Read The End of Diabetes Online
Authors: Joel Fuhrman
IGF-1 is one of the body's important growth promoters in the womb and during childhood growth, but it also has anabolic (body-building) effects in adulthood. It is a hormone with a similar structure to insulin. The production of IGF-1 primarily takes place in the liver, and its production is stimulated by pituitary-derived growth hormone.
Â
IGF-1 signaling is crucial for growth and development in childhood, but it promotes the aging process later in life. Reduced IGF-1 signaling is associated with enhanced life span.
27
There is a tremendous amount of evidence regarding the life-span-enhancing effect of lower levels of IGF-1, especially in adulthood. Centenarians are known to be exceptionally insulin sensitive, which may protect against the insulin-resistance-associated, age-related increase in blood glucose levels. Lower levels of IGF-1 are associated with enhanced insulin sensitivity and enhanced life span.
28
This is critically important for people with diabetes or a tendency to develop diabetes, as higher levels of IGF-1 promote both diabetes and cardiovascular death from diabetes. The higher the biological value of the protein consumed, and the more of it consumed, the more IGF-1 produced. So the regular consumption of animal products is the most significant factor promoting IGF-1. Muscle tissue can produce its own IGF-1 in response to resistance exercise, but this does not raise systemic IGF-1 unless a diet rich in animal protein is consumed.
29
Â
IGF-1 and Cancer
The largest concern about elevated IGF-1 from our modern diet is its link to cancer. Elevated hormone levels caused by the Western diet are thought to contribute to the high rates of cancer in the modern worldânot just sex hormones, such as estrogen and testosterone, but insulin and IGF-1 as well. The connection between increased IGF-1 signaling and cancer has been known for many yearsâin fact, cancer drugs targeting the IGF-1 pathway began to be developed in the late 1990s, and over seventy clinical trials have begun since then, many with encouraging results.
30
Because IGF-1 signaling plays a key role in tumor growth, reducing IGF-1 levels by dietary methods is now considered by most scientists studying this subject to be an effective cancer-prevention measure. IGF-1 signaling is involved in a number of processes relevant to tumor growth: proliferation, adhesion, migration, invasion, angiogenesis, and metastatic growth. A diet rich in antioxidants and phytochemicals results in reduced inflammation, oxidative stress, and IGF-1, which are critical to protecting against cancer and maximizing longevity.
31
Â
Protein Intake Promotes IGF-1
The composition of protein and the amount consumed also modify IGF-1 levels. Protein that is rich in the full array of essential amino acids causes larger increases in IGF-1 compared to protein not as biologically complete.
38
Plant sources of protein are less concentrated. They supply adequate protein, but not excessive amounts like animal products do, and the body needs to combine the amino acids for biological completeness, so they do not promote a surge in IGF-1 like animal proteins do. For example, milk and dairy products contribute to this excessive IGF-1 in circulation. In a meta-analysis of eight randomized controlled trials, circulating IGF-1 was found to be higher in milk-consuming groups compared to control groups.
39
H
IGH
-C
IRCULATING
IGF-1 L
EVELS
H
AVE
B
EEN
L
INKED TO
S
EVERAL
C
ANCERS
Â
Breast Cancer
The European Prospective Investigation into Cancer and Nutrition study found that elevated IGF-1 levels were associated with a 40 percent increased risk for women over the age of fifty.
32
In the Nurses' Health Study, high IGF-1 levels were associated with a doubled risk of breast cancer in premenopausal women.
33
Additional human studies, reviews of literature, and meta-analyses have also associated elevated IGF-1 levels with breast cancer.
34
Â
Colorectal Cancer
Elevated IGF-1 levels are associated with colorectal cancer, and IGF-1 promotes the spread of colorectal cancer cells.
35
Â
Prostate cancer
A 2009 meta-analysis of 42 studies concluded that elevated circulating IGF-1 is associated with increased risk of prostate cancer.
36
Â
Other Cancers
37
Gynecological cancers
Multiple myeloma
Sarcomas
Renal carcinoma
Â
The Calorie Restriction Society is a collection of individuals who believe that consuming fewer calories will lead to a longer life. A six-year study of members of this group found that their IGF-1 levels were not significantly different from control groups on a standard Western diet (of course, body fat, fasting insulin, and inflammation markers were markedly lower in the calorie-restricted group). The Calorie Restriction Society group members were consuming an average of 108 grams of protein per day, far more protein than necessary. This led the researchers to then compare IGF-1 levels in members of the Calorie Restriction Society to vegans who had been consuming a moderately protein- restricted diet, averaging 50 grams of protein per day for at least five years. (One 3.5- to 4-ounce serving of chicken supplies 100 grams of protein.) The calorie intake was greater in the vegan group, but protein intake was lower and IGF-1 levels were indeed much lower.
