Type 2 Diabetes and Vegan Diets 2


Last updated March 2018

Contents

The only prospective study measuring rates of diabetes in vegans, the Adventist Health Study 2, found them to have a 60% less chance of developing the disease than non-vegetarians after two years of follow-up. Previously, a cross-sectional report from the Adventist Health Study-2 showed vegans to have a 68% lower rate of diabetes than non-vegetarians. A number of clinical trials have now shown that a vegan, or mostly vegan, diet can lower body weight, reduce blood sugar, and improve other parameters for type 2 diabetes.

Observational Studies

2017 Meta-Analysis of Observational Studies

A 2017 meta-analysis reviewed 14 studies published in 13 papers (17). Two were cohort studies and the other 12 were cross-sectional.

Vegetarians had a lower incidence of diabetes in eight of the studies while there was no difference in the other five. Based on the pooled analysis of the studies, vegetarians had a 27% lower risk for diabetes compared to omnivores (OR 0.73, 95% CI: 0.61, 0.87).

When the researchers looked at effects in different groups, they found that vegetarian men were less likely to have diabetes than omnivore men, but there was no difference in risk between vegetarian and omnivore women. The researchers also looked at different types of vegetarian diets and found that risk for diabetes was lowest among vegans and lacto-vegetarians. Pesco-vegetarians did not have a lower risk for diabetes compared to omnivores, although semi-vegetarians did.

The main limitation of this meta-analysis is that most of the studies were cross-sectional. In addition, the studies were from diverse populations throughout the world where definitions and composition of vegetarian diets may differ. This might explain why among these studies, the findings were stronger in studies from North America, Europe, and the Western Pacific than in those in Southeast Asia.

2011 Prospective Analysis from Adventist Health Study 2

In 2011, the first prospective study measuring the type 2 diabetes rates of vegans was released. It followed participants of the Adventist Health Study 2 for two years and found vegans to have the lowest rates of diabetes of any diet group (14). The study did not differentiate between type 1 and type 2 diabetes, but it’s safe to assume most cases were type 2. Results are in Table 6.

Table 6. Prospective Diabetes rates in Adventist Health Study-2.
  Vegan Lacto-Ovo Pescoa Semib Non-Veg
Number 3,545 14,099 3,644 2,404 17,695
Odds ratio .38 (.24-.62) .62 (.50-.76) .79 (.58-1.09) .49 (.31-.76) 1.00
aVegetarian except for fish.
bAte meat more than once a month but less than once a week.
Adjusted for age, BMI, race, gender, education, income, TV watching, sleep, alcohol,
physical activity, and smoking.

This study indicates that vegans had a 60% lower risk of developing diabetes as non-vegetarians. A separate analysis was done for black participants only and black vegans had a relative risk of .43 (.25-.74) compared to non-vegetarians.

Black ethnicity was associated with an increased incidence of diabetes (1.36, 1.09-1.70) as was age, male gender, and BMI. A higher income and more sleep were associated with a lower incidence of diabetes.

The authors cautioned that because diabetes rates were determined by reporting a diagnosis of high blood sugar or diabetes, and not by having each participant’s blood sugar measured, cases of diabetes might not have been detected.

As to why vegetarians had lower rates of diabetes, the authors wrote, “Fruits and vegetables may contribute to a decreased incidence of type 2 diabetes through their low energy density, low glycemic load, and high fiber and macronutrient content. Other features of the vegetarian diet are whole grains and legumes. These foods have been shown to improve glycemic control, slow the rate of carbohydrate absorption and the risk of diabetes.”

2009 Cross-Sectional Analysis from Adventist Health Study 2

In 2009, the first study measuring the type 2 diabetes rates of vegans was released. It was a cross-sectional study and found vegans to have the lowest rates of type 2 diabetes of any diet group (12). Results are in Table 5.

Table 5. Cross-sectional Type 2 Diabetes rates in Adventist Health Study-2.
  Vegan Lacto-Ovo Pescoa Semi-vegetarianb Non-Veg
Number 2,731 20,408 5,617 3,386 28,761
Diabetes rate ratioc .51 (.40-.66) .54 (.49-.60) .70 (.61-.80) .76 (.65-.90) 1.00
Diabetes rate ratiod .32 (.25-.41) .43 (.39-.47) .56 (.49-.64) .69 (.59-.81) 1.00
aVegetarian except for fish.
bAte meat more than once a month but less than once a week.
cAdjusted for age, gender, race, activity, education, TV watching, sleep, alcohol,
and BMI.
dAdjusted for all factors above except BMI.

