In general terms, I recommend a diet lower in carbohydrate than conventional guidelines say is healthy. At least part of my thinking is based on abundant evidence linking a relatively carbohydrate controlled diet with benefits in terms of body weight and disease markers for conditions such as heart disease and type 2 diabetes. However, I came across a recent paper which made me think more about the impact a low-carbohydrate might have on risk of another important condition – cancer [1].
You can read a summary of the paper here and download a provisional pdf of the full paper here.
The paper starts with reference to hunter-gatherer diets, and their relatively protein-rich, low-carb nature, and remarks that cancer has been found to be rare in societies eating such a diet. It then goes on to postulate several major mechanisms that may account for this association. These include:
1. Cancer cells feed preferentially on sugar (glucose)
Glucose (from sugary and starchy foods) provides the prime fuel for cancer cells, so a diet lower in carbohydrate may therefore reduce tumour development or progression.
2. Insulin and IGF-1 can stimulate tumour cell growth
High carbohydrate diets increase levels of insulin and what is known as insulin-like growth factor-1 (IGF-1) which stimulate tumour cell growth. A lower carbohydrate diet may reduce tumour proliferation as a result.
3. Ketones suppress cancer
Very low carbohydrate diets can lead to the production of ‘ketones’ (mainly produced from fat) that suppress tumours.
4. Low-carbohydrate and ‘ketogenic’ diets ‘starve’ cancer
Low-carbohydrate diets mimic caloric restriction and ketogenic diets mimic starvation – and caloric restriction/starvation is linked to reduce tumour development and progression.
5. Low carbohydrate diets can reduce inflammation
Inflammation is believed to be a risk factor in the development of cancer, and high-carb diets encourage inflammation. Low-carbohydrate diets have been found to be more effective than low-fat ones in terms of reducing markers of inflammation.
The paper also makes the case that such diets may help better meet the nutritional needs of those with cancer.
I’ve only plucked out some of the highlights of this paper, as you can read it in its entirety if you so wish. If you do, though, you may well find that the paper makes a pretty compelling case for the role of carbohydrate-restricted diets in the prevention and treatment of cancer.
References:
1. Klement RJ, et al. Is there a role for carbohydrate restriction in the treatment and prevention of cancer? Nutrition & Metabolism 2011, 8:75
You forgot to mention that protein can also increase IGF1 and insulin. It’s not just down to carbs.
Also, inflammation is caused by unnatural foods which are unfamiliar to human DNA, rather than carbs. Refined , processed and synthetic foods of plant or animal origin are the cause of inflammation as well as lack of immunity.
You might be interested in this detailed overview of a possible cancer diet, in it, they refer to a more nuanced interpretation of ketogenic diets (rather intermittent than continuous)
http://perfecthealthdiet.com/?p=4739
I have not yet read the original paper, so I don;t know if this comment applies to this case. In general, I wish researchers and their papers would distinguish between high glycemic load carb foods and low glycemic carb foods. Although low glycemic load foods turn into sugar eventually, they avoid spikes in blood sugar and in insulin. Vegetables and fruits have plenty of carbs, but mostly low and medium glycemic in nature. Thoughts?
see my comments on Podcast page.
When somebody is very keto-adapted(like me), his or her blood sugar level is never too low, and fasting BS can be on a high side. What does it mean for a cancer prevention. I am on a ketogenic diet for my migraine control. I feel much better than before overall, stop having flues, don’t need asthma medication, no urinary tract infections, my stamina has increased significantly, but blood sugar is higher than before. When a person in my situation should start to worry?
Agree with Nancy Bruning. Find a higher carb but low GI diet helping with depression, menopause, low energy and weight loss. Found very difficult carb. cravings on the stone age diet. So what is the answer, folks? Is there a gender and age/life stage component that Dr John is missing?
All the items you pick out are true, John, but in the midst of cancer treatment, their application can become utopian, even for those who normally follow a low-carb diet.
http://www.ncbi.nlm.nih.gov/pubmed/17313687
The success of the treatment was attributed in this study – from 2007 – to caloric restriction. Cutting carbs does cut calories.
I agree with Rachel and Nancy. Demonisation of all carbohydrate containing foods is inappropriate (though demonisation of refined, processed and contamintaed foods of all types is appropriate). Natural wholefoods containing carbs are healthy and beneficial- 1) Eat enough natural protein containing wholefoods to replenish the body’s needs for protein, 2) Eat the fat that is contained in natural protein and carb containing foods to help digest the protein and enable metabolism of fat soluble vitamins and other biologically active cofactors 3) eat sufficient of a wide range of natural carbohydrate containing wholefoods in order to maintain proper body weight (not too much body fat), ensure intake of large amounts of micronutrients, and satiate hunger.