How a Vegan Diet Really Works
“Heart disease? Oh, c’mon, that’s so old school.” So went my thinking as I rode a conveyor belt into a CT scan in one of those dreary medical-imaging facilities I’d managed to avoid for the entirety of my 51 years. I was fairly certain this was just another test that didn’t really apply to me, one of the many my doctor had tacked on to the growing list of exams we Americans find ourselves subjected to as we move through the decades.
And why should it? I’d never smoked, I drank only in moderation — usually red wine. I exercised for a half-hour on most days, meditated not infrequently and did all the other things one is supposed to do to manage stress. The EKG tracings of my heartbeats were suitable for framing. True, I didn’t exactly follow Michael Pollan’s dictum to “Eat food. Not too much. Mostly plants.” But I did mostly avoid processed junk. (Doritos while driving were, for some reason, allowed.)
I’d managed to limit myself to what I thought was a tolerable dozen or so pounds of extra weight and I ate red meat only a couple times a month. That my “bad” LDL cholesterol had been creeping up slowly since my early 40s didn’t concern me that much. My “good” HDL levels were, well, good, and my GP assured me that my ratio of good cholesterol to bad was, also, well, good. And anyway, hadn’t the whole cholesterol thing been debunked by some New York Times writer or something?
Yeah, yeah, yeah, both of my grandfathers had died of cardiovascular disease. And yeah, yeah, yeah, my blood pressure had started sneaking up on me too. Just as sneakily, in 2017 the American Heart Association and American College of Cardiology lowered the standard for normal blood pressure by 10 points, placing me on the border of hypertension. Still, I continued to think of all this heart disease stuff as something that only applied to guys who carried around tackle boxes full of pills, listened to Sinatra on AM radio and instructed waitresses to “Go easy on the salt, will ya sweetheart? I gotta watch my presha.”
But unbeknownst to me, as my medical practitioners logged the various changes in my numbers, they were starting to reconsider my normally salubrious state of affairs, moving me out of what they considered “low risk” up into the mid-range for a heart attack or stroke. Which is why, in January of last year, I was told to get a coronary calcium scan (aka heart scan), a test — not covered by insurance, thank you very much — that uses a highly specific X-ray technology to measure amounts of calcium-containing plaque in the arteries of the heart. Even as the CT scanner zoomed back and forth across my chest, I comforted myself that a friend had cholesterol levels nearly twice as high as mine and had just gotten a perfect zero score on hers. “I got this,” I thought.
Two days later, my doctor called to say I scored a 90 out of 400 — more calcification in my arteries than 60% of men my age. Without even asking, he phoned in a prescription for statins. If I followed the doctor’s orders, I would be taking pills every day for the rest of my life. The pharmacy left five messages confirming that my drugs were ready. But I didn’t pick them up. I just didn’t want to. I was convinced that I wasn’t a statin kind of a guy. Wasn’t there another way?
During the next year I would find out that, yes, there was. Although it sure as hell wasn’t as easy as taking a pill.
If there was one comfort in all this, it was the fact that I was hardly alone in the diagnosis I’d received. Heart disease remains overwhelmingly the top cause of death for Americans, picking off more than 800,000 of us every year. According to the American Heart Association, nearly half of all Americans (48%) are living with some form of cardiovascular disease (which includes coronary heart disease, heart failure, stroke, and hypertension), and two-thirds have at least two major cardiovascular risk factors, such as high cholesterol, poor diet quality, and sedentary lifestyle. And while new medical procedures have come along since Sinatra’s salad days — like stents and bypasses that have saved countless lives — most cardiologists focus on addressing the accumulation of arterial plaque before a stent or bypass becomes necessary.
It’s hard to say if I was experiencing a massive kale-induced placebo effect, but I can truthfully say that by month nine of my experiment I felt fantastic.
Plaque is a combination of fats, calcium, cholesterol, and other molecules that can chronically impede blood flow to the heart and brain. An acute situation can arise if a piece of unstable plaque cracks, exposing the blood vessel to clotting agents in the blood — causing a rapid blockage that leads to a heart attack. And in 40% of such cases, that’s that.
Stopping or slowing plaque accumulation is where statins enter the picture. Today, most cardiologists agree that excessive LDL cholesterol, which is produced by the liver, is a major contributor to plaque buildup. Statins block the enzyme that prompts the liver to make LDL cholesterol, and also enables the liver to take up excess LDL from the blood, preventing some or all of it from accumulating. But statins do other interesting things. They can also lock the more dangerous, unstable plaque in place, preventing it from cracking. And studies published in the journal Nature and others have found that these drugs have an anti-inflammatory effect in the body and may relax veins and arteries, easing blood flow.
