Stream this Podcast episode:

Summary:

  • What is one KEY aspect that binds together all the “healthy” diets out there?
  • When you talk about Paleo, the Mediterranean Diet, or the diet of the “Blue Zones” (where people regularly live to over 100 years old), what are some fundamental parts of those diets that allow them to contribute so much to health?
  • One of the key aspects are called polyphenols, and they play some MAJOR roles in keeping us healthy.
  • We cover 6 ways that polyphenols contribute to lasting health in this episode.

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Full (Edited) Transcript:

In this video, we’re going to be discussing one of the key components that makes a diet healthy.

With all of the different fad diets going around right now, whether its keto, carnivore, vegan, or pescatarian, etc… people are confused about what actually makes a diet healthy? Can I just choose any one of these diets and they’ll all be healthy? That doesn’t really make sense…

What are the actual components of a diet that contributes to health?

What do people eat in areas where people routinely live to over 100 (i.e. the “Blue Zones”)?

Why does the Mediterranean Diet consistently get, over and over, positive health benefits? What is in that diet that actually makes it healthy?

In this video, we’re going to be breaking down one of the key components that actually makes a diet healthy: Polyphenols

If you’ve never heard of polyphenols before, it’s a very complicated sounding word, but it’s really just all the different “things” (compounds) in fruits, vegetables, legumes / beans / lentils, nuts, etc. that help give these foods their smell, color, and taste. Polyphenols are responsible for so many positive health benefits.

So if you look at a berry, polyphenols are responsible for what give that berry its color. If you look at nuts, polyphenols are responsible for giving that nut the smell and taste. All different whole foods contain their own unique polyphenols.

(Keep in mind, when I am saying “polyphenols” here, I’m using it as an “umbrella term” to encompass all the various phytonutrients that are not classified as a vitamin or mineral: proanthocyanidins, catechins, tannins, carotenoids, etc.)

So let’s break down what polyphenols actually do and why they’re so important when constructing a diet!

1. Polyphenols are actually what make you healthy from whole foods

When you look at the various types of diets that have been shown to make people healthy, and when you hear nutritionists say “eat whole foods” and “eat unprocessed foods”, one of the main reasons why these are associated with health is due to the abundant amounts of polyphenols that you will consume.

When you take rye bread (or even wheat bread) and you refine it, mill it down, and reduce it to basic parts, you end up getting rid of a lot of the beneficial nutrients in that food, such as:

  • Magnesium
  • B-vitamins (synthetic and often less bioavailable versions are fortified back in)
  • and Polyphenols

This is one of the reasons why refined food / processed food / packaged foods are not going to be as healthy as whole, unrefined food.

When I say polyphenols are one of the things that make food healthy, I am meaning that quite literally.

Let’s take an apple for example.

When you look at what’s in an apple, you find it is over 95% water, a few percent of fiber, a few percent of sugar, and then a little bit of vitamins and minerals.

But if you took a glass of water and filled it over 95% with water, then put in some fiber, then put in some sugar, and then sprinkled in some vitamins and minerals, it would not have nearly the same health benefits that an apple would.

Because you’re missing a crucial ingredient.

You are missing the polyphenols.

Remember the polyphenols are what actually give the apple its color and taste. For an apple, they are mainly concentrated on the skin, which is one of the main reasons why the skin of the apple is more healthy than the inner part.

Polyphenols (and fiber) are what sets apart fruits as healthy compared to other sugar sources (candy, soda, clear juices, etc.).

So let’s talk about actually how polyphenols make you healthy:

2. Polyphenols are one of the best types of antioxidants you can get

When people think about antioxidants, they are usually thinking about vitamin C, vitamin E, etc. They are usually thinking about these “isolated” antioxidants.

The thing about antioxidant research is that when you look at the studies where researchers give large(r) doses of single antioxidants (such as vitamin C, vitamin E, beta-carotene, etc), they tend not to get the best results. Most of the time they get no results, but every once in a while they’ll actually get negative results.

For example, there was a study done where they gave high doses of isolated beta-carotene (one of the polyphenols / carotenoids in carrots and other orange vegetables that give them part of their color) to former smokers, they actually had an increased incidence of lung cancer compared to the group given placebo! (1)

However, a high consumption of vegetables containing beta-carotene has repeatedly been associated with a reduction in lung cancer. So why did this study get a negative result?

Because in whole foods, there are hundreds to thousands of different polyphenols, not just one.

The difference between isolated antioxidant and giving antioxidants from foods in the form of polyphenols is that with the antioxidants from food, you are getting a synchrony of antioxidants. You are not overloading your antioxidant system with just one chemical (which is NEVER found this way in nature / food).

