There is exciting research on the role of a keto diet as a form of treatment for cancer. In one study, the use of a keto diet on patients with advanced cancer was deemed safe, and some evidence suggested it played a role in stabilizing the disease or resulting partial remission. In another study, the keto diet was used as a form of therapy for patients with malignant brain cancer. The study found that the keto diet may carry anti-tumor effects when administered in experimental animal and human brain tumors. The researchers believe this may be due to the reduction in calories, which reduces the circulating glucose needed for tumor growth. It is still unsure whether a keto diet per se plays a role in this or simply calorie restriction. All of this is to say that the research is preliminary, however still promising.
Answer: No—unless you do it for more than a few months. After a few months, the upfront metabolic and weight benefits will begin to reverse and new health problems arise. We know this with confidence. I raise this question once again because more and more people are coming to me reporting problems. It may take months, even years, but the long-term consequences can be quite serious.
Either there are very few participants in the studies, they don’t have an even number of males vs. females, or they don’t last but a few months. One study only looked at 28 people; only 21 completed the study and 20 of these participants were men. On top of this, they were only followed for 16 weeks. Okay, so we see that 20 men can limit their carbohydrates severely for 4 months and lose weight which automatically makes their A1c come down. Great! So, the real question is, how long can these 20 men stay on this diet for the rest of their lives? How long would you like to go without eating any fresh fruit? I’m craving some now, so I’m taking a break to go grab a snack now!
Increases in cholesterol levels need discussion too. We do see temporary increases in cholesterol levels often as individuals transition onto a ketogenic diet. However, when you examine lipid particle size (a more important way to look at the cardiovascular risks), the risk pattern doesn’t seem to increase with a ketogenic diet. Harvard Health has written about lipid particle size here before: http://www.health.harvard.edu/womens-health/should-you-seek-advanced-cholesterol-testing-
Long-term disruption of menstruation can bring on serious side effects, including low bone density. “This is because estrogen is very important to bone health,” says Yawitz. “Studies have also found prolonged menstrual irregularity to increase risk for cardiovascular disease, depression, anxiety, and sexual dysfunction. It’s important to contact your ob-gyn if your cycles become irregular or if you stop having periods.”
The keto diet is an extremely effective way to lose weight over a short period of time—even better, according to some research, than low-calorie and low-fat diets. There a few reasons for this: When you’re in ketosis, your body stores less fat. Dieters feel fuller for longer, partly because of the rich food they’re eating, and partly because ketosis changes your hunger hormone levels.
These findings were backed up in a 2012 study which had obese diabetics follow a ketogenic diet for 12 months. The researchers found lower fasting glucose levels, improved cholesterol markers and improved HA1c readings. Remember, carbs and glucose are not required when on a ketogenic diet, as stable, clean burning energy is sourced from fat. This makes controlling blood sugar levels near foolproof.
These types of back-and-forth weight fluctuations can contribute to disordered eating, Kizer says, or can worsen an already unhealthy relationship with food. “I think this diet appeals to people who have issues with portion control and with binge eating,” she says. "And in many cases, what they really need is a lifestyle coach or a professional counselor to help them get to the bottom of those issues."
More recently, a meta-analysis was published in the Journal of Neurology that assessed the impact of the ketogenic diet in treating epilepsy. It included a total of 19 studies with a total of 1084 patients. After analyzing the data, the researchers noted that the patients who stayed on the diet had a 2.25 times greater probability of treatment success (at least a 50% reduction in seizures).
On the standard keto diet, you plan all meals and snacks around fat like avocados, butter, ghee, fatty fish and meats, olives and olive oil. You need to get about 150 grams a day of fat (the amount in nearly ¾ cup of olive oil and three times what you are likely eating now) in order to shift your metabolism so it burns fat as fuel. At the same time, you need to slash your carbs from about 300+ grams per day to no more than 50 (which is about the amount found in just one blueberry muffin). That means sticking to leafy greens, non-starchy veggies, and low-carb fruits like berries and melon. Finally, you'll eat a moderate about of protein, which is about 90 grams per day or 30 grams at each meal (think 4 ounces of meat, fish, or poultry).
Until recently, ketosis was viewed with apprehension in the medical world; however, current advances in nutritional research have discounted this apprehension and increased public awareness about its favourable effects. In humans, ketone bodies are the only additional source of brain energy after glucose (23,24). Thus, the use of ketone bodies by the brain could be a significant evolutionary development that occurred in parallel with brain development in humans. Hepatic generation of ketone bodies during fasting is essential to provide an alternate fuel to glucose. This is necessary to spare the destruction of muscle from glucose synthesis.
One of the boldest claims about the keto diet is that it can help combat cancer by effectively "starving" cancer cells. It's a claim based on a phenomenon dubbed the "Warburg effect", which, in simple terms, describes how cancer cells are more reliant on sugar than healthy cells. So, the idea is that sticking to a low-carbohydrate diet will make it harder for cancer cells to thrive.
Technically speaking, you're in ketosis when your blood ketones are higher than 0.5 mmol/L, but the optimal level for fat-burning purposes is 1.5 to 3 mmol/L. Nisevich Bede says that seasoned keto dieters report that they can actually feel a difference in this state, citing that they're less hungry and experience mental clarity once they reach ketosis.