But high blood pressure is where hibiscus really shines.134 A double-blind, placebo-controlled study out of Tufts University that compared hibiscus tea with an artificially colored and flavored lookalike showed that three cups of hibiscus tea a day significantly lowered blood pressure in prehypertensive adults better than the placebo beverage.135 But by how much? How does drinking hibiscus tea compare with other interventions?
The PREMIER Clinical Trial randomized hundreds of men and women with elevated blood pressure into an “advice only” control group or an active lifestyle intervention group. The control group was given a brochure and told to lose weight, reduce their salt intake, get more exercise, and eat healthier (i.e., to go on the DASH diet). The behavioral intervention group received the same instruction but also got face-to-face sessions, attended group meetings, kept food diaries, and monitored their physical activity, calories, and sodium intake. Within six months, the intervention group achieved a four-point drop in systolic blood pressure compared with the advice-only group. That may not seem like a lot, but on a population scale, a five-point drop may lead to 14 percent fewer stroke deaths, 9 percent fewer fatal heart attacks, and 7 percent fewer deaths overall each year.136 Meanwhile, in the Tufts study, a cup of hibiscus tea with each meal managed to lower subjects’ systolic blood pressure by six points over the control group.137
To lower blood pressure, you should still lose weight, reduce your salt intake, get more exercise, and eat healthier, but the evidence shows that adding hibiscus tea to your daily routine may offer an additional benefit, comparable even to that provided by antihypertensive drugs. Tested head-to-head against a leading blood pressure drug, two cups of strong hibiscus tea every morning (using a total of five tea bags) was as effective in lowering subjects’ blood pressure as a starting dose of the drug Captopril taken twice a day.138
However, there are differences: Captopril can have side effects, most commonly rash, cough, and taste impairment, and it can even, though extremely rarely, cause fatal swelling of the throat.139 No side effects were reported for hibiscus tea, though it isn’t called sour tea for nothing. If you drink it, make sure to rinse your mouth with water afterward to keep the natural acids in the tea from softening the enamel on your teeth.140 And given the extraordinary manganese content in hibiscus tea,141 to be on the safe side, I wouldn’t recommend drinking more than a liter of it a day.
The Power of NO
Nitric oxide (NO) is a key biological messenger within the body, and its message is: “Open Sesame!” When released by your endothelium (the cells lining your arteries), it signals the muscle fibres within the walls of your arteries to relax, allowing them to open up and for more blood to flow. That’s how nitroglycerin pills work: The nitroglycerin people take when they’re experiencing chest pain is converted into NO, which dilates the coronary arteries, allowing more blood to flow to the heart muscle. Erectile dysfunction (ED) pills like Viagra work the same way; they boost nitric oxide signaling, which relaxes penile arteries and improves blood flow to the penis.
The ED you really need to be concerned about, though, is endothelial dysfunction, the failure of the linings of your arteries to produce enough NO to properly dilate them. Nitric oxide is produced by an enzyme called NO synthase. Its enemy is free radicals, which not only gobble up nitric oxide but can hijack NO synthase and force it to start pumping out additional free radicals.142 Without enough NO, your arteries can then stiffen, become dysfunctional, and raise your blood pressure and your risk for heart attack.
