ketogenic diet An Interview With Sheila Dean, DSc, RDN, LDN, IFMCP
Under usual circumstances, the cells of the body rely on glucose as their primary source of energy. Glucose is derived first from dietary sources and then from the breakdown of glycogen in the skeletal muscle and liver. When glucose is in short supply, the cells tap into fats as an alternative source of fuel. The breakdown of fats leads to the production of ketone bodies and a metabolic state called ketosis.
Nutritional ketosis can be induced by eating an extremely low-carbohydrate and high-fat diet. This is called the ketogenic diet. Originally developed as a way to control epileptic seizures, the ketogenic diet has surged in popularity for its many potential health benefits.
In this interview with Element Senior Writer Sarah Cook, ND, Sheila Dean, DSc, RDN, LDN, IFMCP, discusses the benefits of the ketogenic diet and how to minimize its potential risks.
Sheila Dean, DSc, RDN, LDN, IFMCP, is a registered and licensed dietitian nutritionist and board-certified integrative and functional medicine practitioner. She has taught nutrition at several universities over the last 20 years, and has owned an integrative and functional medicine practice in Palm Harbor, Florida, for 17 years. A published author and national speaker, Dr. Dean is co-founder of the Integrative and Functional Nutrition Academy (www.IFNAcademy.com), an online training and mentoring program for healthcare practitioners.
SARAH COOK:
What’s the origin of the ketogenic diet? Why was it developed?
SHEILA DEAN:
The origin of the ketogenic diet dates back to the time of Hippocrates, when the beneficial effects of fasting on seizure control were noted.
In the early 20th century, detailed medical reports of fasting as a treatment for epilepsy were published. Researchers at Harvard Medical School reported improvements in seizure control after two to three days of fasting and proposed that it was because of a shift in metabolism that forced the body to utilize fat for energy.
In 1921, two groups of researchers independently developed the ketogenic diet. One group was at Rush Medical College in Chicago, and the other was at the Mayo Clinic. The ketogenic diet was designed to mimic the metabolic state of fasting without inducing starvation or malnutrition.
The classic ketogenic diet calculated macronutrient intakes in a ratio of grams of fat to grams of carbohydrate and protein combined. The strictest ratio was 4:1, meaning there were 4 grams of fat for every 1 gram of carbohydrate and protein combined. Another way to calculate a similar macronutrient intake is 10 to 15 grams of carbohydrate per day, 1 gram of protein per body weight, and the remaining calories from fat.
The ketogenic diet was rapidly replaced by anticonvulsant drugs in the 1930s. It wasn’t until the 1990s that there was renewed interest in the diet—partly because of a movie titled First Do No Harm that told a story of a boy who overcame seizures on the ketogenic diet.
In recent decades, variations on the classic ketogenic diet have emerged that are less restrictive and easier to follow. Now it’s not only used for seizure control, but for a variety of other reasons as well.
COOK:
How is the ketogenic diet different from other low-carbohydrate diets?
DEAN:
The average American eats about 50 percent carbohydrate, which amounts to 250 grams per day for a 2,000-calorie diet. In its broadest definition, a low-carbohydrate diet restricts carbohydrate intake to less than 150 grams per day.
There are many types and variations of low-carbohydrate diets. For example, the Atkins diet includes phases of carbohydrate intake that range from 20 to 100 grams per day. The strictest phase of the Atkins diet, at 20 grams of carbohydrate per day, induces ketosis and is an example of a ketogenic diet.
A ketogenic diet is the most restrictive form of low-carbohydrate diets. It’s defined as any diet that results in a metabolic state of nutritional ketosis. The classic ketogenic diet limits carbohydrates to as little as 10 to 15 grams per day, but less restrictive variations allow for as many as 60 grams.
COOK:
Why do you think the ketogenic diet has gained so much recent popularity?
DEAN:
We’ve learned in recent years that the ketogenic diet has far more health benefits than originally thought.
For instance, when we restrict carbohydrates, the blood sugar drops, and the body is forced to rely on fats as an energy source. The body consequently becomes incredibly efficient at burning fat. That can promote weight loss and improve other biomarkers of health. Ketosis is associated with better blood-sugar metabolism, lipid metabolism, and insulin sensitivity.
Also, the ketogenic diet alters the fundamental biochemistry of neurons. When ketones are the primary energy source for neurons, that inhibits neuronal hyperexcitability. The diet also has a neuroprotective effect.
