By Dr. Mercola
Mounting scientific studies have demonstrated that broccoli is one of nature's most valuable health-promoting foods. Science has proven time after time that Mother Nature is the best physician, and food is the best medicine.
A recent study, published in the American Journal of Hypertension,1 adds to the mounting scientific evidence about broccoli's noteworthy health benefits. A compound in broccoli, glucosinolate, produces a metabolite called sulforaphane that can significantly improve your blood pressure and kidney function, according to this latest animal study.
Sulforaphane is an organic sulfur compound found in cruciferous vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower, horseradish and arugula – but it's highest in broccoli sprouts.
Sulforaphane has been shown to have antidiabetic and antimicrobial properties, and also kills cancer stem cells, which slows tumor growth. Researchers believe eliminating cancer stem cells is key to controlling cancer.
This is something current chemotherapies cannot do, but food can! This latest research confirms broccoli's benefits go beyond cancer prevention.
In this 2012 study, hypertensive rats with impaired kidney function were given sulforaphane. The natural compound improved the rats' kidney function and lowered their blood pressure by normalizing a process called DNA methylation.
The Food You Eat Actually Changes Your DNA
What is DNA methylation?
Without getting too far adrift in biochemistry, DNA methylation2 is the process by which a methyl group (one carbon atom attached to three hydrogen atoms) is added to part of a DNA molecule. DNA methylation is a crucial part of normal cell function, allowing cells to "remember who they are and where they have been" and is important in regulating gene expression. DNA methylation also suppresses the genes for things you DON'T want, such as viral and other disease-related genes. Abnormal DNA methylation plays a crucial role in the development of nearly all types of cancer.
Broccoli sprouts have also been shown to inhibit Helicobacter pylori (the bacteria thought to cause gastric ulcers), protect your heart, and may offer protection against UV radiation damage to your skin when applied topically.3 The sulforaphane from broccoli plays a role in activating more than 200 different genes. And you don't have to consume a truckload of broccoli to reap its benefits.
In fact, a 2008 study published in PLoS One4 found that just four servings of broccoli per week could protect men from prostate cancer. One serving of broccoli is about two spears, so that's only 10 broccoli spears per week.
Researchers believe hypertension (and kidney dysfunction) may result from a disturbance in DNA methylation, and it may just be that sulforaphane improves blood pressure and kidney function by ameliorating this problem. So, any food that mediates DNA methylation is very helpful toward keeping you healthy – and broccoli is one of the BEST! But if you hate broccoli, don't fret. Broccoli sprouts aren't your ONLY salvation if you suffer from hypertension or kidney trouble.
Hypertension is a Stroke's Best Friend
You are generally diagnosed with pre-hypertension if your blood pressure is between 120/80 and 140/80, and anything above 140/80 is generally diagnosed as hypertension ("high blood pressure"). Hypertension is dangerous because it typically shows no warning signs or symptoms, and in its complete silence, can cause a stroke. Drugs advertised to "treat" hypertension will not change or in any way address the underlying cause of your hypertension. That's the bad news.
The good news is that more than 85 percent of those who have hypertension can normalize their blood pressure with some basic lifestyle modifications.
The REAL Cause of Most Hypertension May Surprise You
High blood pressure is typically related to your body developing resistance to insulin. As your insulin level rises, your blood pressure rises. Most physicians – even cardiologists – do not understand the crucial connection between blood pressure, blood sugar levels, and insulin.
Dr. Richard Johnson, author of the book The Fat Switch, masterfully ties together the connection between hypertension, kidney disease, obesity and diabetes in his previous book, The Sugar Fix, which is one of the best books written on this issue. Dr. Johnson is the Chief of the Kidney Disease and Hypertension Division at the University of Colorado, and I would encourage you to listen to his interview.
Download Interview Transcript
According to Dr. Johnson, there is one major factor linking ALL of the health problems listed above: high dietary fructose. While sugar (sucrose) is a major source of fructose, it may not be quite as bad as high fructose corn syrup (HFCS).
Americans on the whole are fructose addicts. HFCS is added to sodas, fruit juices, and nearly all processed foods lining supermarket shelves. HFCS in soda is a major source of calories in the typical American diet, so it's no wonder diabetes has risen to epidemic proportions. In fact, the use of high fructose corn syrup in the U.S. diet increased a staggering 10,673 percent between 1970 and 2005, according to a major USDA report.5 That statistic is no major surprise considering that, in addition to soda and sweetened beverages, processed foods account for more than 90 percent of the money Americans spend on their meals.
Unlike glucose, which is burned by fuel in every cell in your body, fructose, if not immediately consumed as fuel, is metabolized into fat by your liver, which can set the ball rolling toward insulin resistance and type 2 diabetes. I highly recommend getting a fasting insulin level test, which must be ordered by your doctor. The level you want to strive for is about 2 to 3. If it's above 5, then you have a problem and you definitely need to get your insulin level down as you are at risk for cardiovascular problems.
