Does cooking destroy Vitamins?
Many untrained health professionals scoff at the notion that cooking has any negative effects whatsoever on the vitamin content of foods. One such article unscientifically states that, “When they tell you that cooking destroys vitamins, they omit the fact that only a few vitamins are sensitive to heat.” (18)
As is often the case, that writer made assertions which are the EXACT OPPOSITE of what is scientifically accurate.
The USDA (United States Department of Agriculture) has conducted widespread studies on percentage losses of numerous nutrients from different types of food and cooking methods (19). The table below shows the numerous vitamins that are susceptible to loss due to heating—such as the heat from boiling, frying, steaming, etc.
The majority are sensitive to heat.
Water-soluble vitamins such as the vitamins B and C dissolve into water when vegetables are boiled and are lost once the water is discarded. (20)
| Vitamin | Soluble in water | Stable to heat exposure | Stable to light exposure | Stable to air exposure |
| A | No | Relatively | Partially | Partially |
| C | Very unstable | No | No | Yes |
| D | No | No | No | No |
| E | No | No | Yes | Yes |
| K | No | No | Yes | No |
| Thiamine (B1) | Highly | >100 °C | ? | No |
| Riboflavin (B2) | Slightly | No | In solution | No |
| Niacin (B3) | Yes | No | No | No |
| Pantothenic Acid (B5) | Quite Stable | Yes | No | No |
| Vitamin B6 | Yes | ? | Yes | ? |
| Biotin (B7) | Somewhat | No | ? | ? |
| Folic Acid (B9) | Yes | At high temp | When dry | ? |
| Cobalamin (B12) | Yes | No | Yes | ? |
Are there widespread nutrient deficiencies?
According to the Food and Nutrition Board, Institute of Medicine, National Academies of Science, more than 90% of Americans fail to reach the Estimated Average Requirement (EAR) (21) or Adequate Intake (AI) (21) of at least 1 vitamin or mineral from food alone. (22, 23) Unlike Recommended Dietary Allowances (RDAs) (21), which represent the nutritional level sufficient for 97% to 98% of all healthy individuals, the EAR represents the quantity of a given nutrient sufficient to meet the requirements of 50% of healthy individuals within a given age and gender-specific group. (24) EAR levels represent a far less stringent metric of dietary adequacy than RDA levels. (24) Yet, the vast majority of Americans fail to meet even this basic measure of dietary adequacy based on food alone. (22, 23)
Estimated Average Requirement (EAR) – a nutrient intake value that is estimated to meet the requirement of half the healthy individuals in a particular life stage and gender group. (21)
Adequate Intake (AI) – a recommended intake value based on observed or experimentally determined approximations or estimates of nutrient intake by a group (or groups) of healthy people that are assumed to be adequate — used when an RDA cannot be determined. (21)
Recommended Dietary Allowance (RDA) – the dietary intake level that is sufficient to meet the nutrient requirement of nearly all (97 to 98 percent) healthy individuals in a particular life stage and gender group. (21)
“Many physicians might be surprised to learn that more than 90% of Americans —and therefore, physicians’ patients as well—fall short in obtaining even the Estimated Average Requirement (EAR) (24) or Adequate Intake (AI) (24) for at least one vitamin or mineral (micronutrients) in their diets. (22, 23) This deficit is particularly striking considering that EARs are a lower “nutritional bar” compared to the Recommended Dietary Allowances (RDAs) (24) or Daily Values (DVs) used on food labels (25).” (26)
“About 85% of Americans do not consume the US Food and Drug Administration’s recommended daily intakes of the most important vitamins and minerals necessary for proper physical and mental development.” (27)
“Unhealthy diet contributes to approximately 678,000 deaths each year in the U.S.” They further noted that, “The typical American diet is too high in calories, saturated fat, sodium, and added sugars, and does not have enough fruits, vegetables, whole grains, calcium, and fiber.” (28)
“Americans at all income levels allocate too little of their food budgets towards healthy foods.” (29)
An extensive study supported by the National Institutes of Health’s National Heart, Lung, and Blood Institute (NHLBI) appeared in the March 7, 2017, Journal of the American Medical Association. (30)
The researchers investigated the relationships of 10 different foods and nutrients with deaths related to heart disease, stroke, and type 2 diabetes. They also compared data on participants’ age, sex, ethnicity, and education. They found that nearly half of all the deaths in the United States in 2012 that were caused by cardiometabolic diseases were associated with suboptimal eating habits. Of 702,308 adult deaths due to heart disease, stroke, and type 2 diabetes, 318,656 (45%) were associated with inadequate consumption of certain foods and nutrients widely considered vital for healthy living, and overconsumption of other foods that are not. (30)
“Dietary factors were estimated to be associated with a substantial proportion of deaths from heart disease, stroke, and type 2 diabetes.” (30)
“Several studies have shown that poor diet is a major challenge in the United States, and little improvement has occurred over the past decades. US residents are not consuming a healthy diet; they tend to consume more calories than needed, and composition is not ideal…The United States needs a comprehensive program to improve dietary intake at national and local levels.” (31)
4 of the most respected nutrition experts in the world have addressed this.