Vegans had a 68% lower risk of type 2 diabetes than did non-vegetarians.

Since this study was cross-sectional, the results could mean that a vegan diet prevents diabetes, or it could mean that people with type 2 diabetes are less likely to adopt a vegan diet – or some combination of both.

Adjusting for BMI diminished the difference between vegans and non-vegetarians to some extent. This should be expected as a high BMI is a risk for type 2 diabetes. However, a lower BMI is possibly caused by a vegan diet, so this should not take anything away from the idea that the diet caused the difference.

Even after adjusting for BMI, the vegans had an advantage. The authors speculated on what else could be beneficial about a vegan diet:

The vegan group consumed about 650 grams/day of fruits and vegetables, about one-third more than the amount consumed by non-vegetarians (data not shown). Observational evidence has shown that these dietary constituents are associated with a reduction in type 2 diabetes of about 40%. Vegetarian diets contain substantially less saturated fat than nonvegetarian diets and saturated fatty acids have been shown to reduce insulin sensitivity, though a recent review concluded that some of the data supporting this idea was flawed. The vegetarian diet typically includes foods that have a low glycemic index such as beans, legumes and nuts. We did not calculate the glycemic load of the diets. Though low glycemic response diets are associated with less type 2 diabetes, cohort studies have not consistently found a relation between dietary glycemic index or load and risk of diabetes; furthermore, whether the glycemic response causes diabetes is not established.

Adventist Health Study

A 1999 report of the results of the original Adventist Health Study showed vegetarians to have about half the risk of diabetes as non-vegetarians (11). This was a 6-year prospective study and vegans were not separated from the lacto-ovo vegetarians.

Clinical Trials

There have been a number of clinical trials using a vegan or near vegan diet to treat type 2 diabetes. They have been successful in reducing diabetes medication and blood sugar levels.

Korea (2016)

The focus of this clinical trial was to compare the effect of a vegan diet to a conventional diabetic diet, as prescribed by the Korean Diabetes Association (KDA), on glycemic control among Koreans (16).

The trial lasted three months. The vegan diet group had 46 people while the KDA diet group had 47. After three months, there was a statistically significant, greater reduction in HbA1c in the vegan group compared to the KDA group (0.5% vs. 0.2%, p = 0.017). When including only participants with high diet compliance, the vegan diet fared even better (0.9% vs. 0.3%, p = .01).

The vegan group ate less calories and saturated fat than the KDA group. Fiber intake for the vegan group and KDA group was 33.7 g and 24.9 g.

The vegan group lost weight while the KDA group didn’t. However, neither group’s blood pressure or LDL-cholesterol went down. The vegan group’s triglycerides went up while the KDA group’s went down; this might indicate the vegan group was eating more simple sugars.

Czech Republic (2011)

In 2011, researchers from the Czech Republic studied a vegetarian (near-vegan) diet compared to a conventional (control) diet for type 2 diabetes (15). The study tested only diet for 12 weeks and then combined diet and exercise for another 12 weeks. Animal products were limited to maximum of one portion of low-fat yogurt a day. The calories in both diets were limited (as distinct from the PCRM studies below in which the vegan diet was unlimited in calories). The vegetarian diet was about 38% fat.

The vegetarian diet group had a greater reduction in diabetes medication (43% vs. 5%), HbA1c, waist circumference, and body fat. LDL cholesterol went down 8% in the vegetarian group only, but HDL cholesterol went up in the control group. Exercise caused the positive differences for the vegetarian diet to be even greater and also raised the HDL in the vegetarian group.

The authors stated:

Several possible mechanisms may explain the beneficial effects of a vegetarian diet: higher intake of fibre, lower intake of saturated fat [and a higher polyunsaturated and saturated fatty acid (P⁄S) ratio], higher intake of non-heme iron and reduction in iron stores, higher intake of vegetable protein in place of animal protein, higher intake of antioxidants and plant sterols. A vegetarian diet was reported to reduce intramyocellular lipid concentrations and this, together with the effect on visceral fat which we observed, might be responsible for a substantial portion of the effect of a vegetarian diet on insulin sensitivity and enzymatic oxidative stress markers.

And:

Especially during exercise, it became evident in our trial that it was easier for subjects to follow a vegetarian diet than a conventional diabetic diet.

