Blueberries are put to the test against insulin resistance, oxidation, and DNA damage.
Blueberries for a Diabetic Diet and DNA Repair
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Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
A famous pair of Harvard studies, which involve so many people over so long a time they’ve by now chalked up millions of “person-years” of data, found that the consumption of “anthocyanin-rich foods”—foods containing those bright-colored plant pigments—was associated with a lower risk of developing type 2 diabetes over time, “particularly blueberries.” Just two or three servings a week associated with a 23 percent lower risk. In my Daily Dozen, I recommend berries every day.
Why, though? What do berries have to do with diabetes? Well, type 2 diabetes is caused by insulin resistance, and interventional studies evidently “clearly show” that dietary berries can “ameliorate… insulin resistance.” Yeah, but that was in… “diabetic mice.” What about in men and women? Those consuming lots of anthocyanin-rich foods, like berries, didn’t just have less inflammation, but significantly lower insulin resistance. Okay, but by how much? By as much as you would get walking like an hour a day, seven days a week. Wow, how many berries were they eating?
That was for 35mg of anthocyanins a day. So, like a cup of strawberries or cherries, a half a cup of raspberries, just a quarter cup of blackberries, or even just a few spoonfuls of blueberries. But that was just a snapshot-in-time cross-sectional study. What we need are interventional trials, where you give people blueberries in a double-blind, randomized, and placebo-controlled clinical trial to truly put them to the test.
Okay, here you go. So they could fake people out with a placebo, they used powdered blueberries—the equivalent of about two cups of fresh blueberries’-worth in a smoothie—and got a significant improvement in insulin sensitivity.
Two cups is a lot, though. Any benefits for just a typical half-cup serving? This study demonstrated a significant reduction in postprandial oxidation, meaning all the free radicals created when you eat some sugary breakfast, like corn flakes. Here’s the antioxidant capacity of your bloodstream taking a nosedive two hours afterwards, as your body tries to cope. But eat it with a half cup of blueberries, and you start out higher and stay higher after the meal. Note they also tried just adding a quarter cup of blueberries, and that was clearly not enough; so, we should strive for a full serving.
The reason we care about free radicals, though, is that they can damage our DNA. Can a single portion of blueberries really improve protection against DNA damage?: “A single portion of blueberry [can improve] protection against DNA damage”! They drew blood from people before and after they ate some frozen blueberries, and exposed their white blood cells to free radicals in the form of hydrogen peroxide. And, “[b]lueberries significantly reduced [the] DNA damage [done within a single] hour after berry consumption.” “However, the protective effect was transient, and [our DNA vulnerability] returned [within two hours].” So, we want to be eating super-healthy foods like berries at every meal. In conclusion, “one portion of blueberries can improve [our] cell[ular] resistance [to] DNA damage, “thus supporting the importance of consuming [healthy plant] foods regularly.”
Please consider volunteering to help out on the site.
- Fung TT, Hu FB, Yu J, et al. Leisure-time physical activity, television watching, and plasma biomarkers of obesity and cardiovascular disease risk. Am J Epidemiol. 2000;152(12):1171-1178.
- Wedick NM, Pan A, Cassidy A, et al. Dietary flavonoid intakes and risk of type 2 diabetes in US men and women. Am J Clin Nutr. 2012;95(4):925-933.
- Takikawa M, Inoue S, Horio F, Tsuda T. Dietary anthocyanin-rich bilberry extract ameliorates hyperglycemia and insulin sensitivity via activation of AMP-activated protein kinase in diabetic mice. J Nutr. 2010;140(3):527-533.
- Del Bó C, Riso P, Campolo J, et al. A single portion of blueberry (Vaccinium corymbosum L) improves protection against DNA damage but not vascular function in healthy male volunteers. Nutr Res. 2013;33(3):220-227.
- Blacker BC, Snyder SM, Eggett DL, Parker TL. Consumption of blueberries with a high-carbohydrate, low-fat breakfast decreases postprandial serum markers of oxidation. Br J Nutr. 2013;109(9):1670-1677.
- Jennings A, Welch AA, Spector T, Macgregor A, Cassidy A. Intakes of anthocyanins and flavones are associated with biomarkers of insulin resistance and inflammation in women. J Nutr. 2014;144(2):202-208.
- Stull AJ, Cash KC, Johnson WD, Champagne CM, Cefalu WT. Bioactives in blueberries improve insulin sensitivity in obese, insulin-resistant men and women. J Nutr. 2010;140(10):1764-1768.
- Cassidy A. Berry anthocyanin intake and cardiovascular health. Mol Aspects Med. 2018;61:76-82.
Image credit: Tookapic via Pexels. Image has been modified.
Motion graphics by Avocado Video
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
A famous pair of Harvard studies, which involve so many people over so long a time they’ve by now chalked up millions of “person-years” of data, found that the consumption of “anthocyanin-rich foods”—foods containing those bright-colored plant pigments—was associated with a lower risk of developing type 2 diabetes over time, “particularly blueberries.” Just two or three servings a week associated with a 23 percent lower risk. In my Daily Dozen, I recommend berries every day.
