I’ll also clear up some common misconceptions about nutrient density, and reveal why an omnivorous diet that includes both animal and plant foods is the best choice from a nutrient density perspective.
Understanding Nutrient Density
The nutrients in our food fall into two categories: macronutrients and micronutrients.
- Macronutrients refer to the three main substances required in large (macro) amounts in the human diet: protein, carbohydrates, and fats.
- Micronutrients are vitamins, minerals, and other compounds required by the body in small (micro) amounts for normal physiological function.
We need a mix of both to stay healthy.
What’s the key to maximizing your nutrient density? Eating nutritious, real food from a variety of sources. Find out which foods pack the most punch.
The term “nutrient density” refers to the concentration of micronutrients and amino acids, the building blocks of proteins, in a given food. While carbohydrates and fats are important, these macronutrients can be partially synthesized by the body for a limited amount of time if dietary intake has been insufficient. (A major exception: the essential omega-6 and omega-3 fatty acids, which we can only get through food.)
Conversely, micronutrients and the essential amino acids found in protein cannot be manufactured by the body and must be consumed from food. (A reminder: the word “essential” in front of fatty or amino acids means that our bodies can’t produce them; we must get them from food sources.)
Nutrient density means two very different things in the conventional nutrition and ancestral health communities. Among conventional practitioners, nutrient-dense foods are defined as those that are high in nutrients but relatively low in calories. According to MyPlate, the current nutrition guide endorsed by conventional medicine, the most nutrient-dense foods are:
- Vegetables
- Fruits
- Whole grains
- Legumes
- Unsalted nuts and seeds
- Lean meats and poultry
- Fat-free or low-fat dairy products
MyPlate’s definition of nutrient density excludes foods that are high in saturated fat and animal fat.
In contrast, while the ancestral health community also acknowledges the nutrient density of meat, poultry, vegetables, nuts, and seeds, it does not demonize or overlook foods that are high in calories and saturated fats.
Instead, the ancestral health perspective recognizes that some of the most nutrient-dense foods on the planet are sourced from animals and contain plenty of fat, such as organ meats, red meat, and full-fat dairy. I consider nutrient density and calorie density separately—because some high-calorie foods are exceptionally nutrient-dense and can be healthy additions to our diet.
Why Nutrient Density Matters
The human body requires approximately 40 different micronutrients for normal metabolic function. Maximizing nutrient density should be the primary goal of our diet because deficiencies of any of these essential nutrients can contribute to the development of chronic disease and even shorten our lifespan. Listed below are just a few examples of how nutrient deficiencies contribute to chronic disease.
- Vitamin C deficiency increases chronic disease risk factors such as C-reactive protein, waist circumference, and blood pressure. (1)
- Vitamin D deficiency is associated with immune dysfunction and an increased risk of metabolic syndrome and cardiovascular disease. (2, 3, 4)
- Magnesium deficiency is linked to depression, metabolic syndrome, and cardiovascular disease. (5, 6, 7)
- Choline deficiency promotes DNA damage and impairs brain development and liver function. (8, 9)
- Vitamin B12 deficiency contributes to cognitive dysfunction and reversible tremors and other Parkinson’s-like symptoms. (10)
- Folate deficiency increases the risk of birth defects and promotes the production of a compound called homocysteine that damages blood vessels when present in large amounts and impairs DNA methylation, which in turn can lead to altered gene expression and an increased risk of cancer. (11, 12)
Nutrient deficiencies are not only a cause of chronic health conditions, but they can also be an effect. Small intestinal bacterial overgrowth (SIBO), dysbiosis, and gastritis impair nutrient absorption in the gastrointestinal tract and increase nutrient needs. Chronic inflammation increases the degradation of and need for vitamin B6 and reduces the body’s production of vitamin D from UVB light exposure. Exposure to environmental toxins such as heavy metals increases the need for essential minerals and nutrients involved in methylation. These factors make nutrient density even more crucial.
The SAD State of Nutrition in the United States
If the United States were to receive a report card rating the quality of the Standard American Diet, it would get a solid “F” for nutrient density. Despite being high in calories, the Standard American Diet (SAD) is nutrient poor. Vegetable oils and sugar, which together comprise 36 percent of the SAD diet, are virtually devoid of nutrients.
