You can even use ground flaxseeds to replace eggs in baking. For each egg in the recipe, whisk one tablespoon of ground flaxseeds with three tablespoons of water until the mixture becomes gooey. Unlike chicken eggs, “flax eggs” are not only cholesterol-free but they’re also packed with soluble fibre to bring your cholesterol down11 instead of up.
It never ceases to amaze me how these tiny little seeds can pack such a health-promoting punch. With just a measly tablespoon a day and so many delicious, easy ways to incorporate ground flax into your sips and bites, there’s no reason you shouldn’t be able to tick this Daily Dozen check box every day.
Nuts and Seeds
Dr. Greger’s Favorite Nuts and Seeds
Almonds, Brazil nuts, cashews, chia seeds, hazelnuts/filberts, hemp seeds, macadamia nuts, pecans, pistachios, pumpkin seeds, sesame seeds, sunflower seeds, and walnuts
Serving Sizes:
30 g nuts or seeds
2 tablespoons nut or seed butter
Daily Recommendation:
1 serving per day
Sometimes it feels like there just aren’t enough hours in a day to get everything done. So instead of trying to make your day longer, why not make your life longer by an extra two years? That’s about how long your life span may be increased by eating nuts regularly—one handful (or about 30 grams) five or more days a week.1 Just that one simple and delicious act alone may extend your life.
The Global Burden of Disease Study calculated that not eating enough nuts and seeds was the third-leading dietary risk factor for death and disability in the world, killing more people than processed meat consumption. Insufficient nut and seed intake is thought to lead to the deaths of millions of people every year, fifteen times more than all those who die from overdoses of heroin, crack cocaine, and all other illicit drugs combined.2
The Uses of Blended Nuts
Nuts make for quick and delicious snacks on their own, but my personal favorite use for them is as green-light sources of fat to make rich, creamy sauces. Whether in a cashew Alfredo, a ginger-peanut sauce, or a tahini-based green goddess dressing, nuts and seeds can maximize nutrient acquisition by both improving absorption and increasing your total intake of vegetables by adding some creamy cachet.
An often overlooked use for nuts is as a key ingredient in soups, such as African peanut stew. When blended and heated, cashews thicken to make an amazingly creamy soup base. Nut and seed butters also pair well with veggies and fruits. Almost everyone loves the classic childhood pairings of peanut butter with celery or apples. One of my favorite treats is dipping fresh strawberries into a decadent chocolate sauce. All you need is half a cup of an unsweetened milk, one tablespoon of chia seeds, one tablespoon of cocoa, one teaspoon of almond butter, and sweetener to taste. (I use one tablespoon of erythritol, discussed here.) Mix all the ingredients, and heat until the almond butter melts and the sweetener dissolves. Pour into a bowl, whisk until smooth, and put it in the fridge to cool. The chia and fibre from the cocoa powder help it thicken into an indulgent delight. (You can grind up the chia seeds first, but I like the tapioca-like texture the little chia balls form.)
Walnuts for the Win
Which nut is healthiest? Normally, my answer is whichever you’re most willing and able to eat regularly, but walnuts really do seem to take the lead. They have among the highest antioxidant3 and omega-34 levels, and they beat other nuts in vitro in suppressing cancer cell growth.5 But how do walnuts fare outside the laboratory in real life?
PREDIMED is one of the largest interventional dietary trials ever performed. Interventional studies, if you remember, are those in which participants are randomized to different diets to see who fares better. This helps researchers avoid the problem of confounding variables when trying to determine cause and effect in cohort studies. For example, in major study6 after study7 after study,8 people who eat nuts tend to live longer and suffer fewer deaths from cancer, heart disease, and respiratory disease. There was a lingering question, though: Did these findings show causation or merely correlation? It could be possible, after all, that nut eaters also tend to have other healthy lifestyle behaviors. Maybe those who eat nuts are more likely to be, well, health nuts. On the other hand, if scientists randomly assign thousands of people to various levels of nut consumption and the nuttier group ends up the healthiest, we could have more confidence that nuts aren’t just associated with better health but actually cause better health. This is what PREDIMED ended up doing.9
More than seven thousand men and women at high cardiovascular risk were randomized into different diet groups and followed for years. One of the groups received a free half pound of nuts every week. In addition to eating more nuts, they were told to improve their diets in other ways, such as eating more fruits and vegetables and less meat and dairy, but weren’t as successful at any of those other goals compared to the control group. Nevertheless, having a free half pound of nuts sent to them every week for four consecutive years did indeed persuade them to start eating more nuts.10 (It’s too bad the researchers couldn’t have slipped in a little free broccoli too!)