So you need to flood your body with antioxidant-rich plant foods throughout the day to extinguish the free radicals and let NO synthase get back to its job of keeping your arteries fully functional. There’s an ultrasound device researchers use to measure the NO-induced dilation of your arteries. One study using this device found that if you take people following a standard Western diet and have them eat even fewer antioxidants, their artery dilation only gets a little bit worse. It seems we’re already near the bottom of the barrel arterial-function-wise, so there’s not much room for further decline. But put people on a high-antioxidant diet by, among many other things, switching their bananas for berries and their white chocolate for dark, and within just two weeks, they experience a significant boost in their arteries’ ability to relax and dilate normally.143
In addition to eating antioxidant-rich foods that can boost your body’s ability to produce NO, you can also eat certain vegetables, such as beetroot and greens, that are rich in natural nitrates, which your body can convert into nitric oxide. (For the difference between nitrates and nitrites, see chapter 10.) This process explains why researchers have been able to show a ten-point systolic blood pressure drop in volunteers within hours of their consuming beetroot juice—an effect that lasted throughout the day.144
That study was performed on a group of healthy subjects, though. Obviously, we need to test the power of beetroot where it counts most—in people with high blood pressure. If nitrate-rich vegetables can so powerfully modulate humanity’s leading risk factor for dying, why did it take until 2015 before such a study was published? Well, who was going to fund it? Big Beetroot? Drug companies rake in more than $10 billion (£6 million) a year from blood pressure medications.145 You can’t make billions on beetroot. That’s why we are fortunate to have charities like the British Heart Foundation, which finally funded a beetroot juice study involving people with high blood pressure.
Half the subjects were provided 250ml of beetroot juice daily for four weeks, while the other half was given an indistinguishable, nitrate-free placebo drink. The researchers found that not only was systolic blood pressure reduced by about eight points in the beetroot-juice drinkers but the benefits grew week by week, suggesting their blood pressure might have continued to improve even further. The scientists concluded that “nitrate-rich vegetables may prove to be both cost-effective, affordable, and favorable for a public health approach to hypertension.”146
The optimal dose appears to be 125ml,147 but beetroot juice is perishable, processed, and hard to find. A typical fifteen-ounce tin of beetroots would provide the same dose of nitrate, but the most concentrated sources of the compound are dark-green, leafy vegetables. The following is a top-ten list of nitrate-rich foods, in ascending order. As you’ll see, eight out of the top ten are greens.
Top-Ten food Sources of Nitrates
10. Beetroot
9. Swiss chard
8. Oak leaf lettuce
7. Beetroot greens
6. Basil
5. Spring greens
4. Butter leaf lettuce
3. Coriander
2. Rhubarb
1. Rocket
Rocket comes out on top with a whopping 480 mg of nitrate per hundred-gram serving, which is more than four times the content of beetroot.148
The healthiest way to get your nitrate fix is to eat a big salad every day. You could take nitrate- and nitric-oxide-boosting supplements, but they have questionable safety 149 and efficacy150 records and should be avoided. What about V8 juice, which boasts both beetroot and spinach juice? It must not have much, because you’d have to drink nineteen liters of it a day to reach your daily nitrate intake target.151
The benefits of nitrates may explain why eating your greens is associated with reduced rates of heart disease152 and a longer life span,153 not to mention the “veggie Viagra” effect. You read that right. There’s a link between vegetable consumption and improved sexual function,154 as well as improved blood flow to the most important organ of the body, the brain.155 And the only side effect of beeting your brains out may be a little extra color in your life—namely, red stools and urine that is pretty in pee-nk.
Doping with Beetroot Juice
A Lamborghini goes faster than a lemon not because the chemistry of petrol combustion is somehow different in a sports car from that in a beater. It’s because the Lambo has a more powerful engine. Similarly, athletes may have bigger muscles and be able to get more oxygen to those mus
cles faster. But fundamentally, the amount of energy a body can extract from oxygen remains the same . . . or so we thought.
About five years ago, one of the gospels of sports physiology got turned on its head—all because of beetroot juice.
Nitrates, concentrated in green, leafy vegetables and beets, not only help deliver oxygenated blood to your muscles by helping dilate your arteries but also enable your body to extract more energy from that oxygen—something never before thought possible. For example, one little shot of beetroot juice has been found to allow free divers to hold their breath for half a minute longer than usual.156 After sipping beetroot juice, cyclists were able to perform at the same level of intensity while consuming 19 percent less oxygen than the placebo group. Then, when they ramped up their bike resistance for an intense bout of what they called “severe cycling,” the time to exhaustion was extended from 9:43 minutes to 11:15 minutes. The beetroot-juice-drinking group exhibited greater endurance while using less oxygen. In short, the beetroot juice made the bikers’ bodies’ energy production significantly more efficient. No drug, steroid, supplement, or intervention had ever before been shown to do what beetroot juice could do.157
This effect works with whole beetroot too. In another study, men and women eating 300 grams of baked beetroot seventy-five minutes before running a 5K race improved their running performance while maintaining the same heart rate and even reported less exertion.158 Faster time with less effort? Them’s some block-rockin’ beets!