Why, though? What do berries have to do with diabetes? Well, type 2 diabetes is caused by insulin resistance, and interventional studies evidently “clearly show” that dietary berries can “ameliorate… insulin resistance.” Yeah, but that was in… “diabetic mice.” What about in men and women? Those consuming lots of anthocyanin-rich foods, like berries, didn’t just have less inflammation, but significantly lower insulin resistance. Okay, but by how much? By as much as you would get walking like an hour a day, seven days a week. Wow, how many berries were they eating?
That was for 35mg of anthocyanins a day. So, like a cup of strawberries or cherries, a half a cup of raspberries, just a quarter cup of blackberries, or even just a few spoonfuls of blueberries. But that was just a snapshot-in-time cross-sectional study. What we need are interventional trials, where you give people blueberries in a double-blind, randomized, and placebo-controlled clinical trial to truly put them to the test.
Okay, here you go. So they could fake people out with a placebo, they used powdered blueberries—the equivalent of about two cups of fresh blueberries’-worth in a smoothie—and got a significant improvement in insulin sensitivity.
Two cups is a lot, though. Any benefits for just a typical half-cup serving? This study demonstrated a significant reduction in postprandial oxidation, meaning all the free radicals created when you eat some sugary breakfast, like corn flakes. Here’s the antioxidant capacity of your bloodstream taking a nosedive two hours afterwards, as your body tries to cope. But eat it with a half cup of blueberries, and you start out higher and stay higher after the meal. Note they also tried just adding a quarter cup of blueberries, and that was clearly not enough; so, we should strive for a full serving.
The reason we care about free radicals, though, is that they can damage our DNA. Can a single portion of blueberries really improve protection against DNA damage?: “A single portion of blueberry [can improve] protection against DNA damage”! They drew blood from people before and after they ate some frozen blueberries, and exposed their white blood cells to free radicals in the form of hydrogen peroxide. And, “[b]lueberries significantly reduced [the] DNA damage [done within a single] hour after berry consumption.” “However, the protective effect was transient, and [our DNA vulnerability] returned [within two hours].” So, we want to be eating super-healthy foods like berries at every meal. In conclusion, “one portion of blueberries can improve [our] cell[ular] resistance [to] DNA damage, “thus supporting the importance of consuming [healthy plant] foods regularly.”
Please consider volunteering to help out on the site.
- Fung TT, Hu FB, Yu J, et al. Leisure-time physical activity, television watching, and plasma biomarkers of obesity and cardiovascular disease risk. Am J Epidemiol. 2000;152(12):1171-1178.
- Wedick NM, Pan A, Cassidy A, et al. Dietary flavonoid intakes and risk of type 2 diabetes in US men and women. Am J Clin Nutr. 2012;95(4):925-933.
- Takikawa M, Inoue S, Horio F, Tsuda T. Dietary anthocyanin-rich bilberry extract ameliorates hyperglycemia and insulin sensitivity via activation of AMP-activated protein kinase in diabetic mice. J Nutr. 2010;140(3):527-533.
- Del Bó C, Riso P, Campolo J, et al. A single portion of blueberry (Vaccinium corymbosum L) improves protection against DNA damage but not vascular function in healthy male volunteers. Nutr Res. 2013;33(3):220-227.
- Blacker BC, Snyder SM, Eggett DL, Parker TL. Consumption of blueberries with a high-carbohydrate, low-fat breakfast decreases postprandial serum markers of oxidation. Br J Nutr. 2013;109(9):1670-1677.
- Jennings A, Welch AA, Spector T, Macgregor A, Cassidy A. Intakes of anthocyanins and flavones are associated with biomarkers of insulin resistance and inflammation in women. J Nutr. 2014;144(2):202-208.
- Stull AJ, Cash KC, Johnson WD, Champagne CM, Cefalu WT. Bioactives in blueberries improve insulin sensitivity in obese, insulin-resistant men and women. J Nutr. 2010;140(10):1764-1768.
- Cassidy A. Berry anthocyanin intake and cardiovascular health. Mol Aspects Med. 2018;61:76-82.
Image credit: Tookapic via Pexels. Image has been modified.
Motion graphics by Avocado Video
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Title
Blueberries for a Diabetic Diet and DNA Repair
LicenseCreative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Content URLDoctor's Note
Berries pack such a nutritional punch that I recommend eating at least ½ cup a day in my Daily Dozen Checklist (download the free iPhone or Android app, or print the checklist here). More benefits of blueberries include:
- The Benefits of Açai vs. Blueberries for Artery Function
- Benefits of Blueberries for Artery Function
- Benefits of Blueberries for Blood Pressure May Be Blocked by Yogurt
- Benefits of Blueberries for the Brain
- Benefits of Blueberries for Mood & Mobility
- Best Brain Foods: Berries & Nuts Put to the Test
- Benefits of Blueberries for Heart Disease
What else may protect against or repair DNA damage? See:
- DNA Protection from Broccoli
- Antimutagenic Activity of Green vs. White Tea
- Kiwifruit & DNA Repair
- Spicing Up DNA Protection
- Carcinogen-Blocking Effects of Turmeric
Type 2 diabetes is caused by insulin resistance, but What Causes Insulin Resistance? Check out the video. And How May Plants Protect Against Diabetes? See also Plant-Based Diets for Diabetes, and my overview video How Not to Die from Diabetes.
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