Finally, research is getting to the heart of the matter. How can we eat in such a way to avoid cancer and live longer?
According to a recent study published in the journal, Aging Cell(2008 Oct;7(5):681-7), reducing dietary protein intake resulted in a significant reduction of IGF-1 (Insulin-like Growth Factor). The study found evidence that protein intake is a "key determinant of circulating 1GF-1 levels in humans, and suggest that reduced protein intake may become an important component of anticancer and anti-aging dietary interventions."
Now, first, let's make it clear that Americans are guilty of eating about double the protein they need. It's estimated we only need about .8 grams protein/kilogram body weight. That adds up to around 40-60 grams protein a day.
But what about this IGF-1? How does it lead to cancer?
According to an article published in the British Medical Journal (BMJ 2000;321:847-848 7oct00):
"The role of insulin-like growth factor-I in promoting cancer has been investigated for many years, but recently the quality and quantity of evidence has increased. In particular, a number of prospective studies using stored blood collected up to 14 years before the onset of disease have shown associations between insulin-like growth factor-I and prostate cancer, premenopausal breast cancer, and colon cancer (emphasis mine).
The risk of cancer is higher among people with raised concentrations of insulin-like growth factor-I..."
So, studies show consuming more protein raises IGF-1 levels which cause different types of cancers. Conversely, decreasing protein to reasonable levels (.8 grams/kg body weight), significantly lowers IGF-1 levels, thereby preventing cancer and other diseases of aging.
Sounds pretty simple. Let's eat to fight cancer.
I am so happy to report an encouraging study published last week in the International Journal of Cancer (October, 2008). Not only are the study results positive, but they help put to rest the milk industry-sponsored paranoia about soy.
Dr. Takeshi Suzuki, at Aichi Cancer Center Research Institute in Nagoya (Japan), and associates conducted a study of 678 women with breast cancer and 3,390 controls matched by age and menopausal status with no history of cancer.
The researchers "observed a significantly reduced risk" of breast cancer among the women who ate the most soy and were ER-positive, HER2 (Human Epidermal Growth Factor Receptor 2)-negative or both.
For women who ate the most soy compared with those who ate the least amount the odds of having ER-positive breast cancer were reduced by 26 percent and for women with HER2-negative breast cancer, the reduced risk was 22 percent.
In their own words, the researchers concluded, "These findings are biologically plausible, and suggest a potential benefit of soybean products in the prevention of breast cancer."
I know this is the opposite of what most of us hear about soy: that it increases the risk of breast cancer. But remember, the estrogen receptor sites on our cells are very good at discerning "real" estrogen vs. plant, or phyto-estrogens in soy and other plant foods. Studies show that phytoestrogens can block those cell receptor sites, keeping real estrogen from entering into our cells - which is how it works to lower breast cancer risk.
This in not an area of controversy in scientific circles, but it is in the public arena due to vested interests.
So please don't be afraid of unprocessed soy products like soybeans (edaname), tempeh, tofu, or soymilk. It won't increase your risk of breast cancer or make your husband and sons less masculine. Plant estrogens work differently than endogenous (internally-produced) estrogen. Which is good to know, since plant estrogens are found in fruit and vegetables, in addition to soybeans and other legumes!
This morning I gave a talk about protein to a group of school kids. Since protein seems to be a such a source of confusion in the public arena, I thought I'd post write some of the notes here. If some of this is a tad remedial for you, I apologize, although I bet there's at least one person you know who has yet to learn this information - so feel free to pass it along.
We used to believe (and many people still continue, unfortunately, to believe) that meat was the ideal source of protein since it contains all 9 essential amino acids. If someone was brave enough to avoid eating meat, they would have to tediously work at "food combining" foods like beans, which contain certain amino acids but not all, with rice, thus creating a "perfect protein". Now we know this is unnecessary, and it is almost impossible to eat enough calories and be deficient in protein. In fact, worldwide, protein deficiency is extremely rare unless there is a chronic shortage of calories, which is termed "Protein-Calorie Malnutrition".
We used to believe that since muscle is made of protein, the more protein we eat, the stronger we become. Now we know this is far from true - for if it were, Americans would be the world's most muscular people, which we are far from. In fact, most people in the U.S. eat about 2x the protein they need, primarily from meat and other animal foods, such as eggs. Eating too much animal protein is dangerous, and causes all kinds of chronic disease, such as:
1) Osteoporosis and Kidney Stones. Sulfuric and uric acid from excess animal protein causes bones to leach calcium as a buffer. Calcium is lost from bones and often piles up in the kidney on exit, causing kidney stones.
2) Arterial Plaque. Animal protein gives us higher levels of homocysteine, a derivative of the amino acid methionine. Homocysteine damages artery lining, causing the body to build plaque as an emergency response. Diets high in animal protein cause continual plaque via homocysteine.
