By Dr. J. Renae Norton
I love prunes, really, really love them. In fact, I cannot stop eating them. I start my day out with them as I have 6 prunes as a part of my wholesome, healthy breakfast every morning. Breakfast includes coffee or tea (I alternate), raw 100% grass-fed cow’s milk, a 100% grass-fed beef stick (warmed in hot water) and an organic, hard-boiled 100% pastured egg (also warmed in a cup of hot water as I make them a dozen at a time) and of course, the organic unprocessed divinely sweet prunes.
Breakfast is not the problem. I get a good blend of healthy fats, protein and carbs in my simple but delectable breakfast. The problem is that every time I open my refrigerator door, the prunes are right there, staring me in the face. I cannot resist. I say I will, but I never do. Before I even know what is happening, I have flipped the lid off of the see-through container and I’m going for the prunes. Speaking of which, why do they put these fiendishly delicious morsels in see-through containers? It is not even a twist-off lid, which might give you a minute to come to your senses. It just pops off with the flick of a finger. I mean, seriously, if there is such a thing as a container that invites bingeing, this is it.
Well you can see how distressing all of this is, especially for someone who is an expert in clean eating and food addiction. Unfortunately, I made some assumptions about prunes that all turned out to be wrong. I assumed that because prunes taste so good, they must be high in sugar and that this would raise my blood sugar levels and mess with my insulin. I was on the Keto diet at the time and kept expecting my blood sugar levels to kick me out of Ketosis but it never happened.
At some point in all of this, I convinced myself that I was somehow “getting away with it.” But I lived in fear that the “cheating” would all come crashing down on me and my insulin and glucose levels would go off the chart. When that didn’t happen I developed delusions of grandeur. I became convinced that I was using mind over matter to control a biological process which prevented the rise in blood sugar and insulin levels that the prunes would normally cause, making it possible for me to eat as many prunes as I wanted with no consequences. I was, I reasoned, practically superhuman in my ability to control my blood sugar levels in spite of the these sweet little buggers.
Turns out that in addition to being delicious, prunes actually have a very low glycemic index/load, which means that they do not raise blood sugar levels enough to cause weight gain. Let’s define a few terms.
What is Glycemic Index and Glycemic Load?
First, remember what causes weight gain? Not fat! Sugar. Or more specifically, blood sugar levels. The glycemic index of a particular food is a simple way of telling us how much of an impact the sugar in that food will have on our blood sugar levels. The higher the glycemic index, i.e. typically 70 and above, the more likely it is to raise our blood sugar levels enough for us to gain weight. By consuming foods with a lower glycemic index, say 55 or lower, we are less likely to gain weight, as low glycemic foods do not provoke a quick rise in blood sugar.
So: High glycemic foods = weight gain
Read more about the adverse health effects of sugar
Please note, most vegetables are lower in their sugar content than fruits. Duh, right? Many are also higher in their fiber content. So what? That means they rarely raise blood sugar levels making very hard to gain weight when eating them. But we are not talking about vegetables today, we are talking about prunes.
Guess what the glycemic index of the prune is? According to Harvard Medical School reports,  the glycemic index for one serving of prunes (60 grams, or about six prunes) is 29. What? Keep in mind that this is for unprocessed, unsweetened, dried prunes. Don’t even think about buying the commercially sold prunes that are artificially sweetened, flavored and/or processed, as they have a much higher glycemic index. When you buy prunes they should have one ingredient, prunes.
Computing and Interpreting the Glycemic index
According to the American Diabetes Association (ADA),  GI scores are rated as follows:
- Low: 55 or below
- Moderate: 56 to 69
- High: 70 and above
The lower the GI score, the more slowly the rise in blood sugar, which can help the body better manage post-meal changes, preventing glucose spikes, and ultimately weight gain.
A more useful estimation of the food-blood sugar effect is the glycemic load (GL), which includes not only the GI, but also how much of the food you ate. In other words, this calculation takes into account the GI, plus the number of grams of carbohydrates in that food.
Makes sense if you think about it. For example, the food with the highest glycemic index is rice. (Yes you read that right, the food with the greatest potential to raise blood sugar levels in innocent looking rice.) But if you only eat a tablespoon of it, it will have a far less damaging impact on your GL than if you eat a bowl of it. (Who are we kidding, who ever eats a tablespoon of rice?)
Let’s do the math on my beloved prunes using the levels below for evaluating GL:
- Low: 0 to 10
- Moderate: 11 to 19
- High: 20 and above
A serving of prunes = 6 and is 60 grams of carbohydrate. If we multiply this by a GI of 29 we get 1740, and divide by 100, we get a GL of 17.4. This puts me in the moderate range for glycemic load 6 prunes at breakfast. Well that does not sound very good….Not so fast.