At baseline, before the study even started, the thousands assigned to the nut group were already eating about half an ounce of nuts a day. Thanks to the ensuing freebies, they ended up bumping up their consumption to a whole ounce (about a handful). As a result, the study was able to determine what happens when people at high risk for heart disease following a particular diet eat an extra half ounce of nuts every day.
With no significant differences in meat and dairy intake, there were no significant differences in saturated fat or cholesterol intake. So, unsurprisingly, there were no significant differences in their blood cholesterol levels or the subsequent number of heart attacks. However, the added-nuts group did end up having significantly fewer strokes. In a sense, all the dietary groups were eating stroke-promoting diets. People in all the groups had strokes after eating each of the diets for years—so, ideally, they’d instead choose diets that can stop or reverse the disease process rather than encourage it. But for those not willing to make major shifts in their diet, just the minor tweak of adding nuts appeared to cut stroke risk in half.11 Those in the extra-nut-eating group still had strokes, but only about half as many. If this works as well in the general population, eighty-nine thousand strokes a year would be prevented in the United States alone. That would be like ten strokes an hour, around the clock, prevented simply by adding about four walnuts, almonds, and hazelnuts to the nation’s daily diet.
Regardless of which group participants were assigned to, those eating more nuts each day had a significantly lower risk of dying prematurely overall.12 Those who consumed more red- and yellow-light sources of fat—olive oil or extra virgin olive oil—failed to have any survival benefit.13 This is consistent with the way Ancel Keys, the so-called father of the Mediterranean diet, viewed olive oil. He thought of its benefit more as a means of replacing animal fats—that is, anything to get people to eat less lard and butter.14
Of all the nuts studied in PREDIMED, the researchers found the greatest benefits associated with walnuts, particularly for preventing cancer deaths.15 People who ate more than three servings of walnuts per week appeared to cut their risk of dying from cancer in half. A review of the scientific literature concluded that “the far-reaching positive effects of a plant-based diet that includes walnuts may be the most critical message for the public.”16
The Power of a Pea-“Nut”
Did you know that peanuts actually aren’t nuts? Technically, they’re legumes, but they’re often lumped together with true nuts in dietary surveys and studies, so it’s been hard to tease out their effects. Harvard University researchers worked to change that in the Nurses’ Health Study by specifically asking people about their peanut butter intake. They found that women at high risk for heart disease who ate nuts or a tablespoon of peanut butter five or more days a week appeared to nearly halve their risk of suffering a heart attack compared to women who ate a serving
or less per week.17 This cross-protection between true nuts and peanuts also appears to extend to fibrocystic breast disease. Adolescent girls in high school who consumed just one or more servings of peanuts a week appeared to have significantly lower risk of developing lumpy breasts, which can be a marker for increased breast cancer risk.18 PB&J to the rescue!
Nuts and Obesity: Weighing the Evidence
Nuts and nut butters are packed with nutrition—and calories. For example, just two tablespoons of a nut or seed butter might contain nearly two hundred calories. Nevertheless, it’s probably better to eat two hundred calories of nut butter than two hundred calories of what most Americans would eat otherwise. Given how concentrated nut calories are—you’d have to eat nearly an entire head of cabbage to get the same amount—if you add a serving of nuts to your daily diet, won’t you gain weight?
