Does Sugar Feed Cancer?

While dietary sugar does not necessarily feed cancer, blood sugar feeds cancer.

Let’s explore 2 meals.

In the first meal, you have a salmon filet, steamed broccoli, and a 3 pieces of dark chocolate for dessert. The protein and fiber balance the sugar, and blood sugar stays level.

In the second meal, you have a bowl of cereal and a glass of orange juice. The starch and sugar quickly spikes blood sugar. The pancreas responds by releasing insulin, the hormone of calorie storage and tissue growth. Insulin raises insulin like growth factor-1 (IGF-1).

Growth factors feed cancer.

Insulin and IGF-1 are growth factors. This growth is helpful in a fetus, a growing child, or for tissue repair after an injury. For most adults, we don’t get taller or develop new organs. So, the only things that grow in response to insulin are our fat cells and our tumors.

Insulin dysregulation has been clearly associated with cancer development, recurrence, and death. Therapies that regulate insulin, such as a low-glycemic diet or Metformin, prevent cancer recurrence and extend survival.

But doesn’t cancer metabolize sugar?

All tissues metabolize sugar. Tumors do, but so does the brain and heart. Cutting off a tumor’s supply of sugar won’t work. The tumor can trick the body into breaking down muscle, fat, and even organs to provide sugar. This is called cachexia.

So, the key is to cut off the tumor’s supply of growth signals instead. Insulin and IGF-1 are growth signals. So are the products of chronic inflammation. Eating a whole foods diet decreases growth signals and inflammation, which then puts the brakes on tumor metabolism.

But isn’t sugar acidic? I thought acid feeds cancer?

Cancer makes acid as part of its anaerobic metabolism. Acid is a byproduct of tumor growth, but it does not cause tumor growth.

Tumors grow faster than the blood vessels that serve them. So, a tumor runs out of oxygen and switches to anaerobic metabolism. This type of metabolism produces acid.

Have you ever had a tough workout, and felt your muscles burn the next day? This “burn” is from lactic acid. Your muscles produced this when they worked too hard and ran out of oxygen. The muscles did some anaerobic metabolism, which is what tumor cells do every day. Just as avoiding sugar before a workout won’t get rid of the “burn” in your muscles, it won’t work to inhibit anaerobic metabolism in tumor cells either.

The acid is the result of the tumor’s growth, not the cause. To regulate tumor growth, we have to block it’s growth factors. These include insulin, inflammation, nutrient deficiency, and reactivation of the “self-destruct button.

Action plan

So, I recommend that you eat a whole foods diet that keeps blood sugar level and inflammation low. There are “good sweets” that you can have as part of a low-glycemic meal. These include whole fruit, dark chocolate, stevia, and xylitol. If you’re going to have a sweet, keep portion size small and pair it with some protein. This will keep you well nourished and keep inflammation and insulin in balance.