To maximize athletic performance, the ideal dose and timing appears to be 125ml of beetroot juice (or three three-inch beetroot, or 180 grams of cooked spinach159) two to three hours before a competition.160
It seems sports news programs are always talking about steroids and other illegal performance-enhancing drugs. Why hasn’t anyone mentioned these mighty and perfectly legit performance-enhancing vegetables? Beets me.
A blood pressure checkup is easy to ignore or postpone. Unlike the case with many of our other leading killers, the insidious consequences of hypertension may not be apparent until you’re lifted into an ambulance or lowered into a grave. So go to your local pharmacy, fire station, or doctor’s office and get your blood pressure checked. If it’s too high, the bad news is that you’ll join the one billion people living with this condition. The good news is that you don’t have to join the millions who die from it every year. Try eating and living healthfully for even just a few weeks, and you may be amazed by the results. Here are just a few stories about people who did just that.
Every day, NutritionFacts.org gets hundreds of e-mails, many from people eager to share how their lives were turned around by taking their health into their own hands. There’s Bob, for example, who once weighed 230 pounds and had a 200-plus cholesterol level and triglycerides through the roof. He was on a battery of blood pressure medications. After starting a whole-food, plant-based diet, he’s now down to 175 pounds, boasts a total cholesterol of 136, and no longer takes any blood pressure medication. At sixty-five, Bob feels better now than he has in decades, not by trying a new exercise program or the latest blockbuster drug—just by changing his diet.
Patricia e-mailed not long ago. Her brother had just been diagnosed with severe high blood pressure and atherosclerosis. He was nearly sixty pounds overweight, and his skin was the color of “white paper.” He was so unhealthy he couldn’t even get a driver’s license. Patricia and her brother decided to start a plant-based diet together. Now he’s fit and trim, his weight is normal, he has no more need for blood pressure drugs, and Patricia most deservedly takes the (sugar-, milk-, and egg-free) cake for best sister ever.
Then there’s Dean. He “filled up” with the standard American diet and became obese. He had high blood pressure, so his doctor put him on medication. Then he got high cholesterol, so his doctor put him on more medication. Moreover, every winter, Dean would suffer from terrible respiratory infections that required antibiotics. Finally, he got fed up and adopted a plant-based diet. He’s now lost fifty pounds. His blood sugar and cholesterol levels, and even his blood pressure, are all normal. And he happily spends his winters ailment-free. Dean ended his note to me with this simple pledge: “I will be on a plant-based diet for the rest of my life.” Thanks to a healthy diet, that may be quite a long time.
CHAPTER 8
How Not to Die from Liver Diseases
There are some patients you never forget. On the first day of my GI rotation (GI stands for gastrointestinal, which means I was about to come face-to-face with any issues in the digestive tract from mouth to tush), I reported in and was told to observe my team of senior doctors in one of the endoscopy rooms, where physicians use a scope to look into the GI tract for all manner of routine procedures. I expected to walk into a colonoscopy looking at a rectal polyp or maybe an upper endoscopy looking at a stomach ulcer. But I’ll never forget what I saw. It fuels me to this day in my mission to help people understand the connection between lifestyle and health (or lack of it).
A sedated patient was lying on a gurney, surrounded by a team of doctors using a scope with a camera. I looked at the monitor, trying to find anatomical landmarks to understand where the scope was. It was definitely down the throat, but the oesophagus was snaked with what looked like throbbing varicose veins. They were everywhere. They looked like worms trying to emerge from under the smooth surface of the oesophagus. Several had eroded through the lining and were spurting blood. I watched as more blood surged out with every one of the patient’s heartbeats. She was basically bleeding to death into her stomach. The doctors tried desperately to cauterize and tie off these fountains of fresh red blood, but it was like a game of Whack-A-Mole. Every time one was cut off, another sprang up.