As a result, the ketogenic diet is now popular not only for people with epilepsy, but also for people with other neurological disorders, cancer, and obesity.
COOK:
Can you explain more about how ketosis supports brain health?
DEAN:
Part of the reason that a ketogenic diet may be so helpful for the brain is that it gives it an alternative fuel source in the form of ketone bodies.
Many neurological disorders seem to involve disrupted glucose metabolism and a decreased ability for the brain cells to utilize glucose. Nutritional ketosis offers a steady source of fuel for the neurons and decreases the likelihood of disruption in energy availability.
Another interesting mechanism is the ketogenic diet’s ability to increase the production and release of gamma–aminobutyric acid (GABA)— an inhibitory neurotransmitter that reduces neuronal excitation. The ketogenic diet has also been shown to block neuronal uptake of the excitatory neurotransmitter glutamate. The overall effect is to decrease the hyperexcitability of neurons that can contribute to neurological disorders.
COOK:
You mentioned other health benefits of the ketogenic diet. Can you elaborate?
DEAN:
When the body transitions to using ketones as the alternative source of cellular fuel, it can be very helpful for anyone who has a problem using glucose. It can open a potential for healing in patients with type 2 diabetes or metabolic syndrome because of its ability to reduce blood sugar and insulin levels.
The ketogenic diet can also promote weight loss and has been shown in some studies to be more effective than a low-fat or low-calorie diet. One study found that the ketogenic diet had beneficial effects on the lipid profile—decreasing triglycerides and LDL cholesterol while increasing HDL cholesterol.
In addition, the ketogenic diet supports mitochondrial health, which may be one reason to consider it for patients with cancer. Also, we know that cancer cells are dependent on the glycolytic pathway. The ketogenic diet limits the supply of sugar to the cells, potentially offering an advantage. Research on the ketogenic diet and cancer is limited, but a 2014 study found that the ketogenic diet could safely be used during chemotherapy or radiation.
According to a review article published in 2013, there is good evidence that the ketogenic diet may be beneficial for epilepsy, weight loss, cardiovascular health, and type 2 diabetes. There is emerging evidence that it may be -beneficial for acne, cancer, polycystic ovarian syndrome (PCOS), Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis (ALS).
COOK:
Are there any pitfalls or potential dangers of the ketogenic diet?
DEAN:
During the first few days of initiating the ketogenic diet, some people experience nausea, vomiting, headaches, dizziness, or other uncomfortable symptoms. People call this the “keto flu.”
Symptoms of the keto flu occur when the body is shifting from burning glucose for energy to burning fat. The changes in metabolism can shift electrolyte balance and cause dehydration. One way to minimize the risk of these symptoms is to gradually transition to the ketogenic diet over three or four days. It’s also helpful to drink plenty of water and to take a mineral or electrolyte supplement.
Another potential pitfall of the ketogenic diet is making poor food choices. The diet is guided by macronutrient ratios rather than food quality, so it doesn’t dictate the exact foods to eat. If people really overdo things like butter and bacon without including any vegetables, the diet may potentially do more harm than good.
Even for people who make an effort to choose high-quality foods, it can be challenging to get sufficient nutrients on such a restrictive diet. There’s a risk of consuming inadequate fiber, minerals, and some vitamins.
There’s also a risk of consuming too few calories. The fat content of the diet can make people feel full and cause them to eat less food. Although this might be a good thing for people who are overweight or obese, it’s not necessarily good for everyone.
Lastly, I encourage practitioners to be mindful of the emotional and psychological effects of drastic dietary changes. When people follow a restrictive diet, there’s a risk of developing a disordered pattern of eating or an unhealthy relationship with food.
Practitioners should routinely assess labs and clinical symptomology. That’s the best way to be sure patients are following the ketogenic diet in a safe and healthy way.
COOK:
How do you recommend patients be monitored when on the ketogenic diet?
DEAN:
The Academy of Nutrition and Dietetics published recommendations for laboratory assessments in its 2017 “Practice Paper of Classic and Modified Ketogenic Diets for Treatment of Epilepsy.” The paper recommends assessing a patient at baseline, one month, three months, and then every six months while on the ketogenic diet.
Labs should be chosen based on the individual patient and their symptomatology. Basic lab testing includes a complete metabolic panel, complete blood count, liver profile, and lipid panel. Also, a urinary organic acids panel gives an excellent overall picture of nutritional status. Other possible tests could include serum beta-hydroxybutyrate, vitamin D3, free and total carnitine, and minerals.
