Conference on Ketogenic Diets
Updated August 01, 2014.
Originally Posted on My Blog on April 13, 2011
Each year I get quite excited about going to the symposium put on by the Nutrition and Metabolism Society. This year it was in Baltimore, and the topic was ketones and ketogenic diets. Briefly, ketones are a group of molecules produced during fat metabolism, and they can mostly be used as fuel for the body. Low-carb diets tend to be ketogenic in that the body will use fat for energy instead of glucose or fructose, but as we will see, it depends on how much carbohydrate and the metabolism of the individual.
There was more intense biochemistry than usual this year. I clearly could benefit from more study in this area. Nevertheless, I learned a lot of practical as well as interesting information. Here are some of the highlights:
- There is no one "ketogenic diet". There is a diet which had been officially dubbed the "Ketogenic Diet", which is used to treat epilepsy. This diet is not only very low in carbohydrate, but limits protein as well. Whether or not a diet is ketogenic is not an either/or situation - it's more accurate to think about the extent to which a diet is ketogenic. A diet lower than 50 grams of carbohydrate per day is ketogenic in most people. A diet lower than 130 grams of carb per day is at least mildly so. But to what extent the body generates ketones thoughout the day is also dependent on other factors such an the individual's metabolism and activity level. The diet of a high-performance athlete may be ketogenic on as much as 200 grams of carb per day. Also, some people's bodies are probably more efficient than others at making glucose from protein (gluconeogenesis), which limits ketogenesis.
- Anecdotally, a growing number of high-performance athletes (marathon runners, triathletes, and some Olympians) are following ketogenic diets, but for the most part they have not been very public about it. Lindsey Vonn (Olympic skier) has said she follows a low-carb diet, but has not released details.
- Lowering insulin production has several plausible mechanisms for inhibiting cancers. Many of the signaling pathways being studied by cancer researchers are also affected by insulin.
- Some types of tumors can't use ketones as fuel. There is a fair amount of rodent work on this. In humans, most of the published work is in the form of case studies so far, but there have been some rather dramatic ones - they showed us pictures of the MRIs of brain tumors.
- Tumors most likely to respond to ketogenic diets are most cancers of the lung, colon, breast, "and many others", but not all tumors depend on glucose, e.g. prostate cancer.
- I'm now totally convinced of the value of recommending added salt during the first week or so of a low-carb diet, when sodium and other minerals are lost along with some water. Hyponatremia (sodium deficiency) isn't common, but it definitely happens. Bouillon is a good source - even better is the deluxe version - real meat broth made from real meat bones - as it has contains other minerals which may be temporarily depleted (magnesium, potassium, etc). Headaches are one of the symptoms which can be caused by lack of sodium.
- Sometimes people experience nausea when starting on a low-carb diet. Apparently, this is less likely to be caused by a lack of sodium. One possible cause of this is consuming too many foods rich in omega-6 fats. As we add fat to the diet we should be careful not to overdo soy oil, corn oil, and most seed oils (exception are high-oleic ones). People often increase their use of mayonnaise and salad dressings - try to avoid using those made with these oils. Tips for healthy salad dressings.
Related Resources:
Originally Posted on My Blog on April 13, 2011
Each year I get quite excited about going to the symposium put on by the Nutrition and Metabolism Society. This year it was in Baltimore, and the topic was ketones and ketogenic diets. Briefly, ketones are a group of molecules produced during fat metabolism, and they can mostly be used as fuel for the body. Low-carb diets tend to be ketogenic in that the body will use fat for energy instead of glucose or fructose, but as we will see, it depends on how much carbohydrate and the metabolism of the individual.
There was more intense biochemistry than usual this year. I clearly could benefit from more study in this area. Nevertheless, I learned a lot of practical as well as interesting information. Here are some of the highlights:
- There is no one "ketogenic diet". There is a diet which had been officially dubbed the "Ketogenic Diet", which is used to treat epilepsy. This diet is not only very low in carbohydrate, but limits protein as well. Whether or not a diet is ketogenic is not an either/or situation - it's more accurate to think about the extent to which a diet is ketogenic. A diet lower than 50 grams of carbohydrate per day is ketogenic in most people. A diet lower than 130 grams of carb per day is at least mildly so. But to what extent the body generates ketones thoughout the day is also dependent on other factors such an the individual's metabolism and activity level. The diet of a high-performance athlete may be ketogenic on as much as 200 grams of carb per day. Also, some people's bodies are probably more efficient than others at making glucose from protein (gluconeogenesis), which limits ketogenesis.
- Anecdotally, a growing number of high-performance athletes (marathon runners, triathletes, and some Olympians) are following ketogenic diets, but for the most part they have not been very public about it. Lindsey Vonn (Olympic skier) has said she follows a low-carb diet, but has not released details.
The Heart
- The heart really "likes" using ketones as fuel. Dr. Yoshihiro Kashiwaya presented data from a series of extremely well-controlled studies showing that the rodent heart is more efficient when using ketones as fuel than when utilizing glucose. There is evidence that this is also true in humans.Cancer
- Hyperinsulinemia is an increasingly recognized risk factor for many cancers (caveat: we must always remember that a "risk factor" is not at all the same thing as a "cause", although risk factors can obviously be causes).- Lowering insulin production has several plausible mechanisms for inhibiting cancers. Many of the signaling pathways being studied by cancer researchers are also affected by insulin.
- Some types of tumors can't use ketones as fuel. There is a fair amount of rodent work on this. In humans, most of the published work is in the form of case studies so far, but there have been some rather dramatic ones - they showed us pictures of the MRIs of brain tumors.
- Tumors most likely to respond to ketogenic diets are most cancers of the lung, colon, breast, "and many others", but not all tumors depend on glucose, e.g. prostate cancer.
Epilepsy
- It is no longer controversial to treat epilepsy with a ketogenic diet. Though it doesn't work on all types (or for all people within any one type), it appears to be just as effective with adult epilepsy as child epilepsy. Kids are usually on the diet for 2-3 years, but there is at least one case of someone on it for 30 years.Tips for Ketogenic Diets
- There seems to be somewhat of a consensus among the presenters that Ketostix (urine dipsticks) are not generally recommended as a method of monitoring ketosis. The results do not correlate well with ketones in the blood. (I would add that this seems to be especially true as time goes on.)- I'm now totally convinced of the value of recommending added salt during the first week or so of a low-carb diet, when sodium and other minerals are lost along with some water. Hyponatremia (sodium deficiency) isn't common, but it definitely happens. Bouillon is a good source - even better is the deluxe version - real meat broth made from real meat bones - as it has contains other minerals which may be temporarily depleted (magnesium, potassium, etc). Headaches are one of the symptoms which can be caused by lack of sodium.
- Sometimes people experience nausea when starting on a low-carb diet. Apparently, this is less likely to be caused by a lack of sodium. One possible cause of this is consuming too many foods rich in omega-6 fats. As we add fat to the diet we should be careful not to overdo soy oil, corn oil, and most seed oils (exception are high-oleic ones). People often increase their use of mayonnaise and salad dressings - try to avoid using those made with these oils. Tips for healthy salad dressings.
Related Resources:
