Whole-Food Plant-Based Diet: Nutritional Benefits
Achieving Optimal Health with a Whole-Food Plant-Based Diet
Our diet is one of the most important determinants of health. Diet can be used to reduce the risk of disease, improve quality of life, and prolong life expectancy, and the health of our planet. A whole-food plant-based diet, rich in vegetables, fruits, legumes, nuts, and whole grains, and with minimal intake of animal products, processed foods, refined carbohydrates, and sugar, can play a significant role in maintaining good health, reducing inflammation, achieving optimal blood pressure and glucose levels, strengthening our microbiome, and reducing the risk of cardiovascular and metabolic related disease.1
Reaching Nutritional Goals with a Whole-Food Plant-Based Diet
It is important to consume adequate amounts of calcium, vitamin D, essential fatty acids, protein, vitamin K, magnesium, vitamin B12 and other nutrients in your diet.2 A whole-food plant-based diet that is well planned can meet your nutritional needs. Diets rich in plant-based nutrients are associated with better overall health outcomes, including reductions in inflammatory markers, often allowing for a reduction in medications.
An appropriate amount of calcium consumption is essential for building and maintaining healthy bones and teeth. Your bones contain 99% of the calcium in your body. Calcium is also important for the function of the heart, muscles, and nerves. Leafy green vegetables such as broccoli, kale, Brussels sprouts, and collard greens are packed with calcium.
Good sources of calcium found in a whole-food plant-based diet include:
- Non-dairy calcium rich foods, like green leafy vegetables
- Fortified plant-based milks such as soy, almond milk
- Calcium-set tofu
- Dried fruit
- Legumes, like beans, peas, and lentils
- Sesame seeds and tahini
A whole-food plant-based diet, rich in fruits and vegetables and vitamin D and K, low in refined carbohydrates, animal protein, and sodium, and well-balanced in essential fatty acids helps improve calcium absorbency.34 Good sources are Chinese cabbage, Bok choy, kale, calcium-set tofu and broccoli.
To improve calcium absorbency, consume a die high in:
- Fruits and vegetables
- Vitamin D
And consume a diet low in:
- Dietary sodium (less than 2400 mg/day)
- Refined carbohydrates
- Animal protein
Vitamin D is necessary for calcium absorption, and therefore bone health. It also acts with vitamin K to encourage bone mineralization. In addition, vitamin D can increase muscle strength, function, and balance.5 Vitamin D is also needed for muscles and nerves and for the immune system. Those at higher risk for vitamin D deficiency include infants, women, older adults, obese persons, and people with darker skin tones.67
Vitamin D can be obtained through a whole-food plant-based diet. Foods rich in vitamin D include:
- fatty ocean fish such as salmon, sardines, and black cod
- orange juice
- fortified milk substitutes, such as soy milk or almond mil
- some yogurts
In addition to its ability to transfer oxygen by means of hemoglobin and myoglobin, iron functions as a cofactor for many important enzymes, such as myeloperoxidase, important for immune function, and has a role in thyroid hormone synthesis and amino acid metabolism. A whole-food plant-based diet can provide adequate iron intake. Vegetarian diets generally contain as much or more iron than omnivore diets. 8-10
Iron intake needs can be met with a whole-food plant-based diet by consuming a diet rich in:
- Dried fruits
- Green leafy vegetables
- Iron-fortified cereal products
- Nuts and seeds
- Whole grains
Vitamin C and other organic acids, including citric, malic, lactic, and tartaric acids, enhance the absorption of iron. Vitamin C also plays a vital role in the formation of collagen, a key component of the bone matrix. It has been found to substantially lower hip and nonvertebral fractures, with a total intake of about 200 mg/day associated with the lowest prevalence of fractures.11,
The best sources of vitamin C are found in a whole-food plant-based diet and include:
- fruits, such as papaya, pineapple, oranges
- vegetables, such as broccoli and bell peppers
Magnesium, required for the conversion of vitamin D to calcitriol, in low levels can cause inflammation and oxidative stress. Low magnesium rates are also associated with several chronic health conditions, including type 2 diabetes and hypertension.12
Good sources of magnesium can be found in a whole-food plant-based diet. These include:
- Dark leafy vegetables
- Nuts and seeds
- Whole grains
Omega-3 Fatty Acids
Omega-3 fatty acids are essential nutrients that aid in the structure of human cell membranes and are related to positive cardiometabolic status. The source of omega-3 fatty acids for vegetarian diets is mainly alpha linolenic acid (ALA). Conversion of ALA is affected by health status, age, dietary composition, and sex.13
The richest sources of ALA in a whole-food plant-based diet are:
- Chia seeds
- Flax seeds
- Hemp seeds
Vitamin B12 is an essential nutrient required for the synthesis of all blood cells, proper functioning of the nervous system, DNA synthesis, and a variety of other biological functions.
