I’m met with an array of reactions when I share that I am a plant-based eater and 25 year cancer survivor who still loves my animal protein. My philosophy on disease prevention has more to do with suggesting that vegetables (and fruits) are a critical factor to cancer prevention (and all disease prevention) not that factors like meat are the causes.
I want to put you at ease in understanding what the controversy around meat and cancer is about and what my recommendations are on the eating plan and lifestyle that I promote.
The story is more complex then a simple elimination diet, and to understand it, we must first understand Insulin Growth Factor-1 (aka IGF-1) and the implications of hormone levels on health, disease, and longevity. IGF-1 plays an important role in growth and development and is also at the center of the meat and cancer controversy.
Insulin-like growth factor-1 (IGF-1) is a natural hormone but ultimately it is correlated with animal protein intake (particularly dairy) and fat intake. There is some correlation with carbohydrates, but overall it doesn’t appear to be as strong as the correlation between animal protein and fats. Although IGF-1 is vital to human health, some studies have found that higher levels of IGF-1 in the blood may increase the risk of breast cancer, prostate cancer, and colon cancer and the jury is still out on other cancers.
At this time we can’t say that insulin or IGF-1 is completely good or completely bad
Science has not stated that insulin is definitely good or definitely bad, as it is contextual in regards to your body response. For example, a reaction of IGF-1 to a sedentary body will build fat cells, while an IGF-1 response in a fit and active body will encourage muscle growth.
Ideally, you want to do everything you can to encourage the healthy effects. When IGF-1 levels are too high, some cancers grow more easily (prostate and breast). This does not mean that meat is “bad” or comparable to smoking cigarettes…it means that you could benefit from decreasing the intake of IGF-1 inducing foods like meats, dairy, and fats and adjust to a lower level. It may also mean that by adding in a daily exercise routine, your body could use IGF-1 for a better purpose.
Don’t be mistaken that low IGF-1 levels are what you want – low IGF-1 is dangerous for your health too, and can include higher risk of cardiovascular disease, dementia, Alzheimer’s, and even cancer.
Animal Protein Raises IGF-1 more than other foods.
This is true, but there are different types of animal protein to take into consideration. Dairy products contain high levels of dioxins, which are proven potent carcinogens. So the argument could be made that toxic dairy foods can cause cancer. Factory meat also contains high levels of dioxins and most of the population is eating factory meat, not high quality wild game or sustainable and organic meat.
*Note: Apart from avoiding processed meat, a strong link between meat and cancer can’t be found.
Low IGF-1 levels are likely to be of concern for many people.
If you are worried about IGF-1 levels, frequent exercise cuts the risk of cancers associated with IGF-1 to a much greater extent than cutting animal protein does. The risks of all of the diseases associated with low IGF-1 are also reduced when you exercise frequently.
Cancer is associated with both high levels of IGF-1 and low levels of IGF-1
The loss of weight, muscle atrophy, weakness, fatigue, and loss of appetite that cannot be nutritionally reversed is a sign of the final stage of cancer and referred to as Cachexia. Cachexia is responsible for about 30% of all cancer deaths (as opposed to the cancer itself). Around 50% of patients with cancer die in a state cachexia and preventing cachexia is an important part of treating cancer, this means that IGF-1 needs to be kept at an optimal level—not too high, not too low.
What can we expect from optimal levels of IGF-1:
- IGF-1 protects the brain, growing new cells in the hippocampus, a region of the brain that is heavily involved in both short and long-term memory.
- Prevent heart disease and strokes
- Lower risk for both Alzheimer’s disease and dementia.
- IGF-1 was higher, not lower, in the female offspring of individuals who lived to be at least 100 years old.
- The diseases associated with high IGF-1 levels kill you before age 65, whereas the diseases and disorders associated with low IGF-1 levels kill you after age 65. (Does this mean we should avoid meat between the ages of 50 and 65? No! CVD, sarcopenia, dementia, and Alzheimer’s all develop over time, and cutting protein intake sharply for 15 years will almost certainly speed up their development.)
Doing IGF-1 the Right Way
- Exercise is an extremely important means to reduce mortality, regardless of cause. Exercise of all types reduces IGF-1 levels and if you exercise frequently, chances are good that the anabolic reactions you’re favoring are the ones, which will help you, develop stronger muscles, not the ones that will increase cancerous cell growth and fat deposition.
- IGF-1 is best when in a “normal” range (“normal” varies depending on age and gender). Both too high and too low of levels have the potential to cause problems. I interpret this to mean moderate intake of high quality animal products and an emphasis on plant based living.
- Don’t be afraid to eat high quality, organic, grass-fed, or wild meat. Avoid conventional grain fed meat because it is “pro-inflammatory and fattening, whereas meat that is grass-fed or is wild game is anti-inflammatory.” You’re more likely to develop a much more life-threatening or quality-of-life-decreasing disease from too low IGF-1 levels than too high. Grass-fed and wild meats are generally the best sources of protein.
- If you get diagnosed with breast cancer or prostate cancer, it may be appropriate to take steps towards lowering IGF-1 levels, under your doctor’s discretion. At this point, talk of ‘risk’ becomes meaningless because the disease is already present.
- Outside of a cancer diagnosis, there is no reliable evidence that lowering IGF-1 will reduce your risk of death or disease. Some evidence suggests that low IGF-1 levels present a significantly greater risk of death and disease than high levels.
- Eat your vegetables and fruits. Vegetables (and fruits) are far and away the best dietary method to protect yourself against the risk, which may or may not be associated with meat. Vegetables contain naturally occurring buffering compounds (alkaline ash) that effectively neutralize any acidifying components of food. Simply put, vegetables are good for you! Individuals with diets highest in fruits and vegetables have the lowest rates of cancer, suggesting that vegetables are the critical factor for health.