Nutrition and academic achievement: Are they related?
Does academic performance depend on what you eat? Is there a link between proper nutrition and academic achievement? Consider some recent findings:
Students who paid attention to their daily nutrient needs performed academically better in school.1
Inadequate nutrition negatively influenced intelligence and academic performance.2
Low levels of protein and iron indicated a correlation with low achievement scores.3,4
Those with poor nutrition scored lower on tests of vocabulary, reading comprehension, arithmetic, and general knowledge.5
Those who did not have breakfast scored lower in tests of speed and accuracy of response on problem-solving.6
Those with iron deficiency anemia were found to have shorter attention spans, irritability, fatigue, and difficulty with concentration, which led to poor vocabulary, reading, and other test scores.7
Protein, in particular tryptophan, improved alertness.8
Those slightly malnourished showed that their intelligence and performance were affected. Improved nutrition corrected these impairments.9, 10
Temporary hunger adversely affected attention, interest, and learning. A review of some 30 studies indicates that skipping breakfast interferes with cognition and learning.11,12
While dietitians cannot guarantee that a student who chooses well what and how much he or she eats will necessarily get all As, nutrition does lay the foundation for an alert, retentive brain, a plus for study. Energy level, attention span, and academic performance are influenced by eating habits.
Those habits are largely your responsibility. You must choose to build a strong, supportive foundation for the learning on which your career is built. Balanced, sound nutrition is an important part of that foundation.
The food we eat provides energy needed for all the body systems to function at optimum levels. Every organ and function of the body requires adequate nutrition and energy. Body cells, including those that are part of the brain, need nutrients and energy for their function and repair. Hence, the importance of what we eat and what we drink.
What shall we eat?
The energy needed by the body comes from only three sources: carbohydrates, proteins, and fats. Carbohydrates are made up of starches and sugars. The body breaks down (metabolizes) the carbohydrates into glucose which is the only source of energy the brain can use.13
Consuming just carbohydrate is not enough. The breakdown process of starches and sugars into glucose requires other nutrients, such as vitamins and minerals. The brain also needs a steady supply of protein, an essential requirement for the health and repair of all body cells. In addition, the brain and the central nervous system need fat to support the myelin sheaf with its fatty layer that surrounds the nerves.
Thus, just as the body in general requires a balanced nutrition consisting of carbohydrates, protein, fat, vitamins, minerals, and water, so does the brain, with its intricate nervous system, in order to function optimally.
How do we ensure balanced nutrition? Several tools are available. Let us note three common ones. First, governments periodically issue national guidelines for nutrition. For example, the United States Departments of Agriculture and Health and Human Services publish the Dietary Guidelines for Americans, based on the research of nutritional scientists. Updated every five years, the guidelines provide a basis for healthy eating habits. Box 1 provides a summary of these guidelines.
A second tool for choosing good nutrition is what is known as the food pyramid. Box 2 pictures the pyramid for vegetarians. My Vegetarian Food Pyramid14 divides foods into groups based on the nutrients found in the foods. The major nutrients of each group are listed in Box 3. The Pyramid also gives the number of servings of each of the food groups recommended to provide the number of calories required by an individual. (To find the calories you need, go to >MyPyramid.gov<, enter your age, gender, and activity level.)
A third tool regarding nutrient contents of a food item is the food label on packaged foods. This may not be available in all countries, but provides a simple guide as to serving size, calorie count, and selected nutrient content. See Box 4 for an illustration of the food label in U.S.A.
With information from the Dietary Guidelines, the food pyramid, and labeling on food packages, you have a reasonable system whereby you can choose foods that will ensure a balanced, sound nutrition. You will also be able to maintain a healthy weight and a sense of well-being.
Proteins: body builds from amino acids
Protein can be found in many foods. In fact in all foods –even celery, watery celery. Not much, but some. The daily recommended allowance for protein is 0.8 grams (gm) per kilogram (kg) body weight. A male weighing 70 kg (154 lbs.) needs 56 gm of protein per day, whereas a female weighing 50 kg (110 lbs.) needs 40 gm per day. Following the My Vegetarian Food recommended servings in number and size for 2,000 calories for women and 2,500 calories for men would result in a total protein per day of 67 grams for women and 80 grams for men.15 Both results exceed the recommendation.
Proteins have been categorized as complete and incomplete, based on the amino acid profile of proteins in a food. Since vegetable protein may have a slightly different amino acid profile from meat, vegetable sources have been labeled as incomplete. In the past vegetarians were encouraged to choose complementary protein sources for a given meal, e.g., milk with cereal, beans with bread, etc. Current findings support consuming a variety of proteins over the course of a day, negating the intentional complementation of proteins at every meal.16
In addition to ingested protein, amino acids are available for absorption and building of proteins the body needs via the desquamated cells from the rapid sloughing of the cells lining the gastrointestinal track. A mixed and varied diet of sufficient calories plus the amino acid pool in the gastrointestinal tract provides sufficient protein.17
Vegetable proteins provide the amino acids necessary for good health without several negative substances abundant in meat. Saturated fat, especially tender cuts of meat, is a major negative, since it enhances the formation of cholesterol. All meats contain cholesterol, the waxy substance deposited in blood vessels as atherosclerotic plaques. Pre-formed cholesterol, too, is a major negative. Better diets use vegetable proteins, i.e., beans, legumes, meat alternates, nuts, and seeds. These protein foods are not accompanied with saturated fat and cholesterol.