Turns out there are other things which can bring the GI of a food down, one of which is eating fat with the carb. Got it covered at breakfast: My beef sticks have 5 grams of fat; I use a tablespoon of coconut oil in my coffee/tea which has 14 grams of fat; I drink 2/3 cup of raw milk which has 7 grams of fat; ½ cup of almond milk in my coffee for another 1.75 grams of fat. This gives me a grand total of 27.5 grams of fat. When I eat the prunes along with the fat in the rest of the meal, the GL drops down into the low range. All right!
I would also point out that after breakfast, I generally never eat more than 2 prunes, and usually only 1 at a time, for the rest of the day. The problem is that I do that 4 or 5 times a day, and it isn’t “planned.” Still in terms of blood sugars, for 2 prunes which are 20 grams of carbohydrate multiplied by 29 which equals 580 divided by 100, the GL is 5.8 which is in the low range and half that, or 2.9, if I only eat 1 prune, which happens more often than not.
The foods that I eat for the rest of the day tend to be higher in protein, lower in fat, and the carbs are all from fruits and vegetables (mostly vegetables) that have a naturally low GI. In other words, the 10 prunes I eat throughout the day do add 230 calories but do not necessarily raise blood sugar levels in a way that might cause weight gain or insulin and glucose problems. Also, the prunes are very filling and satisfying. which is why I usually only eat 1 or 2. And because I love the taste of them, they are my only snack besides other fruits such as pears, apples and oranges and cherries and grapes in season.
Say it with me, “Sugar causes weight gain, not fat.” That’s why people on Keto who are eating 70% of their calories in fat lose weight.
Read more about Glycemic Load
Prunes vs. Other Foods
As fruits, prunes carry higher sugar content than other foods, such as vegetables. But compared to other common fruits, such as bananas, apples and watermelons, all ranging between 39 and 72 GIs, prunes have a relatively low glycemic index. This low glycemic index reflects the high fiber content in prunes.
The other justification for not giving up the prunes, even though I am clearly addicted to them, is that it turns out that they are SUPER good for you. I really did not know that either. I think it never occurred to me to check, which is very unusual for me, because I assumed that they were way too high in sugar and I am as against sugar as I am heroin. I thought of them as my heroin in fact, and like any good addict, did not want to be confused with the facts. Little did I know, prunes are a powerhouse when it comes to nutrition. Here are the facts:
One cup of prunes provides 87 percent of the recommended daily intake of vitamin K, more than 20 percent of most B vitamins, 8 percent of calcium and 27 percent of potassium. The “problem” is that you really can’t eat a cup of prunes, which equals about 18 prunes, and exceeds the recommended serving size of 6 prunes. That said, the fact that these nutritional values are so high, means that even if you only eat 6, you are still taking in a lot of nutrients.
Nutrients in 1 Serving: 4-5 Prunes (40 grams)
- 100 calories
- 3 grams fiber
- 290mg potassium – involved in nervous system, muscle function and blood pressure regulation
- 32% of Vitamin K – important for strong bones and blood clotting
Other Health Benefits
It turns out that prunes provide some very important health benefits. Here are the highlights:
One prune delivers 3 percent of the recommended daily intake of vitamin A. Vitamin A is the vitamin that gives us carotenoids that the body converts into the form of vitamin A used by cells in the eyes. Getting enough of it may prevent macular degeneration.
May Reduce Colon Cancer Risk
According to the Journal of the American College of Nutrition  the anthocyanins in prunes may also decrease your risk of colon cancer (aka colorectal cancer). The antioxidant effect of anthocyanins combats oxidative stress, the biological state that allows cancer cells to grow and spread in the colon.
Prunes contain manganese, iron and plant phenolics that function as antioxidants
- Manganese – protects mitochondria (the cellular structures that create energy) — from damage caused by free radicals.
- Iron – best known for carrying oxygen, is also an antioxidant that protects cells in the immune system because iron neutralizes the immune systems response.
Helps Weight Management and Loss
I do not have to worry about my weight, largely because I eat such clean food, but also because I have a high metabolism and I work out even though I hate working out. But according to many researchers, the fiber in prunes may help to control hunger because the fiber in prunes increases the sense of fullness. I can attest to this as 1 prune fills me up more than an entire apple or orange.
Supports Bone Health
One of the most important things the prune does is give us vitamin K and boron, which are both key nutrients for good bone health.  Vitamin K supports the process by which calcium binds to bones and boron makes vitamin D more bio-availble. Finally, potassium may also reduce bone loss by decreasing bone-depleating acids. Ultimately, vitamin K, boron, and potassium in prunes all help calcium protect your bones. 