Patients can use keto strips to monitor their urinary ketones (acetoacetate) or serum ketones (beta-hydroxybutyrate) at home. This can be a helpful way to be sure they’re maintaining nutritional ketosis.
COOK:
Does the ketogenic diet put patients at risk for ketoacidosis?
DEAN:
The nutritional ketosis induced by the ketogenic diet is very different than ketoacidosis, which is a derangement of metabolism that can occur as a complication of type I diabetes.
In diabetic ketoacidosis, blood sugar is high because insulin levels are low. Sugar can’t enter the cells, so cells are starving for energy. Symptoms can include high blood sugar, rising ketones in the urine, increased urination, thirst, nausea, vomiting, fruity odor on the breath, and a risk of losing consciousness. Diabetic ketoacidosis is a medical emergency.
In nutritional ketosis, blood sugar is low. The metabolism shifts to become extremely efficient at utilizing ketones for energy, and ketones provide a steady supply of fuel for the cells. Unlike diabetic ketoacidosis, the metabolic changes associated with nutritional ketosis can have many positive effects.
Although it’s extremely rare, there have been documented cases of ketoacidosis in nondiabetic patients adhering to a ketogenic diet. Practitioners should be aware of this and always monitor patients.
COOK:
Are there any patients who should NOT go on a ketogenic diet?
DEAN:
The ketogenic diet is contraindicated for anybody who has a history of a metabolic disorder that limits fat metabolism or carnitine production. Examples include primary carnitine deficiency, beta-oxidation defects, pyruvate carboxylase deficiency, and porphyria.
There is some concern about implementing the ketogenic diet when there is a yeast or fungal infection. Neutrophils are important for the immune response against yeast, and they do this by producing myeloperoxidase. Ketones inactivate myeloperoxidase, potentially interfering with the immune response to yeast or fungal infections.
Yeast and fungi also use ketones as fuel, but it’s controversial whether ketones or sugar are a more important energy source. The jury is out as to whether a ketogenic diet is problematic for people with fungal infections, but practitioners should be aware that there is a potential interaction.
COOK:
How do you optimize nutrient intake for the ketogenic diet?
DEAN:
Start by teaching patients how to make healthy food choices on the ketogenic diet. Eggs, fish, avocados, nuts, and seeds are keto-friendly and nutrient-dense foods. Non-starchy vegetables like broccoli, cauliflower, spinach, kale, and chard should be included every day. Herbs, spices, lemon juice, and other low-carb condiments can add nutritional value as well.
Supplementation can be used to fill in any potential nutrient gaps in the ketogenic diet. Fiber is often under-consumed and can be supplemented. I also recommend a multivitamin with minerals, calcium, and vitamin D.
COOK:
Should the ketogenic diet be considered a lifestyle change?
DEAN:
The answer to that depends on the patient. Because the ketogenic diet originated as a therapeutic diet to treat epilepsy, it was administered and tightly monitored in a hospital setting. Now there are less restrictive variations that people are able to follow at home. For some patients, it makes sense to adopt the ketogenic diet as a lifestyle change.
Patients who follow the ketogenic diet because they have epilepsy or a neuro-degenerative disorder will only continue to see the benefits of the diet and will enjoy a higher quality of life for as long as they remain on it. This may also be true for some patients with cancer or a history of cancer.
For healthy adults who adopt the ketogenic diet for weight loss, it makes sense to follow the diet for three to six months or until goal weight is achieved. Then for weight maintenance, they can transition to a less restrictive version of a low-carb diet that includes more variety of plant-based foods.
Following the ketogenic diet for some time and then gradually adding in more carbohydrates is also a reasonable approach for people with insulin resistance or metabolic syndrome.
Although the “keto lifestyle” has gained popularity and momentum, the research to support the ketogenic diet for general health promotion is not strong. An analysis published in the Journal of Clinical Nutrition compared the effects of 13 dietary patterns on biomarkers of health. The Mediterranean diet pattern was the only one that resulted in a positive effect on every biomarker.
That’s why, when it comes to general health promotion, I recommend a Mediterranean-style, plant-based diet with plenty of fruits and vegetables, small amounts of lean protein, and organic eggs.
I consider the ketogenic diet to be a therapeutic approach to heal. Depending on a person’s unique genetics and biochemistry, the ketogenic diet has the potential to improve function and offer a quality of life that could never be achieved otherwise.
Selected References
Dyson PA, Beatty S, and Matthews DR. Diabet Med 24, no. 12 (2007): 1430–35.
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