What shall we drink?
The body needs water. Approximately 50 to 60 percent of one’s total body weight is water. Sources of dietary water include liquid foods (yogurt, ice cream, custard, pudding), drinks (water, beverages), solid foods (fruits and vegetables are 73 to 95 percent water), and water of oxidation (200 to 300 cc per day). The estimated requirement for water intake is one milliliter per calorie ingested. An young adult needing 2,000 calories would require 2,000 milliliters or 8.3 cups of water a day.18
Bottled water is costly but may not be avoided in countries where pure drinking water is not available. A disadvantage with bottled water is that its mineral content may vary considerably, depending on its source.19 Dentists have also noted a rise in cavities possibly related to the prevalence of the use of bottled water, since many brands do not contain the fluoride that is essential to dental health.
Young adults often choose beverages that do not provide any nutrients. Soda pop, for example, is flavored water and sugar without any nutritional benefit. Each 12 ounce can contains 150 to 180 calories or 7.5 to 9 teaspoons of pure sugar. Ellen White spoke of other non-nutritive beverages: “In relation to tea, coffee, tobacco, and alcoholic drinks, the only safe course is to touch not, taste not, handle not.”20
Studies regarding the use of coffee and tea give conflicting results. Some studies show that caffeine increases athletic endurance,21,22,23 elevates mood,24 ,25 enhances a sense of happiness,26 may reduce the risk of obesity by decreasing white adipose tissue proliferation,27 and may increase resistance to cold by increasing brown fat.28
On the other hand, studies have also documented certain risks associated with coffee-drinking: a decrease of muscle tone,29 a decrease of memory functions in the presence of distracting noises or at high dosages,30 an increase of distractibility,31 mood depression on withdrawal,32 blood pressure decrease,33 possible tachycardia with high doses,34 blockage of adenosine receptors which may cause CNS stimulation,35 acting as a diuretic by increasing renal blood flow,36 decrease of cerebral blood flow with possible increase of blood glucose,37, 38 increase of anxiety in those that are caffeine sensitive,39,40,41,42 possible increase of anger, aggression, and violence in young but a decrease in older men,43 and possible increase of urinary calcium loss and negative calcium balance.44, 45 Studies also show caffeine intake may cause gastroesophageal reflux,46,47, 48 lead to caffeine addiction,49,50 increase risk of dehydration,51 increase the incidence of myocardial infarction in women consuming more than five cups of coffee a day,52 increase incidence of primary cardiac arrest in men and women drinking more than five cups a day,53 and raise blood glucose levels in those who are insulin independent.54 The ingestion of caffeinated and other soft drinks may also decrease the consumption of milk and fruit juice.55
The popular media tends to extol the virtues of alcohol, wine in particular, as beneficial to health. The phytochemical, resveratrol, in wine is responsible for the benefit; resveratrol comes from the skin of the red grape. Eating the grape or drinking red grape juice provides the same benefit. The American Heart Association has stated that with the relationship of ethanol “to a number of health hazards…there is little current justification to recommend alcohol (or wine specifically) as a cardioprotective strategy.”56
With all these cautions and concerns, what should one do about beverages? The best course is to choose beverages that benefit your health. My Vegetarian Food Pyramid suggests that your health is well served by milk and its products, juices of fruits and vegetables, and water. If you choose alternates to milk, choose brands that provide the nutrients of milk. A serving of milk typically provides 8 grams of protein, 20 to 30 percent of the Daily Value (DV) of calcium, 30 percent DV of riboflavin, 20 to 25 percent DV of Vitamin D, 25 to 35 percent Vitamin B12 . Read the label on the milk replacement –soy, nut or rice– you choose.
With so much evidence about making the right choice in what you should eat and drink and how diet affects your performance in study and your health, it is only reasonable to give yourself the benefit of a sound nutritional advantage. Ellen White wrote some 150 years ago: “Fruits, grains, and vegetables, prepared in a simple way, free from spice and grease of all kinds, make, with milk or cream, the most healthful diet. They impart nourishment to the body, and give a power of endurance and vigor of intellect that are not produced by a stimulating diet.”57
That intellectual vigor and power of endurance is yours to have. Give yourself a major advantage throughout your academic career, and indeed the rest of life, with balanced, sound nutrition. Follow the nutritional guidelines available to you, choose wisely what you eat and drink, exercise regularly, and follow the health principles that are part of the Adventist advantage (For more information on nutritional guides, consult the sources available online. See Box 6). Your brain needs the nutrients good food provides. Maximize the time, energy, and financial investment of higher education by attending to your nutritional needs. Your lifetime career depend on an alert, retentive, well-fed brain.
