10:13 surgery. However, there was a big trial of 10:17 extended-release niacin in a group of patients with LDLs starting down in the 10:22 low 60s, and researchers saw further 10-point drop after a few years that 10:26 should have dropped their risk by at least 5 or 6% but failed to offer a 10:31 statistically significant benefit in the end, so there's at least one example of 10:35 that line of argument failing. There is that ezetimibe that does have a 10:41 similar mechanism of action as phytosterols, that is, blocking 10:44 cholesterol absorption. It partially blocks the cholesterol absorption 10:48 receptor, so cholesterol absorption is reduced by about 50%. When it was put to 10:54 the test, it did indeed significantly improve cardiovascular outcomes. And the 10:59 13-point drop in LDL achieved by blocking cholesterol absorption with the 11:03 drug is almost the exact same drop in LDL we'd expect from blocking 11:07 cholesterol absorption with phytosterols based on more than a hundred randomized 11:12 controlled trials. Does blocking cholesterol absorption 11:16 work even if you don't eat any cholesterol? Yes, because the bulk of 11:20 the cholesterol flowing through our digestive tract is dumped there from our 11:24 liver's own production. It also works for those on statin drugs. 11:29 In fact, adding 2 g of phytosterols a day to your routine may be equivalent to 11:33 like quadrupling your statin dose. So, if you are going to try phytosterols 11:39 to lower your LDL level, what's the best dose? And what's the best source? 11:44 The recommended daily dosing is between 2 to 3 g a day based on dose-response 11:48 curves where the benefit appears to plateau at about those two or three 11:53 daily grams. There's a comparable benefit curve with plant stanols, which 11:58 are similar molecules. Plant sterols and stanols are absorbed better if taken 12:03 with meals because the maximum cholesterol load to the intestine occurs 12:07 after gallbladder contraction and delivery of cholesterol-rich bile to the 12:11 intestine. Indeed, the same dose of phytosterols 12:14 may have more than double the LDL-lowering effect when taken with 12:17 meals rather than between them on an empty stomach.
Choosing and Using Phytosterol Supplements 12:22 The full LDL cholesterol-lowering effect can be detected after just 2 weeks and 12:27 may last as long as you take them, but as soon as you stop, the 12:30 cholesterol-lowering effect will be lost within a week or two. 12:34 Phytosterols in those kinds of doses are available in supplements and in 12:38 fortified foods, which lower LDL equivalently. 12:42 As I talked about before, the margarines are total non-starters. 12:46 Are there any healthy phytosterol-fortified foods? 12:50 Not any that I could tell where I live. In Australia, there's a plant 12:55 sterol-fortified shredded wheat, but I don't know if you can get it anywhere 12:59 else. That leaves us with supplements. 13:03 So, it's good to have third-party certification of authenticity, though I 13:07 think there's only one USP-certified brand at the moment, but ConsumerLab 13:13 also tested and approved three others. They're also pretty expensive, so I was 13:17 excited to see that you can get it in bulk, and you could presumably just 13:21 sprinkle a bit on your food, but that presumption may be wrong. As a 13:26 crystalline powder, the free phytosterols are much less efficient at 13:30 inhibiting cholesterol. That's why the initial studies a half 13:33 century ago were using doses of like 10 to 20 g a day. 13:39 Then researchers figured out how to make them more soluble by making fatty 13:43 phytosterol esters, which is what you see in the capsules. There are studies 13:48 suggesting that free sterols block cholesterol absorption as much as 13:51 esterified sterols, but they included equal parts of an emulsifier to improve 13:56 absorption. A study showing free sterols could lower 13:59 LDL similarly relied on some proprietary means for solubilizing it. 14:06 Just for fun, I tried taking the bulk powder for a month, and indeed, sadly, 14:10 saw a zero effect, whereas I got a nice 17-point drop in LDL taking the exact 14:15 same dose in encapsulated ester form. Normally, I'm not a big fan of lab 14:21 tests, but if you do start phytosterol supplements, I would get your 14:26 cholesterol tested before and after a month or so on them. You should be able 14:31 to get your cholesterol tested for free through your doctor, but these days, you 14:35 can get your cholesterol tested at low cost or free even without insurance or a 14:39 doctor visit. While some individuals respond immediately and get a major 14:43 shift in lipid profiles, others are more resistant or even completely insensitive 14:48 to plant sterols or do even worse. Just because the average response is around a 14:55 10% drop in LDL cholesterol, maybe you'll be lucky and respond even better. 15:00 These are all individual patients, and this first person saw a 38% drop. 15:05 But it's also possible you won't respond as well, or your cholesterol may 15:11 actually go up. That unfortunate person at the end had a 33% increase in LDL, so
Closing Remarks and Resources 15:16 even though the average effect is good, you want [music] to make sure it's 15:20 actually working for you. Visit nutritionfacts.org/audio 15:25 to see all the podcast episodes with descriptions that include links to the 15:29 associated videos. Sources cited and other details are 15:32 available on each video's page. Information about my books, How Not to 15:36 Die, How Not to Diet, and How Not to Age, is at nutritionfacts.org/books. 15:41 All proceeds [music] which I get are donated directly to charity, and I've 15:46 got a new book in the publication pipeline, the manuscript for How Not to 15:51 Hurt on diet and lifestyle approaches to pain 15:54 management. It's been handed in and will be published December 15th. 15:58 >> [music] >> I'm going to be doing a series of 16:00 webinars to feature some of the new research I discovered. Sign up for our 16:03 free newsletter at nutritionfacts.org/subscribe 16:08 to stay updated on when those will be. Nutritionfacts.org is a science-based 16:14 nonprofit, and everything on the website is free. There are no ads, no corporate 16:18 sponsorships, no kickbacks. We're strictly noncommercial, not selling 16:21 anything, just put up as a public service as a labor of love as a tribute 16:26 to my grandmother, whose own life was saved with 16:28 evidence-based nutrition. We just have like a 16:31 a Wikipedia-type nonprofit model where everything's free, and we just hope 16:35 maybe, >> [music] 16:36 >> you know, one in a thousand people will find it so valuable that they'll kick in 16:39 a few bucks so we can continue to churn out new content to help you and your 16:44 family be healthier. Thanks for listening.
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