To date, there have been about twenty clinical trials on nuts and weight, and not a single one showed the weight gain you might expect. All the studies showed less weight gain than predicted, no weight gain at all, or weight loss—even after study subjects added a handful or two of nuts to their daily diets.19 However, these studies lasted just a few weeks or months. Perhaps prolonged nut consumption leads to weight gain? That question has been examined six different ways in studies lasting up to eight years. One found no significant change, and the other five measures found significantly less weight gain and reduced risk of abdominal obesity in those who ate more nuts.20
The first law of thermodynamics states that energy can neither be created nor destroyed. If calories, which are units of energy, can’t just disappear, then where are they all going? In one trial, for instance, participants who ate up to 120 pistachios as an afternoon snack every day for three months didn’t appear to gain a pound.21 How could thirty thousand calories vanish into thin air?
One theory offered was dubbed the Pistachio Principle: Maybe nuts just take a lot of work to eat. Pistachios are typically bought in their shells, which slows consumption time, allowing your brain to better regulate your appetite.22 Sounds plausible, but what about shelled nuts like almonds and cashews? A study out of Japan did suggest that increasing “dietary hardness” (meaning chewing difficulty) is associated with a slimmer waist.23 Perhaps all that chewing simply tires you out?
Then there’s the fecal-excretion theory. Many of the cell walls of chewed almonds, for example, remain intact in the gastrointestinal tract. In other words, it’s possible a lot of the calories in nuts just never get digested and wind up in your waste because you didn’t chew well enough. Both of these theories were put to the test by an international group of researchers who gave participants either 60 grams of unshelled peanuts or 60 grams of peanuts ground into peanut butter. If either the Pistachio Principle or the fecal-extraction theory were correct, the peanut-butter group would gain weight, since no calories would be left in undigested nuts, and no calories would be burned chewing. But in the end, neither group gained weight, so there must be another answer.24
What about the dietary-compensation theory? The idea here is that nuts are so satiating and good at suppressing appetite that you end up eating less food overall. This could explain why some studies found that people lost weight after eating nuts. To test this idea, Harvard Medical School researchers gave two groups smoothies with the same number of calories, but one contained walnuts, and the other didn’t. Despite drinking the same amount of calories, the placebo (nut-free) smoothie group reported feeling significantly less full than the walnut group.25 So, yes—it does seem that nuts can make you feel fuller faster than some other foods.
At this point, it looks as if 70 percent of nut calories are lost through dietary compensation and 10 percent are flushed as fat in your feces.26 But what about the last 20 percent? Unless all the calories are accounted for, you would still expect some weight gain. The answer appears to lie in the ability of nuts to boost metabolism. When you eat nuts, you burn more of your own fat. Researchers have found that while control-diet subjects were burning about twenty grams of fat within an eight-hour period, a group eating the same number of calories and fat, but with walnuts included in their diet, burned off more—about thirty-one grams of fat.27 If a pill could do that, drug companies would be raking it in!
The bottom line? Yes, nuts are high in calories, but through a combination of dietary compensation mechanisms, your body’s failure to absorb some of the fat, and increased fat-burning metabolism, nuts can be a lifeline without expanding your waistline.
Pistachio Nuts for Sexual Dysfunction
Erectile dysfunction (ED) is the recurrent or persistent inability to attain or maintain an erection for satisfactory sexual performance. It is present in up to thirty million men in the United States and approximately one hundred million men worldwide.28 Wait a second. The United States has less than 5 percent of the world’s population yet up to 30 percent of the impotence? We’re number one!
The reason may be due to our artery-clogging diet. Erectile dysfunction and our number-one killer, coronary artery disease, are actually two manifestations of the same disease—inflamed, clogged, and crippled arteries—regardless of which organs are affected.29 Not to worry, though, because Americans have red, white, and blue pills like Viagra . . . right? The problem is that these pills just cover up the symptoms of vascular disease and don’t do anything for the underlying pathology.