Absorption of vitamin B12 may be impaired in older adults who are vegetarians due to age-related changes in the gastrointestinal track. Pregnant and lactating women who are vegetarians along with their offspring are at a high risk of vitamin B12 deficiency due to physiological and anatomical changes and higher demands for nutrients during these stages of the life cycle.
A deficiency of vitamin B12 may take years to develop in adults, as most of the B12 secreted into the gut via the bile gets reabsorbed, thus conserving the body stores. Therefore, a regular consumption of adequate B12 is important to avoid a subclinical deficiency that can go undetected for years and cause elevated homocysteine.
A whole-food plant-based diet that does not include dairy and/or meat products, such as those on this diet who are vegetarians or vegans, can obtain adequate vitamin B12 through the consumption of:
- Fortified breakfast cereals
- Fortified plant-based beverages
- Fortified vegetarian meat analogs
- Vitamin B12 supplement
Unfortified plant foods, such as fermented soy foods, leafy vegetables, seaweeds, mushrooms, and algae, including spirulina, do not contain sufficient amounts of active vitamin B12 to meet daily needs.14
Protein increases insulin-like growth factor levels and intestinal absorption of calcium. Additionally, protein is essential for the growth and maintenance of healthy bones, skin, muscle, and the immune system. Protein can however increase urinary calcium loss but components such as phosphorus in meat and potassium in legumes can partially offset this effect.15
Several studies have shown that an increased ratio of vegetable to animal protein is protective against fractures. Other studies have found that a diet with adequate amounts of calcium and vitamin D in combination with an increase in protein intake can have a favorable effect on bone health.16
In general, if a variety of high-quality protein rich food are consumed, a whole-food plant-based diet can provide all essential amino acids.
The best sources of protein in a whole-food plant-based diet include17
- Nuts and seeds
- Soy foods
Only 5% of Americans are getting enough fiber, putting them at an elevated risk for developing serious health conditions, including type 2 diabetes and arthritis. Fiber can help with digestion, weight loss, and heart health. Fiber has also been known to reduce junk food cravings and depression. Fiber-rich plant foods have been found to have prebiotic effects and are associated with increases in butyrate-producing microbes and other beneficial microbes. Hence, the gut microbial composition is greatly influenced by dietary fiber as well as by polyphenols and other phytochemicals and their metabolites, all of which are more highly consumed by vegetarians.18, 20
There are two types of fiber, soluble and insoluble. Soluble fiber helps with the reduction of cholesterol by acting like a sponge and attracting cholesterol in the digestive tract and removing it from the body. Soluble fiber is found in beans, lentils, vegetables, and fruits. Insoluble fiber is found in whole grains, fruits, vegetables, beans, and bran.
A whole-food plant-based diet rich in fiber includes:
- Legumes, such beans, and lentils
- Nuts, such as walnuts, almonds, and pistachios
- Whole grains, such as bran
Tea, such as black and green teas, which are part of a whole-food plant-based diet, appears to have beneficial effects on health because of its anti-inflammatory effects, cardiovascular benefits, and cancer protective properties.21
Foods to Limit
Processed Foods: Processed animal and plant foods are stripped of their nutrient value and far from their natural state. These processed foods, made with refined grains and flour, such as chips, cereal, crackers, and white bread, are suboptimal for health.
Sugar: Avoid the consumption of excess sugar. The presence of too much sugar in your body can cause mitochondrial dysfunction,22 inflammation,21 nonalcoholic fatty liver disease,23 and ultimately lead to insulin resistance24 and its sequalae, type 2 diabetes and heart disease.
Sodium: High salt diets have been linked to hypertension and are known to increase urinary calcium. An increase in calcium and potassium can potentially offset the urinary losses of calcium. The recommended sodium intake is <2400 mg/day.25
Alcohol: Limit your intake of alcohol. If you do not consume alcohol, it is best not to start. If you do, consume no more than one serving a day for women or two for men. One serving = 12 ounces of beer, 5 ounces of wine, or 1.5 ounces of liquor.
The Bottom Line
A whole-food plant-based diet, one composed largely of unrefined plant foods, can help you reach your nutritional goals, offer greater protection against chronic disease, and achieve optimal health. Build your diet around plants: fruits, legumes, nuts, seeds, vegetables, and whole grains. A minimum goal is to consume at least five servings of fruits and vegetables daily.
- Arnett DK, Blumenthal RS, Albert MA, et al. 2019 ACC/AHA guideline on the primary prevention of cardiovascular disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol. 2019;74(10):e177-e232.
- Langsetmo L, Berger C, Kreiger N, et al. Calcium and vitamin D intake and mortality: results from the Canadian Multicentre Osteoporosis Study (CaMos). J Clin Endocrinol Metab. 2013;98(7):3010-3018.
- Heaney RP, Dowell MS, Hale CA, Bendich A. Calcium absorption varies within the reference range for serum 25-hydroxyvitamin D. J Am Coll Nutr. 2003;22(2):142-146.
