There are a couple dozen peer-reviewed studies of raw vegan diets (see summary below). As is true with studies of conventional vegan diets, the results are generally positive, but with some potential pitfalls here and there.
If you are interested in a raw vegan diet, a reputable textbook is Becoming Raw
, by Registered Dietitians Brenda Davis and Vesanto Melina: https://www.amazon.com/dp/B00BTKEKGA/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
Here is the list of peer-reviewed studies on raw vegan diets:
1) An uncooked vegan diet shifts the profile of human fecal microflora:
computerized analysis of direct stool sample gas-liquid chromatography
profiles of bacterial cellular fatty acids., Appl Environ Microbiol 1992
GLC profiles changed significantly in the test group after the induction and discontinuation of the vegan diet but not in the control group at any time, whereas quantitative bacterial culture did not detect any significant change in fecal bacteriology in either of the groups. The results suggest that an uncooked extreme vegan diet alters the fecal bacterial flora significantly when it is measured by direct stool sample GLC of bacterial fatty acids .
2) Antioxidant status in long-term adherents to a strict uncooked vegan
diet., Am J Clin Nutr 1995 Dec;62(6):1221-7
The present data indicate that the "living food diet" provides significantly more dietary antioxidants than does the cooked, omnivorous diet, and that the long-term adherents to this diet have a better antioxidant status than do omnivorous control subjects.
3) Antioxidants in vegan diet and rheumatic disorders., Toxicology 2000
The shift of fibromyalgic subjects to LF resulted in a decrease of their joint stiffness and pain as well as an improvement of their self-experienced health. The rheumatoid arthritis patients eating the LF diet also reported similar positive responses and the objective measures supported this finding. The improvement of rheumatoid arthritis was significantly correlated with the day-to-day fluctuation of subjective symptoms. In conclusion the rheumatoid patients subjectively benefited from the vegan diet rich in antioxidants, lactobacilli and fibre, and this was also seen in objective measures.
4) Consequences of a long-term raw food diet on body weight and menstruation: results of a questionnaire survey., Ann Nutr Metab 1999;43(2):69-79
CONCLUSIONS: The consumption of a raw food diet is associated with a high loss of body weight. Since many raw food dieters exhibited underweight and amenorrhea, a very strict raw food diet cannot be recommended on a long-term basis.
5) Coumarin 7-hydroxylation in long-term adherents of a strict uncooked
vegan diet., Eur J Clin Pharmacol 1996;50(1-2):133-7
CONCLUSION: According to the present study, the clearly different dietary patterns and nutrient intakes between the vegans and the omnivores resulted in similar extent and rate of 7-hydroxycoumarin formation, indicating only a minor effect on coumarin hydroxylase (CYP2A6) activity by the plant substances in the uncooked vegan diet.
6) Dental erosions in subjects living on a raw food diet., Caries Res
Nevertheless, the results showed that a raw food diet bears an increased risk of dental erosion compared to conventional nutrition.
7) Divergent changes in serum sterols during a strict uncooked vegan diet in patients with rheumatoid arthritis., Br J Nutr 2001 Feb;85(2):137-9
Our results suggest that a strict uncooked vegan diet changes the relative absorption rates of these sterols and/or their biliary clearance.
8) Effect of a strict vegan diet on energy and nutrient intakes by Finnish rheumatoid patients., Eur J Clin Nutr 1993 Oct;47(10):747-9
Shifting to the uncooked vegan diet significantly increased the intakes of energy and many nutrients. In spite of the increased energy intake, the group on the vegan diet lost 9% of their body weight during the intervention period, indicating a low availability of energy from the vegan diet.
9) Effect of a vegan diet on biomarkers of chemoprevention in females., Hum Exp Toxicol 1996 Oct;15(10):821-5
The significance of these changes as biologically relevant indicators of beneficial effects of vegan diets in humans needs to be determined in studies with a larger number of subjects.
10) Effects of a raw food diet on hypertension and obesity., South Med J 1985 Jul;78(7):841-4
After a mean duration of 6.7 months, average intake of uncooked food comprised 62% of calories ingested. Mean weight loss was 3.8 kg and mean diastolic pressure reduction 17.8 mm Hg, both statistically significant (P less than .00001). Eighty percent of those who smoked or drank alcohol abstained spontaneously.
11) Effects of eating an uncooked vegetable diet for 1 week., Appetite 1992 Dec;19(3):243-54
It is concluded that this vegetable diet may be of some benefit in the short term but any longer-term use requires evaluation.
12) Faecal microbial flora and disease activity in rheumatoid arthritis during a vegan diet., Br J Rheumatol 1997 Jan;36(1):64-8
We conclude that a vegan diet changes the faecal microbial flora in RA patients, and changes in the faecal flora are associated with improvement in RA activity.
