Low Carb Paleo Diets vs. Cancer: A Follow-up Note To Steve Jobs
By: Dave Asprey
“There’s no statistical significance in the sad passing of Steve Jobs and his choice of vegan diet.”
That’s a quote from one of the comments on the previous article about how Steve Jobs’ diet contributed to his early death (or at least it didn’t slow it down). The article has received 64 comments, often from people saying there is no way his vegan diet could have contributed to cancer, or people saying that we have to accept that diet plays no role whatsoever.
As always, the best course of action is to look at the research. Luckily, German researchers from the University Hospital of Würzburg just published one of the largest reviews on the benefits of low-carbs diets for cancer patients.
Published in the Journal of Nutrition and Metabolism, this large scale review would have been useful in helping to prevent Steve’s early demise. Instead of following a low-carb diet, Mr. Jobs trusted his health to the Dean Ornish, high-carb, low-fat, macrobiotic, pseudo-vegan diet. I’ve already discussed why this diet was terrible for treating cancer, but some of the readers were unconvinced. At some least the vegans and vegetarians weren’t… (yet – this blog has transformed nearly 2 dozen former vegans back into powerful people full of more life than they had before…)
A vegan diet isn’t necessarily high-carb. There has to be at least five or so vegans who live off of avocados and olive oil. All jokes aside, the vast majority of vegans eat a high-carb, low-fat, grain based diet. Even if you aren’t vegan, eating a high-carb diet is going to increase your risk of cancer.
The first sentence of the abstract reinforces how research has shown a high-carb diet diet is horrible for cancer patients.
“Over the last years, evidence has accumulated suggesting that by systematically reducing the amount of dietary carbohydrates (CHO) one could suppress, or at least delay, the emergence of cancer, and that proliferation of already existing tumor cells could be slowed down.”
By limiting carbohydrates, you can decrease your risk of cancer and improve your chances of recovery. You can also slow down the progress of an existing cancer.
The researchers went even further to suggest a low-carb diet could be preventative against cancer. So much for “no statistical evidence a vegan (ahem, high-carb) diet contributes to cancer.”
According to this review, a high-carb diet is believed to contribute to cancer in six ways:
1. Cancer cells depend almost exclusively on glucose. The mitochondria of cancer cells are dysfunctioning (because of UCP2), which prevents them from metabolizing ketone bodies or free fatty acids. Chronically elevated glucose levels feed tumors and cancer cells. Elevated insulin levels also promote the growth of tumors.
“Evidence exists that chronically elevated blood glucose, insulin and IGF1 levels facilitate tumorigenesis and worsen the outcome in cancer patients.”
The best way to fix this problem is to lower both glucose and insulin levels. This method is especially effective in people with advanced stage cancer (like Steve Jobs).
“High fat, low CHO diets aim at accounting for these metabolic alterations. Studies conducted so far have shown that such diets are safe and likely beneficial, in particular for advanced stage cancer patients.”
2. High insulin and insulin like growth factor, “resulting from chronic ingestion of CHO-rich Western diet meals”, can “directly promote tumor cell proliferation via the insulin/IGF-1 signaling pathway.” High insulin levels from a high-carb diet promote tumor growth.
3. Many cancer patients develop insulin resistance, which can make a high-carb diet deleterious to their health in numerous ways. As the researchers stated, patients may “profit from an increased protein and fat intake.” (But they didn’t differentiate between good and bad proteins like we do in the Bulletproof Diet.)
4. High amounts of circulating glucose are extremely inflammatory. Inflammation exacerbates almost all diseases, including cancer.
5. Rodent studies have found ketone bodies to inhibit cancer cell growth. This has yet to be proven in humans – but the clinical observations are very strong.
6. A grain based diet contributes to inflammation, depletes nutrient stores, and prevents the absorption of nutrients.
Low-Carb Diets: Fasting Without Fasting (for cancer patients)
Caloric restriction is another effective way to lower both insulin and glucose levels, but it comes with some negative side effects. Cancer patients often lose weight and become malnourished during their treatment, and starving them isn’t going to improve the situation. Luckily, carbohydrate restriction can take advantage of almost all the benefits of caloric deprivation, without starving the patient.
“CHO restriction mimics the metabolic state of calorie restriction or – in the case of KDs (ketogenic diets) – fasting. The beneficial effects of calorie restriction and fasting on cancer risk and progression are well established. CHO restriction thus opens the possibility to target the same underlying mechanisms without the side-effects of hunger and weight loss.”
By cutting carbs (and adding MCT oil to enter ketosis faster), cancer patients might be able to utilize the benefits of caloric restriction, without cutting calories and suffering from malnourishment. Speaking of malnourishment…
Grains Are Horrible Even on A Low-Carb Diet
The most interesting part of this study was the role grains played in causing cancer. Vegans, vegetarians, and most Americans get the majority of their carbs from grains. As the researchers pointed out, grain based carbs might be the main problem, not carbs in general.
A high-carb diet is bad for cancer patients, but a grain based diet is even worse.
“Usually, CHO restriction is not only limited to avoiding sugar and other high-GI foods, but also to a reduced intake of grains. Grains can induce inflammation in susceptible individuals due to their content of omega-6 fatty acids, lectins and gluten [159, 160]. In particular gluten might play a key role in the pathogenesis of auto-immune and inflammatory disorders and some malignant diseases.”
