The strongest argument against a 100% raw food diet is the lack of any convincing arguments for such a way of eating.
Many ideas that are still widespread today, including the idea that a completely raw vegan diet would be the most "natural" diet, and that grains and legumes are not healthy foods, have been around for well over 100 years. What is (and has been) assumed here is there is something like the "natural diet for the human organism" and that this "perfect diet" is also the healthiest diet for all humans. If one follows these (unproven) ideas of a raw vegan diet being "the natural diet" and therefore decides to eat only fruit, vegetables, nuts and seeds, it is likely that the result will be a suboptimal to insufficient intake of certain nutrients - but this can be avoided if the raw vegan diet is well-planned.
For athletes who have a very high intake of food and calories it is probably easier to get sufficient amounts of micronutrients (from non-fortified foods) with a 100% raw food diet compared to non-athletes (13) - but this does not apply to vitamin B12 or vitamin D, which are typically practically absent from non-fortified plant foods.
A raw diet, like other healthy diets, can help people to lose excess body weight, which will also result in beneficial effects for artery health (2, 14, 15).
2. Koebnick C, Garcia AL, Dagnelie PC, Strassner C, Lindemans J, Katz N, Leitzmann C, Hoffmann I. Long-term consumption of a raw food diet is associated with favorable serum LDL cholesterol and triglycerides but also with elevated plasma homocysteine and low serum HDL cholesterol in humans. J Nutr 2005; doi:10.1093/jn/135.10.2372.
3. Hobbs SH. Attitudes, practices, and beliefs of individuals consuming a raw foods diet. Explore (NY) 2005; doi:10.1016/j.explore.2005.04.015.
4. Donaldson MS. Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements. Ann Nutr Metab 2000; doi:10.1159/000046689.
5. Cheeke R. Vegan bodybuilding and fitness. The complete guide to building your body on a plant-based diet. Healthy Living; Publishers Group UK [distributor]: Summertown, Tenn., Enfield, 2011.
6. Fontana L, Shew JL, Holloszy JO, Villareal DT. Low bone mass in subjects on a long-term raw vegetarian diet. Arch Intern Med 2005; doi:10.1001/archinte.165.6.684.
7. Garcia AL, Mohan R, Koebnick C, Bub A, Heuer T, Strassner C, Groeneveld MJ, Katz N, Elmadfa I, Leitzmann C, et al. Plasma beta-carotene is not a suitable biomarker of fruit and vegetable intake in german subjects with a long-term high consumption of fruits and vegetables. Ann Nutr Metab 2010; doi:10.1159/000262295.
8. Garcia AL, Koebnick C, Dagnelie PC, Strassner C, Elmadfa I, Katz N, Leitzmann C, Hoffmann I. Long-term strict raw food diet is associated with favourable plasma beta-carotene and low plasma lycopene concentrations in Germans. Br J Nutr 2008; doi:10.1017/S0007114507868486.
9. Strużycka I, Rusyan E, Bogusławska-Kapała A. Erozje zębów - problem interdyscyplinarny. [Tooth erosion - a multidisciplinary approach]. Pol Merkur Lekarski 2016; 40:79–83.
10. Ganss C, Schlechtriemen M, Klimek J. Dental erosions in subjects living on a raw food diet. Caries Res 1999; doi:10.1159/000016498.
11. O'Toole S, Bernabé E, Moazzez R, Bartlett D. Timing of dietary acid intake and erosive tooth wear: A case-control study. J Dent 2017; doi:10.1016/j.jdent.2016.11.005.
12. Koebnick C, Strassner C, Hoffmann I, Leitzmann C. Consequences of a long-term raw food diet on body weight and menstruation: results of a questionnaire survey. Ann Nutr Metab 1999; doi:10.1159/000012770.
13. Leischik R, Spelsberg N. Vegan triple-ironman (raw vegetables/fruits). Case Rep Cardiol 2014; doi:10.1155/2014/317246.
14. Fontana L, Meyer TE, Klein S, Holloszy JO. Long-term low-calorie low-protein vegan diet and endurance exercise are associated with low cardiometabolic risk. Rejuvenation Res 2007; doi:10.1089/rej.2006.0529.