PCRM 2004-05 Study

In 2004, researchers affiliated with the Physician’s Committee for Responsible Medicine (PCRM) started a 74-week study with 99 participants, comparing a vegan diet to an American Diabetes Association recommended diet for people with type 2 diabetes.

Table 2. 2004 Study on People with Type 2 Diabetes
  Vegan Dieta Control Dietb
Calorie restriction No Yes
Number at baseline 49 50
Adherence at:
22 weeks
74 weeks
33
25
22
24
Calories
Baseline
22 weeks
74 weeks
1745
1432sw
1366sw
1844
1458sw
1422sw
Carbohydrates (g)
Baseline
22 weeks
74 weeks
202
244sb, sw
226sb, sw
210
170
165
Fiber (g)
Baseline
22 weeks
74 weeks
11
35sb, sw
22sb, sw

11
18sw
13sw
Fat (g)
Baseline
22 weeks
74 weeks
71
32sb, sw
34sb, sw
74
56
54
Saturated fat (g)
Baseline
22 weeks
74 weeks
24
7sb, sw
8sb, sw
22
16
16
BMI (kg/m2)
Baseline
22 weeks
74 weeks
33.9
31.8sb, sw
32.3sb, sw
35.9
34.3sw
34.8sw

Fasting glucose (mmol/L)
Baseline
22 weeks
74 weeks
9.1
7.1sw
8.0sw
8.9
7.0sw
8.1
HbA1c
Baseline
22 weeks
74 weeks
8.0%
7.1%sw
7.7%
7.9%
7.4%sw
7.8%
Total cholesterolc (mg/dl)
Baseline
22 weeks
74 weeks
187
159sw
166sw
198
174sw
184sw
Triglycerides (mg/dl)
Baseline
22 weeks
74 weeks
148
120sw
114sw
158
133
150
Diabetes medications
22 weeks

74 weeks

43% reduced; 8% increased
35% reduced; 14% increased
26% reduced; 8% increased
20% reduced; 24% increased
aNo oils, fried foods, avocados, nuts, or seeds • Favored low glycemic-index foods • < 10% of energy from fat.
bAmerican Diabetes Diet 2003 guidelines
cMany subjects were on lipid-lowering medications and adjusted them during the study.
sbStatistically significant effect between diet groups
swStatistically significant effect within diet groups compared to baseline

In this study, the vegan diet was once again a very low-fat diet; less than 10% of calories. Vegan dieters were asked to avoid fatty foods, added oils, fried products, avocados, nuts, and seeds. This time, instead of avoiding all refined grains, they were merely asked to favor low glycemic index foods (see Table 4 for an explanation of the glycemic index).

The control group was put on an American Diabetes Diet (ADA) of 15 – 20% protein, < 7% saturated fat, 60 – 70% carbohydrate and monounsaturated fats, and < 200 mg/day of cholesterol. The diets were individualized, based on body weight and plasma lipids. Those with a BMI > 25 kg/m (2) (all but three) were prescribed energy deficits of 500 – 1,000 kcal.

For this article, I’ve reviewed four papers on this study:

  • Medical outcomes at 22 weeks (2)
  • Nutrient intakes at 22 weeks (3)
  • Medical outcomes and nutrient intakes at 74 weeks (4)
  • Acceptability of, and adherence to, the diets at 74 weeks (5)

Once again, the vegan group ate less calories and had significant weight loss. Intake of fiber and carbohydrate went up, while fasting blood sugar and HbA1c went down (only statistically significant for the first 22 weeks). Cholesterol and triglyceride levels also decreased, and many participants were able to reduce their diabetes medications.

The ADA diet group also made improvements in weight loss, HbA1c, total cholesterol, and medications.

Among participants in the vegan group with no changes to diabetes medications, HbA1c had fallen 1.2% points at 22 wk and 0.8% points by 74 wk. Among medication-stable participants in the conventional diet group, the HbA1c reduction was 0.3% points at 22 wk, and 0.2% points at 74 wk.

The only statistically significant differences between diet groups for medical outcomes was that vegan dieters lost more weight than did the ADA diet group. See Table 2 for more details.

The acceptability of the vegan diet was rated about the same as the acceptability of the ADA diet. Although the participants in the vegan group rated the difficulty of preparing the foods as higher, they reported less dietary restraint, probably due not to having to limit calories or count carbohydrates. Vegan dieters’ cravings for sweets and fats also decreased.

