Note: The article below is based upon a chapter in Rosacea 101: Includes the Rosacea Diet by permission of the author:
Sugar is the fuel that burns the inflammation in rosacea. Think of the fire triangle: Heat, Fuel, and Oxygen. Sugar is like adding some very combustible fuel to the burning inflammation of rosacea. Sugar = Rosacea Fire
Reduce the fuel and the fire is reduced. To understand why sugar has a role in rosacea you should understand the affect high glycemic sugar has on human health.
Sugar and spice and everything nice. Sugar is not nice.
The above two statements cannot be both true. Mom and the processed food industry conditioned you that sugar is nice. (See Appendix W—The Diet Authority) Sugar is not nice. Sugar is toxic. Sugar triggers the rosacea inflammation. Sugar Busters! by H. Leighton Steward, Morrison C. Bethea, M.D., Samuel S. Andrews, M.D., and Luis A Balart, M.D. states on page 17 that “SUGAR IS TOXIC!” Three of the authors are medical doctors and recommend a low-sugar diet, avoiding carbohydrate with a high glycemic index. Do you get it? Medical doctors are saying that sugar is toxic. How can they write a book stating that sugar is toxic and still be licensed physicians? That is because it is true, sugar is cumulatively toxic over time. William Dufty summarizes the toxic effect of sugar in his book, Sugar Blues, when he kicked the habit. Dufty threw all the sugar in his kitchen out and just ate grains and vegetables. He wrote, “In about forty eight hours, I was in total agony, overcome with nausea, with a crashing migraine. If pain was a message, this was a long one, very involved, intense but in code. It took hours to break the code. I knew enough about junkies to recognize reluctantly my kinship with them. I was kicking cold turkey, the thing they talked about with such terror. After all, heroin is nothing but a chemical. They take the juice of the poppy and they refine it into opium and then they refine it to morphine and finally to heroin. Sugar is nothing but a chemical. They take the juice of the cane or the beet and they refine it to molasses and then they refine it to brown sugar and finally to strange white crystals. It’s no wonder dope pushers dilute pure heroin with milk sugar —lactose—in order to make their glassine packages a treat to the eye. I was kicking all kinds of chemicals cold turkey—sugar , aspirin, cocaine, caffeine, chlorine, fluorine, sodium, monosodium glutamate, and all those other multisyllabic horrors listed in fine print on the tins and boxes I had just thrown in the trash. I had it very rough for about twenty-four hours, but the morning after was a revelation. I went to sleep with exhaustion, sweating and tremors. I woke up feeling reborn.” 
You may or may not experience such withdrawals depending on how much you are addicted to sugar. Dufty ate a high carbohydrate diet when he went off sugar, which was at the very least, better than eating a diet full of sugar. Eating a high carbohydrate diet helps reduce the addictive withdrawal symptoms of getting off sugar. Carbohydrate is units of different type sugar. If you eat the ‘typical American diet’ that includes 149 pounds of sugar a year, addiction to sugar is no doubt the reason many cannot stop eating sugar.
William Dufty wrote in 1975 on page 175 of his book, “It is mind boggling today to read through medical histories and other tomes and find again and again that the basic cause of diabetes mellitus is still unknown, that it is chronic and incurable, or that it is due to the failure of the pancreas to secrete an adequate amount of insulin . It’s still Greek to the best of them.”  In 2007 on the American Diabetes Association’s website, when you click on Basic Diabetes Information, you may read this statement:
“The cause of diabetes continues to be a mystery, although both genetics and environmental factors such as obesity and lack of exercise appear to play roles.” 
Thirty-two years after Dufty’s statement that ‘it’s still Greek to the best of them’ holds true. And PubMed shows similar results:
“Cardiovascular disease is the main cause of mortality in patients with diabetes.” 
“Although the link between diabetes and cardiovascular disease is not fully understood, loss of the modulatory role of the endothelium could be implicated in the pathogenesis of diabetic vascular complications.” 
