The old saying “an apple a day keeps the doctor away” is as true as it ever was, but we might have to expand the prescription to include a handful of nuts. People who eat nuts regularly are less likely to have heart attacks or to die from heart disease than those who don’t. Some of the largest and most important long-term studies such as the Nurses’ Health Study, the Iowa Women’s Health Study, and the Adventist Study, have shown a consistent 30 to 50 percent lower risk of heart attacks or heart disease associated with eating nuts several times a week.
Walter Willett, M.D., Dr. P.H., professor of epidemiology and nutrition at Harvard’s School of Public Health and a professor of medicine at Harvard Medical School, and arguably the most distinguished nutrition researcher of our time, suggests that there may be several mechanisms at work here. One of them may be the fact that nuts contain arginine. Arginine is an amino acid that is touted for its role in protecting the inner lining of the arterial walls, making them more pliable and less susceptible to atherogenesis.
Arginine is also needed to make an important molecule called nitric oxide, which helps relax constricted blood vessels and ease blood flow. In addition, nuts are a great source of numerous phytonutrients—bioactive chemicals found in plants. These compounds have powerful health benefits, not the least of which are their antioxidant activity, which is linked to the prevention of coronary heart disease.
One of the mechanisms that’s almost certainly responsible for the health benefits of nuts is their fat. When this book was first written, the notion that fat might have significant health benefits was considered delusional. Ten years later, not so much. In the intervening years there have been a spate of popular books touting the benefits of high-fat diets, including one which I coauthored—Smart Fat (with Steven Masley, M.D.). As far as the fat in nuts goes, the jury isn’t even out anymore: it’s all good!
Most of the fat in nuts is monounsaturated (more about that in a moment). Some is polyunsaturated, and, in the case of walnuts (see here), a significant amount of it is a specific type of polyunsaturated fat known as omega-3, whose health benefits are legion. Omega-3s have been the subject of more research than almost any food component I know of, with the possible exception of vitamin C. Some of the fat in nuts is saturated, and as you may have guessed by now, this does not concern me in the least.
Monounsaturated fat, also known as omega-9, is the main type of fat in nuts. That’s the same fat that’s predominant in the Mediterranean diet, which has been shown in virtually every research study to be associated with lower levels of heart disease and cancer, not to mention longer life spans. In the famous Lyon Diet Heart Study, people who had a heart attack between 1988 and 1992 were counseled either to follow the standard post–heart attack dietary advice (reduce saturated fat) or to follow the Mediterranean diet which contains a high percentage of monounsaturated fat. After about four years of follow-up, the people on the Mediterranean diet experienced 70 percent less heart disease (about three times the reduction in risk achieved by statin drugs!). Not only that, but their overall risk of death was 45 percent lower.
In 2015, researchers designed an interesting study in which people ate a basic Mediterranean-style diet but supplemented the diet with either extra nuts or extra olive oil. Those eating the Mediterranean diet plus olive oil had a relatively lower risk of breast cancer. Both groups—the Mediterranean diet plus nuts and the Mediterranean diet plus olive oil—had significantly improved cognitive function. (The study was published in JAMA Internal Medicine in 2015.)
So which nuts are best? There’s no perfect answer to that question. My personal answer is they’re all good. Almonds, hazelnuts, pecans, walnuts, macadamia nuts, and pistachio nuts all alter the composition of the blood in ways that would be expected to reduce the risk of coronary disease. And it doesn’t take a ton of them to give you the health benefits found in the research. One 1-ounce (28 g) serving a day—or 5 ounces (140 g) a week from a variety of nuts—ought to do it. It’s possible you’d get benefits with even less.
Melissa Stevens, M.S., R.D., L.D., the nutrition program coordinator for preventive cardiology and rehabilitative services at the Cleveland Clinic, has come up with some quick, easy tips for adding nuts to your diet. Here are some of my favorites:
• Add cashews or peanuts to a stir-fry
• Toss roasted pine nuts into a marinara sauce
• Add slivered almonds to yogurt
• Toss walnuts into a spinach and strawberry salad
• Create your own homemade trail mix (I suggest nuts, dates, raisins, and oats.)
And of course, there’s the snack that I’ve been recommending for two decades: natural peanut or almond butter smeared on an apple or a few sticks of celery. It’s old school, but you really can’t beat it!
Almonds are our oldest cultivated nut and one of the great foods of all time. And to think, not so long ago they were avoided by health-conscious consumers because of their fat content. We’ve come a long way, baby!
Let’s get the “almonds are fattening” thing out of the way right at the start. Epidemiologic studies such as the Nurses’ Health Study, the Adventist Health Study, and the Physicians’ Follow-up Study universally show that those who eat the most nuts also tend to have the lowest body mass indexes (a measure of overweight). Nuts are most definitely not fattening.
Sure, almonds have fat and calories, and you can’t eat two tons of them at a time and expect to lose weight, but there is a massive amount of research showing that fat (and protein) are highly satiating, and that almonds eaten in moderation can actually help with weight loss. One study compared two groups of dieters eating the same number of calories; one group ate 520 of their calories from almonds and lost more weight. Preliminary research is indicating that almond cell walls may partially limit the amount of dietary fat available for digestion or absorption, so it’s possible that a small portion of the calories from almonds are not fully absorbed. In any case, research is quite clear that replacing a given amount of calories in the diet with an equal number of calories from almonds does not equal weight gain. Quite the opposite.