3) Heterocyclic Amines (HCA's). When meat is cooked at high temperature, creatine (an amino acid only found in meats, including fish and poultry) combines with other amino acids to create HCA's, which are known carcinogens. HCA's are highest in meats that are fried, broiled, BBQ'd, charred or "well done", although they occur at lower levels in most meats.
4) High amounts of animal protein are associated with cancer. In the book, The China Study, by T. Colin Campbell, PhD, we learn all about this. I've written on this blog about Dr. Campbell's studies, which are downright flabbergasting. I highly recommend this book to every person interested in preventing cancer through diet.
5) Bioaccumulation. Animal protein comes from foods at the top of the food chain - where are the toxins concentrate, including mercury, pesticides, dioxin and PCB's.
6) High amounts of animal protein are associated with decreased fertility in women. Again, too much to cover here - although I've written on this topic in a previous post - read the book, The Fertility Diet, by Walter Willett, PhD.
7) Animal protein has no fiber. If you've spent much time on this blog, you know that fiber is instrumental in preventing diabetes, colon health - and weight loss. Americans aren't overweight just because we overeat, but because we don't eat enough fiber. It is near impossible to consume the recommended amount (25-40 grams/day) of fiber when animal protein is a large part of your diet.
On the flip side:
Legumes, such as beans, peas, lentils, nuts and seeds not only have plenty of protein, but are loaded with fiber and antioxidants. Eating a diet high in plant protein, such as legumes, cause weight loss and prevents disease, including cancer.
Now we know: Beans Are the New Meat. So share the wealth.
Labels: animal protein
I wasn't going to write on this topic. I really wasn't. I said I wouldn't write on something outside my area of expertise, which obviously is nutrition and not medicine. But then I got this great email request to share my thoughts on vaccines... and of course I did. Then I thought - what exactly makes someone an "expert" on the relationship between vaccines and chronic disease? Certainly not just a medical degree - so why not?
Actually, my best friend and mother of three young children is much closer to an expert than I am. Her Master's degree is in Microcellular Biology and she has been exploring the relationship between vaccines and pathology whenever she has time.
Not long ago, my friend had grandparents watch her children for a week that she devoted to reviewing current research on this subject. While her research is nowhere near complete at this time, she did find some interesting information about the amount of aluminum in vaccines.
One conclusion was there is a lot of aluminum in most vaccines. More than is considered safe for infants (there is a maximum safety level of aluminum for infants on IV drips - and it's MUCH less than the amount we find in the average single vaccination).
And since aluminum salts tend to act as antacids, this could change the environment of the gut lining and cause dysbiosis (an imbalance of beneficial intestinal flora and harmful bacteria). As I've written ad nauseum in this blog, dysbiosis is how we develop "Leaky Gut Syndrome", which is the doorway to just about all food intolerances, as well as auto-immune disorders, including - but certainly not limited to - autism, ADD and ADHD.
So there's that.
Also, aluminum stores in bone marrow, precisely where the body produces white blood cells, or "immune cells". So if tiny tykes are storing aluminum in the same organs responsible for a healthy immune system, it seems that this just might have something to do with auto-immune disorders.
Just some things to think about.
I'm really not an expert, so if this is a subject of concern to you, I advise you to do your own research and draw your own conclusions. I do suggest however, that you ask yourself exactly what does make someone an expert on this subject. Since there is so little research on aluminum salts in vaccines and Leaky Gut Syndrome, I find I'm wondering that myself.
According to a recent article (October 2008) published in the Journal of the American Dietetic Association, a vegan diet is more likely to cause weight loss and glucose control compared to the standard diet recommended by the American Diabetes Association (ADA).
What I find especially ironic is that the vegan diet participants in this study not only consumed more fiber, but more - gasp - carbohydrates. That's right folks, people who ate a higher carb diet actually had lower blood sugar levels - precisely the opposite of what we hear. But here's the rub: consuming a diet higher in fiber is what is important when you want to beat diabetes, and fiber comes from high "carb" foods (not to mention fiber is a carbohydrate) such as fruit, vegetables, whole grains and legumes.
This is why if you know someone who is diabetic, and they've tried lowering their carbs to less than 45 grams a day... it's pretty much gotten them nowhere. I can't tell you how many people have tried the ADA recommended diet (what their dietitian or doctor told them), and said it didn't have much effect on their blood sugar. Yet when those same people read my book or blog or attended my seminar and increased the fiber in their diet, that's when their doctor took them off insulin! Even 70 year old people!
So please, please, please don't worry about carbs if you're a diabetic. Just eat more foods high in fiber (not Metamucil). If you're eating 25-40 grams a day, you will see a monumental change in your blood sugar after a couple of weeks, or even sooner. Oh yeah, and you'll lose weight too.
Turner-McGrievy GM, Barnard ND, Cohen J, Jenkins DJA, Gloede L, Green AA. Changes in nutrient intake and dietary quality among participants with type 2 diabetes following a low-fat vegan diet or a conventional diabetes diet for 22 weeks. J Am Diet Assoc. 2008;108:1636-1645.