13) Fatty acid composition of erythrocyte, platelet, and serum lipids in strict vegans., Lipids 1995 Apr;30(4):365-9
The results show that, in the long term, the vegan diet has little effect on the proportions of oleic and arachidonic acids, whereas the levels of n-3 fatty acids are depressed to very low levels with prolonged consumption of the high linoleic and oleic acid components of this diet.
14) Fibromyalgia syndrome improved using a mostly raw vegetarian diet: An observational study., BMC Complement Altern Med 2001;1(1):7
CONCLUSION: This dietary intervention shows that many fibromyalgia subjects can be helped by a mostly raw vegetarian diet.
15) Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements., Ann Nutr Metab 2000;44(5-6):229-34
People following the Hallelujah diet and other raw-food vegetarian diets should regularly monitor their urinary MMA levels, consume a sublingual cobalamin supplement, or consume cobalamin in their food.
16) Raw food and immunity, Fortschr Med 1990 Jun 10;108(17):338-40
In view of this, uncooked food can be seen as a useful adjunct to drugs in the treatment of allergic, rheumatic and infectious diseases.
17) Raw Food Eaters: Health Habits and Nutrient Intake(FULL TEXT), Poster for the 16th International Congress of Nutrition, 27.7-1.8.1997, Montreal, Canada
The data show that an almost exclusive consumption of raw fruit and vegetables bear some advantages for nutrient intake but also may carry the threat of serious deficiencies. These findings need to be verified by analyses of nutrient status, a further aspect of this study which is currently under way.
18) Shifting from a conventional diet to an uncooked vegan diet reversibly alters fecal hydrolytic activities in humans., J Nutr 1992 Apr;122(4):924-30
Results suggest that this uncooked extreme vegan diet causes a decrease in bacterial enzymes and certain toxic products that have been implicated in colon cancer risk.
19) Survey of Food and Nutrient Intake of Hallelujah Vegetarians, Nutrition & Food Science 2001;31(6):293-303
What this study reveals is that intakes of most vitamins and minerals are adequate while following The Hallelujah Diet. Only vitamins B12 and D were extremely low. Hallelujah Acres recommends a vitamin B12 supplement and sunshine, the natural source of vitamin D, to make up for these low intakes.
20) Uncooked, lactobacilli-rich, vegan food and rheumatoid arthritis., Br J Rheumatol 1998 Mar;37(3):274-81
The results showed that an uncooked vegan diet, rich in lactobacilli, decreased subjective symptoms of rheumatoid arthritis. Large amounts of living lactobacilli consumed daily may also have positive effects on objective measures of rheumatoid arthritis.
21) Vegan diet alleviates fibromyalgia symptoms., Scand J Rheumatol 2000;29(5):308-13
It can be concluded that vegan diet had beneficial effects on fibromyalgia symptoms at least in the short run.
22) Vegan diet in physiological health promotion., Acta Physiol Hung 1999;86(3-4):171-80
The fibromyalgic subjects eating LF (living food) lost weight compared to their omnivorous controls. The results on their joint stiffness and pain (visual analogue scale), on their quality of sleep, on health assessment questionnaire and on general health questionnaire all improved. It appears that the adoption of vegan diet exemplified by the living food leads to a lessening of several health risk factors to cardiovascular diseases and cancer. Rheumatoid patients subjectively benefited from the vegan diet which was also seen in serum parameters and fecal analyses.
23) Vegetarian Raw Food Dietary Regimens: Health Habits and Nutrient Intake(FULL TEXT), Presented as Poster at the Third Internatiobnal Congress on Vegetarian Nutrition, Loma Linda, California USA, March 24-26 1997
The intake of nutrients that are usually provided by foods of animal origin is insufficient. These include Vitamins B12 and D, zinc and calcium. On the other hand, the intake of certain protective nutrients, such as Vitamin C and other antioxidants, lie above the national average.
24) Vitamin B-12 status of long-term adherents of a strict uncooked
vegan diet ("living food diet" is compromised., J Nutr 1995 Oct;125(10):2511-5
The cross-sectional study revealed significantly (P < 0.001, paired t test) lower serum vitamin B-12 concentrations in the vegans (mean 193 pmol/L, range 35-408) compared with their matched omnivorous controls (311, 131-482). In the vegan group, total vitamin B-12 intake correlated significantly (r = 0.63, P < 0.01) with serum vitamin B-12 concentration. The vegans consuming Nori and/or Chlorella seaweeds (n = 16) had serum vitamin B-12 concentrations twice as high as those not using these seaweeds (n = 5) (mean 221 pmol/L, range 75-408, vs. 105, 35-252, P = 0.025). In the longitudinal study, six of nine vegans showed slow, but consistent deterioration of vitamin B-12 status over a 2-y observation period. On the basis of these results we conclude that some seaweeds consumed in large amounts can supply adequate amounts of bioavailable vitamin B-12.