“Although diabetes mellitus is predominantly a metabolic disorder, recent data suggest that it is as much a vascular disorder.” 
“The vascular chronic complications are the main cause of morbidity and mortality in patients with diabetes mellitus … Knowledge of the molecular mechanisms involved in the pathogenesis of endothelial dysfunction may ultimately result in novel approaches to the treatment and prevention of cardiovascular disease in people with diabetes mellitus.” 
However a recent report in 2007 revealed the following novel idea:
“A promising nutritional approach suggested by this thematic review is carbohydrate restriction. Recent studies show that, under conditions of carbohydrate restriction, fuel sources shift from glucose and fatty acids to fatty acids and ketones, and that ad libitum-fed carbohydrate-restricted diets lead to appetite reduction, weight loss, and improvement in surrogate markers of cardiovascular disease.” 
You would think that there would be some diabetic research on diet’s role in diabetes, now wouldn’t you? Notice this report:
“There are no high quality data on the efficacy of the dietary treatment of type 2 diabetes” 
The authors of the above report didn’t think the following study reported in 1997 was of high quality even though this was done at the Department of Nutrition, Harvard School of Public Health:
“Our results support the hypothesis that diets with a high glycemic load and a low cereal fiber content increase risk of diabetes in women..”407
Nor did they find this one of high quality done at the same group:
“Intake of carbohydrates that provide a large glycemic response has been hypothesized to increase the risk of NIDDM, whereas dietary fiber is suspected to reduce incidence … These findings support the hypothesis that diets with a high glycemic load and a low cereal fiber content increase risk of NIDDM in men.” 
And you ask, why point out research reports on diabetes? Because there are not any reports on the role of a high glycemic diet and rosacea. I am merely pointing out how the medical and clinical researchers ignore the role diet plays in vascular disorders and diabetes. There is evidence that diet plays a role in the metabolic syndrome (See Appendix 8—Metabolic Syndrome ) There is evidence that diet plays a role in acne.. (See Appendix U—Diet and Acne) There is a theory that rosacea is a vascular disorder (See Chapter, What Causes Rosacea?) and that diabetes may not only be a metabolic syndrome but also a vascular disorder.
There is a connection here. Sugar plays a role in rosacea too.
The mainstream health authorities appear to be clueless to diet’s connection with disease. But you do see the connection don’t you? Some of the above quotes show that obesity plays a factor in diabetes. Diet plays a role in the metabolic syndrome .
Medical authorities agree that diabetics are at a higher risk for heart disease. Yet connecting sugar consumption over the years to either disease is overlooked, minimized or lacking by these medical authorities.
If you look at a graph published in the book Sugar Busters!, it shows how the consumption of sugar has climbed dramatically only in the last couple of centuries. Now compare this with a graph on the dramatic climb of diabetes during this same period, it doesn’t take a clinical study to see the connection. The damage of high sugar consumption to a person’s body not only effects diseases like diabetes and heart disease but also possibly is one of the major factors in many other diseases. Remember 170 million people on this planet have diabetes and the number continues to rise along with increases in world sugar production.
Obesity is now the culprit used by medical authorities as being the factor for several major diseases. Does diet play a factor in obesity? Sugar is a huge factor in obesity. Reducing sugar in your diet will reduce obesity. Eliminating sugar from your diet promotes health and well being. Eliminating sugar in a rosacean diet controls rosacea and you will see improvement over a 30 day period if you reduce your carbohydrate intake to 30 grams a day. Weight loss will result when you reduce sugar in your diet. How does this happen? Your body breaks down all food into glucose so that the cells can use the energy and live. Any excess glucose is converted to glycogen (“animal starch”) and stored in your liver, muscles and blood to be used if needed. This is a wonderful storehouse of packed energy that can easily be converted back to glucose when needed. There is one problem. The body can only store about 14 ounces of glycogen or about 400 grams.409 A gram of glucose has four calories. The entire amount of stored glycogen is approximately 1600 to 1800 calories.
