In recent years much has been written about the health value of dark chocolate. Much—but not all—chocolate contains a class of so-called “flavinoids,” or “flavanols,” which are widely present in cocoa, green tea, red wine and some fruits. These components seem to be helpful in lowering blood pressure and improving cardiovascular health.   Most research indicates that cocoa or dark chocolate, consumed daily, produce beneficial effects on human health, consisting of a modest reduction in blood pressure with dilation of arteries, resulting in increased circulation to various organs (the brain for one, perhaps most notably).  Consuming milk chocolate or white chocolate, or drinking fat-containing milk with dark chocolate, appears to largely negate the various health benefits.

For instance, survivors of heart attacks who eat chocolate at least two or three times a week reduce their risk of death by a factor of up to three times compared to survivors who did not eat chocolate. These apparently beneficial effects seem to derive from the positive role of cacao and cocoa products on cardiovascular risk factors such as blood pressure, cholesterol levels, atherosclerosis, and improving how the body handles insulin (potentially helping diabetes, another potent risk factor).

But the picture is not without drawbacks, for over-consumption of chocolate can have harmful effects such as weight gain and obesity. Moreover, chocolate that contains the most flavanols seems to confer the most benefit, whereas that being poor in these components possess little, if any, benefit.


Recently, researchers from Columbia University in New York gave 37 trial participants, aged between 50 and 69, a drink containing cocoa for which flavonols were extracted from cocoa beans. The amount of flavonols consumed varied: Half of the participants received 900 mg daily; the other half received only ten milligrams.

Then the scientists measured the blood flow in the brain. In the flavonol-rich group, a higher circulation was found. Moreover, the participants of this group achieved significantly better results in memory tests. If a participant had the memory of a typical 60-year-old at the beginning of the study, “after three months that person on average had the memory of a typical 30- or 40-year-old”, said study author Scott Small. However, the study did not include participants with dementia or similar conditions, but did include people with healthy memory and age-related memory declines, the authors emphasized.

Supporting of these findings, another study of thirty–two healthy participants underwent two baseline sessions after one night of undisturbed sleep and two experimental sessions after one night of total sleep deprivation. Two hours before each testing session, participants were randomly assigned to consume high or low flavanol chocolate bars. Indirect measures of blood flow to the brain were also studied.

Interestingly, after sleep deprivation, those who received high flavanol chocolate showed no decrease in the expected loss of memory, whereas those receiving low flavanol chocolate failed to retain memory in much the same way as normal loss of sleep produces. Moreover, these results correlated with changes in blood flow to the brain, i.e., those receiving high flavanol chocolate showed evidence of more blood flow to this organ.

Not All Chocolate Is Created Equal, but greater Benefits likely from more Flavanol
One of the biggest challenges in comparing the research on chocolate and health is the wide variety of the types of chocolate consumed. While clinical trials most often use dark chocolate, which can vary greatly in flavanol content, epidemiologic studies have examined overall chocolate consumption, including dark and milk chocolate. Unfortunately, flavanol-rich cocoa and chocolate products have a distinctly bitter taste.

Milk chocolate, which is the most widely consumed chocolate in the United States, is much lower in flavanols than dark chocolate. But even dark chocolate can vary greatly in flavonol content, depending on the amount of cocoa solids it contains and how it’s processed. Flavanol content even varies among crops of cacao beans. Manufacturers typically purchase cacao beans from several countries and from many suppliers and then combine them. This practice results in varying flavonoid levels from batch to batch of chocolate produced.

The labeling of the flavanol content of chocolate products isn’t mandatory, but as a general rule, the higher the percentage of cocoa solids in a chocolate product and the more bitter the taste, the higher the flavanol levels. But while this association isn’t consistent, it‘s the best indicator available of flavanol content. And then, of course, there’s white chocolate, which isn’t chocolate at all; it contains zero flavanols.

So what should the individual do about chocolate? Be aware that most chocolate products are high in sugar, fat, and calories. While much of this fat is the kind that doesn’t raise cholesterol levels, it does add a significant number of calories. It’s not wise to add a daily dose of chocolate if it’s not already part of your diet, especially if you’re overweight or obese. However, some researchers have suggested that if total calorie intake is balanced, chocolate flavanols can be part of a healthful diet in general, especially for those with high blood pressure. If you are a chocolate lover who regularly indulges, choose dark chocolates that are high in cocoa solids and therefore usually rich in heart-healthy flavanols. Increasingly, dark chocolate products are providing the percentage of cocoa solids on the label, and some newer varieties, such as CocoaVia, are even listing the amount of flavanols on the label, boasting as much as 350 mg per serving.

Despite these touted health benefits, Americans overwhelmingly prefer the taste of milk chocolate over dark—and we’re not alone. A study from Australia found that one-half of the participants in a 24-week period said it was hard to eat 50 g (about 3 oz) of dark chocolate every day, and 20% said it was an unacceptable long-term treatment option. Yet the truth is the darker the chocolate, the more bitter the taste and the more healthful it is for the heart. What a bummer!