It should come as no surprise that nutrient deficiency is widespread in the United States; recent statistics indicate that nearly one-third of Americans are at risk for at least one vitamin deficiency or anemia, with hundreds of thousands of people at risk for multiple deficiencies. (13)
To make matters worse, the RDA (recommended dietary allowance) used in studies to assess nutrient sufficiency merely represents the daily intake level required to avoid acute deficiency symptoms—it does not represent the nutrient intake needed to promote optimal health! (RDAs were originally developed during World War II to create “nutritious” rations for soldiers. While they have been updated since then, RDA numbers represent the minimum amount of a nutrient a person needs in order to avoid a malnutrition-triggered disease, like scurvy or rickets. Furthermore, they don’t really take into account gender, age, or health, meaning that a teenage athlete and a middle-aged sedentary person are given the same RDAs.)
The Crucial (But Underappreciated) Role of Bioavailability
No discussion of nutrient density would be complete without considering another critical nutritional factor: bioavailability.
“Bioavailability” refers to the portion of a nutrient that is absorbed in the digestive tract and released into the bloodstream for the body’s use. The amount of bioavailable nutrients in a food is almost always lower than the amount of nutrients the food contains. For example, the bioavailability of calcium from spinach is only 5 percent. Of the 115 mg of calcium present in a serving of spinach, only 6 mg is absorbed. This means you’d have to consume 16 cups of spinach to get the same amount of bioavailable calcium in one glass of milk. (14)
Factors That Impact Bioavailability
Three factors influence the bioavailability of nutrients in food:
- The form of the nutrients
- The presence of other nutrients that boost bioavailability (nutrient synergy)
- The presence of nutrient inhibitors and anti-nutrients
The form that nutrients take significantly impacts their bioavailability in the body. For example, heme iron, a form of iron found only in animal products such as meat and poultry, is far more bioavailable than nonheme iron, found in plant foods. Fifteen to 35 percent of heme iron is absorbed, whereas only 2 to 20 percent of nonheme iron is absorbed.
The absorption of nutrients is also affected by the presence (or lack) of other nutrients. For example, vitamin C enhances the absorption of iron and fat increases the solubility of fat-soluble nutrients such as vitamins A, D, E, and carotenoids.
Nutrient inhibitors and anti-nutrients reduce the bioavailability of nutrients in foods. Phytate, an anti-nutrient found in large amounts in grains and legumes, binds to calcium, iron, and zinc, making them unavailable for absorption. The impact of anti-nutrients on bioavailability is one of the reasons why our Paleolithic ancestors developed nutrient deficiencies when they transitioned from a hunter–gatherer lifestyle, largely free of high amounts of phytate-rich foods, to one that revolved around agriculture.
The concept of nutrient synergy is closely related to bioavailability. Nutrient synergy refers to how nutrients, enzymes, and other cofactors work together to create greater health effects. Examples of nutrient synergy are found in the family of fat-soluble vitamins (vitamins A, D, E, and K2), which must be balanced to promote optimal health. Another example is the importance of copper for maintaining normal iron metabolism in red blood cell formation. While synergistic groups of nutrients occur naturally in foods, they are often not included in synthetic vitamins.
The role of nutrient synergy may explain the surprising results of studies that looked at supplementation with isolated antioxidants. In fact, both beta-carotene and vitamin E have been associated with increased cancer risk. (15, 16)
The bioavailability of protein is another essential component of nutrient density. Researchers rely on a measure called the Protein Digestibility Corrected Amino Acid Score (PDCAAS), which combines the amino acid profile of a protein with a measure of how much of the protein is absorbed during digestion, to assess protein bioavailability. The PDCAAS rates proteins on a scale of 0 to 1, with values close to 1 representing more complete and better-absorbed proteins than ones with lower scores.
On the scale, animal proteins have much higher scores than plant proteins; casein, egg, milk, whey, and chicken have scores of 1, indicating excellent amino acid profiles and high absorption, with turkey, fish, and beef close behind.
Plant proteins, on the other hand, have much lower scores; legumes, on average, score around 0.70, rolled oats score 0.57, lentils and peanuts are 0.52, tree nuts are 0.42, and whole wheat is 0.42. Importantly, the PDCAAS does not consider the anti-nutrient content of foods. If anti-nutrients were taken into consideration, plant proteins would score even lower on the bioavailability scale due to their high anti-nutrient levels.
In Search of a Nutrient-Dense Diet
A nutrient-dense diet is the best protection against nutrient deficiencies. But what exactly is the most nutrient-dense diet?