Yes, heart disease, on a population level, is as serious as it is common, and “on a population scale, statins are miracles,” according to renowned diet-centered physician Michael Greger, M.D., author of the bestselling How Not to Die. Which is why the default for my very mainstream cardiologist was to call in the medication cavalry. Most studies put the mortality risk reduction between 5% and 25%. But when you take it down to a personal level, Greger told me, the benefits of statins are not as great. In men 70 and older (two factors that automatically up your odds) with no previous history of heart disease, the risk of dying from a heart attack or stroke is reduced much less — only by around 0.1% “No doctor tells people that because no one would take these drugs if they did,” said Greger. “I mean, what risk reduction would you need to justify taking a drug every day for the rest of your life?”
Now, that’s what I wanted to hear. I am an individual, damn it, not a population. And I am a pretty motivated one to boot. What if I adopted the most heart-healthy eating pattern possible, amped up my exercise regime and dropped those pesky extra pounds? I decided to give myself a year to make it work. And if it didn’t, the drugstore was right around the corner.
Ever since writing a book about heart-healthy omega-3 fatty acids, I’d been interested in the differences in outcomes from diet to diet. I’d also been circling around the idea that the best diet for your body might also be the best one for the planet. So when I began researching what to eat for my yearlong heart-improvement project, my attention eventually zeroed in on going vegan. For the planet, there’s little doubt that veganism works. Animal agriculture contributes nearly two-thirds of the greenhouse gas emissions created by food production globally — and 78% of its methane emissions. And for me, a vegan diet felt straightforward; it eliminated whole categories of foods I might be too tempted by.
In terms of health outcomes, plant-based diets have shown promising results — although there’s conflicting evidence as to whether going vegan, vegetarian or eating mostly plants but allowing for some meat, fish, and dairy is best. What I found most impressive were the studies that cardiologist Dean Ornish, M.D., founder of the Preventive Medicine Research Institute, conducted in the 1990s — looking at what happened to cardiac patients when they were put on a plant-based (though not completely vegan) diet. In many cases, Ornish discovered that with people like me who had significant calcification, their arteries actually opened up. This phenomenon has been attributed in part to the high amounts of anti-inflammatory micronutrients that a plant-centered diet — full of vegetables, fruits, whole grains, pulses, and nuts — delivers.
More recently, a review published in the American Journal of Clinical Nutrition reported that among a group of 96,000 Seventh-Day Adventists — who adhere to varying types of plant-based diets — those who were vegan had the lowest risk of hypertension, as well as the lowest BMIs, compared to participants eating a vegetarian diet or a plant-based diet that included small amounts of animal foods. Other research on this cohort has linked veganism to better cholesterol levels, reduced inflammation, and lower rates of heart disease.
So, plants it was. But which plants? Here again, I turned to Ornish, or rather Greger, Ornish’s colleague. In his hundreds of short nerdfest online videos, Greger has over the years tried to take all the studies of all the foods out there and wedge them into what amounts to a mega meta-analysis of everything from broccoli to beans to beets. Based on that distillation, Greger recommends a diet to his patients that meets nearly all of your nutritional needs and delivers the fiber, antioxidants, and other micronutrients that are thought to be the key to tamping down inflammation, lowering LDL cholesterol, and improving cardiovascular health. What most decidedly wasn’t on the list were animal products and highly processed foods of any kind.
The transition was choppy. Going out to eat was a nightmare. Restaurants had to be pre-vetted and I became that irritating member of a social circle who didn’t partake in the shared appetizer platter. At home, though, things went much smoother. I’ve always loved to cook and swapping in mushrooms for pork in my Bolognese didn’t bother me much. In fact, I was impressed with all the many ways plant-based cooking had advanced since I last tried vegetarianism back in the ’80s. Making cashew mozzarella was a revelation, as was the totally convincing swap of aquafaba (canned-chickpea water) for eggs in homemade mayonnaise. And by the time I arrived for my three-month checkup, I felt confident that I could sustain my new diet.
In preparation for my experiment, I had also switched to a more lifestyle-centered cardiologist, Suzanne Steinbaum, D.O., president of the SRSHeart Center for Women’s Prevention, Health, and Wellness in New York City. She’s used to challenging establishment assumptions, having been a leader in drawing attention to the overlooked fact that for American women, too, cardiovascular disease is the №1 cause of death. But even Steinbaum was cautious about the idea of holding off on drugs. In fact, like pretty much every doctor I interviewed for this article, Steinbaum saw many benefits in statins. “I know cardiologists who, after putting in so many stents on so many patients say, ‘They should just put statins in the water,’” she told me. Indeed, many of the cardiologists I talked to were themselves on statins.