“More than 93%, 61%, and approximately 50% of adults in the United States do not get the Estimated Average Requirement of vitamins D and E, magnesium, and vitamin A and calcium, respectively, from their diet, including enriched and fortified foods (32). Further, 98% and 71% do not meet the Adequate Intake of potassium and vitamin K, respectively (32). Many of these percentages are even higher among subpopulations with increased micronutrient needs, including older adults, African Americans, and obese persons. Conversely, persons taking a daily multivitamin and mineral supplement formulated at approximately the Daily Value do fill many of these nutritional gaps effectively, safely, and at low cost…and long-term use is not associated with any adverse health effects” (32, 33). (34)
Dr. Balz Frei, Ph.D., Director & Endowed Chair Emeritus, Linus Pauling Institute at Oregon State University. (34)
Dr. Bruce Ames, Ph.D., Professor of Biochemistry and Molecular Biology Emeritus at the University of California, Berkeley, and a senior scientist at Children’s Hospital Oakland Research Institute. Dr. Ames is one of the most cited scientists in history. (34)
Dr. Jeffrey B. Blumberg Ph.D., FACN, CNS, Professor Friedman School of Nutrition Science and Policy Senior Scientist, Jean Mayer USDA Human Nutrition Research Center on Aging Tufts University. (34)
Dr. Walter C. Willett, M.D., Dr. P.H., is Professor of Epidemiology and Nutrition at Harvard T.H. Chan School of Public Health and Professor of Medicine at Harvard Medical School and the most-cited nutritionist in the world. (34)
93% of Americans are missing the Estimated Average Requirement for Vitamin D according to the experts! (34)
MUST SEE VIDEO!
Dr. Anthony Fauci– “If you’re deficient in vitamin D, that does have an impact on your susceptibility to infection. I would not mind recommending, and I do it myself, taking vitamin D supplements. The other vitamin that people take is Vitamin C because it’s a good antioxidant, so if people want to take a gram or so of vitamin c, that would be fine.” –
https://youtu.be/gglY7BI1jfk?t=1931
This study of 18,063 participants aimed to determine the total nutrient intakes of 19 micronutrients from all sources as well as the relative contributions of foods (including both naturally occurring nutrients and those added via enrichment and/or fortification) and of dietary supplements within a nationally representative sample of the U.S. population aged 2 years and older. This was done using National Health and Nutrition Examination Survey (NHANES) data collected by the National Center for Health Statistics (NCHS) and the Centers for Disease Control (CDC). (32)
This study determined that large percentages of children with total usual intakes below the EAR (Estimated Average Requirement) (21) were observed for vitamin D (73%), vitamin E (66%), calcium (45%), magnesium (34%), vitamin A (25%), and vitamin C (16%). Similarly, the percentage of adults with total usual intakes below the EAR (Estimated Average Requirement) (21) was considerable for vitamin D (68%), vitamin E (58%), magnesium (48%), vitamin A (37%), calcium (36%), and vitamin C (28%). (21)
Estimated Average Requirement (EAR) – a nutrient intake value that is estimated to meet the requirement of half the healthy individuals in a particular life stage and gender group. (21)
“If you eat the standard American diet, or anything close to it, then you’re deficient in multiple minerals and vitamins…” Dr. Ken D. Berry, M.D.
What does the Centers for Disease Control say about this?
The following examples reporting a widespread lack of proper nutrition are from the CDC’s Second National Report on Biochemical Indicators of Diet and Nutrition (35):
30 million Americans (10.5%) have a vitamin B6 deficiency, with higher rates among non-Hispanic blacks (15.7%) and those older than age 60 years (16%). (35) (26)
23 million Americans (8.1%) have “severe” vitamin D deficiency. Non-Hispanic blacks (31.1%) and Mexican-Americans (11.3%) are more likely to be vitamin D-deficient compared with non-Hispanic whites (3.6%). (35) (26)
7.5 million women aged 12-49 years (9.5% of that group) have low body iron status, with higher rates among Mexican Americans (13.2%) and non-Hispanic blacks (16.2%). (35) (26)
Approximately one-third of pregnant women in the United States are marginally iodine deficient (ie, with intakes bordering on insufficient). (35, 36) (37)
“Most persons in the United States are not “well-nourished” and do not meet the Institute of Medicine’s recommendations for the dietary intake of all vitamins and essential minerals.” (34)
Dr. Balz Frei, Ph.D., Director & Endowed Chair Emeritus, Linus Pauling Institute at Oregon State University. (34)
Dr. Bruce Ames, Ph.D., Professor of Biochemistry and Molecular Biology Emeritus at the University of California, Berkeley, and a senior scientist at Children’s Hospital Oakland Research Institute. Dr. Ames is one of the most cited scientists in history. (34)
Dr. Jeffrey B. Blumberg Ph.D., FACN, CNS, Professor Friedman School of Nutrition Science and Policy Senior Scientist, Jean Mayer USDA Human Nutrition Research Center on Aging Tufts University. (34)
Dr. Walter C. Willett, M.D., Dr. P.H., Chair of Nutrition, Professor of Epidemiology and Nutrition at Harvard T.H. Chan School of Public Health and Professor of Medicine at Harvard Medical School and the most-cited nutritionist in the world. (34)
“Practically everybody is deficient in something, and then some people like the obese are deficient in everything.” -Dr. Bruce Ames, Ph.D
We hope you enjoyed part 3 of this article in our Debunking Bad Advice series. For part 4, click the link below.
Should we take nutrition supplements? – Part 4