There are several studies that have attempted to answer this question. In the most comprehensive one, referred to as the Maillot study, researchers looked at seven major food groups and 25 subgroups, characterizing the nutrient density of these foods based on the presence of 23 qualifying nutrients. The table below displays the results; each food was giving a numbered score for reference, with the highest numbers corresponding to the highest levels of nutrient density. (17)
| Food Group | Nutrient Density Score |
|---|---|
| Meat | |
| Organ meats | 754 |
| Shellfish | 643 |
| Fatty fish | 622 |
| Lean fish | 375 |
| Eggs | 212 |
| Poultry | 168 |
| Red meats | 147 |
| Deli meats (processed) | 120 |
| Fruits and Vegetables | |
| Vegetables | 352 |
| Fruits | 134 |
| Nuts | 120 |
| Dried fruits | 85 |
| Dairy Products | |
| Milk | 138 |
| Yogurt | 119 |
| Cheese | 101 |
| Starches and Grains | |
| Legumes | 156 |
| Whole grains | 83 |
| Potatoes | 75 |
| Refined grains | 40 |
| Added Fats | |
| Vegetable fats | 80 |
| Animal fats | 25 |
Even without considering bioavailability, all categories of meat and fish, vegetables, fruit, nuts, and dairy were more nutrient dense than whole grains. Meat and fish, veggies, and fruit were more nutrient dense than legumes, which were slightly more nutrient dense than dairy and nuts.
What would the scale have looked like had researchers separated caloric density from nutrient density? Harvard University chemist Dr. Mat Lalonde used a formula similar to that used in the Maillot study, but without penalizing foods for having more calories. (18) (He used a different scoring scale, but higher numbers still correlate with higher nutrient density.) The results, which he shared at the Ancestral Health Symposium in 2012, are below.
| Category | Average Nutrient Density Score |
|---|---|
| Organ meats | 21.3 |
| Herbs and spices | 12.3 |
| Nuts and seeds | 7.5 |
| Cacao | 6.4 |
| Fish and seafood | 6.0 |
| Beef | 4.3 |
| Lamb, veal and wild game | 4.0 |
| Vegetables (raw) | 3.8 |
| Pork | 3.7 |
| Eggs and dairy | 3.1 |
| Poultry | 3.1 |
| Processed meat | 2.8 |
| Legumes | 2.3 |
| Vegetables (cooked or canned) | 2.0 |
| Fruit | 1.5 |
| Plant fats and oils | 1.4 |
| Grains and pseudograins* | 1.2 |
| Animal fats and oils | 1.0 |
*Pseudograins include quinoa and amaranth.
On the Lalonde scale, organ meats are again the most nutrient-dense foods by far, followed by:
- Herbs and spices
- Nuts and seeds
- Cacao
Seafood, red meat, and wild game were more nutrient dense than raw vegetables; all forms of meat, fish, fruit, and vegetables (raw and cooked) were more nutrient dense than grains and pseudograins (such as quinoa or amaranth).
If bioavailability had been taken into account in both the Maillot study and Lalonde’s analyses, legumes and grains would have been even lower on the scales when compared to organ meats, meats, dairy products, and fruits and vegetables.
It’s worth noting that both the Maillot and Lalonde analyses only included nutrients like vitamins, minerals, protein, fiber, and essential fatty acids, all of which have been proven to be essential. As I touched on earlier, in a nutrition context, the word “essential” doesn’t just mean “important” or “must-have.” It means we can’t live without these substances and we must get them from food sources, as our bodies can’t manufacture them.
Although these nutrients should always be the primary focus, research over the past two decades has shown that other nutrients, while not essential, play a vital role in health. They include:
- Polyphenols
- Carotenoids
- Flavonoids
- Diallyl sulfides (from the allium class of vegetables)
- Lignans
These nutrients are found primarily in whole fruits and vegetables, so had they been factors in the Maillot and Lalonde analyses, fruits and vegetables would have scored higher.
Putting It All Together
Animals and plants each contain different nutrients that our bodies require, as Dr. Sarah Ballantyne indicated in her excellent article, “How Much Meat versus Veggies.”