Promote Heart Health
High blood pressure and high blood cholesterol are two of the main risk factors for heart disease. Believe it or not, the mighty prune can help manage both. In terms of blood pressure, the potassium in fruits such as prunes reduces the tension and pressure in the arterial walls while the anthocyanins found in prunes relax the arteries and lower high blood pressure.
As for high blood cholesterol, the fiber and anthocyanins in prunes have your back again, in a big way as the soluble fiber actually binds to the cholesterol in your gut and you poop them out. Effectively, the fiber lowers LDL “bad” cholesterol, and the anthocyanins increase HDL “good” cholesterol while protecting heart cells from oxidative stress. 
Listen to my podcast as I go on a deep dive of the good and bad cholesterol and how it affects our health. Listen HERE
If you want good bones you have to have magnesium, vitamin K, boron, copper and potassium. Guess what prunes have? All of those. Studies,  show that prunes may play a significant role in reducing bone turnover (loss of bone density) in postmenopausal women AND may even increase bone density in the spine and forearm. While the women in the study were eating about 10 prunes a day, this research is quite interesting and shows that a consistent intake of dried plums may actually have a monumental impact in the area of osteoporosis prevention!
In case you are wondering, I have grrrrreat bones!
About 60% of the dietary fiber in prunes is pectin, a type of soluble fiber that may lower blood cholesterol levels. Yup! Prunes also contain a specific type of antioxidant called phenolics which have been shown to help lower the risk of heart disease and prevent oxidation of LDL cholesterol. It is the oxy cholesterol that is dangerous, as these are the tiny sticky LDL molecules that clog the arteries. The big fat LDL molecules you do not have to worry about so much. (Check out this article on cholesterol from my book.)
Prunes are known for their laxative effect which is caused by both the fiber and the sorbitol found in prunes. Moderation is key, even with the mighty prune. Unfortunately, many individuals think that they need a fiber supplement for constipation or irregularity. Now days, they often come in the form of a fiber “gummies.” Have you read the ingredients in those things? They are often loaded with sugar (calories), dyes and a lot of unnecessary, chemical ingredients.
My thinking, and I know I am biased by my prune-addicted brain, is why would I use a processed supplement when the real thing tastes so good and works the best? The research is pretty clear – prunes are actually more effective than psyllium. 
Turns out that there are some other delicious fruits with a low GI/GL:
GI score: 25
GL score: 3
- Dried apricots
GI score: 32
GL score: 9
GI score: 38
GL score: 4
GI score: 39
GL score: 5
GI score: 40
GL score: 5
I cannot end this article without saying thank you to my grandmother Lucille Shoemaker. She died way too young at the age of 95 and the world has never been quite the same for me. I was her first grandchild and I hung on her every word.
From the time that I was a little girl until the week before she died, grandma told me true. She dosed us with cod-liver oil when we were little and insisted that we would thank her someday. That was a stretch even for me, although I do supplement today with fermented cod liver oil and Krill oil so I guess that one goes to her.
She was a dairy farmer, so of course she was all about the benefits of raw 100 grass-fed milk and butter. Her cows relaxed in the sun and ate grass. But her chickens were her prized possessions. They all had names and followed her around like little soldiers. No cold barn for these chickens in the Wisconsin winters, Grandma made sure that they had heat!
She touted the goodness of fat, as long as it was “real” fat. No processed fat for her, her 10 children or her hundreds of grandchildren. She was adamant that fat did not make you fat. She should know, never more than 100 pounds herself even after 10 children.
But most importantly she told me about prunes. She ate 6 prunes every day as she said it kept her regular. She was my role model in so many of my health-related beliefs and habits. So much of what I value and know I learned from her. I miss you grandma, you were one of a kind and you were right about it all, especially the prunes. Rest in peace.
4. Journal of Osteoporosis, Vitamin K and Bone Health: A Review on the Effects of Vitamin K Deficiency and Supplementation and the Effect of Non-Vitamin K Antagonist Oral Anticoagulants on Different Bone Parameters, December 31, 2019
Dr. Renae Norton specializes in the treatment of eating disorders. Located in Cincinnati, Ohio. Call 513-205-6543 to schedule an appointment or fill out our online contact form for someone to call you to discuss your concerns. Tele-therapy sessions available. Individual and family sessions also available.
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Materials contained on this site are made available solely for educational purposes and as part of an effort to raise general awareness of the psychological treatments available to individuals with health issues. These materials are not intended to be, and are not a substitute for, direct professional medical or psychological care based on your individual condition and circumstances. Dr. J. Renae Norton does not diagnose or treat medical conditions. While this site may contain descriptions of pharmacological, psychiatric and psychological treatments, such descriptions and any related materials should not be used to diagnose or treat a mental health problem without consulting a qualified mental health care provider. You are advised to consult your medical health provider about your personal questions or concerns.