At week 22, 67% of the vegans were adhering to the diet. By week 74, it was down to 51%. This drop in adherence was probably influenced by the change in the program from weekly meetings for diet and cooking instruction, to bi-weekly optional meetings for weeks 23 to 74.

Table 3. 2005 PCRM Study on Postmenopausal, Overweight Women.
  Vegan Dieta Control Dietb
Calorie restriction No No
Number of participants 29 30
Calories
Baseline
14 weeks
1774
1408
1762
1424
Carbohydrates (g)

Baseline
14 weeks
232
274
231
221
Fiber (g) 30 sb 21
Fat (g)
Baseline
14 weeks
62
18sb
58
31
Saturated fat (g) – 14 weeks 3sb 9
BMI (kg/m2)
Baseline
22 weeks
33.6
31.5sb
32.6
31.2
Fasting glucose (mmol/L)
Baseline
14 weeks
5.4
5.0sw
5.6
5.5
Insulin sensitivity
Baseline
14 weeks
4.6
5.7sw
4.3
4.6
aNo oils, avocados, olives, nuts, nut butters, or seeds, < 10% fat
bNCEP Step II diet
sbStatistically significant effect between diet groups
swStatistically significant effect within diet groups compared to baseline

PCRM 2005 Study on Glucose and Insulin

In 2005, PCRM researchers published results from a study performed on postmenopausal women who were overweight or obese, but did not have type 2 diabetes (6). This study put half the women on a very low fat vegan diet of less than 10% calories as fat and no oils, avocados, olives, nuts, nut butters or seeds. No mention was made of refined carbohydrates or high glycemic foods. This diet was compared to a National Cholesterol Education Program (NCEP) Step II Guidelines diet, which was less than 30% fat, less than 7% saturated fat, protein about 15% of calories, and less than 200 mg/day of cholesterol.

After 14 weeks on the vegan diet, fasting glucose decreased and insulin sensitivity increased. The NCEP Step II diet did not result in such changes. Table 3 includes more results from this study.

In total, these studies suggest that a very low-fat, primarily whole foods vegan diet is an appropriate diet for people with type 2 diabetes, and as effective as an American Diabetes Association diet. I want to emphasize the primarily whole foods aspect of this diet. If someone is eating a vegan diet with a lot of refined grains and sugars (including breads, white rice, and juices) they might not realize many of these benefits.

White potatoes are the one whole, plant food that might be harmful for people with type 2 diabetes if eaten in more than small amounts. White potato starch has a chemical structure that makes the sugar quickly digested and absorbed, and white potatoes produce a large glycemic load and insulin response (see Table 4) (7).

Table 1. 1999 Pilot Study on People with Type 2 Diabetes.
  Vegan Dieta Control Dietb
Calorie restriction No No
Number of participants 7 4
Calories
Baseline
12 weeks
1683
1409
1430
1526
Carbohydrates (g)
Baseline
12 weeks
194
264
164
194
Fiber (g)
Baseline
12 weeks
14
26
12
20
Fat (g)
Baseline
12 weeks
64
17
50
53
Saturated fat (g)

Baseline
12 weeks
19
5
18
14
Weight (lbs)
Baseline
12 weeks
213
197sb
213
205
Fasting glucose (mmol/L)
Baseline
12 weeks
10.7
7.8 sb
9.7
8.6
HbA1c

Baseline
12 weeks
8.3%
6.9%
8.0%
7.0%
Total cholesterol (mg/dl)
Baseline
12 weeks
203
179
215
190
Triglycerides (mg/dl)
Baseline
12 weeks
188
165
203
164
Oral hypoglycemic agents 1 of 6 discontinued
3 of 6 reduced
0 of 4 reduced
Insulin 2 of 2 reduced None were taking
Blood pressure medication 2 of 5 discontinued 1 of 4 reduced
Lipid-lowering no changes no changes
aNo oils, sugars, refined carbs, < 10% fat
bNo red meat < 30% fat
sbStatistically significant effect between diet groups.

PCRM Pilot Study (1999)

The first was a pilot study of only 12 weeks and 11 participants, published in 1999 (1). The study participants all had type 2 diabetes.

The study put some of them on a (very) low-fat vegan diet. They could not eat added oils, sugars, or refined carbohydrates such as white bread or pasta. The diet was designed to have less than 10% of calories as fat. The control diet was designed to be less than 30% of calories as fat, and prohibited red meat but substituted fish and poultry. There was no limit on calories or portion sizes on either diet.