- Vermeer C, Theuwissen E. Vitamin K, osteoporosis and degenerative diseases of ageing. Menopause Int. 2011;17(1):19-23.
- Shuler M, Franklin D, Schlierf T, Wingate M. Preventing falls with vitamin D. Published online 2014.
- Ganji V, Zhang X, Tangpricha V. Serum 25-hydroxyvitamin D concentrations and prevalence estimates of hypovitaminosis D in the US population based on assay-adjusted data. J Nutr. 2012;142(3):498-507.
- Singh G. Prevalence and implications of vitamin D deficiency in applicants for insurance. J Insur Med N Y NY. 2014;44(2):103-109.
- Gropper, S.S.; Smith, J.L.; Carr, T.P. Advanced Nutrition and Human Metabolism, 7th ed.; Cengage Learning: Boston, MA, USA, 2017.
- Craig, W.J. Nutrition concerns and health effects of vegetarian diets. Nutr. Clin. Pract. 2010, 25, 613–620.
- Dawson-Hughes, B.; Harris, S.; Kramich, C.; Dallal, G.; Rasmussen, H.M. Calcium retention and hormone levels in black and white women on high—And low-calcium diets. J. Bone Miner. Res. 1993, 8, 779–787. [CrossRef]Gillooly, M.; Bothwell, T.H.; Torrance, J.D.; MacPhail, A.P.; Derman, D.P.; Bezwoda, W.R.; Mills, W.; Charlton, R.W.; Mayet, F. The effects of organic acids, phytates and polyphenols on the absorption of iron from vegetables. Br. J. Nutr. 1983, 49, 331–342. [CrossRef] [PubMed]
- Sahni S, Hannan MT, Gagnon D, et al. Protective effect of total and supplemental vitamin C intake on the risk of hip fracture—a 17-year follow-up from the Framingham Osteoporosis Study. Osteoporos Int. 2009;20(11):1853-1861.
- Leung, A.M.; Lamar, A.; He, X.; Braverman, L.E.; Pearce, E.N. Iodine status and thyroid function of Boston-area vegetarians and vegans. J. Clin. Endocrinol. Metab. 2011, 96, E1303–E1307. [CrossRef14.
- Lane, K.; Derbyshire, E.; Li, W.; Brennan, C. Bioavailability and Potential Uses of Vegetarian Sources of Omega-3 Fatty Acids: A Review of the Literature. Crit. Rev. Food Sci. Nutr. 2014, 54, 572–579. [C
- National Institutes of Health. Office of Dietary Supplements. Vitamin B12. Available online: https://ods.od.nih.gov/factsheets/ VitaminB12-HealthProfessional/ (accessed on 11 November 2021).
- Cooper C, Atkinson E, Hensrud D, et al. Dietary protein intake and bone mass in women. Calcif Tissue Int. 1996;58(5):320-325.
- Dawson-Hughes B, Harris SS. Calcium intake influences the association of protein intake with rates of bone loss in elderly men and women. Am J Clin Nutr. 2002;75(4):773-779.
- Mariotti F, Gardner CD. Dietary Protein and Amino Acids in Vegetarian Diets-A Review. Nutrients. 2019 Nov 4;11(11):2661. doi: 10.3390/nu11112661. PMID: 31690027; PMCID: PMC6893534.
- Corrêa, T.A.F.; Rogero, M.M.; Hassimotto, N.M.A.; Lajolo, F.M. The Two-Way Polyphenols-Microbiota Interactions and Their Effects on Obesity and Related Metabolic Diseases. Front. Nutr. 2019, 6, 188.
- Papier, K.; Tong, T.Y.; Appleby, P.N.; Bradbury, K.E.; Fensom, G.K.; Knuppel, A.; Perez-Cornago, A.; Schmidt, J.A.; Travis, R.C.; Key, T.J. Comparison of Major Protein-Source Foods and Other Food Groups in Meat-Eaters and Non-Meat-Eaters in the EPIC-Oxford Cohort. Nutrients 2019, 11, 824.
- David, L.A.; Maurice, C.F.; Carmody, R.N.; Gootenberg, D.B.; Button, J.E.; Wolfe, B.E.; Ling, A.V.; Devlin, A.S.; Varma, Y.; Fischbach, M.A.; et al. Diet rapidly and reproducibly alters the human gut microbiome. Nature 2014, 505, 559–563
- Gardner E, Ruxton C, Leeds A. Black tea–helpful or harmful? A review of the evidence. Eur J Clin Nutr. 2007;61(1):3-18.
- Zhang DM, Jiao RQ, Kong LD. High dietary fructose: direct or indirect dangerous factors disturbing tissue and organ functions. Nutrients. 2017;9(4):335.
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- Bedford JL, Barr SI. Higher urinary sodium, a proxy for intake, is associated with increased calcium excretion and lower hip bone density in healthy young women with lower calcium intakes. Nutrients. 2011;3(11):951-961.