These were known as oesophageal varices—veins swollen with backed-up blood due to a cirrhotic liver. Watching this nightmare unfold, I wondered how the patient first came down with cirrhosis. Was she an alcoholic? Did she contract hepatitis? I remember thinking how devastated she must have felt when she found out she had end-stage liver disease. How was her family coping? I was jerked back from my thoughts by screeching monitor alarms. She was bleeding out.
The doctors couldn’t transfuse blood faster than the patient was losing it internally. Her blood pressure fell, and her heart stopped. The staff jumped into action with chest compressions, paddles delivering shocks, and injections of adrenaline, but within minutes, she was gone.
It was my job to talk to the patient’s family. I learned that her cirrhosis was not due to drinking too much or from being an IV drug user. Her liver had scarred over because she was obese and had developed a fatty liver. Everything I had just witnessed was preventable, a direct result of lifestyle choices. When people are overweight, they can suffer from social stigma, knee problems, and increased risk for metabolic disorders like diabetes, but this was the first person I saw bleed to death before my eyes.
The family cried. I cried. I swore to myself I’d do whatever was necessary to help prevent this from ever happening to anyone under my care.
You can make do with only one kidney. You can survive without a spleen or a gallbladder. You can even get by without a stomach. But you can’t live without a liver, the body’s largest internal organ.
What exactly does the liver do? Up to five hundred different functions have been attributed to this vital organ.1 First and foremost, it plays the role of bouncer, keeping unwanted guests out of your bloodstream. Whatever you absorb through your digestive tract isn’t immediately circulated throughout your body. The blood from your intestines first goes straight to the liver, where nutrients are metabolized and toxins are neutralized. It’s no surprise, then, that what you eat can and does play a critical role in liver health and disease.
About sixty thousand Americans die of liver disease every year, and the death rates have risen each of the last five years.2 The incidence of liver cancer alone has been rising about 4 percent every year over the last decade.3 Liver dysfunction can run in families, like the i
ron-overload disease hemochromatosis. It can be caused by infections that can lead to liver cancer, or it can stem from drugs—most often inadvertent or intentional overdoses of Tylenol.4 The most common causes, however, are drink and food: alcoholic liver disease and fatty liver disease.
Alcoholic Liver Disease
According to a famous series of papers in the Journal of the American Medical Association called the “Actual Causes of Death in the United States” [emphasis added], the leading killer of Americans in the year 2000 was tobacco, followed by diet and inactivity. The third-leading killer? Alcohol.5 About half of alcohol-related deaths were due to sudden causes like motor vehicle accidents; the other half were slower, and the leading cause was alcoholic liver disease.6
Excessive alcohol consumption can lead to an accumulation of fat in the liver (what’s known as fatty liver), which can cause inflammation and result in liver scarring and, eventually, liver failure. The CDC defines excessive drinking as the regular consumption of more than one drink a day for women and more than two a day for men. A drink is defined as 12 ounces of beer, 8 ounces of high-alcohol beer, 5 ounces of wine, or 1.5 ounces (a “shot”) of spirits.7 Progression of the disease can usually be halted by stopping drinking, but sometimes it’s too late.8
Heavy alcohol consumption can cause a fatty liver in less than three weeks,9 but it usually resolves within four to six weeks after stopping drinking.10 But in 5–15 percent of cases, the disease continues to progress, and the liver starts to scar despite alcohol cessation.11
Similarly, once alcohol-induced hepatitis (liver inflammation) is diagnosed, three-year survival rates can be as high as 90 percent among people who stop drinking after diagnosis.12 But as many as 18 percent of them go on to develop cirrhosis, an irreparable scarring of the liver.13
How Not to Die Page 19