Despite not being required to limit calories, the vegan diet participants did reduce calories and lost weight. They also reduced fat and saturated fat, and their cholesterol and triglyceride levels went down.

The vegan dieters increased carbohydrates and fiber. Despite increasing carbohydrates, their fasting blood sugar levels went down, and their HbA1c (a measure of how much sugar has been in your blood over the previous three to four months) also went down.

The differences in medical outcomes between groups were that vegan dieters lost more weight and reduced blood sugar levels further. Many of the vegan dieters reduced or eliminated medications, while only one of the control dieters was able to. See Table 1 for more details.

Table 4. Definitions
Glycemic index –
Measurement of how quickly glucose from a specific, solitary food is released into the blood.
Glycemic load –
Measurement of how much glucose from a specific, solitary food is released into the blood over the course of a certain
amount of time (e.g., two hours).
Insulin load –
Measurement of how much insulin is released into the blood over a certain amount of time, in response to eating a
specific food.

Glycemic index is of little use for preventing or treating chronic disease, as foods with very little sugar can have high glycemic indexes.

White pastas, on the other hand, have a low glycemic load and insulin response (7) and although they are processed they might be about the same as many whole plant foods in terms of their affects on blood sugar. Spaghetti, especially if it hasn’t been overcooked, has a low glycemic and insulin load (8).

Presumably, the researchers from the PCRM studies picked such a low fat vegan diet, without nuts or avocados, because they wanted to guarantee weight loss and cholesterol improvements. However, most of the research on nuts has suggested at least moderate amounts are beneficial to heart disease and weight loss (9). It seems safe to eat moderate amounts of nuts if you have type 2 diabetes, such as 1 – 2 oz per day. A 2009 study of people with type 2 diabetes showed that 30 g of walnuts per day resulted in a greater reduction in insulin levels (13).

There has not been much research on avocados and their effects on diabetes or weight loss. It is reasonable to project that small amounts, about 1/4 an avocado per day, would be beneficial both for heart disease and weight loss. A half a cup of cubed avocados has 120 calories and 5 grams of fiber which is a reasonable amount.

There are concerns about the long-term effects of a diet with less than 10% of calories from fat. Fat is important for cell membranes, nerve tissue, and aids in the digestion of fat-soluble vitamins. Unsaturated fats keep HDL (good cholesterol) at healthy levels. Omega-3 fats are also important for reducing heart disease and nerve tissue. The average vegan eats about 27-29% (10) of their calories from fat. That much may not be necessary, but a diet of less than 20% fat might not be best over the long term. That doesn’t mean you have to get your fat from French fries, but nuts, avocados, and small amounts of olive and canola oil can be a healthy addition to the diet.

Conclusion

In conclusion, it appears safe to say that:

  • A whole foods vegan diet is safe for people who have type 2 diabetes and is as beneficial, if not moreso, than a typical ADA diet.
  • Vegans have a lower risk of type 2 diabetes than non-vegetarians.

In their 2017 Standards of Medical Care, the American Diabetes Association says, “A variety of eating patterns are acceptable for the management of type 2 diabetes and prediabetes including Mediterranean, DASH, and plant-based diets.”

More Information

References

1. Toward improved management of NIDDM: A randomized, controlled, pilot intervention using a lowfat, vegetarian diet. Nicholson AS, Sklar M, Barnard ND, Gore S, Sullivan R, Browning S. Prev Med. 1999 Aug;29(2):87-91.

2. A low-fat vegan diet improves glycemic control and cardiovascular risk factors in a randomized clinical trial in individuals with type 2 diabetes. Barnard ND, Cohen J, Jenkins DJ, Turner-McGrievy G, Gloede L, Jaster B, Seidl K, Green AA, Talpers S. Diabetes Care. 2006 Aug;29(8):1777-83. PubMed PMID: 16873779. (Medical outcomes at 22 weeks.)

3. Changes in nutrient intake and dietary quality among participants with type 2 diabetes following a low-fat vegan diet or a conventional diabetes diet for 22 weeks. Turner-McGrievy GM, Barnard ND, Cohen J, Jenkins DJ, Gloede L, Green AA. J Am Diet Assoc. 2008 Oct;108(10):1636-45. (Nutrient intakes at 22 weeks.)

