One of my patients – who suffered from obesity, uncontrolled diabetes and the cost of her medications – agreed in June 2019 to adopt a more plant-based diet.
Excited by the challenge, she did an outstanding job. She increased her intake of fresh fruits and vegetables, stopped eating sweets, cookies and cakes, and reduced her intake of foods of animal origin. In six months, she lost 19 pounds and her HbA1c – a measure of her average blood sugar – fell from 11.5% to 7.6%.
She was doing so well that I expected her HbA1c to continue to drop and she was one of our herbal success stories that reversed diabetes.
Her three-month follow-up visit in March 2020 was canceled due to COVID-19 lockdowns. When I finally saw her again in May 2021, she had regained weight and her HbA1c had climbed to 10.4%. She explained that her diabetes doctor and a diabetes nurse educator had told her that she was eating too much “sugar” on the plant-based diet.
She had been advised to limit carbohydrates by reducing her intake of fruits and starches and eating more fish and chicken. Candies, cakes, cookies and sugar-free artificial sweeteners were encouraged. Faced with conflicting medical opinions, she fell back on the conventional wisdom that “sugar” is bad and should be avoided whenever possible, especially if you have diabetes.
I am a medical doctor, certified in preventive medicine with a lifestyle medicine Morehouse Healthcare clinic in Atlanta. This emerging medical specialty aims to help patients change their healthy lifestyle habits. Patients who adopt whole, plant-based diets increase their carbohydrate intake and often see a reversal of chronic diseases, including diabetes and hypertension. In my clinical experience, “sugar” and carbohydrate myths are common among patients and healthcare professionals.
Fruit versus sugar
Your body runs on glucose. It is the simple sugar that cells use to produce energy.

Glucose is a molecular building block of carbohydratesone of the three essential elements macronutrients. The other two are fats and proteins. Starches are long branched chains of glucose.

Natural carbs move into nutrient-dense packages such as fruits, vegetables, whole grains, nuts, and seeds.
Humans have evolved to crave sweet tastes to get the nutrients they need to survive. A daily intake of vitamins, minerals and fibers is necessary because our body cannot manufacture them. The best source of these substances for our ancient ancestors was sweet, ripe and delicious fruits. In addition, fruits contain phytonutrients and antioxidants, chemicals produced only by plants. Phytonutrients such as ellagic acid in strawberries have anti-cancer properties and promote heart health.
Refined sugars, on the other hand, are highly processed and devoid of all nutrients except calories. They are a concentrated form of carbohydrates. The food industry produces refined sugars in many forms. The most common are sucrose crystals, which you recognize as table sugar, and high-fructose corn syrup, which is found in many processed foods and sugary drinks.
If you continually satisfy your sweet tooth with foods that contain refined sugar—rather than the nutrient-dense fruits at the heart of this evolutionary craving—you may not get all the nutrients you need. Over time, this deficit can create a vicious cycle of overeating that leads to obesity and obesity-related health problems. Women who eat the most fruit tend to have lower rates of obesity.
Sugar toxicity
Refined sugars are not directly toxic to cells, but they can combine with proteins and fats in food and in the blood to produce toxic substances such as advanced glycation end products (Age). High blood sugar can produce glycated low density lipoproteins. Elevated levels of these and other glucose-related toxicants are associated with an increased risk of a wide range of chronic health problems, including cardiovascular diseases and diabetes.
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The disease most commonly associated with sugar is type 2 diabetes. A surprising number of people, including medical professionals, mistakenly believe that sugar consumption causes type 2 diabetes. about lowering blood sugar and “carb counting” while ignoring the real cause: progressive loss of pancreatic beta cell function. At the time of diagnosis, a patient may have lost between 40% and 60% of their beta cells, responsible for the production of insulin.
Insulin is a hormone that controls the amount of glucose in the blood by blocking glucose production in the liver and driving it into fat and muscle cells. Loss of beta cell function means that not enough insulin is produced, leading to high blood sugar levels characteristic of type 2 diabetes.
beta cells have low levels of antioxidants and are susceptible to attack by metabolic and dietary oxidized free radicals and AGEs. The antioxidants in fruits can protect beta cells. Researchers have found that eating whole fruits lower the risk of type 2 diabeteswith those who eat the most fruit with the lowest risk.

sugar detox
People interested in losing weight and improving their health often ask if they should do a “sugar detox.” In my opinion, it is a waste of time, because it is not possible to eliminate sugar from the body. For example, if you only eat baked chicken breasts, your liver will convert protein to glucose in a process called gluconeogenesis.
Low-carb diets can lead to weight loss, but at the expense of health. Diets that drastically reduce carbohydrates are associated with nutrient deficiencies and higher risk of death from any cause. Low carb ketogenic diets the the body will break down the muscles and turn their proteins into glucose. Lack of fiber causes constipation.
Eliminating foods sweetened with refined sugar is a worthy goal. But don’t think of it as a “detox” – it should be a permanent lifestyle change. The surest way to “detox” refined sugar is to increase your intake of nutrient-dense fruits and vegetables. Once you eliminate refined sugar, you’ll likely find that your taste buds become more sensitive to — and appreciate — the natural sweetness of fruit.

This article is part of a series examining the effects of sugar on human health and culture. You can read the articles on theconversation.com.