40
This study cautions that overconsumption of protein, even when restricting calories, can keep IGF-1 levels elevatedâto a point similar to those of typical Western eaters, who overconsume calories overall, blunting the potential of a longevity-inducing diet style. For example, many people eat egg whites believing that because they are almost pure protein and have no fat, they must be healthy. In truth, the high concentration of a biological protein makes egg whites disease promoting. Plant-based protein is much healthier.
Â
Refined Carbohydrates Promote IGF-1
Although protein is the most important determinant of IGF-1 levels, excess intake of refined carbohydrates can also have an effect. Insulin regulates energy metabolism and affects IGF-1 signaling by increasing production of IGF-1 and decreasing IGF-1-binding proteins. It is likely that the Western diet increases IGF-1 via both excess protein and excess refined carbohydrate. Type 2 diabetes is associated with breast, colon, and pancreatic cancers, and there is evidence that insulin-mediated stimulation of IGF-1 production is partially responsible.
41
The take-home message here is to recognize that refined carbohydrates from processed foods and our nation's preoccupation with eating animal protein are both at the core of our cancer and diabetes epidemic. Until now, we have mistakenly focused on fat as the bad apple, endorsing egg whites and white meat, when actually these foods are not favorable for longevity. Note that switching to grass-fed beef or wild meats does not solve the problem with consumption of too many animal products, as the negative effects are not limited to fattened and sickly farm-raised animals. The heterocyclic amines, the heme iron, and the concentration of high biological protein are all negatives, especially for people prone to diabetes.
For many people, even a moderate amount of animal protein in the diet maintains unfavorably elevated IGF-1 levels and impedes the cholesterol-lowering and blood-sugar-lowering effects of a plant-based diet. But when we strive to consume most of our protein from plants, we solve the IGF-1 issue and help prevent both cancer and diabetes. The amino acids in plants are not as complete as those in animal products, so they do not raise IGF-1 to harmful levels, and they complement each other so we can achieve adequate levels of protein without going into excess.
Â
Eating More Plant Protein Is the Key to Increasing Our Micronutrient Intake
It is interesting to note that foods such as peas, green vegetables, and beans have more protein per calorie than meat does. But what is not generally considered is that the foods that are rich in plant protein are usually the foods that are richest in nutrients and phytochemicals. By eating more of these high-nutrient, low-calorie foods, we get adequate protein and our bodies are simultaneously flooded with protective micronutrients. This fuels the reversal of diabetes and heart disease, helps heal the kidneys, and restores the body to a more youthful state. Animal protein is low-nutrient food. It does not contain antioxidants or phytochemicals, but plant protein does.
Â
P
ROTEIN
C
ONTENT FROM
S
ELECTED
P
LANT
F
OODS
FOOD | GRAMS OF PROTEIN |
Almonds (3 ounces) | 10 |
Banana | 1.2 |
Broccoli (2 cups) | 10 |
Brown Rice (1 cup) | 5 |
Chick Peas (1 cup) | 15 |
Corn (1 cup) | 4.2 |
Lentils (1 cup) | 18 |
Peas, frozen (1 cup) | 9 |
Spinach, frozen (1 cup) | 7 |
Tofu (4 ounces) | 11 |
Whole Wheat Bread (2 slices) | 5 |
When you drop body fat, your cholesterol lowers somewhat, but when you reduce or eliminate animal protein intake and increase vegetable protein intake, you lower cholesterol radically. This clearly is a vegetable-based diet, not one based in grains or animal products. Vegetables are rich in protein but also have almost no saturated fat or cholesterol, and they are higher in nutrients than any other food is. The cholesterol-lowering effect of vegetables and beans is without question. In addition, they contain an assortment of heart-disease-fighting nutrients independent of their ability to lower cholesterol. Amazingly, they also fight cancer. This food plan is designed to use large quantities of the most powerful anticancer, disease-fighting foods on the planet. The point to keep in mind is that even if you completely ditch animal protein, or significantly minimize your consumption, you will still receive the protein your body needs through your vegetable-based diet.