The Fructose-Insulin Connection
What is the link between fructose and blood pressure? Fructose in your diet raises your blood pressure in three key ways:
- When your liver breaks down fructose, uric acid is produced as a byproduct. Uric acid also drives up your blood pressure by inhibiting nitric oxide in your blood vessels. Nitric oxide helps your blood vessels maintain their elasticity. When you consume large amounts of fructose, increasing uric acid levels drive up your blood pressure. If your uric acid levels are chronically elevated, you have an increased risk for hypertension, kidney disease, metabolic syndrome and diabetes. Large amounts of fructose also place a great strain on your liver, which is responsible for most of the metabolic burden.
- As metabolic physician and nutrition expert Dr. Ron Rosedale has explained, insulin stores magnesium. If your insulin receptors are blunted and your cells grow resistant to insulin, you can't store magnesium, so it passes out of your body through urination. Magnesium relaxes muscles; so, when your magnesium level is low, your blood vessels will constrict rather than relax, which further raises your blood pressure.
- Insulin causes your body to retain sodium, which in turn causes fluid retention. Fluid retention results in elevated blood pressure and can ultimately lead to congestive heart failure.
If your blood pressure is elevated and you consume a lot of sugar – especially in the form of fructose (such as high fructose corn syrup) – lowering your blood pressure might be as simple as cutting all forms of sugar and grains out of your diet. Normalizing your blood glucose levels will normalize your insulin and bring those blood pressures down into a healthy range. I strongly advise keeping your TOTAL fructose consumption below 25 grams per day, or as low as 15 grams if you have high blood pressure, are overweight, or diabetic.
The fructose in whole fruits is generally healthy, unless you consume large amounts, and/or in the form of fruit juices or dried fruits. Still, if you have any of the health issues just mentioned and you're consuming large amounts of fruit, you would be wise to restrict your fruit intake to under 15 grams of fructose per day as well until your condition has normalized.
Tips for Achieving a Healthy Blood Pressure without Drugs
Besides drastically reducing or eliminating fructose consumption, there are some basic lifestyle modifications that will help optimize your blood pressure, improve your liver and kidney function, and reduce your overall risk for disease. Make sure you address each of the following:
- Use exercise as a drug. Physical activity is by far one of the most potent "drug" there is, especially for increasing insulin sensitivity and normalizing blood glucose and blood pressure levels. We have developed a comprehensive fitness program that includes high intensity interval burst-type activity, stretching, and resistance training, which are all important components of a complete fitness program.
- Follow a good nutrition plan that's right for your body. It should be rich in fresh, organic vegetables, raw nuts and seeds, raw organic dairy, eggs from pastured hens, grass-fed meats, healthy fats such as coconut oil and animal-based omega-3, and plenty of fresh pure water.
- Optimize your vitamin D levels. Sunlight, and the vitamin D it causes your body to produce, has a normalizing effect on your blood pressure. Vitamin D deficiency has been linked to insulin resistance and metabolic syndrome.
The best source for vitamin D is direct sun exposure. But for many of us, this just isn't practical during the winter. The next best option to sunlight is the use of a safe indoor tanning device. If neither natural nor artificial sunlight is an option, then using oral vitamin D3 supplements is your best bet. If you wish to take an oral vitamin D3 supplement, follow my dose recommendations, which are based on the latest scientific research. The only way to know your optimal dose is to get your blood tested. Ideally, you'll want to maintain a vitamin D level of 50-70 ng/ml year-round.
For an in-depth explanation of everything you need to know about vitamin D, please listen to my FREE one-hour vitamin D lecture.
- Manage your stress. Stress puts the "tension" into hypertension! The long-term activation of your stress-response system can disrupt nearly all of your body's processes, and elevated blood pressure is one of many negative effects. Finding a way to deal with life's everyday stressors is a necessity for good health. My preferred tool is the Emotional Freedom Technique (EFT).
- Get plenty of deep, restorative sleep each night.
WARNING to Those Taking Blood Pressure Medications
I rarely recommend the use of drugs, but in some cases it may be appropriate to keep taking them as a temporary measure until you are healthy enough to wean yourself off. If you have serious hypertension, this is one of those cases.
If you are on medication for high blood pressure, please do not discontinue it without consulting your healthcare provider. Stroke risk is a serious concern. As you gradually make the necessary lifestyle changes, your need for medication will lessen, and eventually you'll probably be able to discontinue the drug altogether. It takes determination and commitment, but it IS possible – I've seen it many times! So keep taking your medications as prescribed, working with your healthcare provider, and keep eating your broccoli.
What's the Secret Key to Eliminating Hypertension?
Humans are genetically programmed to seek energy-dense foods, which served us well for thousands of years, when food was scarce. However this is maladaptive in today's environment of readily available, cheap, high-calorie but nutritionally bankrupt foods.
The standard American diet has tripped our "fat switch," as Dr. Johnson discusses in his new book, which results not only in unwanted pounds but also in related health problems such as hypertension, diabetes, and kidney disease. Once you understand how fructose-rich foods activate your body's "fat switch," you can finally say goodbye to many of your most nagging health problems.