15. Douglass JM, Rasgon IM, Fleiss PM, Schmidt RD, Peters SN, Abelmann EA. Effects of a raw food diet on hypertension and obesity. South Med J 1985; doi:10.1097/00007611-198507000-00017.
16. Amoroso S, Scarpa M-G, Poropat F, Giorgi R, Murru FM, Barbi E. Acute small bowel obstruction in a child with a strict raw vegan diet. Arch Dis Child 2019; doi:10.1136/archdischild-2018-314910.
17. Cundiff DK, Harris W. Case report of 5 siblings: malnutrition? Rickets? DiGeorge syndrome? Developmental delay? Nutr J 2006; doi:10.1186/1475-2891-5-1.
18. Koeder C. Veganismus. Für die Befreiung der Tiere. 1. Auflage. Koeder: Ellwangen, 2014.
19. Willett W, Rockström J, Loken B, Springmann M, Lang T, Vermeulen S, Garnett T, Tilman D, DeClerck F, Wood A, et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. The Lancet 2019; doi:10.1016/S0140-6736(18)31788-4.
20. Satija A, Hu FB. Plant-based diets and cardiovascular health. Trends Cardiovasc Med 2018; doi:10.1016/j.tcm.2018.02.004.
21. Davis B, Melina V, Berry R. Becoming raw. The essential guide to raw vegan diets. Book Publishing Company: Summertown, Tennessee, 2010.
First, it is important to note that there are many different types of raw food diets: 100% raw or mainly raw food diets, vegan, ovo-lacto-vegetarian, or non-vegetarian raw food diets, fruit-based or sprout-based or raw food diets, and raw foods diets that include or exclude legumes (legume sprouts), grains (sprouts), nuts, cold-pressed oils, cold-pressed juices, spices, etc.
The following text only deals with vegan raw food diets.
Many ideas that are still widespread today, including the idea that a completely raw vegan diet would be the most "natural" diet, and that grains and legumes are not healthy foods, have been around for well over 100 years. What is (and has been) assumed here is there is something like the "natural diet for the human organism" and that this "perfect diet" is also the healthiest diet for all humans. If one follows these (unproven) ideas of a raw vegan diet being "the natural diet" and therefore decides to eat only fruit, vegetables, nuts and seeds, it is likely that the result will be a suboptimal to insufficient intake of certain nutrients - but this can be avoided if the raw vegan diet is well-planned.
Nutrients to consider and possible food/supplement sources (also see my Nutrient recommendations for vegans):
- Vitamin B12: take a supplement (1-4) (see link above)
- Protein (especially the amino acid lysine but also just a sufficient protein intake in terms of protein quantity): eat large amounts of legume sprouts (mung bean sprouts, for example) and maybe use a raw protein powder. Very large amounts of green juices can also contribute quite relevant amounts of protein (5).
- Calcium: consume calcium-rich water, green leafy vegetables (rich in calcium, low in oxalic acid), and possibly use a supplement (~300 mg per day) (6)
- Vitamin D: get a lot of sunshine (6) (many raw foodist do, actually) and/or take a supplement (see link above)
- Iodine: consume seaweed like nori or wakame, use iodized salt (not sea salt, Himalaya salt, etc.), or take an iodine-containing supplement (see link above)
- Omega-3 fatty acids: good sources are, for example, walnuts, flaxseeds/linseeds, hemp seeds, chia seeds, etc. (see link above)
- Iron and zinc: consume large quantities of legume and grain sprouts (and also green vegetables, nuts, and seeds daily)
- Selenium: eat a Brazil nut per day (or two) (see link above)
- Provitamin A: consume carrot juice or green leafy vegetable juice (7) or plenty of orange-coloured fruits like mangos and papayas (see link above)
With certain foods it can be recommended to preferentially consume them in their raw form: especially fruit as well as cold-pressed oils, particularly highly unsaturated cold-pressed oils such as flaxseed/linseed oil.
Certain nutrients are more readily absorbed from cooked foods, such as lycopene (from tomatoes) and beta-carotene (provitamin A) (7, 8).
Cooking and bread making with yeast or sourdough improves the absorption of minerals such as iron and zinc from cereals.