Plant Foods
- Vitamin C
- Carotenoids (like lycopene, beta-carotene, lutein, and zeaxanthin)
- Diallyl sulfide (from the allium class of vegetables)
- Polyphenols
- Flavonoids (like anthocyanins, flavan-3-ols, flavonols, proanthocyanidins, procyanidins, kaempferol, myricetin, quercetin, and flavanones)
- Dithiolethiones
- Lignans
- Plant sterols and stanols
- Isothiocyanates and indoles
- Prebiotic fibers (soluble and insoluble)
Animal Foods
- Vitamin B12
- Heme iron
- Zinc
- Preformed vitamin A (retinol)
- High-quality protein
- Creatine
- Taurine
- Carnitine
- Selenium
- Vitamin K2
- Vitamin D
- DHA (docosahexaenoic acid)
- EPA (eicosapentaenoic acid)
- CLA (conjugated linoleic acid)
We end up avoiding processed, refined foods because they are calorie dense and nutrient poor. We eat fresh, local, organic, whole foods that are not only higher in nutrients than their conventional counterparts, but also lower in pesticides and other toxins. We eat meat, eggs, wild-caught seafood, and pasture-raised, full-fat dairy when tolerated. Finally, we naturally eat less because nutrient-dense foods tend to be more satiating, have more fiber and water, and often have fewer calories.
Fine-Tuning Your Diet
Some people may need to fine-tune the nutrient density of their diet to replenish depleted nutrients. Some of the key nutrients to consider when refining the nutrient density of your diet include vitamins A, D, E, and K2, magnesium, iodine, and calcium.
Vitamin A
Preformed vitamin A can be obtained by eating three to six ounces of beef liver or chicken liver per week or by regularly consuming egg yolks. Carotenoids in carrots, sweet potatoes, winter squash, kale, spinach, collard greens, and pumpkin serve as precursors to vitamin A. If you find that these foods are not enough, you can also take one teaspoon of cod liver oil per day as a source of vitamin A.
Vitamin D
Sun exposure is the best “nutrient” for raising vitamin D levels. Full-body exposure to midday summer sun yields approximately 1,000 IU of vitamin D, though this value is highly dependent on your skin tone and latitude. Frequent sun exposure is not always possible, and vitamin D deficiency is widespread, so one teaspoon of cod liver oil per day (a natural source of vitamin D) may be a beneficial addition to your diet.
Vitamin E
Vitamin E supplementation is also not recommended because long-term studies indicate that alpha-tocopherol, the form of vitamin E typically used in multivitamins, may increase the risk of cardiovascular disease. (19) Instead, get your vitamin E from foods such as:
- Spinach
- Turnip greens
- Chard
- Sunflower seeds
- Almonds
- Bell peppers
- Asparagus
- Collards
- Kale
- Broccoli
- Brussel sprouts
Eating these foods with fat—plant or animal—will enhance vitamin E absorption.
Vitamin K2
The primary forms of vitamin K2 are menaquinone-4 (MK-4) and menaquinone-7 (MK-7). Grass-fed, full-fat dairy products, gouda, brie, poultry liver (especially goose liver), and pastured egg yolks are excellent sources of MK-4, while natto and other fermented foods are rich sources of MK-7.
Magnesium
The optimal intake of magnesium is 500 to 700 mg/day from food and supplements. Food sources of magnesium include:
- Leafy greens
- Molasses
- Dark chocolate
- Bananas
- Pumpkin seeds
- Almonds
- Lentils
It is hard to get enough magnesium from food alone, so you may need to supplement with 100 to 500 mg of magnesium glycinate or magnesium malate per day.
Iodine
Ironically, iodine deficiency may be more common in people who eat healthier diets, due to the avoidance of iodized salt and processed foods that contain iodized salt. To boost your iodine levels, eat sea vegetables (such as nori), cod, yogurt, milk, and eggs.
Calcium
Most calcium supplements, with the exception of bone meal, are no longer recommended due to studies linking them to an increased risk of cardiovascular disease, kidney stones, and other problems—even increased risk of fracture. Instead, focus on food sources such as:
- Bone-in sardines
- Canned sockeye salmon with bones
- Yogurt
- Cheese
- Sesame seeds
- Collard greens
- Spinach
- Turnip greens
- Bok choy
- Almonds
- Summer squash
- Herbs and spices
If you are looking for nutritional powerhouses that can deliver a bundle of nutrients at once, consider eating liver, beef, and oysters. Liver is nature’s most concentrated source of vitamin A and is an excellent source of B vitamins, bioavailable iron, CoQ10, copper, zinc, and chromium. Beef contains highly bioavailable zinc, iron, selenium, and B vitamins, especially B12. Last but not least, oysters contain 111 percent of the RDA for zinc, 110 percent for selenium, 267 percent for B12, 79 percent for copper, and 28 percent of the RDA for iron. They are also an excellent source of omega-3 fatty acids.