Research shows that almonds may help lower cholesterol, but if you’ve read my book, The Great Cholesterol Myth, you know I don’t think that’s terribly important. Far more important than the fact that they may lower cholesterol is the fact that almonds are rich in monounsaturated fat, which has heart-health benefits well beyond the reduction of cholesterol. About 70 percent of the fat in almonds is monounsaturated fat, which is anti-inflammatory. That matters, because inflammation is a part of every disease of aging that we know of.
Monounsaturated fat is the main fat in the Mediterranean diet, which has been shown in virtually every research study to be associated with lower levels of heart disease and cancer, not to mention longer life spans.
One of the best studies on the Mediterranean diet was the famous Lyon Diet Heart Study. In this study, people who had already had one heart attack were put into two groups. One was counseled to follow the standard post–heart attack dietary advice (reduce saturated fat and cholesterol). The other was counseled to follow the Mediterranean diet. After about four years of follow-up, the people on the Mediterranean diet experienced 70 percent less heart disease (about three times the reduction in risk achieved by statin drugs!). Not only that, but their overall risk of death was 45 percent lower. These astonishing results were obtained despite the fact that there wasn’t much change in their cholesterol levels, showing that cholesterol may not have as much to do with heart disease as we’ve previously believed (the premise of our 2012 book, The Great Cholesterol Myth). The Lyon study results were so impressive that the study had to be stopped early for ethical reasons—all participants were given the advice to follow the Mediterranean diet, with its generous amount of monounsaturated fat, the same kind found in almonds.
Almonds also contain about 6 g of protein in an ounce (28 g), not to mention a hefty 3 g of dietary fiber. And almonds are rich in calcium—1 ounce contains 80 mg. They also contain phosphorus and vitamin E and are an excellent source of magnesium. They contain virtually no carbohydrates, making them a perfect food for diabetics and those with blood sugar issues.
One ounce of almonds (or a smear of almond butter) together with a piece of fruit like an apple makes a great snack and is one of my five favorite pre-workout snacks. The almond butter also goes great smeared on a few sticks of celery. Total calories for either snack is reasonable (about 250), and the nutrient density is terrific.
Brazil nuts have the highest selenium content of any food I know of, and for this reason alone belong among the world’s healthiest foods. Selenium is an essential trace element that, in tons of research, has been shown to have a protective effect against cancer. According to the Physicians’ Desk Reference, it’s “antioxidant, immunomodulatory, anticarcinogenic, and anti-atherogenic,” which translated into English means that it protects the cells, boosts the immune system, helps fight cancer, and helps prevent heart disease. Not exactly an undistinguished résumé.
Unless we’re taking selenium supplements or eating Brazil nuts, we most likely get selenium from fish or from plants and the animals that graze on them (beef, chicken). How much we get depends on the soil in which the plants were grown (and how much fish we eat). In countries with selenium-poor soil—and consequently low selenium intake—all kinds of health problems have been noted, including higher rates of cancer. As far back as 1984, the government of Finland started adding selenium to fertilizers as a way of improving the selenium intake of its citizens. High plains areas such as northern Nebraska and the Dakotas have selenium-rich soil because it was derived from volcanic deposits. Most of the rest of the country is not so lucky. In any case, many Americans don’t eat nearly enough plant foods anyway, and it’s reasonable to assume that many people don’t get nearly enough to get the protective benefits of this mineral.
Low intakes of selenium are associated with increased incidence of prostate, lung, colorectal, gastric, and skin cancers. And it’s essential for healthy immune function. It also seems to be responsible for maintaining the structure of sperm, at least if you’re a mouse. But it’s probably so in humans as well: infertile men have low selenium levels.
Selenium also helps antagonize the effects of a number of toxic metals. Some of these toxic metals, such as cadmium, are found in cigarette smoke and other places, and they are carcinogenic. Others, like mercury, are just plain bad news. Selenium seems to bind with some of these bad guys, creating inactive complexes and helping to rid the system of them.
The thyroid is dependent on selenium to function properly. Selenium is a component of the enzyme that helps convert T4 (thyroxine), the less-active thyroid hormone, to the active one, T3 (triiodothyronine). If you’re on conventional thyroid medication like Synthroid, which is pure T4, you need selenium to convert it. Sub-optimal levels of selenium may impair thyroid function.
People often fear eating seafood—one of the best foods on Earth because of concerns about mercury. And there’s no doubt about it—mercury is a nasty compound, a neurotoxin, and something you definitely want to avoid, particularly if you’re pregnant. But here’s a very interesting factoid: Selenium has a major role in preventing mercury toxicity, and the research on that has existed since 1967!
A number of studies have shown the power of selenium to counteract the effects of mercury exposure (Strain, 2015). Some researchers believe that mercury is toxic partly because it binds to selenium and renders it ineffective. So even if you had normal selenium levels, a lot of mercury exposure could put you at risk. But fish is pretty high in selenium, which may in fact, counter some of the negatives associated with mercury.
The Republic of Seychelles turns out to be the perfect place to examine any potential impact of persistent low level mercury exposure because the folks there consume about ten times more fish than we do in the US and Europe. That’s why the Seychelles Child Development Study was started in the 1980s—to study the impact of fish consumption and mercury exposure on childhood development.
Yet numerous analyses have shown that even the children of mothers who ate, on average, twelve meals of fish each week during pregnancy, there was no evidence of a correlation between mercury exposure from fish and any neurological impairment.
Why? Probably because of selenium. An impressive amount of research by Nicholas Ralston, Ph.D., and his colleagues at the University of North Dakota has demonstrated that selenium protects against mercury toxicity and when a food—such as fish—has more selenium than it does mercury, it poses no neurological or developmental risk. The Seychelle islanders eat an awful lot of selenium-rich fish.