Since there is limited glycogen storage, if your diet includes a generous amount of sugars and carbohydrate and your glycogen storehouse is full, the excess sugars and carbohydrate will be converted to FAT and the body gains weight. The Rosacea Diet stops this excess conversion of sugars and carbohydrate into fat, thus resulting in weight loss over time. This is just one of the reasons why sugar should be avoided in your diet not to mention you will feel healthier!
Refined sugar [sucrose] in crystallized form is artificial usually made from either sugar beets or sugarcane. Some may claim that sugar is natural , but would you call the crystallized powder heroin derived from morphine ‘natural ,’ because it is made from the opium of a poppy? Refined table sugar doesn’t occur naturally, it is an artificially manufactured process. I toured a sugar plantation and factory in Kauai, Hawaii in 2003 and saw the process how sugar cane is made into raw sugar . Lime is used. What is done to raw sugar to make this product into a pure white crystal? There is no way you can call this natural . It is a manufactured processed artificial sugar reducing the sugar cane plant into an addictive pure white crystal not unlike how the poppy flower is used to make opium into morphine and heroine. This process is a manufacturing artificial process not found in nature. You simply do not find these white crystals called sugar or heroine in nature. You may ask, ‘if sugar is so bad for your health, why do the health or diet authorities minimize the toxic effects of sugar ?’ The Sugar Buster! authors put it this way on page 36–37 of their book, “… Pro-sugar lobbying by sugar growers, cola manufactures and the packaged-food industry has been very effective in influencing our government. What politician wants to tell his constituents they should no longer eat sugar?”
Why do health ‘authorities’ continue to bless sugar ? Another reason may be the quote below:
“The American Dietetic Association, which trains registered dieticians to direct preparation of hospital and institutional food, has been soundly criticized for its association with the Sugar Association and companies like Coca Cola and M&M Mars. Such groups supply about 15% of the ADA’s annual budget …” 
Sugar is big business. It permeates the food industry. If you think the tobacco industry is powerful, the sugar industry is just as entrenched powerfully in the world’s economy if not more so. Even if it reached the point of a warning label of sugar ’s toxic effects like the tobacco industry has been forced to use on its product, people will continue to eat sugar just as those who smoke ignore the warning label. Only people who care about their health will be motivated enough to remove sugar from their diet.
There is so much information on the web or in your public library showing the harmful effects of sugar . Just go to any major search engine and type in ‘sugar ’ in the search box and you will be amazed at the results. Or spend a few hours at your local library.
Any dentist will tell you that sugar causes cavities:
“There is new evidence showing that excessive sugar consumption increases the risk of caries, even if the correlation between sugar intake and dental health has weakened due to exposure to fluoride.” 
“Numerous lines of evidence have conclusively established the role of sugars in caries etiology and the importance of sugars as the principal dietary substrate that drives the caries process has not been scientifically challenged … Measures to educate the public on the dangers of frequent sugar consumption, combined with recommendations for proper oral hygiene and fluoride use, are still warranted.” 
If you stop eating sugar , it may not help the cavity already formed in your tooth, but it will help prevent other cavities from forming. Does that mean you will not ever get a cavity again if you never eat sugar again? Well, no, you might get one, but your chances are drastically reduced to practically zero. Most dentists will tell you that as long as you brush your teeth and avoid sugar you will reduce your cavity possibilities to near zero in a normal healthy adult. Have you noticed how many people are losing their teeth and how much sugar they consume? Dentists know the connection sugar has with rotten teeth. They are only glad to replace your teeth with artificial ones. Do you really think that cavities are the only thing ‘rotten’ in your body from all the sugar you have been eating over your lifetime? And is obesity the only health problem aggravated by sugar?
