Dr Liam West (@Liam_West), Johann Windt (@JohannWindt), & Ania Tarazi
We’re back and nutrition is once again in the spotlight here at the #LCHF Summit in Cape Town. If you haven’t yet seen them yet, go back to read Day 1 & Day 2 Blogs. It is a very polarised topic, but what exactly is the best diet to follow to stay healthy and increase performance? Here’s the Day 2 and Day 3 Storify from the summit!
Dr Michael Eades – 40 years of flawed nutritional science. What will it take for change to be accepted?
Using anthropological data, Dr. Eades argued that when humans used to eat #LCHF diets they were in better health. Dr Eades discussed an Isotope Analysis used by Richards (2000) which showed Neanderthals had diets high in protein & when diet changed to include CHO and how pathological consequences ensued.
Dr Aseem Malhotra – How Dietary changes can rapidly and substantially reduce risk of cardiovascular death
In a bold address, Dr Aseem Malhotra (@DrAseemMalhotra) covered both the worries of the quality of current medical research and also how diet can impact heart disease. For more from Dr Malholtra, listen to this BJSM Podcast here.
Dr Malhotra identified “7 sins that contribute to lack of knowledge” [Extra reading]:
1) Biased funding of research,
2) biased reporting in medical journals,
3) biased patient pamphlets
4) biased reporting in the media,
5) Commercial conflicts of interest
6) Defensive medicine
7) Medical curricula that fail to teach doctors how to comprehend & communicate health statistics.
On one hand, Dr Malhotra challenged physicians. He highlighted the imperative of physicians to focus on a patient-centred approach through sharing the decision making process – For example, providing patients with informed consent prior to procedures shown in this PCI study as an example. Dr Malhotra also identified that many doctors do not understand health statistics and therefore cannot evaluate the evidence for or against a treatment.
On the other hand, Dr Malhotra criticized the uphill battle patients face in the area of diet due to industry funding biases, in the face of strong data for the efficacy of diet primary prevention of cardiovascular disease. He also stated that saturated fat is not the major issue, read more in this study: Cambridge MRC.
For people with low risk of CVD, “Statins are not the answer”, Dr Malhotra emphasized. It is more likely that are pushed by industry bias (BMJ). The primary prevention of CVD was achieved through the Mediterranean diet to date PREDIMED RCT.
Dr Malhotra then went onto discuss the #ObesogenicEnvironment we live in surrounded by processed, energy dense foods. He explained that we have toxic hospital food environments with fast food on-site and hospital snack trolleys.
Dr Jason Fung – Novel Management of diabetes & insulin resistance
In his second talk of the summit, Dr Jason Fung narrowed his focus to the treatment of diabetes and insulin resistance. Dr Fung predicated his discussion on the fact that increased insulin levels produces and exacerbates insulin resistance, the underlying problem in T2DM. In this model:
- Under conditions of high persistent insulin: Liver becomes full of sugar and fat. The reduction in insulin levels (via decreased CHO intake, sugar intake, increased fiber intake, caloric restriction) can restore beta cell function – improve the diabetes.
- Type 2 Diabetes Mellitus (T2DM) has 2 phases prior to diagnosis. Initial slow phase with building resistance and then late stage sharp increases in fasting glucose due to Beta Cell Dysfunction
- Insulin resistance has shown to be reversible through surgery, fasting, and diet. For that reason, Dr. Fung argued that diabetes should not be considered a progressive, chronic disease. This contributes to a learned helplessness, the targeting of blood glucose control when it is just a symptom of diabetes. Should aim to lower insulin and to do this lower CHO intake.
In summary, Dr. Fung argued that insulin and subsequent insulin resistance causes T2DM, not blood glucose. Therefore, treatments should work to lower insulin, not simply manage the symptom of blood sugar.
Dr. Gary Fettke – Nutrition and lifestyle related illnesses
“So you think you need sugar? Cancer needs it more!” Dr Fettke challenged delegates to consider whether we have the right focus for the treatment of cancer. Discussing the metabolic model of cancer, he highlighted the various types of cancer with the same metabolic pathway – glucose – and the possibility that it is the metabolically derived free radical production that changes chromosomal structure. He then connected this to ketogenic diets which could have an ability to slow tumour growth through lowering glucose availability
Prof Tim Noakes – Why did I support high CHO diets for athletes for so long? Review of scientific studies supporting either high or low CHO diets for athletes
Few people are more qualified to present on the topic of athletic performance as Professor Tim Noakes. In this particular address, Professor Noakes explained his own U-Turn from recommending carbohydrate loading and high carbohydrate diets for athletes to now promoting #LCHF diets. Attendees were taken through a review of the performance data from a carb-centred approach, then again from a fat-focused approach. Take home messages included:
- For endurance athletes, the preservation of muscle glycogen is an important performance parameter, and historically attempts have focused on loading and maintaining glycogen/glucose supplies throughout activity. However, increased fat oxidation during exercise will similarly spare glycogen through supplying a greater proportion of exercise energy through fat metabolism.
- In a brief address from Prof. Noakes’ colleage, Dr. James Smith showed that in athletes adapted to a low-carbohydrate diet, fat oxidation during exercise is significantly higher than those on a higher carbohydrate diet.
- Though traditional diet-performance studies focus on the effects of diet and nutrients on single exercise bout performance, it is important to consider long term health effects as well as the effects of diet on recovery measures and total training volume.
- Athletes who are insulin sensitive may continue to perform best on higher carbohydrate diets, whereas insulin resistant athletes will most benefit from the #LCHF approach.
- Though endurance athletes may benefit from a #LCHF diet, there is more research needed to evaluate their efficacy in other sports such as strength/power sports, or intermittent sports such as cricket or golf.
Dr. Stephen Phinney – 30 years studying low CHO diets for athletes
Continuing the theme of #LCHF diets and athletic performance, Dr. Stephen Phinney discussed his many years of work with keto-adapted athletes. Similarly to Prof. Noakes, Dr. Phinney discussed data showing that endurance athletes, once adapted to a low-carbohydrate diet, can form at least as well as control diets. Most notably, he presented data that would require the reconsideration of classical exercise physiology textbook sections, demonstrating that the rates of fat oxidation at different exercise intensities are significantly different in athletes who are fat-adapted. Data that indicate anti-inflammatory effects of ketogenic diets provide preliminary insight into the potential effects of ketogenic diets in minimizing exercise-related muscle damage, increased training volume, and reducing overtraining. Additional potential benefits of nutritional ketosis in various sporting contexts remain an area in need of robust research.
So to return to the title of this blog, have we finally found the key to open the door to optimal nutrition after this #LCHF summit? No, not entirely. The door is definitely ajar and the data in the room is certainly promising. However, there is a need for further robust research before we can walk through the threshold into a new consensus of nutrition. At this point, low carbohydrate diets have documented effects on reducing weight, improving glycemic control, improving cardiovascular risk profiles (with variable LDL responses), and promising evidence in the area of endurance sports. For this reason, they should be considered a valuable and viable dietary option. Indeed, a universal one-size-fits-all approach to diet would certainly be premature and ill-advised at this point, but to dismiss and ignore the evidence on the efficacy of low-carbohydrate diets would be negligent.