Certain foods should NOT be eaten raw (uncooked). These include kidney beans and small red beans, cassava, bamboo shoots and (ideally) mushrooms.
A high intake of fresh fruit can damage your tooth enamel because of the acids in acidic fruit and because of the sugar in fruit which can stick to your teeth. A fluoride-containing toothpaste and practicing good oral hygiene is recommended (9-11). Do not brush your teeth immediately after eating acidic foods such as oranges or grapefruits. Rather rinse your mouth with water before brushing your teeth.
It should be noted that "detoxification phases" ("going through detox") which is often described in the raw food literature usually reflects nutrient deficiencies. That is, if you feel weak and ill after getting on a 100% raw vegan diet, it is not because you are "detoxing" but because your body is not getting enough nutrients. This may be beneficial for very short periods of time - as in fasting - but not for long periods of time.
Typical symptoms of severe underweight, for example, are reduced muscle mass, muscle strength, and bone density, the absence of menstruation (amenorrhoea) (12), a high sensitivity to cold, and a weak immune system.
For athletes who have a very high intake of food and calories it is probably easier to get sufficient amounts of micronutrients (from non-fortified foods) with a 100% raw food diet compared to non-athletes (13) - but this does not apply to vitamin B12 or vitamin D, which are typically practically absent from non-fortified plant foods.
A raw diet, like other healthy diets, can help people to lose excess body weight, which will also result in beneficial effects for artery health (2, 14, 15).
It is particularly important to note that a 100% or predominatly raw food diet is not suitable for babies and toddlers, as their stomach volume is small, which makes it difficult for them to get enough nutrients on a raw diet.
In the case of illness, you should under no circumstance rely on the (believed) "naturalness" and the associated (desired) "healing power" of a raw food diet to cure yourself. Instead, a raw food diet should be very well planned. For children this means that the fibre content (16) of the diet should only be moderate, and for everyone this means that a sufficient intake of calories and the above-mentioned nutrients must be ensured. In children, their growth and mental and physical development must be well monitored (17). In England, the United States, and Germany (and other countries) there have been isolated cases of babies or infants dying as a result of particular raw food diets: for example, a diet consisting mainly of fruit, vegetables, and nuts or a diet of mainly wheatgrass juice, coconut water, and homemade almond milk or a diet of mainly homemade almond milk and coconut milk (18). The lesson to be learned from these cases is not that a raw food diet must be terrible under all circumstances but that a mixture of "nature faith", a raw food diet and a complete rejection of supplements and modern medicine can be a deadly recipe (17).
Some criticism of current health systems is indeed justified, including the near complete absence of some of the most important factors which influence health, namely diet and lifestyle, from the way medicine is often practiced today, the influence of personal greed, egomania, and anti-science attitudes prevalent in medicine as well as the influence of pharmaceutical corporations on medical practice but also scientific research. But a complete rejection of modern medicine can also be very dangerous.
Even before Homo sapiens existed, our ancestors used fire to cook their food. There is nothing to suggest that our species has adapted to a specific dietary pattern over the course of evolution - and that this diet would then be the healthiest one. Unlike wild speculation about human evolution, modern day nutritional epidemiology (nutrition science focused on the effect of diet on health) provides strong scientific evidence which indicates that a plant-based dietary pattern, based on fruit, vegetables, legumes, whole grains, nuts, seeds, and healthy oils, promotes good health, well-being, and longevity (19, 20).
For those interested in raw foods, the book "Becoming raw" by Vesanto Melina and Brenda Davis is highly recommended (21).
For those interested in raw foods, the book "Becoming raw" by Vesanto Melina and Brenda Davis is highly recommended (21).
References
1. Yunatskaya TA, Turchaninova NS, Kostina NN. Hygienic assessment of nutrition in vegetarians and people with mixed feeding. Gig Sanit 2015; 94:72–5.
2. Koebnick C, Garcia AL, Dagnelie PC, Strassner C, Lindemans J, Katz N, Leitzmann C, Hoffmann I. Long-term consumption of a raw food diet is associated with favorable serum LDL cholesterol and triglycerides but also with elevated plasma homocysteine and low serum HDL cholesterol in humans. J Nutr 2005; doi:10.1093/jn/135.10.2372.