The Australians have a report about a guideline for sugar consumption:
“The Australian Dietary Guidelines are currently being revised and updated. There has been public discussion about the advisability of retaining a guideline for sugar because of insufficient evidence linking sugar consumption to ill health. However, there are concerns about the quality of the self-reported food intake data on which this conclusion is based. In addition, the doubling in diabetes prevalence in Australia in the past 20 years, which is linked to increased obesity from consumption of energy-dense foods, including those with added sugars (sugar -sweetened drinks being particularly important), provides a strong rationale for retaining a dietary guideline for sugar .” 
Do you think that sugar only causes cavities in your teeth? Could sugar play a role in your rosacea? If you continue to study this topic you will be more convinced of the role sugar has in your rosacea and you can do something about it.
There are a number of articles and books you may read on this subject which are listed below or can be found on the web or ordered through your local library:
Pure, White and Deadly, John Yudkin, Viking, 186, Penguin, 188, Davis-Poynter Ltd; ASIN: 070670006
Sweet and Dangerous: The New Facts About the Sugar You Eat As a Cause of Heart Disease, Diabetes, and Other Killers. by John Yudkin
Metabolic Effects of Utilizable Dietary Carbohydrate by Sheldon Reiser (Editor) (Hardcover—August 1982)
The Saccharine Disease: Conditions Caused by the taking of Refined Carbohydrate, such as sugar and white flour by T. L. Cleave; Nurs Times. 1974 Aug 15;70(33):1274-5
Dismantling a Myth: The Role of Fat and Carbohydrate in Our Diet by Wolfgang Lutz
Refined Carbohydrate Foods and Disease: Some Implications of Dietary Fiber by D. Burkitt
The conception of the saccharine disease. An outline. Cleave TL; J R Nav Med Serv. 1971 Spring;57(1):10-9
Letter: Sugar , heart-disease, and diabetes. Cleave TL; Lancet. 1974 Mar 23;1(7856):515
Sugar and sugars: myths and realities. Coulston AM, Johnson RK; J Am Diet Assoc. 2002 Mar;102(3):351-3
Carbohydrate and sucrose intake in the causation of atherosclerotic heart disease, diabetes mellitus, and dental caries. Bierman EL; Am J Clin Nutr. 1979 Dec;32(12 Suppl):2644-7
Carbohydrates, sucrose, and human disease. Bierman EL; Am J Clin Nutr. 1979 Dec;32(12 Suppl):2712-22
Sucrose, coronary heart disease, diabetes, and obesity: do hormones provide a link?—Yudkin J; Am Heart J. 1988 Feb;115(2):493-8
Sugar and disease. Danowski TS; J Med Soc N J. 1979 Nov;76(12):849-50
Are you beginning to believe and understand that sugar is something a rosacean should avoid and is a trigger for rosacea?
Diabetes and Rosacea (Update)
The GWAS by Chang et al., also revealed that patients with rosacea shared a genetic locus with type 1 diabetes mellitus; this association was further confirmed by a population-based study as well. A recent study also revealed the presence of insulin resistance in rosacea, demonstrating significantly higher fasting blood glucose levels in patients with rosacea than in controls. As increased glucose intolerance along with dyslipidemia and hypertension are the factors that comprise metabolic syndrome, this association in rosacea might be related to cathelicidin, oxidative stress and endoplasmic reticulum (ER) stress, which are implicated in the pathogenesis of both rosacea and metabolic disorders. However, the advanced state of diabetes mellitus, which is associated with longer disease duration or high hemoglobin A1c levels, has conversely been recently associated with a decreased risk of rosacea. Thus, the underlying mechanism involved in this paradoxical association remains to be clarified."
Int J Mol Sci. 2016 Sep; 17(9): 1562.