Without a doubt, Brazil nuts are the best source of selenium. One ounce (six to eight kernels) has a whopping 544 mcg. The next best sources are clams, oysters, tuna, turkey, and beef, but none comes close to Brazil nuts. Brazil nuts also have protein, calcium, and 2 g of fiber per ounce, and they are a good source of heart-healthy monounsaturated fat.
I love cashews. Who doesn’t? They got a bad rap for a short time during low-carb mania because their carb content is higher than any other nut, but for all but the most inveterate carb-gram counters this shouldn’t be a deterrent from enjoying this delicious food.
The benefits of cashew nuts—besides how good they make you feel when you eat them—are similar to the benefits you get when you eat nuts in general. People who eat nuts regularly are less likely to have heart attacks or to die from heart disease than those who don’t. Some of the largest and most important long-term studies, such as the Nurses’ Health Study, the Iowa Women’s Health Study, and the Adventist Study, have shown a consistent 30 to 50 percent lower risk of heart attacks or heart disease associated with eating nuts several times a week.
About half the fat in cashews is heart-healthy monounsaturated fat, the key fat found in the Mediterranean diet, which has been shown in virtually every research study to be associated with lower levels of heart disease and cancer, not to mention longer life spans. Compared with carbohydrates, for example, monounsaturated fat has a positive effect on blood lipids. In the Lyon Diet Heart Study, people following the Mediterranean diet, with its high level of monounsaturated fat (the same kind that’s in cashews) experienced 70 percent less heart disease risk than is achieved by taking statin drugs. Monounsaturated fat is also anti-inflammatory, which is a very good thing indeed.
Cashews are slightly lower in calories than other nuts. They’re also slightly higher in carbs. Like other nuts they are mineral rich (magnesium, calcium, phosphorus, potassium, copper, and selenium) and full of protein (5 g per ounce of nuts). They also have about 1 g of fiber per ounce (28 g).
And here’s some really interesting trivia for you: Raw cashews aren’t really raw. The nut meat has an outer protective layer that itself contains a rather nasty, caustic oil that is highly irritating to the skin—not surprising because cashews are a member of the poison ivy family. The oil is removed by heating the nuts in an inclined, perforated, rotating drum. (You can’t heat them in a shallow pan because the oil spurts and causes blisters.) Once they’re rid of the oil, the harvesters spray the nuts with water to cool them. The ones closer to the heat source tend to get scorched and are sold at a cheaper price as a lower-grade nut, though they’re just as tasty and nutritious. (Grade 1 nuts are white; grade 2 are lightly scorched.)
Chia seeds have become popular largely on the strength of their omega-3 content. They’re one of a handful of plant foods (flaxseeds and hemp seeds are other examples) that contain omega-3 fat, though it’s worth noting that it’s not the same omega-3 fat found in fish. The omega-3s found in fish and animal foods such as grass-fed beef are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) while the plant-based omega-3s in chia seeds are ALA (alpha-linolenic acid).
Chia seeds are small black seeds that come from a plant called Salvia hispanica, which grows in South America. Though they’re famous for their omega-3 content, they offer a lot more than that. A 1-ounce (28 g) serving of chia seeds has an astonishingly high 11 g of fiber. That same ounce also has double digit percentages of the RDA for calcium (18 percent), manganese (30 percent), magnesium (30 percent) and phosphorus (27 percent).
I think the RDAs or RDIs for most nutrients are woefully inadequate—particularly magnesium—but chia seeds still offer a lot of nutrition for a modest number of calories (137 calories per ounce [28 g] with only 1 gram of carbohydrate that isn’t fiber.
They are also high in antioxidants, which is a good thing because those very antioxidants protect the fat in the seeds from going rancid. What’s more they contain 4 grams of protein per ounce (28 g), and a good balance of essential amino acids. The combination of protein and fiber is excellent for weight loss.
Research has found improvements in health markers from a diet that mixed chia seeds with a few other ingredients, but the study that’s most impressive is one that specifically investigated the effects of chia seeds on diabetes and cardiovascular risk factors. In this 2007 study, researchers randomly assigned diabetic patients on conventional medications to one of two groups. One group was supplemented with 37 g a day of chia seeds (about 11/3 ounces), while the other group was supplemented with an equivalent amount of wheat bran. (The subjects continued with their conventional diabetes meds during the study.)
The folks who were supplemented with chia seeds reduced their systolic blood pressure, their hs-CRP (a systemic marker for inflammation) and decreased their hemoglobin A1C (a standard metric for diagnosing diabetes). Researchers concluded that long-term supplementation with chia seeds reduces blood pressure and other factors “safely beyond conventional therapy while maintaining good glycemic and lipid control in people with well-controlled type 2 diabetes.”
Barlean’s makes two chia seed products that I really like. One is organic chia seed, the other is a wildly popular flax-chia-coconut mix, which imparts a great texture and flavor to all kinds of dishes. I sprinkle one or the other on my famous antiaging dish, Dr. Jonny’s Berries and Cherries: Frozen blueberries, frozen dark cherries, full-fat yogurt, a splash of pomegranate juice, almonds, coconut flakes, and a light sprinkling of either Barlean’s chia seeds or the flax-chia-coconut mix. Both products are available on Amazon and at Thrive Market.