The bottom line? Clearly, not everyone is a fan of dark chocolate, but it’s the one to consume for heart health. Eating too much chocolate, like any high-calorie snack, can have harmful effects, but the research strongly suggests a potential health benefit from regular consumption of dark, flavanol-rich chocolate as part of a healthful diet. But the refrain from researchers is the same: We need more research before we can make any definitive recommendations.




     This category includes nuts from trees, including almonds, hazelnuts, walnuts, pistachios, pine nuts, cashews, pecans, macadamias, and Brazil nuts. Although not technically a “tree nut”, peanuts possess similar traits and are, therefore, including in this category.

    Most of these nuts provide good sources of caloric energy, primarily from unsaturated fats (oils), useful also for lowering cholesterol.  Moreover, the essential amino acids contained in nuts are vital for constructing protein, i.e., the building blocks for our muscles and other tissues. Although each type of nut does not supply, in itself, a complete source of these amino acids, consuming a variety of nuts will provide a complete complement of the various necessary (essential) components. Other nutritional elements provided by nuts include folic acid, vitamin E, potassium, magnesium, and calcium. Especially noteworthy is their uniformly low sodium content, a highly desirable feature (provided that no salt is added). They also contain polyphenols, bioactive constituents that seem to be beneficial to heart health that extends beyond one’s other dietary efforts.

     During the past 20 years, mounting evidence indicates that consuming these nuts (including peanuts and peanut butter) at least twice weekly provides substantial protection from cardiovascular disease and overall death rates as compared to those consuming them only rarely or not at all#.  These desirable results seem to be obtained primarily through the lowering of unfavorable cholesterol components, and despite a substantial caloric content, nuts do not seem to promote obesity, probably because of their prominent satiating effect. For unknown reasons, nuts also appear to prevent diabetes, another contributor to cardiovascular disease.  Research studies have also indicated that, if  the” Mediterranean” diet, which, in itself is healthy, if supplemented by extra mixed nuts (one ounce daily) and extra virgin olive oil (one quart total per week), substantial additional reductions of cardiovascular disease and stroke can be accomplished.


    Edible seeds that contribute to human nutrition include grains (e.g. wheat, corn, rice, barley, millet and oats), legumes (e.g. soybeans), cocoa and coffee beans.  Some grains, however, are less beneficial, and these include white rice, white bread, pasta, noodles, and refined grain products with added sugar, fat, and sodium (e.g.  biscuits, pastries and cakes). Cocoa beans are the seeds of the tropical tree Theobroma cacao, from which chocolate is derived.

    Whole grains comprise germ, bran, and endosperm. Refining them reduces their nutritional quality by removing beneficial constituents that include germ and bran along with fiber, vitamins minerals, phenolic compounds and phytochemicals. Large studies have demonstrated a 21% lower risk of cardiovascular disease for those individuals consuming an average of 3-5 servings per day compared with those who rarely or never consumed whole grains. This group also had a 26% lower risk for the development of diabetes. In comparison to germ, bran seemed to be more potent in this regard.

    Cocoa and chocolate require special comment. All research clearly confirms the value of chocolate in the prevention of cardiovascular disease, probably through improved cholesterol and blood pressure levels as well as reduced development of diabetes. Most studies point to the value of dark chocolate (as opposed to white or milk  chocolate) being the most beneficial, but the effect of milk chocolate alone cannot be clearly established since many studies do not separate the two types for individual analysis.

    The effects of coffee on health are less certain. This product contains little of nutritional value. Although some data suggest that coffee consumption is associated with a slightly lower mortality risk, one can safely conclude that at least coffee appears to do no harm.

     Seeds, nuts and chocolate possess high fat content, but of the polyunsaturated varieties that decrease cholesterol levels, metabolism of sugar (reducing diabetic tendency) and cardiovascular risk. Whole grains are rich in insoluble fiber (bran), a beneficial nonabsobable nutrient that, for unclear reasons, is also associated with reduced diabetes and cardiovascular risk   


    “Pulses” are the seeds of plants contained within pods, and they include lentils, chickpeas, black-eyed peas, and a variety of beans that include pinto, kidney, navy, and fava beans.

    Scientific studies regularly indicate that consumption of these food sources reduces the incidence of cardiovascular disease. One study demonstrated that their consumption four times weekly was associated with a 22% lower risk of heart disease in comparison with those who consumed them less than once weekly. Similar results are found when beans are substituted for white rice.

     The beneficial effects of pulses seem to result primarily from their favorable effects on cholesterol components and enhancement of sugar metabolism that improves prevention and control of diabetes. 


    In general, one should attempt to substitute whole grains and legumes for refined grains in all diets. Moderate consumption of cocoa products can be incorporated. Coffee can be consumed with possible benefit, or at least with no added risks. Separating the effects of different components of seeds and nuts is not possible, and therefore, dietary recommendations should include a wide array of these foods as a major part of a plant-based diet. These modifications should be included with other components of a healthy diet that are well known, such as avoidance of red meat, reduction of salt intake, limitation of caloric intake, and regular inclusion of breakfast.   

# Ros E. and Hu FB. Consumption of plant seeds and cardiovascular health. Epidemiological and clinical trial evidence. Circulation 2013;128:553-565.

Bao Y. et al. Association of nut consumption with total and cause-specific mortality. N. England J. Med. 2013;369:2001.