The low-nutrient standard diet that is enjoyed by most Americans results in fatty deposits in the walls of the blood vessels. These eventually lead to blood vessel narrowing and blood clots that cause strokes and heart attacks. This occurs because of too many animal products, too many processed foods, and not enough natural, high-nutrient plant foods. The disease-building process is not the by-product of aging; it is the by-product of a diet poorly designed for humans. This diet gradually causes more and more damage as time goes on. Eventually, certain diseases and conditions crop up, mainly:
Â
Heart attacks and anginaâdiseased blood vessels in the heart (coronary arteries)
High blood pressure and strokesâdiseased blood vessels leading to and in the brain
Dementiaâdiseased blood vessels in the brain
Impotenceâdiseased blood vessels leading to and in the penis
Claudicationâdiseased blood vessels in the legs
Unfortunately, the drug-favoring dietary advice typically offered to diabetics and heart patients is not science based, and it caters to Americans' social and food preferences and food addictions. In contrast, the nutritarian diet maximizes benefits for weight reduction, cardio protection, and diabetes reversal, effectively preventing and reducing the effects of all these conditions. And the food is delicious. With time, you will be shocked not only with the results but with the taste as well.
Susan Carno, an eighty-year-old female, was diagnosed with type 2 diabetes in 1987. She was on insulin therapy for twenty years, during which time she experienced a hypoglycemic episode (abnormally low glucose) at least once a month. Her blood sugar would be exceptionally high at times, and then in a few days, too low. She gained a significant amount of extra weight while she was on insulin. She also had a history of high cholesterol and high blood pressure and a family history of heart disease, diabetes, and hypertension. During the last year before becoming my patient, she was experiencing increased frequency of hypoglycemic reactions. A grand mal seizure attributed to the hypoglycemia finally convinced her that she needed to do something different and motivated her to find me.
Susan's physician had initially prescribed statin drugs for high cholesterol, but when Susan developed muscle aches, the medication was discontinued. Besides taking insulin (30 units of Lantus once a day and 5 units of Humalog with each meal), she was also taking metformin and Byetta injections for diabetes.
I talked to Susan on the phone briefly almost every day to check her morning glucose number, and she was able to cut back on the insulin more quickly than I expected. Originally I thought that she would still need some insulin even on this diet because she was eighty years old and her pancreatic beta cell reserve was likely compromised. I was wrong. Once she started my nutritarian approach for diabetes, I was able to discontinue all of her insulin within the first ten days. The diet was more powerful than 45 units of insulin, even with no change in her activity level.
Susan was able to discontinue all of her diabetes medications by the end of the first month. Her HbA1C went from 7.3 to 6.6 with no drugs. It takes three months for HbA1C to reflect new low glucose readings, and at the three-month checkup, on no medications, her glucose was running around 100. She also had no further hypoglycemic reactions. She lost thirty-eight pounds, going from 148 pounds to 110 pounds. Her blood pressure declined from 172/82 to 130/75. Her total cholesterol did not change much, but her cholesterol/HDL ratio improved from 4.0 to 3.3, and her triglycerides improved considerably.
Susan was thrilled. While taking insulin, she'd felt like a prisoner inside her own body, aging rapidly. It made her feel hungry and overall left her feeling constantly sick. For twenty years, she injected herself because she saw no other option. When the insulin stopped, Susan suddenly discovered she had a great deal more energy. Over the year after we started working together, Susan's exercise endurance increased considerably and she was able to comfortably walk for a full hour or more. She has been enjoying sixty-minute walks every day. After being on the diet for a year, she celebrated with her favorite ice cream. Surprisingly, she did not like it as much as the fresh fruit sorbet I taught her how to make. It was just too sugary for her, so after the first few spoonfuls she stopped!
B
eans, green vegetables, seeds, and some fruits are high in soluble fiber. Soluble fiber supplies a gelatinous-like material in the bowel. It is not absorbed and does not give us calories. Soluble fiber is very important, as it slows the absorption of glucose and helps lower cholesterol. Beans are especially high in soluble fiber.
Insoluble fiberâroughageâis important too. It provides bulk to our stool and keeps us regular. And guess what: seeds, nuts, vegetables, and, yes, beans have plenty of insoluble fiber too.
