Blood Vessel Health

How can we improve the capacity of our blood vessels to repair themselves?  Here’s our first story.

How can we remain young at heart? The capacity of our blood vessels to repair themselves is dependent on endothelial progenitor cells that emerge from stem cells in our bone marrow to patch up any holes in our endothelium––the innermost lining of our blood vessels that keeps our blood flowing smoothly. Lower levels of circulating endothelial progenitor cells in the blood correlate with arterial diseases, like erectile dysfunction. Higher numbers, on the other hand, are correlated with a significantly reduced risk of death from cardiovascular causes. Before we explore how to boost our levels, let‘s first establish cause and effect.

A randomized, double-blind, placebo-controlled trial was performed in men and women with peripheral vascular disease––a circulation disorder characterized by the narrowing of blood vessels outside of the heart or brain. The arteries supplying blood to their legs were so ravaged by disease they could only walk about a minute before the muscles in their legs cried out in pain from lack of oxygen. For each study participant, one leg was randomly selected to be injected with cells from their own bone marrow, and the other was injected with their own peripheral blood as a control. Not only was pain-free walking time significantly extended in the marrow-injected leg, they were less likely to subsequently lose it. Severe limb ischemia (lack of oxygen) from peripheral vascular disease carries a 10 to 40 percent amputation rate within six months. In the control group, 14 percent were forced to undergo a major amputation, compared to zero in the bone marrow group. Given these remarkable benefits, the link between higher numbers of endothelial progenitor cells and lower risk of dying from cardiovascular disease may indeed be causal. Short of sticking a large-bore needle into your hip, how else can we cultivate and release more endothelial progenitor cells into our system?

Smoking cessation is one of the most important and effective lifestyle changes to increase the number and function of active endothelial progenitor cells. Cutting down isn’t enough. There are twenty cigarettes in a pack. If you only smoke about one a day, wouldn’t you think you’d only have about one-twentieth the risk of cardiovascular disease, compared to smoking the whole pack? Based on a meta-analysis of more than a hundred studies, smoking only about one cigarette a day caused around ten times the risk of cardiovascular disease you’d expect by that logic, compared to smoking a pack a day. There is no safe level of smoking when it comes to heart attack and stroke risk. Even exposure to second-hand smoke can deteriorate our circulating endothelial progenitor cell count. So, even just being around smokers is risky.

Randomized controlled trials show exercise training can actually boost endothelial progenitor cell circulation. In a study of middle-aged and older sedentary men, for example, three months of moderate aerobic exercise—mostly walking with some participants starting to jog a bit as their fitness improved—led to a doubling of endothelial progenitor cells in their bloodstream. Regular aerobic exercise could be considered a “first line” strategy for helping to prevent and treat arterial aging. What about diet?

A randomized controlled trial showed that reducing saturated fat (mostly in the form of butter) significantly elevated endothelial progenitor cell numbers––consistent with a study on baboons showing that even a few weeks of a high-cholesterol, high-fat diet could cause dramatic premature epithelial cell senescence. Individual foods that have been shown to increase circulating endothelial progenitor cells include berries, onions, and green tea, and a diet centered completely around whole plant foods not only showed a boost in endothelial progenitors, but an improvement in endothelial function, along with a drop in LDL cholesterol.

In our next story, we look at how vegetables, such as beets and arugula, can improve athletic performance by improving oxygen delivery and utilization.

It’s great that we can improve athletic performance eating a few beets, but so what if you run 5 percent faster? It can be a fun experiment to eat a can of beets and maybe shave a minute off your 5K time, but these are the people who could really benefit from a more efficient use of oxygen: those suffering from emphysema. Yeah, young healthy adults eating greens and beets can swim, run, and cycle faster and farther, but what about those who get out of breath just walking up the stairs? Do nitrate-rich vegetables work where it counts? Yes, significantly extended time on the treadmill after two shots of beet juice.

It’s great that beet juice can decrease blood pressure in young healthy adults, but what about in those who really need it: older, overweight subjects? Just one shot of beet juice a day versus berry juice as a control, and in a few weeks, a significant drop in blood pressure; but within just a few days after stopping—after three weeks of beet-ing themselves up—blood pressure went back up. So, we have to eat our vegetables, and keep eating our vegetables.

Why did it take until 2015 to publish a study on lowering blood pressure in people with high blood pressure? You’d think that’d be the first group to try it on. Who’s going to fund it, though—Big Beet? Blood pressure medications rake in more than $10 billion a year. You can’t make billions on beets. But that’s why we have charities like the British Heart Foundation, which funded a study to give folks with high blood pressure a cup of beet juice a day for four weeks. After all, high blood pressure may be the #1 risk factor for premature death in the world. In ten years, it could affect nearly one in three adults on this planet. But put them on beet juice, and blood pressures drop and kept dropping, until it was stopped after a month. With so many people with high blood pressure even despite treatment, an additional strategy, based on the intake of nitrate-rich vegetables, may prove to be both cost-effective, affordable, and favorable for a public health approach to hypertension.