Poor hazelnuts. Nobody loves them, at least not enough to invite them to the A-list parties in Hollywood. Sure, you’ll find a few hanging out in the nut bowl, but you know they’re just there because the supermarket stuck them in the variety pack. This is a shame, because they’re so good for you.
Hazelnuts—like pecans—contain beta-sitosterol, a plant sterol that has been found to have two very important properties: One, it lowers cholesterol. Two, it lessens the symptoms of benign prostatic hyperplasia (BPH). BPH is the annoying condition every man over forty is familiar with, as it causes multiple trips to the bathroom at night. It’s harmless, but it’s a nuisance. A study in The Lancet showed that men with this condition who were given 20 mg of beta-sitosterol three times a day showed significant improvements in urinary difficulties. Of course, that’s way more beta-sitosterol than is in one serving of filberts, but still, it’s nice to know it’s in there.
Hazelnuts also contain potassium, magnesium, phosphorus, and some vitamin E. And 1 ounce (28 g) contains almost 3 g of fiber. Hazelnuts add a rich, crisp texture and a smooth, mellow flavor to prepared foods.
Hazelnuts got a nice public relations boost when they were discussed on Oprah. Mehmet Oz, M.D., told a national TV audience that hazelnuts are a source of omega-3 fatty acids during a show segment called “Inside Secrets to Make You Younger and Healthier.” Now maybe they’ll get invited to those Hollywood parties.
Because he died before I even began writing this book, I didn’t get a chance to ask Robert Atkins, M.D., to submit a list of his top ten favorite healthy foods. But if he had, I’m pretty darn sure macadamia nuts would have been on his list. Here’s what he said about them in Health Revelations, November 1996: “I’ve always looked for a food that could serve as a meal in itself—nutritionally complete and safe as a snack. All you need to do is keep a jar of macadamia nuts handy. I snack on them whenever a meal is late… I simply will not board an airplane without them.”
Now I wouldn’t go so far as to say that macadamia nuts are the perfect food, but they sure are a good one. The oil in macadamia nuts is more than 80 percent monounsaturated, higher than any other nut (olive oil is about 75 percent monounsaturated). Monounsaturated fat is the main fat in the Mediterranean diet, which has been shown in virtually every research study to be associated with lower levels of heart disease and cancer, not to mention longer life spans. In the Lyon Diet Heart Study, those following a Mediterranean diet, with its high intake of monounsaturated fat, experienced three times the reduction in risk for heart disease than that achieved by statin drugs, and they had an overall risk of death that was 45 percent lower. There’s not much question that monounsaturated fat—such as the kind found in macadamia nuts—is awfully good for you.
These nuts contain calcium, phosphorus, and magnesium (for strong bones and teeth), heart-healthy potassium, plus a couple of grams of fiber per ounce (28 g). Macadamia nuts also contain a small amount of selenium, a trace mineral with significant anticancer properties. And they contain phytosterols, including beta-sitosterol, which has been shown to help lower cholesterol and to promote prostate health, possibly by its anti-inflammatory activity.
Macadamia nuts are very high in calories—about 204 per ounce (28 g)—so if you’re trying to lose weight, don’t just go munching on them out of the jar. Instead, substitute an ounce of the nuts two or three times a week for an equivalent number of calories from other sources.
As former peanut farmer President Jimmy Carter would be the first to tell you, peanuts aren’t nuts. They’re actually legumes—like beans and peas—and they grow underground. But because their nutritional properties so resemble nuts—plus they look like nuts—plus everyone calls them nuts—I figured the nut section of the book is where you’d look for them.
Peanuts are surprisingly high in antioxidants. In a study published in the Journal of Food Chemistry, researchers at the University of Florida’s Institute of Food and Agricultural Sciences found that peanuts rivaled many fruits for antioxidant content. “When it comes to antioxidant content, peanuts are right up there with strawberries,” said Steve Talcott, one of the researchers. “We expected a fairly high antioxidant content in peanuts, but we were a bit shocked to find they’re as rich in antioxidants as many kinds of fruit.”
Researchers at the University of Florida also found that peanuts contain a high concentration of a polyphenol called p-coumaric acid. P-coumaric acid has been studied for its antioxidant abilities and its potential as an anticancer agent, though much more research is needed to determine the ideal dose. One research paper in the American Journal of Physiology-Cell Physiology showed that p-coumaric acid worked as a powerful antioxidant in rats, significantly inhibiting the oxidation of their LDL (“bad”) cholesterol. And another study (in Pharmacological Research) concluded that it might be worthy to “consider the usefulness of p-coumaric acid as adjuvant therapy in cancer management.” Of course, you have to remember that the amount of p-coumaric acid concentrates given in research is way more than found in a handful of peanuts—still, it’s nice to know that these healthy compounds are found in the food in the first place. And best of all, research has shown that roasting can increase the level of p-coumaric acid, boosting their overall antioxidant content by as much as 22 percent.
Don’t get me wrong—peanuts are not blueberries or kale, or any of the other superpowers in the antioxidant world. But they’re about equal in antioxidants to blackberries or strawberries. It’s not just the obscure, newly discovered compounds such as p-coumaric acid that make peanuts a good food. Researchers at Purdue University investigated the impact of peanut consumption on total diet quality. “We found that including peanuts in the diet significantly increased magnesium, folate, fiber, copper, vitamin E, and arginine consumption, all of which play a role in the prevention of heart disease,” said Richard Mattes, M.P.H., Ph.D., one of the principal investigators. The study was published in the Journal of the American College of Nutrition under the impressive title “Eating Peanuts Improves Cardiovascular Risk Factors in Healthy Adults.” Their findings were consistent with a previous study at Penn State University that found a 13 percent decrease in triglyceride levels when participants consumed a diet with peanuts and peanut butter, compared to the average American diet. Peanuts are also high in niacin, a B vitamin important for keeping the digestive system, skin, and nerves healthy. Niacin is also critical to releasing energy from carbohydrates and helping to control blood sugar levels.