But a week later, when the results of my first blood tests came back, Steinbaum was impressed. In just a few months, my LDL had dropped from 160 to 127 mg/dL. My blood pressure — which had been stubbornly stuck at 140/90 mm Hg — was trending downward to something like 135/85. Still, she said, we should really dive deeper to try to figure this out. In other words, more tests.
We have come a long way in the last 60 years in understanding the root causes of heart disease. Way back in the Rat Pack days, when the physiologist Ancel Keys first started peering into arteries and finding fatty deposits in the vascular system of middle-aged males, the thought was that fat and cholesterol from food were somehow literally oozing into our blood vessels and clogging them up: a kind of plumbing problem. But as medical research has become more fine-scaled in its ability to identify nuanced pathways, we’ve come to understand that coronary artery disease is a multi-factor issue, one that hinges on a complicated interlinking dynamic of diet, lifestyle, and genes.
As I entered the second quarter of my vegan trial, Steinbaum and I started trying to tease out how I stood on those other factors. She ordered a battery of new tests that looked both at my liver’s natural ability to deal with cholesterol, as well as at my genetic proclivity to have faulty LDL-clearing enzymes in the first place. (I should say here that I am lucky to be covered under my partner’s excellent insurance — or getting to the root of things could have made a serious dent in my finances.)
On the good side, a test for APOE (apolipoprotein E), a hereditary marker that is strongly linked to heart disease and Alzheimer’s, came back with a normal reading. On the not-so-great side was the result of a panel of tests done by Boston Heart Diagnostics. Generally, Boston Heart judged me to be sound. But one factor that showed red in the user-friendly pamphlet the lab gives its patients was an elevated level of apolipoprotein B — the protein component of what cardiologists call “small and dense” LDL. These particles are very strongly associated with heart attack risk. Worse, small dense LDL levels don’t change all that much in response to what we eat. If it turned out that apoB-driven LDL was at the root of my problem, it’s possible that my endeavors might hit a wall, regardless of how much broccoli and beets I shoved down my gullet. Nevertheless, I persisted.
When I let Greger know that I’d lowered my LDL by more than 40 points, he was pleased but not particularly surprised. Most of his patients, he said, saw a 30% reduction in LDL in just a few weeks after switching to a vegan diet. This is partially due to actual changes the diet seems to engender in the functioning of the liver, but also because the switch generally drops your weight. And weight has a considerable correlation with cholesterol. Greger explained that for every pound lost, people also tended to shed about one point of LDL. Seeing as I was still above the normal BMI range, I decided to up my exercise and see if I could knock both numbers down.
This might have been as important a choice for me as changing diets. Exercise, it turns out, is about the most statistically effective form of intervention there is for reducing cardiac “events,” as doctors call heart attacks and strokes. According to Benjamin Levine, M.D., a professor of internal medicine and cardiology at UT Southwestern Medical Center and Texas Health Presbyterian Dallas, in people like me with calcium scores of less than 100, studies have found a whopping 50% reduction in heart attacks and strokes when subjects exercised regularly compared to those who remained sedentary. (He notes that the benefit seems to plateau at around five hours a week.) Besides shaving off pounds and reducing stress, exercise also lowers blood pressure, stabilizes the heart’s rhythm, and even improves its overall structure. Particularly relevant to my dilemma: There is evidence, too, that exercise helps transform unstable plaque into the calcified stuff that won’t break off and cause … an event.
Since I had already been doing 30 minutes a day, I upped my “dose” to the upper part of Levine’s range and started running 45 minutes daily.
It’s hard to say if I was experiencing a massive kale-induced placebo effect, but I can truthfully say that by month nine of my experiment, I felt fantastic. I had lost a dozen pounds, had more energy and could manage 10K runs without joint pain or shortness of breath, though I did miss a good steak from time to time. And my labs from Steinbaum cheered me. “The most compelling markers that we have are the cholesterol and blood pressure,” she wrote. “Your LDL cholesterol before you started your trial in February was 160, in May it decreased to 127 and now it is 118. Your ambulatory blood pressures in May were 120–145/80–95. Currently your blood pressures are in the 120s/70–80s.” Based on all that, it seemed I had beaten the rap. On the presumption that a continuation of my diet and exercise plan would further lower my numbers, Steinbaum was holding off on statins for the moment.
