A study of more than 2,300 Italians has shown that high bread consumption significantly raises the risk of renal cell carcinoma, the most common type of kidney cancer.
Pasta and rice may also raise the risk, but eating vegetables could lower it.
The 12-year study examined 767 adults with this kidney cancer and 1534 who did not have the disease. The researchers asked participants to fill out food frequency questionnaires, which gauged the average weekly consumption for 78 different food items.
There was a significant direct association for bread consumption, and to a lesser extent pasta and rice. A decreased risk was associated with consumption of poultry and all vegetables.
The association between grain products and cancer may be due to the high glycemic index of these foods and their association with insulin-like growth factors.
Here's one more reason to strongly consider limiting your grains, besides all the other important ones I've discussed in the past. This is especially true if you are a protein type.
The association between grains and kidney cancer shouldn't surprise you at all, considering more than 85 percent of Americans have trouble controlling their insulin levels because so many patients are addicted to bagels, pizza and waffles -- and would die rather than give them up.
Renal cell carcinoma accounts for 2 percent of all cancers, and is far from the only cancer -- or the only disease -- affected by diet.
Insulin, stimulated by the excess carbohydrates in our overabundant consumption of grains, starches and sweets, is the cause of many problems.
It's responsible for all those bulging stomachs and fat rolls in thighs and chins, and even worse, high insulin levels suppress two other important hormones -- glucagons and growth hormones -- that are responsible for burning fat and sugar and promoting muscle development, respectively.
So insulin from excess carbohydrates promotes fat, and then wards off the body's ability to lose that fat. Excess weight and obesity lead to heart disease and a wide variety of other diseases. But the ill effect of grains and sugars does not end there.
They suppress the immune system, contributing to allergies, and they are responsible for a host of digestive disorders. They contribute to depression, and their excess consumption is, in fact, associated with many of the chronic diseases in our nation, such as cancer and diabetes.
Do your body a favor.
Cut as much sugar as possible out of your diet, and limit your grain consumption unless you are a carb type. Yes, even whole grains for many people can push your physiology in the wrong direction.
As unsurprising as the effect of grains on renal cell cancer is the association of a decreased risk of the cancer with all vegetables. Vegetables such as broccoli, cauliflower and cabbage can jump-start your natural DNA repair of cells that prevents cancer.
Keep in mind, however, your body's unique nutritional type will exert a great deal of influence on which foods are best to eat, and broccoli may not be right for you.
What's important is to listen to your body, and nobody else -- including me or any scientist.
The confusing aspect here is a person's nutritional type, as about one-third of people will actually do well on grains (whole grains preferred of course), but the other two-thirds, clearly the majority of the population, seem to do better to avoid or severely limit their grain intake.
If you haven't taken our free mini course on nutritional typing please do as it will help you understand these concepts even more.