About half of the fat in peanuts comes from monounsaturated fat—the same kind that’s so plentiful in the Mediterranean diet, which has been shown in virtually every research study to be associated with lower levels of heart disease and cancer, not to mention longer life spans. In the Lyon Diet Heart Study, people following the Mediterranean diet had 70 percent less heart disease risk than is achieved by taking statin drugs.
Note: A new peanut has been developed called a “high-oleic” peanut. This is good news—oleic acid is the official name of the monounsaturated fat that all the shouting is about. The new high-oleic peanut has been engineered to have about 80 percent of its fat (instead of 50 percent) from oleic acid, thus boosting the monounsaturated fat content even higher.
Pecans deserve their reputation as a health food largely because of their monounsaturated fat content. Monounsaturated fat is the same kind of heart-healthy fat that you find in olive oil. Pecans are also loaded with nutrients like potassium, vitamin E, phytosterols, and beta-sitosterol, a plant compound that has been found to lower cholesterol. And one portion of pecans has almost 3 g of fiber, more than the average slice of bread with none of the negatives.
Three studies from Harvard University, two of which appeared in the Journal of the American Medical Association, all confirmed that nuts such as pecans belong in a healthy diet. One of the studies found that eating nuts may help lower the risk of type 2 diabetes. Another concluded that one of three strategies to effectively prevent coronary heart disease was a diet high in fruits, vegetables, nuts, and whole grains and low in refined grains. When I was in school, we were told to remember the good nuts by the acronym PAW: pecans, almonds, and walnuts. Actually there are others, but it’s still a good acronym.
Pecans are indigenous to the United States and are grown mainly in Texas, Louisiana, Mississippi, and Georgia. There are more than 300 varieties. It’s a good idea to eat them really fresh (within three weeks of harvesting), because they can go rancid pretty quickly because of the very thing that makes them healthy: their high oil content. Buying them in the shell ups the odds that they won’t be rancid, because shelled ones can go south pretty quickly. You might want to keep them in the fridge or frozen in an airtight container, where they can keep for up to a year.
Nuts are one of those foods where portion control really makes a difference. They’re amazingly healthy, but they’re high in calories. A 1-ounce (28 g) portion is 196 calories, and nuts are very easy to overeat. I don’t worry at all about the fat content—it’s all good fat, and besides, if your calories are where they should be, who cares? The high fat content doesn’t make the slightest bit of difference. But I have seen people go through bags of these babies. Remember: A portion equals twenty pecan halves. If you can’t be trusted with the family-size bag, count out a portion and step away from the nuts.
If pistachio nuts had a public relations agent, she would have been mighty happy with the results of a study in the Journal of Agriculture and Food Chemistry. The study was the most comprehensive analysis of nut and seed varieties to date—it examined twenty-seven different products. Though pistachio nuts did not have the highest phytosterol content of all (that distinction went to sesame seeds and wheat germ), they did have the highest phytosterol content of any product generally considered a snack food (270 mg per 100 g). “Given the many possible mechanisms of action of phytosterols on cholesterol metabolism, it is important to have quantitative estimates of total phytosterol content,” reported the team of researchers from Virginia Polytechnic Institute and State University. The main phytosterol identified in all the nut and seed samples was beta-sitosterol, which is known not only for lowering cholesterol but also for supporting prostate health.
Unsalted pistachios have a very high potassium-to-sodium ratio, which helps normalize blood pressure and maintain water balance in the body. Pistachio nuts also contain the powerful antioxidant vitamin E, which boosts the immune system. Best of all, the vitamin E in pistachio nuts is mostly the gamma-tocopherol form, which may have even more health benefits than the more common alpha-tocopherol form found in most supplements. Pistachios also contain magnesium and phosphorus and trace amounts of other minerals and vitamins, as well as phytosterols. Extracts from the pistachio kernel have shown significant antiviral activity.
And they’re so delicious.
Note: Some pistachio growers and importers dye the nut red, which exposes the kernels to chemical dyes. You’re better off with the plain kind.
It’s hard to pick up a vitamin supplement geared to men these days—especially a prostate support formula—without seeing pumpkin seed extract in the list of ingredients. That’s because pumpkin seeds contain beta-sitosterol, a phytosterol that has some benefit in treating BPH (benign prostate hyperplasia). BPH is the annoying condition that causes men over forty to have to go to the bathroom several times a night. It’s not dangerous—but it’s annoying as hell.
But here’s the irony: Pumpkin seeds don’t actually contain all that much beta-sitosterol. Researchers at the department of biochemistry and chemistry at Virginia Polytechnic Institute and State University tested twenty-seven nut and seed products commonly consumed in the United States. Pumpkin seeds were relatively low in beta-sitosterol (only 13 g per 100 g of seeds). But that doesn’t mean pumpkin seeds don’t have a role in prostate health. They may work synergistically with other botanicals like saw palmetto, as a couple of studies have demonstrated. And pumpkin seeds contain chemicals called cucurbitacins, which are believed to interfere with the production of a metabolic by-product of testosterone known as DHT (dihydrotestosterone). DHT is partly responsible for both hair loss and benign prostate hyperplasia. Men want to keep their DHT as low as possible—believe me, I know.
