High in fat, low in carbohydrates. Is it as simple as that? Dartmouth Cancer Center clinical dietician Dianne Kelecy, MS, RD, LD, gets into why a ketogenic or “keto” diet may or may not be a good diet option for you.
Keto origin story
You may associate a high-fat, low-carb diet with “Atkins.” But the keto diet dates way back to the 1920s. Dr. Russell Wilder at the Mayo Clinic developed it as a treatment for epilepsy. And it works really well, even to this day. We use this diet at Dartmouth Hitchcock Medical Center, especially with our pediatric patients with epilepsy.
How does it work? When you eat carbs, your glucose or blood sugar levels rise. Your pancreas comes to the rescue and secretes insulin. Insulin escorts those glucose molecules into your cells, which convert them to energy. With the keto diet, we don't have those carbs to use. So your glucose levels are going to fall. Your liver reacts by breaking down fats into molecules called ketones. Ketones circulate in the blood and become the main source of energy for the cells in the body. It's a roundabout way of getting energy to your cells without your sugars rising. Wilder’s team found that the ketones also help control seizures by interacting with the neurotransmitters in the brain.
Dr. Atkins entered the picture in the 1970s. He revived interest in this low-carb, high-fat, high-protein approach to promote weight loss. And thus, “The Atkins Diet” was born. The main difference is that he was promoting a little more protein than Dr. Wilder was back in the 1920s.
The keto breakdown
The standard American diet has about 50 to 60 percent of calories coming from carbs. In a ketogenic diet, 65 to 70 percent of calories come from fat. That's a lot of fat. Carbs are only at 5 to 10 percent and protein is 20 to 25 percent. In a standard 2,000-calorie diet, if it’s a keto diet:
- 1,500 of these calories would come from fat—that’s a whopping 167 grams of fat!
- 400 calories would come from protein, which equates to about 100 grams, which is a good amount.
- 100 calories from carbs, which is 25 grams.
Limiting carbs is very challenging to do. It takes a lot of discipline, because carbs are everywhere in our universe and they go down really easy.
Not as simple as cutting sugars
Back in 1931, Dr. Otto Warburg won a Nobel prize for his work in the metabolism of tumors and how they responded to ketones versus sugar. He really sparked an area of interest with sugar and cancer. Hence, we have the “Warburg Effect.”
The complicated definition is the cancer cells rewire their metabolism to promote growth, survival, proliferation and long-term maintenance. The common feature of this altered metabolism is increased glucose uptake and fermentation of glucose to lactate.
In other words, cancer cells have a strong preference for sugar compared to healthy cells. Cancer cells are also unable to use ketones for energy—they starve. In theory, this makes perfect sense, right? Get rid of the sugar, the cancer cells can't survive, and all is good. But in real life, it’s more complicated. The research doesn't back this theory up as strongly as we wish it did.
Possible benefits
A ketogenic diet may possibly provide some benefit, especially with gliomas, or brain cancers. Studies in animals show promise, but human studies are still inconclusive. There might be something to the elevated insulin levels that happen when you're eating a high carb diet—that may be a factor too that needs to be studied.
The good news is that no adverse effects were observed in those following a keto diet. It seemed to be safe to at least give it a try. Both intermittent fasting and the keto diet have shown some benefit to patients going through chemotherapy, such as a reduction in some drug toxicity and improved quality of life. The dietitians here at the Cancer Center have had a few patients going through chemotherapy who have opted to give this diet a try and they've done pretty well with it.
If you want to learn more, really read some articles on this. There was one published in the journal Nutrients in May of 2021 (Dowis et al.), which gives a nice overview of the potential health benefits of the keto diet. If you want to give it a go, we highly recommend you work with a registered dietitian who can set you up for success and make sure your body is getting all the nutrients it needs to stay healthy and strong.
To hear Dianne's full presentation on vegan, plant-based, ketogenic, Mediterranean and several other popular diets and diet trends, please visit Dartmouth Health video page.