As I started taking a victory lap, I consulted a bunch of other doctors to fact-check (but also to crow about my numbers). Sadly, several suggested that my whole experiment might be flawed. “The oversimplification of LDL has been driven by the promotion of drugs that lower LDL, rather than the science which says the driver is inflammation,” Mark Hyman, M.D., head of strategy and innovation at the Cleveland Clinic Center for Functional Medicine, explained on a Zoom call this past winter. “While LDL is a useful risk factor, it is not as important as the overall pattern of cholesterol — small dense LDL particles, high triglycerides, low HDL — and inflammation. The most dangerous pattern is driven by a diet high in sugar and starch not fat.”
Other physicians I interviewed agreed that animal fat isn’t the biggest problem. Rather, it’s sugars and simple carbs that drive insulin spikes and inflammation and, in turn, heart disease. Indeed, a study review published in Progress of Cardiovascular Diseases found that some sources of saturated fat may have no impact on heart disease, while refined carbs — particularly added sugar — lead to an uptick in inflammation, LDL, and other changes that increase heart disease risk and can lead to a threefold risk of dying from it.
“But I bake my own bread and it’s 100% whole-wheat!” I protested. Not enough, Hyman said. “My rule of thumb is the only bread you should eat is a loaf you can stand on that won’t squish.” As a precaution, I followed his advice and switched to a Danish health loaf that indeed bears a certain resemblance to a tasty brick. And in general, as I continued to modify my diet, I favored Greger’s advice to eat only whole, plant-based foods and eschewed the products coming out of the rapidly emerging highly processed vegan-food sector.
If there is one thing I’ve learned after a year of being more in contact with the medical world than I’d normally care to be, it’s that tests beget tests. As I geared up to see Steinbaum for a final evaluation, we planned a repeat cardiopulmonary exercise test (CPET) to see if the impressive 112% VO2 score I’d gotten earlier was a fluke or a trend. We’d redo the apoB test and find out if I’d managed to tackle the “very bad” bad cholesterol issue. And we’d test to see if I had any “endothelial dysfunction,” a way of charting whether the calcium picked up in my calcium score was inside or outside of my arteries.
But then the coronavirus swept across New York City. All nonessential services were shut down, including Steinbaum’s office. In mid-March, I developed a dry cough, slight difficulty breathing, a fever, and extreme fatigue. I knew people with impaired heart health were particularly vulnerable to Covid-19 and I was sure I had it. I worried.
And then, just as suddenly as they arrived, my symptoms vanished. My breathing returned to normal. I started running again. I felt great. Had my improved cardiovascular health contributed to my mild viral experience? Had all that diet and exercise paid off in actual life-saving in the face of a deadly pandemic? I wanted to think so. When I finally tested positive for Covid antibodies in May, that very much seemed to be the case.
Now I’m just waiting for Steinbaum’s office to open up again so we can keep on improving my numbers. I’ve seen the results of changes in lifestyle and diet and am committed to doing better with how I eat and exercise. Because, really, in these crazy times with all the stresses ahead, I know I’m going to need a whole lot of heart.
Here are a few takeaways from my year as a vegan. You are not me. Come up with a plan that your doctor agrees with based on your numbers. For example, if you get a calcium score over 300 (as opposed to my 90), statins are probably in your future. And if you’ve already had a heart attack or stroke, don’t think about any of this until you’ve consulted your cardiologist. Stick to dense, fiber-rich whole grains. Eat “bread that you can stand on without squishing it” as Dr. Hyman says. Go easy on the salt. Not all people are salt-sensitive meaning their blood pressure ticks up in response to a high-sodium diet — but salt is a major contributor to hypertension, which in turn is one of the major risk factors for heart attack and stroke. Consider supplements. If you’re going full-on vegan you will likely have to supplement your diet with vitamin B12 and omega-3 fatty acids — nutrients that are primarily found in nonvegan foods like fish and eggs. Animal-free forms of both are widely available. Question your “healthy” diet. Log it and record what you’re really eating (yes, even those Doritos in the car). Measure your exercise. Are you getting three to five hours a week? If not, up it. It’s OK to cheat. (Full disclosure: I did several times, a piece of meat here and there is not apt to blow out your arteries). Rather, as Dr. Michael Greger notes, the goal is a significant overall decrease in saturated fat and increase in anti-inflammatory plant-based foods.
An earlier version of this article first appeared in the September 2020 issue of Eating Well Magazine
More heart-healthy and earth friendly eating tips in The Climate Diet