Atherosclerosis is considered a systemic disorder that uniformly affects all major blood vessels in the body. Hardening of the arteries can lead to softening of the penis, since stiffened arteries can’t relax open and let the blood flow. Thus, erectile dysfunction may just be the flaccid tip of the iceberg in terms of a systemic disorder.30 For two-thirds of men showing up at emergency rooms with crushing chest pain, their penises had been trying to warn them for years that something was wrong with their circulation.31
Why does atherosclerosis tend to hit the penis first? The arteries in the penis are half the size of the “widow-maker” coronary artery in the heart. Therefore, the amount of plaque you wouldn’t even feel in the heart could clog half the penile artery, causing symptomatic restriction in blood flow.32 This is why erectile dysfunction has been called “penile angina.”33 In fact, by measuring blood flow in a man’s penis with ultrasound, doctors can predict the results of his cardiac stress test with an accuracy of 80 percent.34 Male sexual function is like a penile stress test, a “window into the hearts of men.”35
In medical school, we were taught the forty-over-forty rule: 40 percent of men over age forty have erectile dysfunction. Men with erection difficulties in their forties have a fiftyfold increased risk of having a cardiac event (like sudden death).36
We used to think of erectile dysfunction in younger men (those under age forty) as “psychogenic”—meaning it’s all in their heads. But now we’re realizing that ED is more likely an early sign of vascular disease. Some experts believe that a man with erectile dysfunction—even if he doesn’t have cardiac symptoms—“should be considered a cardiac . . . patient until proved otherwise.”37
The reason even young men should care about their cholesterol levels is because they predict erectile dysfunction later in life,38 which in turn predicts heart attacks, strokes, and a shortened life span.39 As one medical journal put it, the take-home message is that “ED = Early Death.”40
What does this have to do with nuts? A clinical study found that men who ate three to four handfuls of pistachios a day for three weeks experienced a significant improvement in blood flow through the penis, accompanied by significantly firmer erections. The researchers concluded that three weeks of pistachios “resulted in a significant improvement in erectile function . . . without any side effects.”41
This is not just a male issue. Women with higher cholesterol levels report significantly lower arousal, orgasm, lubrication, and sexual satisfaction. Atherosclerosis of the pelvic arteries can lead to decreased vaginal engorgement and “clitoral erectile insufficiency syndrome,” defined as “failure
to achieve clitoral tumescence [engorgement].” This is thought to be an important factor in female sexual dysfunction.42 We learned from the Harvard Nurses’ Health Study that eating just two handfuls of nuts weekly may extend a woman’s life as much as jogging four hours a week.43 So eating healthier may not only extend your love life but also your entire life.
Why are beans, nuts, and whole grains so health promoting? Maybe it’s because they are all seeds. Think about it: All it takes for an acorn to explode into an oak tree is water, air, and sunlight. Everything else is contained within the seed, which possesses the entire complex of protective nutrients required to mature into a plant or tree. Whether you’re eating a black bean, a walnut, a grain of brown rice, or a sesame seed, in essence you’re getting the whole plant in a tiny little package. As two noted nutrition experts concluded, “[D]ietary recommendations should embrace a wide array of seeds as part of a plant-based dietary pattern . . .” 44
Nuts may be the easiest and tastiest Daily Dozen check box to check off. For those with peanut or tree nut allergies, seeds and seed butters can often be used as safe alternatives. But what about nut consumption if you have diverticulosis? For fifty years, doctors have told patients with this common intestinal condition to avoid nuts, seeds, and popcorn, but when the issue was finally put to the test, it turns out these healthy foods actually appear to be protective.45 So diverticulosis shouldn’t stop you from meeting this Daily Dozen mark, either. This one simple and delicious act could add years to your life without adding on pounds.
Herbs and Spices
Dr. Greger’s Favorite Herbs and Spices
Allspice, barberries, basil, bay leaves, cardamom, chili powder, cinnamon, cloves, coriander, cumin, curry powder, dill, fenugreek, garlic, ginger, horseradish, lemongrass, marjoram, mustard powder, nutmeg, oregano, smoked paprika, parsley, pepper, peppermint, rosemary, saffron, sage, thyme, turmeric, and vanilla
How Not to Die Page 44