Misconceptions about Nutrient Density
There are some common misconceptions about nutrient density that circulate throughout the nutrition world and blogosphere. Since these misconceptions have the potential to significantly impact the nutrient density of your diet and your long-term health, I’d like to set the record straight by addressing a few of them here.
“Many Vegetables Are High in Vitamin A.”
This is a common misconception that is even promoted on food labels! Vegetables, especially dark green, orange, and yellow vegetables, are often described as good sources of vitamin A. In reality, they contain vitamin A precursors called carotenoids. Carotenoids must be converted into vitamin A in the body, and unfortunately, this conversion is inefficient for many people. (20)
“You Can Get Vitamin B12 from Fermented Foods and Brewer’s Yeast.”
This is a common myth among vegetarians and vegans. B12 is found exclusively in animal products, with the exception of rarely consumed plant foods like nori and wild mushrooms. (21) Some plant foods do contain compounds that resemble B12, but in most cases these are B12 analogs (meaning that they have a similar chemical structure). Despite their molecular similarity, B12 analogs actually block B12 receptors, increasing the need for this crucial vitamin. (22)
“You Can Get All the Calcium You Need from a Vegan Diet.”
Although foods included in a vegan diet contain calcium, the calcium is far less bioavailable. You would need to eat 16 servings of spinach to get the same amount of calcium in one glass of milk. (23) Oxalate and phytate, which are frequently found in plant foods that contain calcium, inhibit calcium absorption. Dairy products and bone-in fish remain the most bioavailable sources of calcium.
“Vegetarian Foods Are Loaded with Iron.”
Many plant foods contain nonheme iron, but it is far less bioavailable than heme iron in animal foods. Furthermore, phytates and oxalates reduce the absorption of nonheme iron.
“You Can Get Omega-3 Fatty Acids from Plant Foods Such as Chia Seeds and Flax Seeds.”
Some plant foods, such as flax and chia, contain alpha-linolenic acid. It’s possible for alpha-linolenic acid to be converted into EPA and DHA, the omega-3 fatty acids that are essential to our health, but conversion is poor in many people. (24)
Nutrient Deficiencies on Vegetarian and Vegan Diets
The nutrition myths mentioned above are often promoted by advocates of vegetarian and vegan diets. Perhaps not surprisingly, nutrient deficiencies are very common on such diets. (25) Deficiencies frequently occur in vegetarian and vegan diets because the main food sources in these diets are grains, legumes, vegetables, and fruits, which are not as nutrient dense as foods included in omnivorous diets, including meat, seafood, and dairy products.
Also, many of the staple foods of vegetarian and vegan diets, especially grains and legumes, are high in phytic acid and other nutrients and thus have low bioavailability. If your goal is to optimize the nutrient density of your diet, then vegetarianism and veganism may not be your best option. For more information on the nutritional pitfalls of vegetarian and vegan diets, check out my article “Why You Should Think Twice about Vegetarian and Vegan Diets.”
Can Taking a Multivitamin Prevent Nutrient Deficiencies?
For decades, people have been encouraged by nutrition authorities to take a daily multivitamin. Currently, more than a third of Americans take a daily multivitamin, but do we really need one? A recent review of multivitamins published by Examine indicates that multivitamins are only useful for some populations, such as: (26)
- People who can’t afford or access quality food
- The elderly
- Pregnant women
- Those who can’t obtain nutrients from food (likely due to illness or other health conditions)
Contrary to what we’ve been told, most studies show no health benefits from multivitamins, and some even suggest that they cause harm. How could a multivitamin possibly be harmful? Supplemental nutrients don’t have the same effect on the body as nutrients obtained from food, and large doses of isolated nutrients may promote oxidative stress and inflammation. Foods remain the safest source of nutrients, as they contain a full spectrum of nutrients in forms that are recognized by the body. Furthermore, it is much harder to overdose on nutrients with foods than with supplements.
I hope this article has helped you gain a better understanding of nutrient density and its crucial role in your health. By consuming a diet composed of nutrient-dense foods and being aware of bioavailability, you can optimize your nutrition status, protect yourself from nutrient deficiencies, and create the foundation for lifelong health.
The post What Is Nutrient Density and Why Is It Important? appeared first on Chris Kresser.
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