For years, nutritionists and scientists thought there were only two kinds of fiberâsoluble and insoluble. Now we know there is a carbohydrate that acts like a fiber too. It is called resistant starch. It supplies few calories, and most of the calories do not raise glucose levels. It is called resistant starch because it is resistant to stomach acid and digestive enzymes. It is not digested in the small intestine but passes to the large intestine, where it undergoes fermentation. Fermentation means that the bacteria decompose and degrade this starch into simpler compounds. When the bacteria in the bowel degrade the resistant starch, it forms new compounds that have health benefits. Resistant starch is important for good health and has beneficial effects for diabetics.
Legumes such as beans, lentils, peas, and chickpeas fall far below grains on the list of foods Americans eat. However, legumes are richer in nutrients, protein, and fiber, and they contain much higher levels of resistant starch. Considering their favorable effects on blood sugar and weight loss, they are the preferred carbohydrate source for people who have diabetes or are at risk for diabetes.
Most starchy foods have a small amount of resistant starch in them. At the beginning of human history, fruits contained more resistant starch and fiber and less sugar than fruits that are commonly available now. Wild foods, the same as those early human foods, are more fibrous compared to what is bred, cultivated, and processed today. If you were to taste a wild pineapple, wild lychee, or wild plantain in the tropical jungle, you would find that any of them are hardly sweet, much chewier, and fibrousâand filling from all the fiberâbut they are certainly not calorically dense. It is certain that in a primitive tropical habitat that provided a diet of just wild food and greens and maybe some fish, there would be no overweight or diabetic people. If you were ever shipwrecked on a deserted island, it would be almost impossible to become or remain overweight.
Proponents of high-protein, low-carbohydrate diets argue that intake of carbohydratesâespecially starchâshould be restricted or eliminated and substituted with animal products instead. This might seem logical on a superficial level, but when you look deeper into the science, you find that fiber-less animal products contribute to diabetes-related health risks, while beansâeven though they are largely carbohydratesâ directly lessen these risks and promote the reversal of diabetes.
Dietary starch is most often converted to glucose. When not burned as energy for immediate use, it is stored as glycogen, a high molecular- weight polymer of glucose. The body is capable of storing approximately 300 to 500 grams of glycogen at one time. Any excess glucose that is not rapidly burned as fuel or stored as glycogen is converted to fat and stored as body fat. Meat-based-diet proponents argue that to lose weight, we should eat less starch. They are right to a degree. Certainly we should eat less high-glycemic, low-nutrient starch, and certainly we should not overeat. When we eat mostly high-starch foods, especially refined carbohydrates, it promotes swings in blood glucose, putting excess work on the pancreas to produce a huge insulin load. Plus if we overeat, our glycogen stores could be already full, meaning the extra carbohydrate calories we don't need will be stored as fat on the body. But not all carbohydrates fall into this high-glycemic, low-nutrient starch category.
Â
The Whiter the Bread, the Sooner You're Dead
Some people think that sugar-free cookies, cakes, and pastries can actually help their diabetes or help them lose weight. This is not the caseâthese sugar-free products are essentially low-nutrient junk foods. White flour actually makes your blood sugar rise almost as much as plain sugar does. Carbohydrates are chains of sugar molecules lined in a row. They are found in all plants and foods made from plants. Carbohydrates can be a single sugar, or three or four bound together, but when thousands of sugars are bound together, they are called starch. When these simple carbon molecules are bound together so tightly that your body cannot break them down and digest them, they are called fiber.
Only simple sugars can pass from your intestines into your bloodstream. When your digestive enzymes break down the carbohydrates into simple glucose molecules, they are absorbed immediately and enter the body just as if you had sucked on a sugar cube. Indeed, eating sugar and white flour does not cause just diabetes; these foods are also linked to heightened risk of cancer. Quite a few studies have linked the consumption of high-glycemic, low-nutrient food to cancer. One study showed over a 200 percent increase in risk of breast cancer in women eating more than half their diets as refined carbohydrates.
1
Too many Americans still eat this type of diet, with more than half their calories coming from processed foods. These individuals are slowly destroying their health. Eating processed foods is like snorting cocaine. Eventually you will pay a big priceâyour health. And the more a person consumes this deadly white stuff, the stronger the cravings for more.