Prostate health aside, these delicious seeds pack a great nutritional wallop. In the Virginia Polytech research, published in the Journal of Agriculture and Food Chemistry in 2005, pumpkin seeds had a high phytosterol content (265 mg per 100 g), second only to pistachio and sunflower kernels in the subgroup of foods commonly consumed as snacks. Plant sterols have multiple health benefits, not the least of which is lowering cholesterol.
Pumpkin seeds are a rich source of minerals, especially magnesium, potassium, and phosphorus. Interestingly, the roasted kind have far more protein, at least according to the USDA food database. (They also have a lot more calories.) The roasted kind also have way more magnesium, phosphorus, and potassium, as well as more zinc, fiber, and cancer-fighting selenium. Both have a nice amount of manganese, an important trace mineral that’s essential for growth, reproduction, wound healing, peak brain function, and the proper metabolism of sugars, insulin, and cholesterol. Ultimately, both the raw (dried) and the roasted are nutrient dense.
You can roast your own pumpkin seeds really easily and combine them with great oils and spices to multiply their health benefits even further. Try melting some organic butter—or macadamia nut or olive oil—then tossing in the pumpkin seeds and spreading them on a single layer on a baking sheet. Season ’em with turmeric, garlic, or cayenne pepper, and bake them till they’re crisp. You can also add pumpkin seeds to trail mix, sautéed vegetables, and salads, not to mention my favorite—oatmeal.
I first heard about sacha inchi when I was doing a story on protein powders. I’ve long been a fan of whey protein, but my editor wanted to be sure that I covered some vegetarian protein powders as well. That led me to investigate some of the more popular choices such as soy protein, pea protein, brown rice protein, hemp protein, and one that I had never heard of before—sacha inchi.
Sacha inchi is relatively new to the American market, but it’s been around for thousands of years. Also known as the Inca peanut, it’s the seed of a plant native to Peru that’s been a food source for three thousand years in the Amazon rain forest. The seeds produce a fruit that’s pretty much inedible—but the seeds themselves taste great when they’re lightly roasted.
The plant itself—Plukenetia volubilis—is a rain forest vine that has star-shaped pods containing seeds that, when roasted, have been compared to dark roasted peanuts with a slightly woody flavor. The oil derived from the “nuts”—let’s just agree to call them nuts even though, as mentioned, they’re technically a seed—has traditionally been used for skin care and for treating wounds, insect bites and skin infection.
Besides being a terrific snack food, sacha inchi nuts have become a popular source of vegetarian protein, especially in combination with other vegetarian protein sources like rice, pea, or hemp. The seeds go through solvent-free and cold-pressed processing to remove most of the oil, leaving a kind of protein meal that is then ground into a powder, according to the food industry website NutraIngredients. It’s said to be highly digestible, and it contains all nine essential amino acids.
One of the things that distinguishes sacha inchi as a protein powder is that it’s very high in omega-3 fatty acids. Remember that the omega-3s found in plant foods such as sacha inchi (and in flax, chia, and hemp seeds) are different from the two omega-3s found in animal foods such as salmon and grass-fed beef. The plant-based omega-3 found in sacha inchi (and the other seeds mentioned above) is called alpha-linolenic acid (ALA); the omega-3s found in animal foods like salmon (or fish oil) are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Both EPA and DHA have been widely studied and are considered the superstars of the omega-3 family. But ALA has benefits of its own. People who eat a diet high in alpha-linolenic acid are less likely to have a fatal heart attack. Other population studies show that as people eat more foods with alpha-linolenic acid, heart disease deaths go down.
Sacha inchi nuts are also high in fiber, and so is sacha inchi protein powder. Each 1 ounce (28 g) serving contains 4 to 6 g of fiber (depending on manufacturer), which isn’t bad, especially considering that protein powder typically has no fiber at all.
I wish there were more research on sacha inchi, or more information that didn’t come from the manufacturers. But all the available evidence points to the conclusion that this is a healthy food, whether in the roasted nut version or the supplemental protein powder version.
As they say in politics, sacha inchi “checks a lot of boxes.” It’s completely plant-based, and suitable for vegans and vegetarians. It has a healthy dose of plant-based omega-3 fat, and it has a decent amount of fiber. Plus it’s non-GMO, gluten-free, and (often) organically grown.
As my grandmother used to say, “What’s not to like?”
The sesame seed is truly ancient. In fact, sesame is the oldest known plant grown for its seeds and oil, and it is especially valued in Eastern, Mediterranean, and African cultures. The sesame seed pod bursts open when it reaches maturity, the origin of the famous phrase “Open sesame!” from The Arabian Nights.
In popular health food books, and on countless Internet sites, there is much confusion over the names of the healthful phenolic compounds found in sesame seeds and their oil. It’s understandable, and you’ll see why in a minute. The seeds contain 50 to 60 percent of a fatty oil that is characterized by two members of the lignan family: sesamin and sesamolin. When the seeds are refined (as in the making of sesame oil), two other phenolic antioxidants—sesamol and sesaminol—are formed.
You don’t need to know all the technical names and metabolites of the lignan family to understand that these plant chemicals are very good for you indeed. Sesame seed lignans—including the aforementioned sesamin and sesaminol—enhance vitamin E’s absorption and availability, improve lipid profiles, and help normalize blood pressure. Animal studies show that sesame lignans enhance the burning of fat by increasing the activity of several liver enzymes that actually break down fatty acids. That research did not escape the notice of the manufacturers of bodybuilding supplements, which immediately began offering sesamin supplements for fat loss all over the Internet. Do they work? No idea.
