Sweet and Vicious: Sugar and Sugar Substitutes


Sugar does not feed cancer cells any differently than it feeds healthy cells.

There is so much confusion surrounding sugar and sweeteners in the health community and especially in relation to cancer. The devastating diagnosis of cancer often acts as an impetus for people to make dietary changes. Over and over patients ask me if sugar feeds cancer.

I’ve heard doctors say that sugar must be avoided as much as possible while others insist patients to eat “whatever” they want. As a medical community we foster misconceptions and obfuscate diet recommendations. We occupy a moral safe house where everyone else is to blame so no one is responsible.


Oftentimes during anti-cancer treatment like chemotherapy and radiation, sugar and carbohydrate foods are tolerated best. It must be devastating to think that sugary foods most easily tolerated are also the ones feeding the disease. Let me assuage all guilt as this is simply untrue. Cancer hijacks the circulatory system to gain access to nutrients. Every cell in our body needs glucose (sugar) to survive and the trouble is cancer cells need nutrients to grow the exact same way healthy cells do. Sugar does not feed cancer cells any differently than it feeds healthy cells. Even if we removed all sugar and carbohydrates from our diets, our bodies will naturally create sugar from protein and fat by a biochemical process called gluconeogenesis.

While added sugar and refined carbohydrates aren’t directly causing cancer to grow, it’s hardly healthy either, especially when eaten in excess. Natural sugars that occur in fruit; starchy vegetables like peas and whole grains like bulgur, barley or quinoa are perfectly healthy and help make a balanced diet. A banana, pineapple and potato never gave anyone diabetes, obesity or cancer. The highly processed iterations of whole foods sing an entirely different tune. Extrinsic sugars are added to foods like sugar added to tomato sauce or muffins and other processed foods. On average, American adults eat about 22 teaspoons of added sugar per day. This is beyond excessive when the American Heart Association recommends no more than six teaspoons for women and nine for men per day at maximum.

Sugar does not feed cancer cells any differently than it feeds healthy cells.

Sugar does not feed cancer cells any differently than it feeds healthy cells.

Added sugars are empty calories — providing little to no nutrients — and do not foster a healthy immune system. Excess added sugar can lead to oxidative stress, hyper-insulinemia and glucose intolerance, diabetes, high blood pressure, dyslipidemia, metabolic syndrome, heart disease, digestive diseases, immune compromise, overweight and obesity. Many of these resulting conditions may increase a person’s risk for cancer.

It’s easy to be seduced by ostensibly healthy products. Reduced fat products are a classic example of this. Food manufacturers compensate for reduced fat by adding sugars instead. For example, many fat free yogurts and health bars have more sugar than pop tarts! Juices can have more sugar than a can soda! Muesli can have more sugar than Froot Loops! “Light” ranch dressing has double the sugar than regular ranch dressing!

Chemical Cuisine

In an attempt to reduce overall added sugar intake, artificial sweeteners have become widely used both in food manufacturing and in the home kitchen. Artificial sweeteners are attractive products because they have very little to no calories and the argument is that because they’re so intensely sweet, we use less overall. As more and more data have started to coalesce, a very different picture has been painted. Artificial sweeteners actually cause strong cravings and increased appetite, resulting in a propensity to overeat thereby replacing whatever calories we tried to avoid by choosing a sugar-free product to begin with. Because the sweetness of artificial sweeteners is not also associated with calories, our neurobiology of food reward builds a tolerance, like a drug user. The more you eat, the less you feel the reward so you eat more and more to achieve the same reward. Artificial sweeteners start to compromise the integrity of the gut bacteria we play host to after only two weeks of use. By satisfying our own sweet tooth, we essentially starve these beneficial little buggers resulting in weakened immune system.

Artificial sweeteners are just one type of sugar substitute. Others include sugar alcohols and non-sugar natural sweeteners. In response to this burgeoning evidence, many people including health and wellness demagogues have repositioned themselves next to more natural sweeteners like honey, molasses, maple syrup, agave and stevia in order to distance themselves from sugar and artificial sweeteners. While honey and agave may happen to be lower “glycemic index” they are oh-so concentrated in fructose that they are metabolized directly by the liver causing a jump in triglycerides and inflammation increasing fat storage and risk for heart disease.

Final Say

A medical community that demonstrates a vision of wellbeing that is positive, aspiring and healthy is good. It is healthy for everyone to cut back on added sugars and refined carbohydrates. More simply, it is healthy for everyone to cut back on processed foods.

  • Don't drink it: Whether sweetened with sugar or sucralose or stevia, the best place to start for everyone, patients with cancer included, would be to limit or avoid sweetened beverages like juice, soda, coffee and tea. Strive to shift your palate back to normal on the spectrum of sweetness. Aim to make all beverages unsweetened.
  • Read food labels: You'll quickly start to realize how many products are adulterated with added sugars and sweeteners. Even things that don't taste sweet are packed with it.
  • Don't go cold turkey: If you normally add three packets of sugar or sweetenter to your coffee, cut back to two and eventually you'll be drinking it unsweetened. Our palates fall on a spectrum so we need to slowly shift it back to normal.
  • Free sweets aren't free: Resist the urge to eat sugar-free products because it adds up at the end of the day and we're eating too much of the artificial stuff too.
  • Add more flavor: Use herbs and spices to add flavor without added sweetness.
  • Treat train: Re-learn how to enjoy sweets in moderation. Plan for it and make rules for yourself like only splitting a portion on a Sunday. Work hard to eat healthy the rest of the day in anticipation of the treat.

Be kind to yourself. Remember, it took a lifetime to develop your current eating habits. Collaborate with your inner body and mind to work on simple changes to add up to a big difference. Consistency is imperative.

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