Georgia E. Hodgkin, (Ed.D., Loma Linda University) is Professor of Nutrition and Dietetics, Associate Chair of the Department of Nutrition and Dietetics at the School of Allied Health Professions, Loma Linda University, California, U.S.A. Email address: email@example.com.
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- Center on Hunger, Poverty, and Nutrition Policy, “Statement on the Link between Nutrition and Cognitive Development in Children,” (Medford, Massachusetts: Tufts University School of Nutrition, 1995).
- American School Food Services Association, “Impact of Hunger and Malnutrition on Student Achievement,” School Board Service Research Review 1 (Spring 1989):17-21.
- L. Parker, The Relationship Between Nutrition and Learning: A School Employee’s Guide to Information and Action (Washington, D.C.: National Education Association), 1989).
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- See note 4.
- C. R. Markus, L. M. Jonkman, J. H. Lammers, N. E. Deutz, M. H. Messer, and N. Rigtering, “Evening Intake of Alpha-Lactalbumin Increases Plasma Tryptophan Availability and Improves Morning Alertness and Brain Measures of Attention,” American Journal of Clinical Nutrition 81 (2005) 5:1026-33.
- S. Schoenthaler, “Abstracts of Early Papers on the Effects of Vitamin-mineral Supplementation on IQ and Behavior,” Personality and Individual Differences 12 (1991) 4:343
- S. Schoenthaler, S. Amos, H. Eysenck, E. Peritz, and J. Yudkin, “Controlled Trial of Vitamin-mineral Supplementation: Effects on intelligence and performance,” Personality and Individual Differences 12 (1991) 4:361
- D. Benton and P. Y. Parker , “Breakfast, Blood Glucose, and Cognition,” American Journal of Clinical Nutrition 67 (1998) suppl.:772S-8S.
- See note 1.
- See note 11.
- General Conference (of Seventh-day Adventists) Nutrition Council, My Vegetarian Food Pyramid, Silver Spring, Maryland, 2006.
- V. R.Young and P. L. Pellett, “Plant Proteins in Relation to Human Protein and Amino Acid Nutrition,” American Journal of Clinical Nutrition 59 (1994) suppl.:1203S-12S.
- L. K. Mahan and S. Escott-Stump, Krause’s Food, Nutrition, & Diet Therapy ed. 12 (Philadelphia: Saunders, 2008), pp. 63, 64.
- S .R. Rolfes, K. Pinna, and E.Whitney, Understanding Normal and Clinical Nutrition ed. 7 (Belmont, California: Wadsworth, 2006), pp. 396-399, 456.
- Ellen G. White, The Ministry of Healing (Mountain View, California: Pacific Press Publ. Assn., 1942), p. 335.
- R. J. Lamarine, “Caffeine as an Ergogenic Aid,” in G.A. Spiller (ed.), Caffeine (Boca Raton: CRC Press, 1998), pp. 234-250.
- B. D. Smith, and K. Tola, “Caffeine: Effects on Psychological Functioning and Performance,” in Spiller, op cit., 252-299.
- D. C. Bell, I. Jacobs, J. Zamecnik, “Effects of Caffeine, Ephedrine, and Their Combination on time to Exhaustion During High-Intensity Exercise,” European Journal of Applied Physiolog, 77 (1998) 5:427-433.
- See note 21.
- See note 22.
- L. J. Bukowiecki, J. Lupien, N. Follea, and L. Jahjah, “Effects of sucrose, caffeine, and cola beverages on obesity, cold resistance and adipose tissue cellularity,” American Journal of Physiology 244 (1983) 4:R500-507.
- See notes 21 and 22.
- See note 22.
- J. Stamler, A. Caggiula, G. A. Grandits, M. Kjelsberg, and J. A.Cutler, “Relationship to Blood Pressure of Combinations of Dietary Macronutrients. Findings of the Multiple Risk Factor Intervention Trial (MRFIT), Circulation 94 (1996) 10:2417-2423.
- G. A. Spiller, “Basic Metabolism and Physiological Effects of Methylxanthines,” in Spiller, pp. 225-231.
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- P. J. Arciero, A. W. Gardner, N. L. Benowitz, and E. T. Poehlman, “Relationship of Blood Pressure, Heart Rate and Behavioral Mood State to Norephinephrine Kinetics in Younger and Older Men Following Caffeine Ingestion,” European Journal of Clinical Nutrition 52 (1998):805-812.
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- E. R. Eichner, “Treatment of Suspected Heat Illness,” International Journal of Sports Medicine 19 (1998) suppl. 2:S150-153.
- J. R. Palmer, L. Rosenberg, R. S. Rao, and S. Shapiro, “Coffee Consumption and Myocardial Infarction in Women,” American Journal of Epidemiology 141 (1995) 8:724-731.
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- American Heart Association Nutrition Committee, “Diet and lifestyle: Recommendations Revision,” Circulation 114 (2006):82.
- Ellen G. White, Counsels on Diet and Foods (Washington, D.C.: Review and Herald Publ. Assn., 1976), p. 92.