Sesame lignans also help reduce cholesterol. In a study published in the Journal of Lipid Research, sesamin lowered both serum (blood) and liver cholesterol levels. The researchers suggested that sesamin deserves further study as a “possible hypocholesterolemic agent of natural origin.” Of course cholesterol is becoming less and less of a target in the quest to lower heart disease, and this result may not seem as important as it once did, but there it is. In a study in the Journal of Nutrition, 50 g of sesame seed powder taken daily for five weeks by twenty-four healthy postmenopausal women improved total cholesterol, LDL (“bad”) cholesterol, cholesterol ratio, and antioxidant status. The researchers noted some improvements in sex hormone status as well and suggested a benefit of sesame for postmenopausal women.
It’s hardly surprising that sesame seeds help reduce cholesterol because they are so rich in cholesterol-lowering phytosterols. How rich? Get this: A team of researchers from Virginia Polytechnic Institute and State University tested twenty-seven different nut and seed products. Sesame seeds (and wheat germ) had the highest phytosterol content of all the products tested: 400 mg per 100 g. The main phytosterol identified in all the nut and seed samples was beta-sitosterol, which is known not only for lowering cholesterol but also for supporting prostate health.
Sesame seeds are very high in calcium, but there is some controversy over how useful that calcium is to the body because much of it is bound to oxalic acid, making it less bioavailable. Hulling (the process of removing the outer skin) removes the oxalic acid, but it also removes most of the calcium, plus the fiber and a lot of the potassium and iron. In certain parts of Japan, whole sesame seeds are an essential part of the diet and are prepared as a condiment known as gomasio, made by toasting whole sesame seeds with unrefined sea salt at high temperatures. Toasting the whole sesame seeds at these high temperatures may improve the assimilation of calcium by getting rid of the oxalates.
Calcium aside, sesame seeds are also a rich source of minerals, fiber, and protein. Two tablespoons (16 g) of seeds contain iron, magnesium, phosphorus, potassium, and manganese, 35 percent of the Daily Value for copper, 2 g of fiber, and 3 g of protein—more protein than any other nut or seed.
You can really enhance their nutty flavor by toasting them in a dry skillet over medium heat until they’re golden brown. They come in shades of black, brown, and yellow as well as the more common beige variety. The black seeds have a stronger flavor. Sesame butter is a great alternative to peanut butter and it is usually made of whole roasted sesame seeds. Tahini is made from hulled sesame seeds and is therefore a more refined product, though still delicious. It is an essential part of hummus, a Middle Eastern appetizer made of ground chickpeas, garlic, and tahini. It is also found in baba ghanoush, which has a base of roasted eggplant seasoned with tahini, lemon juice, garlic, and salt.
According to research by Katherine Phillips, Ph.D., in the department of biochemistry at Virginia Tech, the sunflower kernel is rich in a number of components that have been shown to protect against disease and to act as antioxidants and anticarcinogens; thus, the kernel can be considered a functional food. Functional foods are generally defined as foods that provide benefits beyond basic nutrition. Pretty good for something that was once considered only useful as birdfeed!
Sunflower seeds contain a wide variety of nutrients and protective plant compounds known as phytosterols. Phytosterols are well known for their ability to lower cholesterol and provide other health benefits. “Given the many possible mechanisms of action of phytosterols on cholesterol metabolism, it is important to have quantitative estimates of total phytosterol content,” reported a team of researchers from Virginia Polytechnic Institute and State University, who tested twenty-seven different nut and seed products for phytosterol content. The results would have made the sunflower association very happy. Of all the products tested that are typically consumed as snacks, sunflower kernels were one of the two richest sources of phytosterols (the other was pistachio nuts). The main phytosterol identified in all the nut and seed samples was beta-sitosterol, which is known for lowering cholesterol and for supporting prostate health.
Sunflower seeds contain a potent antioxidant team of selenium and vitamin E to fight cancer and heart disease. Vitamin E is one of the most powerful antioxidants in the body, and 1/4 cup serving of dried sunflower seed kernels provides more than 40 percent of the recommended Daily Value (yes, I personally think the Daily Value is too low, but still). Better yet, that same 1/4 cup provides 30 percent of the Daily Value for selenium, a vitally important cancer-fighting trace mineral that works synergistically with vitamin E.
Sunflower seed kernels are also rich in protein and fiber, with 1/4 cup (36 g) providing more than 8 g of protein and almost 4 g of fiber, not to mention 248 mg of potassium, 127 mg of magnesium, 254 mg of phosphorus, more than 2 mg of iron, plus manganese, copper, and zinc.
These little kernels are also a source of betaine (also known as trimethylglycine [TMG]), which may help lower homocysteine, a risk factor for heart disease. And they have a higher arginine content than almonds, hazelnuts, or pecans. Arginine is an amino acid that is touted for its role in protecting the inner lining of the arterial walls, making them more pliable and less susceptible to atherogenesis. It’s also needed to make a very important molecule called nitric oxide, which helps relax constricted blood vessels and ease blood flow.
I’ve been known to eat the whole seed, hull and all. They’re great to chew on, and take longer to consume—plus, who knows what beneficial compounds might be in the shell that haven’t been discovered yet.
Also, it lets me share my stash with the birds, who don’t seem to mind which version I feed them.