You can think of antioxidants as similar to acids and bases.

Strong acids or strong bases are both bad for the body. You don’t want either one. What you need is a good “buffer” in the blood so that the blood pH stays in the middle where it should be.

Similarly with antioxidants, you don’t want oxidative stress, but you also don’t want “reductive stress” (TOO much antioxidant power). (2)

The polyphenols from foods act like this “buffer”. Because you are getting hundreds to thousands of “redox” compounds at once, they all can interact with each other and with the entire system to ensure that overall oxidation stays where it should, and doesn’t swing too far in one direction or the other.

Furthermore, large doses of single antioxidants can actually turn into pro-oxidants themselves! (3)

You’re much better off getting your antioxidants from food.

3. Polyphenols increase our OWN antioxidant system

When you take synthetic or isolated antioxidants in large amounts, they can actually reduce the antioxidants our body naturally creates (primarily glutathione, superoxide dismutase, and catalase).

The really cool thing about polyphenols is that they actually activate different genes in our body to increase our antioxidant defense system! (4, 5)

This is very similar to what exercise does.

When you exercise, one of the things that happens is that you body gets better at being able to make its own antioxidants to combat oxidative stress.

Now, I’m not saying polyphenols can be a replacement for exercise. You should get BOTH. But these things will help your body better combat inflammation and oxidative stress!

But, what *real*, tangible benefits will you get from having these antioxidative polyphenols floating around in your bloodstream?

4. Polyphenols can decrease high blood pressure and decrease the stiffness of the arteries

Most people have heard that if they have high blood pressure they should lower their salt intake and increase their potassium and water intake.

However, most people don’t know that high blood pressure is actually primarily a result of oxidative stress in the arteries (even if it comes from too much refined salt or potassium deficiency, the underlying reason is oxidative stress in the arteries, such that they can no longer dilate and expand like they should be able to because they are constantly being bombarded by “free radicals”.) (9)

By providing our body with a vast array of different types of antioxidants (what polyphenols are) and increasing the ability of our body to increase its own antioxidants (what polyphenols and exercise do), we can fight / reduce the damage that occurs in the arteries.

Multiple studies have shown that either supplementing with polyphenols or increasing polyphenols in the diet (by adding foods high in polyphenols) can decrease high blood pressure. (ref) (6, 7, 8)

Other studies have shown that providing diets containing higher levels of polyphenols can also reduce the stiffness in the arteries, even in perfectly healthy individuals!

For example, arterial stiffness significantly decreased in only TWO weeks when participants were given 7 oz of “purple potatoes” each day (these are regular potatoes, but purple in both the skin and interior). The group given white potatoes experience no change. The only difference was that the purple potatoes contained a good amount of polyphenols! (ref)

5. Polyphenols decrease lipogenesis (i.e. creating fat from carbs)

I’m going to go back to fruit to explain this one.

Many people are afraid of fruit becuase they’ve been told that sugar is bad for you, and fruits contain sugar, therefore fruits are bad for you.

However, they are getting the research mixed up.

All of the research that shows that sugar has negative health consequences is with respect to sugar from refined sources, such as soda, candy, table sugar, clear fruit juices, etc.

However, the research on fruit is very clear: whole fruit virtually without exception is associated with positive health benefits.

See my article on How Fruit is GOOD For You EVEN THOUGH It’s Filled With Sugar! (opens in new tab)

Now many people think: Well what’s the difference? Sugar is sugar, right? What’s the difference where it comes from?

Well now you know one big difference: polyphenols (the other big one is fiber)

When we eat too much sugar, our liver goes to work to start turning a lot of the sugar we ate to fat (in particular, a long-chain saturated fat most often, not good). We see this on our blood test as elevated triglyceride levels. (Yes, when triglyceride levels are high on a blood test, it is almost always from too much refined sugar / refined carbs in the diet [usually along with too many overall calories as well]).

However, polyphenols downregulate the enzymes that convert the sugar into fat in the liver.

This means that the polyphenols from fruit (along with the fiber) help to prevent the sugar from the fruit being turned into fat by the liver! (10, 11)

Due to similar reasons, polyphenols can also help prevent the increase in LDL (bad cholesterol) that can come from pure sugar.

In one study, researchers found that “clear” apple juice (i.e. polyphenols removed) increased the participants’ LDL levels, while “cloudy” apple juice (as well as apple pomace and whole apples) actually lowered their LDL levels. (12)

6. Polyphenols protect your brain

If you’ve ever heard that blueberries are good for your brain, now you know why: the polyphenols.