What about those with peripheral artery disease? Tens of millions with atherosclerotic clogs impairing blood flow to their legs, which can cause a cramping pain in the calves, called claudication, due to lack of blood flow through the blocked arteries, severely limiting one’s ability to even just walk around. But just drink some beet juice and walk 18 percent longer. This is really neat—I’ve never seen this before. They measured the actual oxygenation of their blood within their calf muscle. Placebo’s in white; beet is in black, showing how they were able to maintain more oxygen in their muscles with just vegetables.

The nitric oxide from vegetable nitrates not only improves oxygen efficiency, but also oxygen delivery by vasodilating blood vessels, opening up arteries so there’s more blood flow. I’m surprised beet juice companies aren’t trying to position themselves as veggie Viagra; it could certainly explain why those eating more veggies have such improved sexual function, though this study was just a snapshot in time. So, you can’t tell which came first. However, it seems more reasonable that low fruit and vegetable consumption contributes to erectile dysfunction, rather than the other way around.

What about the most important organ, the brain? Poor cerebral perfusion—lack of blood flow and oxygen in the brain—is associated with cognitive decline and dementia, and they showed that the nitrate in vegetables may be beneficial in treating age-related cognitive decline. They showed a direct effect of dietary nitrate on cerebral blood flow within the frontal lobes, the areas particularly compromised by aging. This is a critical brain area for so-called executive function, basic tasks and problem-solving important for day-to-day functioning. The nitrite from nitrate has been shown not only to increase blood flow to certain areas of the body, but also acts preferentially in low oxygen conditions, allowing it to increase blood flow precisely in the areas where it is needed most. And, that’s what they found in the brain: increased blood flow to the at-risk areas of the aging brain. And, the only side effects of beet-ing your brains out? A little extra color in your life.

Do legumes—beans, chickpeas, split peas, and lentils—work only to prevent disease, or can they help treat and reverse it as well? Here are some answers.

“Legumes [by which they mean all kinds of beans, chickpeas, split peas, and lentils] are an excellent source of many essential nutrients…vitamins, minerals, fibers, antioxidants…” And, not just an excellent source; perhaps the single cheapest source. In terms of nutrition density per penny, the four that really pull away from the pack are pinto beans, lentils, black beans, and kidney beans.

And, all that nutritional quality may have beneficial effects on excess body weight, insulin resistance, high cholesterol, inflammation, and oxidative stress—all “major cardiovascular risk factors.” So, do men and women who eat more beans tend to have less heart disease? Yes, suggesting that “increasing legume intake may be an important part of a dietary approach to the primary prevention of [coronary heart disease] in the general population”—meaning prevention of heart disease in the first place. But, maybe those eating more bean burritos are just eating fewer beef burritos? They took that into account, controlling for meat intake, fruits and vegetables, and smoking, and exercise. And, still, the bean-eaters appeared to be protected.

Note the highest category was eating legumes four or more times a week. In my Daily Dozen, I recommend people eat legumes three times—a day! In Costa Rica, they were able to find enough people eating beans every day. And, so, even after controlling for many of the same things, like intake of saturated fat and cholesterol, one bean serving a day was “associated with a 38 perecent reduction in the risk of [heart attack].” Yeah, but do you actually get to live longer, too? Yes, apparently so: an 8 percent lower all-cause mortality, again after adjusting for other dietary factors. You can’t control for everything, though. You can’t really prove cause-and-effect until you…put it to the test.

Randomized controlled interventional trials have found that “dietary [bean] intake [does] significantly reduce…[bad] cholesterol levels,” dating back a half century to 1962. Measure cholesterol levels at baseline, and then add beans to their diet, and then remove beans from their diets.

And, look, beans have “a low glycemic index and saturated fat content, and are high in fiber, potassium, and plant protein, each of which independently confers BP-lowering effects.” But, “[w]hether there’s sufficient evidence to emphasize [beans] alone to lower BP…is unclear.” Therefore, what we need is “a systematic review and meta-analysis of controlled feeding trials.” And, here it is. And, what they found is that beans do indeed lower blood pressure, no matter where you start out.

Okay, so, beans may be able to prevent artery disease, but what about reversing it? Can the daily consumption of beans—other than soy—reverse vascular impairment due to peripheral artery disease? Peripheral artery disease “results from a decrease in blood flow to the [legs] due to the [buildup of] atherosclerotic plaque” higher up. Yeah, soybeans may help. But what about other beans? So, they had 26 individuals with peripheral artery disease consume one serving a day of a combination of beans, split peas, lentils, and chickpeas for eight weeks.

Basically, how you diagnose and follow the disease is with “the ankle-brachial index,” which is just the ratio of blood pressure at your ankle compared to your arm. Once it dips below point nine, that means you must have some kind of clogs in blood flow to your lower body. But, eat some beans, and you may get a significant increase, enough to push four of 26 participants up into the normal range after just eight weeks, eating some beans! Now, there was no control group, but people tend to get worse, not better. The researchers conclude: “A legume-rich diet can elicit major improvements in arterial function.”