Bagels, white bread, pasta, pizza, and rolls are all staples of the American diet, and they are a large contributor to our epidemic of obesity, diabetes, heart disease, and cancer. Commercial wheat products are also treated with fungicide, sprayed with insecticides, and bleached with chlorine gas or other chemicals. They return little nutrient bang for all their calories. To put it bluntly, these staples of our diets are disease-promoting junk food. All the white starchesâbasically, white bread, white rice, and even white potatoesâare very rapidly converted to glucose, which is sugar, and absorbed into the bloodstream, shooting blood sugar levels up.
When blood sugar skyrockets, it overworks the pancreas to match the load of sugar with a large amount of insulin. This is not only stressful to the body and the pancreas, but metabolizing that large energy load without a concomitant intake of micronutrients creates metabolic havoc in the cells. Toxic metabolites build up in cells when we consume calories without antioxidant and phytochemical micronutrients needed to remove and control the toxic by-products. So as we eat more low-nutrient and low-fiber carbohydrates, we build up more cell toxicity, leading to disease and food addiction.
Most of the common carbohydrates we eat are turned into glucose, but it is important to realize that the conversion efficiency and rate vary greatly from one type of carbohydrate to another. For example, the starch in potatoes, cereals, and baked goods digests very rapidly; all their calories are converted quickly, supplying the body with a huge glucose load. The starch in beans, barley, and black wild rice is digested more slowly and causes a much slower and lower blood sugar rise. Beans are at the top of the preferred carbohydrate totem pole because they contain more of both slowly digestible starch and resistant starch.
Unique properties of the carbohydrates in beans and legumes include:
Â
â¢Â Higher amount of slowly digestible starch
â¢Â Higher amount of resistant starch
â¢Â Higher amount of insoluble fiber
â¢Â Higher amount of soluble fiber
Â
Resistant starch actually goes all the way through the small intestine without being digested at all. In this way, it is more like fiber, and in some cases is classified as a type of insoluble fiber.
Â
Resistant Starch Is the Secret
There are different types of resistant starch in foods. Amylose and amylopectin are examples. It is starch that is tightly packed in a stable crystalline form within foods, making it difficult to digest. The more resistant starch that reaches the colon undigested, the less calories we absorb from that food. When resistant starch reaches the colon, the bacteria there use it for fuel. The resistant starch is also, therefore, a prebiotic, meaning it serves to fuel the growth of beneficial bacteria in the colon.
This process of degrading these starches by bacterial action is called fermentation, and it produces a type of fat called short-chain fatty acids (SCFAs). In other words, the resistant starch does not even get converted to a simple sugar; it gets converted into a simple fat. Only a small percent of these calories are absorbed by the body, but they are highly beneficial.
2
So calories from resistant starch are listed on the food labels but almost 90 percent of those calories do not get absorbed and they do not raise blood sugar at all. Resistant starch is especially associated with one type of SCFA called butyrate.
Now here's the fascinating part: even though only a small amount gets absorbed, butyrate offers a wide array of health benefits, including strong protection against colon cancer. It protects our bodies in lots of other ways too, namely by enhancing the absorption of beneficial minerals like calcium and magnesium and so, importantly, improving insulin sensitivity. It has the opposite effect of eating sugary or high-glycemic starches. It actually improves diabetic glucose numbers the day after it's eaten.
3
Most importantly, these SCFAs slow down glycolysis in the liver, thus delaying hunger, and they increase the breakdown of body fat as a source of energy, facilitating weight loss. As you recall, glycolysis is the breakdown of the stored glycogen back into glucose for use by the body. The small amount of SCFAs that are absorbed increases fat oxidation, meaning your body burns fat for energy more efficiently, encouraging weight loss.
4
When you eat a meal of mostly green vegetables, eggplant, onions, mushrooms, and a cup of beans, biochemical events occur that work medicinally; they repair the biochemical defects that would lead to diabetes. In fact, in direct contrast to meat and potatoes, just one additional serving of green vegetables in a diet has been demonstrated in meta-analysis to offer significant diabetes protection independent of the effects on weight reduction.
5
The authors of the study speculate these profound benefits were due to the high levels of beneficial micronutrients in greens. Then you add beans, and more magic happens.
Â
Beans store well and are inexpensive, highly nutritious, and entertaining.
Let's review some of the benefits of eating greens and beans, instead of bread, rice, and potatoes:
Â
â¢Â Increased nutrients, SCFAs, bacterial activity, and fiber, which lower cholesterol and triglycerides
6
â¢Â A sensation of fullness or satiety, leading to meal satisfaction even though fewer calories are consumed