Published online 2016 Sep 15. doi: 10.3390/ijms17091562, PMCID: PMC5037831
Rosacea: Molecular Mechanisms and Management of a Chronic Cutaneous Inflammatory Condition
Yu Ri Woo, Ji Hong Lim, Dae Ho Cho, and Hyun Jeong Park
Addendum and Updates
There is evidence that sugar is connected to acne. A NY Time article discusses this connection. The article refers to the following study:
The effect of a high-protein, low glycemic–load diet versus a conventional, high glycemic–load diet on biochemical parameters associated with acne vulgaris: A randomized, investigator-masked, controlled trial
Robyn N. Smith, BAppSc (Hons), Neil J. Mann, BSc (Hons), BAppSc, PhD, Anna Braue, MBBS, MMed, Henna Mäkeläinen, BAppSc, George A. Varigos, MBBS, FACD, PhD,
A paper published in Dermatology Practical and Conceptual (2017), Diet and rosacea: the role of dietary change in the management of rosacea, doesn't mention sugar or carbohydrate as a rosacea trigger, which is another example of how the medical community ignores sugar or carbohydrate as rosacea triggers. 
"These results show that in cases with metabolic syndrome, high blood sugar levels make them more susceptible to infestation of Demodex folliculorum." 414
 Dermatol Pract Concept. 2017 Oct 31;7(4):31-37. doi: 10.5826/dpc.0704a08. eCollection 2017 Oct. Full Text
Diet and rosacea: the role of dietary change in the management of rosacea
Emma Weiss, Rajani Katta
398 Sugar Blues, William Dufty, 1975, Warner Books, Inc, p. 22–3
399 Sugar Blues, William Dufty, 1975, Warner Books, Inc, p. 77-8
401 The pathophysiology of cardiovascular disease in diabetes mellitus and the future of therapy. Thomas JE, Foody JM; J Cardiometab Syndr. 2007 Spring;2(2):108-13
402 Endothelial dysfunction in diabetes mellitus. Cosentino F, Lüscher TF; J Cardiovasc Pharmacol. 1998;32 Suppl 3:S54-61
403 Clinical significance of cardiovascular dysmetabolic syndrome . Deedwania PC; Curr Control Trials Cardiovasc Med. 2002 Jan 7;3(1):2
404 The endothelial dysfunction in diabetes mellitus. Pănuş C, Moţa M, Vladu D, Vanghelie L, Răducanu CL. Rom J Intern Med. 2003;41(1):27-33
405 Low-carbohydrate nutrition and metabolism.
Westman EC, Feinman RD, Mavropoulos JC, Vernon MC, Volek JS, Wortman JA, Yancy WS, Phinney SD; Am
J Clin Nutr. 2007 Aug;86(2):276-84
406 Dietary advice for treatment of type 2 diabetes mellitus in adults.
Nield L, Moore H, Hooper L, Cruickshank J, Vyas A, Whittaker V, Summerbell C. Cochrane Database Syst Rev.
2007 Jul 18;(3):CD004097
407 Dietary fiber , glycemic load, and risk of non-insulin -dependent diabetes mellitus in women.
Salmerón J, Manson JE, Stampfer MJ, Colditz GA, Wing AL, Willett WC.
JAMA. 1997 Feb 12;277(6):472-7
408 Dietary fiber , glycemic load, and risk of NIDDM in men.
Salmerón J, Ascherio A, Rimm EB, Colditz GA, Spiegelman D, Jenkins DJ, Stampfer MJ, Wing AL, Willett WC;
Diabetes Care. 1997 Apr;20(4):545-50
409 Nutrition For Dummies, 1997, Carol Ann Rinzler, IDG Books Worldwide, Inc., p. 81
410 Nourishing Traditions, Sally Fallon with Mary G. Enig, Ph.D, New Trends Publishing, 1999, P. 571
411 Eating patterns, diet and dental caries.
Karjalainen S; Dent Update. 2007 Jun;34(5):295-8, 300
412 Sugars—the arch criminal?
Zero DT; Caries Res. 2004 May-Jun;38(3):277-8
413 Importance of retaining a national dietary guideline for sugar.
O’Dea K, Mann JI; Med J Aust. 2001 Aug 6;175(3):165-6
414 J Cosmet Dermatol. 2020 Oct 05;:
Association between Demodex folliculorum and Metabolic Syndrome.
Toka Özer T, Akyürek Ö, Durmaz S