There are hundreds of reasons grains contribute to cancer, so this article will cover just a few.
Grains cause inflammation by themselves, regardless of whether or not the diet is low in carbohydrates. This occurs through several pathways.
Grains contain omega-6 fats, lectins, phytates, damaging fiber, and gluten. Anything that contributes to inflammation will make cancer worse, but gluten has several special characteristics that exacerbate cancer growth. Gluten overstimulates the release of zonulin, a protein that regulates the space between epithelial cells in the small intestine. This causes dysregulation between cells which promotes cancer growth throughout the digestive tract.
“In the small intestine, gluten triggers the release of zonulin, a protein that regulates the tight junctions between epithelial cells and therefore intestinal, but also blood-brain barrier function. Recent evidence suggests that overstimulation of zonulin in susceptible individuals could dysregulate intercellular communication promoting tumorigenesis at specific organ sites”
Reducing total carbohydrate load was not nearly as important as removing grain based carbohydrates. It’s sad to think that Steve Jobs was being told to eat not only a high-carb diet, but also to eat 8-11 servings of “healthy” whole grains a day.
The study authors were quick to offer a solution: the paleo diet. Both animal and human studies have shown the paleo diet is extremely effective at improving glucose tolerance and decreasing your risk for disease – far more so than the grain based Mediterranean diet. Switching to a paleo diet would remove grains, and lower the total glycemic index of the person’s diet. Vegetables have a far lower glycemic index than grains. Studies have shown this results in better glucose control and less inflammation.
“Paleolithic-type diets, that by definition exclude grain products, have been shown to improve glycemic control and cardiovascular risk factors more effectively than typically recommended low-fat diets rich in whole grains . These diets are not necessarily very low CHO diets, but focus on replacing high-GI modern foods with fruits and vegetables, in this way reducing the total GL.”
Even if the diet was high in carbohydrates, it would be better than a low-carb, grain based diet. But none of them would touch the Bulletproof Diet, which also accounts for another major inflammation (and cancer) contributor: mycotoxins.
Cancer: A Novel (Neolithic) Problem
Cancer is a modern disease, and was almost unheard of before the agricultural revolution. After switching from a high protein, high fat, moderate carb, low toxin diet to a grain based diet, people started getting cancer.
“Thus, the switch from the “caveman’s diet” consisting of fat, meat and only occasionally roots, berries and other sources of carbohydrate (CHO) to a nutrition dominated by easily digestible CHOs derived mainly from grains as staple food would have occurred too recently to induce major adoptions in our genes encoding the metabolic pathways.”
Humans aren’t made to eat a grain based diet. I discuss this at length in the Better Baby Book, (Wiley, 2012!) and go into detail as how grains negatively effect epigenetics and our health. Our genes are made to respond to certain foods both positively and negatively. Cancer is a pretty negative response.
The researchers were smart to mention that diet isn’t the only factor in the development of cancer. There are other components such as “regular physical activity, sun exposure, sufficient sleep, low chronic stress and the lack of foods that would also not have been available to our pre-neolithic ancestors.” Okay, so diet was still the most important part.
Before you start ranting about how this only applies to high GI carbs and touting “complex carbs” and “healthy whole grains”, remember that whole grains have an equal or greater insulin response to white flour. Regardless of the kind of grains you’re eating – they’re still going to produce a large insulin release.
The researchers go on to mention the importance of “sufficient vitamin D.” This is particularly interesting since grains deplete vitamin D stores and interfere with vitamin D absorption. There are even cases of people on a grain based diet developing rickets, despite adequate vitamin D intake. Vitamin D deficiency is yet another pathway by which grains cause cancer.
Should Cancer Patients Go Zero Carb?
No. As Dr. Paul Jaminet has pointed out, it’s important for cancer patients to avoid glucose deficiency. Glycosolated proteins are needed for intracellular signaling, so too little glucose can disrupt this process. Without enough glucose, these proteins can’t form efficiently. When cells don’t communicate properly, cancer often ensues. Ketogenic diets have had some success in treating cancer, though it’s not conclusive. Keeping a small amount of carbohydrates in the diet (about 100g) would be the best option.
The Verdict: Low-Carb Paleo Beats Cancer
This study is one of the best showing a high-carb, grain based diet contributes to cancer. It also shows a low-carb, paleo diet is an effective treatment for cancer.
Low-carb diets aren’t perfect for everyone. They’re horrible for endurance athletes, and you shouldn’t eliminate all carbs for long periods of time. But low carb diets can be extremely effective in treating cancer. Excess glucose feeds tumor cells, and insulin drives the overgrowth of cancerous tissue. Grains are particularly disastrous as they also increase inflammation, deplete nutrient stores, and serve as a cheap source of carbs. Reducing carbohydrates should have been one of the first things Steve Jobs tried, but instead it looks like he was advised to maintain a high-carb, low-fat, grain based diet. I designed the Bulletproof Diet (moderate carb) to reduce my own chance of an early death, and make myself more resilient to cancer if it does strike. Plus, I like to feel good and have abs too.
What do you think of this study? What are its strengths and limitations? Lets discuss in the comments.