It’s not just blueberries but any type of berry or fruit that is loaded with polyphenols is going to have neuroprotective benefits. (13)

Thus, making sure you are eating berries / fruits, vegetables, nuts, legumes / beans, spices / herbs, etc. will help provide the polyphenols you need to protect your brain as you age.

The brain is very susceptible to oxidative stress because it contains a lot of polyunsaturated fat that is VERY easy to oxidize. (Omega 3s are polyunsaturated for example, and thus I store mine in the freezer because of how easy they are to oxidize when exposed to heat, light, or oxygen).

Polyphenols work in tandem with our own antioxidants to make sure that the fats and other components of the brain don’t get harmed by excess “free radicals”. (14)

Now you know a KEY component to a healthy diet! Make sure you focus on whole foods and a large variety of high-polyphenol-containing foods!

P.S. If you want more evidence-based health information LIKE THIS, then make sure you subscribe to my FREE weekly newsletter. (If on desktop, you can see the sign up on the right side of the page, if on mobile, it will be at the bottom!)

References:

  1. Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group. The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. N Engl J Med. 1994;330(15):1029-1035. doi:10.1056/NEJM199404143301501
  2. Pérez-Torres I, Guarner-Lans V, Rubio-Ruiz ME. Reductive Stress in Inflammation-Associated Diseases and the Pro-Oxidant Effect of Antioxidant Agents. Int J Mol Sci. 2017;18(10):2098. Published 2017 Oct 5. doi:10.3390/ijms18102098
  3. Sotler R, Poljšak B, Dahmane R, et al. PROOXIDANT ACTIVITIES OF ANTIOXIDANTS AND THEIR IMPACT ON HEALTH. Acta Clin Croat. 2019;58(4):726-736. doi:10.20471/acc.2019.58.04.20
  4. Rahman I. Dietary polyphenols mediated regulation of oxidative stress and chromatin remodeling in inflammation. Nutr Rev. 2008;66 Suppl 1(Suppl 1):S42-S45. doi:10.1111/j.1753-4887.2008.00067.x
  5. Martínez-Huélamo M, Rodríguez-Morató J, Boronat A, de la Torre R. Modulation of Nrf2 by Olive Oil and Wine Polyphenols and Neuroprotection. Antioxidants (Basel). 2017;6(4):73. Published 2017 Sep 26. doi:10.3390/antiox6040073
  6. Zhang H, Liu S, Li L, et al. The impact of grape seed extract treatment on blood pressure changes: A meta-analysis of 16 randomized controlled trials. Medicine (Baltimore). 2016;95(33):e4247. doi:10.1097/MD.0000000000004247
  7. Lockyer S, Rowland I, Spencer JPE, Yaqoob P, Stonehouse W. Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial. Eur J Nutr. 2017;56(4):1421-1432. doi:10.1007/s00394-016-1188-y
  8. Miranda AM, Steluti J, Fisberg RM, Marchioni DM. Association between Polyphenol Intake and Hypertension in Adults and Older Adults: A Population-Based Study in Brazil. PLoS One. 2016;11(10):e0165791. Published 2016 Oct 28. doi:10.1371/journal.pone.0165791
  9. Loperena R, Harrison DG. Oxidative Stress and Hypertensive Diseases. Med Clin North Am. 2017;101(1):169-193. doi:10.1016/j.mcna.2016.08.004
  10. Aguirre L, Portillo MP, Hijona E, Bujanda L. Effects of resveratrol and other polyphenols in hepatic steatosis. World J Gastroenterol. 2014;20(23):7366-7380. doi:10.3748/wjg.v20.i23.7366
  11. Kim JJ, Tan Y, Xiao L, Sun YL, Qu X. Green tea polyphenol epigallocatechin-3-gallate enhance glycogen synthesis and inhibit lipogenesis in hepatocytes. Biomed Res Int. 2013;2013:920128. doi:10.1155/2013/920128
  12. Ravn-Haren G, Dragsted LO, Buch-Andersen T, et al. Intake of whole apples or clear apple juice has contrasting effects on plasma lipids in healthy volunteers. Eur J Nutr. 2013;52(8):1875-1889. doi:10.1007/s00394-012-0489-z
  13. Silva RFM, Pogačnik L. Food, polyphenols and neuroprotection. Neural Regen Res. 2017;12(4):582-583. doi:10.4103/1673-5374.205096
  14. Bhullar KS, Rupasinghe HP. Polyphenols: multipotent therapeutic agents in neurodegenerative diseases. Oxid Med Cell Longev. 2013;2013:891748. doi:10.1155/2013/891748


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