The “doctrine of signatures” is a concept in herbalism that’s been around for centuries and is based on the idea that God marked everything God created with a sign (signature). The signature was an indication of the item’s purpose. According to the doctrine of signatures, because the walnut looks just like a human brain, its purpose is to support that organ. This just might be one case of modern science supporting centuries-old wisdom, because walnuts—like fish—are truly brain food. Read on.
Walnuts contain the highest amounts of omega-3 fats of any other nuts. In addition to the other remarkable things omega-3s do for you, like help lower triglycerides and reduce plaque formation, they also support brain function on a number of levels. One of those levels has to do with mood and feeling.
There are compelling population studies linking the consumption of large amounts of fish (omega-3 fatty acids) to low rates of depression. Controlled clinical trials of omega-3s in depression are under way at any number of research centers. There is biochemical evidence of low levels of omega-3s in depressed patients (as well as a number of other behavioral and cognitive disorders and conditions). Here’s why it makes sense: Fats in the diet are incorporated into cell membranes. Omega-3s are soft and fluid and give the cells enough “give” to allow them to communicate with each other, facilitating the movement of feel-good neurotransmitters like dopamine and serotonin in and out of the cells, and helping to support memory and thinking as well. Omega-3s truly are “brain food,” and walnuts are rich in them.
Several studies have demonstrated greater attention, reduction in behavioral problems, and less ADD-like behaviors in schoolkids when they’re given omega-3s. Because it’s hard to get kids to eat fish, let alone carry it to school in their lunchbox, walnuts are a really smart idea for a kid snack.
And walnuts may also be a great tool for weight management. According to experts at Loma Linda University, eating a few walnuts (say four to six halves) before meals decreases levels of hunger and may cause people to eat less at meals. “Walnuts help alleviate hunger and are naturally nutrient dense, meaning you consume many essential nutrients for a relatively small percentage of daily calories,” said Joan Sabate, M.D., M.P.H., Dr.P.H., chair of the department of nutrition.
Just don’t add walnuts to an already high-calorie diet and expect to lose weight. As long as you replace some calories from your regular diet with an approximately equal number of calories from walnuts, you’ll do fine. The nuts may even work as a natural appetite controller in addition to providing all those nutrients.
Walnuts, like most nuts, are nutrient rich, especially in minerals. They have protein, fiber, calcium, magnesium, phosphorus, and potassium, plus about half the Daily Value for manganese, an important trace mineral that’s essential for growth, reproduction, wound healing, peak brain function, and the proper metabolism of sugars, insulin, and cholesterol.
Natural-foods expert Rebecca Wood cautions that you should purchase walnuts in the shell and crack them just before use. If you choose to purchase shelled whole walnut halves, make sure their flesh is white rather than yellow because the yellow indicates rancidity. Wood also points out that organic walnuts have darker brown shells, and their color will vary depending on how much sun the branch they grew on was exposed to.
There are two common kinds of walnuts—the English (most of which ironically come from California) and the black walnut, which is native to North America. They differ slightly in their nutritional profile—the English has slightly less protein and slightly more fat. Both are great.
Daniel Amen, M.D. has been called “the most popular psychiatrist in America” by the Washington Post. He’s double board certified, has written more New York Times best-selling books than I could list in this paragraph (including Change Your Brain, Change Your Life, the Brain Warrior’s Way, Healing ADD, and Memory Rescue), and had more hit PBS specials than anyone I know. He’s also the founder and CEO of Amen Clinics, where they have the world’s largest database of functional brain scans relating to behavior, totaling nearly 100,000 scans on patients from 111 countries. It was Daniel, in fact, who once told me “the prettiest looking brains I’ve seen are on gingko biloba.”
I’ve known Daniel and his extraordinary wife, Tana, for about a decade, and he’s my go-to guy for all things brain related. I’ve thanked him in the acknowledgments sections of most of the books I’ve written in the past decade. He offered this list of top 11 foods for “bright minds.” (Fun fact: Daniel once told me that from a brain point of view, the healthiest, most life-extending, brain-protecting sport in the world is Ping-Pong.)
1. Cayenne pepper —I like this for its enhancing effect on blood flow.
2. Cloves —These are healthy for their antioxidant power, which is beneficial especially for aging populations.
3. Wild salmon —Its omega-3 fatty acids and ability to fight inflammation are among its health and nutritional benefits.
4. Turmeric —This spice helps decrease the formation of beta amyloid plaque in the brain.
5. Shrimp —It boosts acetylcholine, an important neurotransmitter, which is beneficial for head trauma.
6. Brassica vegetables —This family of vegetables, including cauliflower, cabbage, broccoli, and Brussels sprouts, stimulates the body to make important detoxification enzymes.
7. Saffron —Saffron has been shown to ease depression symptoms.
8. Garlic —Garlic has many health benefits, including its ability to boost immunity.
9. Eggs —I recommend eggs for their cholesterol*.
10. Lentils —These legumes are rich in fiber.
11. Tart cherries —They increase levels of melatonin and have been shown to improve the quality of sleep.
*No, that is not a misprint. Daniel was an early endorser of my book, The Great Cholesterol Myth (coauthored with Stephen Sinatra, M.D.), and has known for a long time that conventional medicine is wrong on cholesterol and fat. He includes eggs on his list precisely because they contain cholesterol, a vitally important nutrient for brain health, not to mention hormone production and vitamin D.
I never asked Daniel this but I’m 99 percent sure he’d agree with me that egg-white omelets are one of the dumbest experiments in nutritional history, and I’m sure he’s a mystified as I am by why they are still a thing.