3. Hobbs SH. Attitudes, practices, and beliefs of individuals consuming a raw foods diet. Explore (NY) 2005; doi:10.1016/j.explore.2005.04.015.
4. Donaldson MS. Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements. Ann Nutr Metab 2000; doi:10.1159/000046689.
5. Cheeke R. Vegan bodybuilding and fitness. The complete guide to building your body on a plant-based diet. Healthy Living; Publishers Group UK [distributor]: Summertown, Tenn., Enfield, 2011.
6. Fontana L, Shew JL, Holloszy JO, Villareal DT. Low bone mass in subjects on a long-term raw vegetarian diet. Arch Intern Med 2005; doi:10.1001/archinte.165.6.684.
7. Garcia AL, Mohan R, Koebnick C, Bub A, Heuer T, Strassner C, Groeneveld MJ, Katz N, Elmadfa I, Leitzmann C, et al. Plasma beta-carotene is not a suitable biomarker of fruit and vegetable intake in german subjects with a long-term high consumption of fruits and vegetables. Ann Nutr Metab 2010; doi:10.1159/000262295.
8. Garcia AL, Koebnick C, Dagnelie PC, Strassner C, Elmadfa I, Katz N, Leitzmann C, Hoffmann I. Long-term strict raw food diet is associated with favourable plasma beta-carotene and low plasma lycopene concentrations in Germans. Br J Nutr 2008; doi:10.1017/S0007114507868486.
9. Strużycka I, Rusyan E, Bogusławska-Kapała A. Erozje zębów - problem interdyscyplinarny. [Tooth erosion - a multidisciplinary approach]. Pol Merkur Lekarski 2016; 40:79–83.
10. Ganss C, Schlechtriemen M, Klimek J. Dental erosions in subjects living on a raw food diet. Caries Res 1999; doi:10.1159/000016498.
11. O'Toole S, Bernabé E, Moazzez R, Bartlett D. Timing of dietary acid intake and erosive tooth wear: A case-control study. J Dent 2017; doi:10.1016/j.jdent.2016.11.005.
12. Koebnick C, Strassner C, Hoffmann I, Leitzmann C. Consequences of a long-term raw food diet on body weight and menstruation: results of a questionnaire survey. Ann Nutr Metab 1999; doi:10.1159/000012770.
13. Leischik R, Spelsberg N. Vegan triple-ironman (raw vegetables/fruits). Case Rep Cardiol 2014; doi:10.1155/2014/317246.
14. Fontana L, Meyer TE, Klein S, Holloszy JO. Long-term low-calorie low-protein vegan diet and endurance exercise are associated with low cardiometabolic risk. Rejuvenation Res 2007; doi:10.1089/rej.2006.0529.
15. Douglass JM, Rasgon IM, Fleiss PM, Schmidt RD, Peters SN, Abelmann EA. Effects of a raw food diet on hypertension and obesity. South Med J 1985; doi:10.1097/00007611-198507000-00017.
16. Amoroso S, Scarpa M-G, Poropat F, Giorgi R, Murru FM, Barbi E. Acute small bowel obstruction in a child with a strict raw vegan diet. Arch Dis Child 2019; doi:10.1136/archdischild-2018-314910.
17. Cundiff DK, Harris W. Case report of 5 siblings: malnutrition? Rickets? DiGeorge syndrome? Developmental delay? Nutr J 2006; doi:10.1186/1475-2891-5-1.
18. Koeder C. Veganismus. Für die Befreiung der Tiere. 1. Auflage. Koeder: Ellwangen, 2014.
19. Willett W, Rockström J, Loken B, Springmann M, Lang T, Vermeulen S, Garnett T, Tilman D, DeClerck F, Wood A, et al. Food in the Anthropocene: the EAT–Lancet Commission on healthy diets from sustainable food systems. The Lancet 2019; doi:10.1016/S0140-6736(18)31788-4.
20. Satija A, Hu FB. Plant-based diets and cardiovascular health. Trends Cardiovasc Med 2018; doi:10.1016/j.tcm.2018.02.004.
21. Davis B, Melina V, Berry R. Becoming raw. The essential guide to raw vegan diets. Book Publishing Company: Summertown, Tennessee, 2010.