4. A low-fat vegan diet and a conventional diabetes diet in the treatment of type 2 diabetes: a randomized, controlled, 74-wk clinical trial. Barnard ND, Cohen J, Jenkins DJA, Turner-McGrievy G, Gloede L, Green A, and Ferdowsian H. Am J Clin Nutr 2009;89(suppl):1S-9S. (Medical outcomes and nutrient intakes at 74 weeks.)

5. A low-fat vegan diet elicits greater macronutrient changes, but is comparable in adherence and acceptability, compared with a more conventional diabetes diet among individuals with type 2 diabetes. Barnard ND, Gloede L, Cohen J, Jenkins DJ, Turner-McGrievy G, Green AA, Ferdowsian H. J Am Diet Assoc. 2009 Feb;109(2):263-72. (Acceptability and adherence at 74 weeks.)

6. The effects of a low-fat, plant-based dietary intervention on body weight, metabolism, and insulin sensitivity. Barnard ND, Scialli AR, Turner-McGrievy G, Lanou AJ, Glass J. Am J Med. 2005 Sep;118(9):991-7.

7. An insulin index of foods: the insulin demand generated by 1000-kJ portions of common foods. Am J Clin Nutr. Holt SH, Miller JC, Petocz P. 1997 Nov;66(5):1264-76. PubMed PMID: 9356547.

8. International tables of glycemic index. Am J Clin Nutr. 1995 Oct;62(4):871S-890S. Review. Foster-Powell K, Miller JB.

9. Impact of peanuts and tree nuts on body weight and healthy weight loss in adults. Mattes RD, Kris-Etherton PM, Foster GD. J Nutr. 2008 Sep;138(9):1741S-1745S. (Asbstract)

10. EPIC-Oxford: lifestyle characteristics and nutrient intakes in a cohort of 33 883 meat-eaters and 31 546 non meat-eaters in the UK. Davey GK, Spencer EA, Appleby PN, Allen NE, Knox KH, Key TJ. Public Health Nutr. 2003 May;6(3):259-69.

11. Fraser GE. Associations between diet and cancer, ischemic heart disease, and all-cause mortality in non-Hispanic white California Seventh-day Adventists. Am J Clin Nutr. 1999 Sep;70(3 Suppl):532S-538S.

12. Type of Vegetarian Diet, Body Weight and Prevalence of Type 2 Diabetes. Tonstad S, Butler T, Yan R, Fraser GE. Diabetes Care. 2009 Apr 7. [Epub ahead of print]

13. Long-term effects of increased dietary polyunsaturated fat from walnuts on metabolic parameters in type II diabetes. Tapsell LC, Batterham MJ, Teuss G, Tan SY, Dalton S, Quick CJ, Gillen LJ, Charlton KE. Eur J Clin Nutr. 2009 Aug;63(8):1008-15. Epub 2009 Apr 8. PubMed PMID: 19352378.

14. Tonstad S, Stewart K, Oda K, Batech M, Herring RP, Fraser GE. Vegetarian diets and incidence of diabetes in the Adventist Health Study-2. Nutr Metab Cardiovasc Dis. 2013 Apr;23(4):292-9.

15. Kahleova H, Matoulek M, Malinska H, Oliyarnik O, Kazdova L, Neskudla T, Skoch A, Hajek M, Hill M, Kahle M, Pelikanova T. Vegetarian diet improves insulin resistance and oxidative stress markers more than conventional diet in subjects with Type 2 diabetes. Diabet Med. 2011 May;28(5):549-59.

16. Lee YM, Kim SA, Lee IK, Kim JG, Park KG, Jeong JY, Jeon JH, Shin JY, Lee DH. Effect of a Brown Rice Based Vegan Diet and Conventional Diabetic Diet on Glycemic Control of Patients with Type 2 Diabetes: A 12-Week Randomized Clinical Trial. PLoS One. 2016 Jun 2;11(6):e0155918.

17. Lee Y, Park K. Adherence to a Vegetarian Diet and Diabetes Risk: A Systematic Review and Meta-Analysis of Observational Studies. Nutrients. 2017 Jun 14;9(6).


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2 thoughts on “Type 2 Diabetes and Vegan Diets

  • Peter Andrews

    “This study indicates that vegans had a 60% lower risk of developing diabetes as non-vegetarians.”

    No it doesn’t: (17,695 – 3545)/17,695 = 79% lower.

    3,545 14,099 3,644 2,404 17,695

    • JackNorrisRD Post author

      Peter,

      The “number” row is the number of people in the study following that diet, not the number who were diagnosed with diabetes. The risk for the vegans was 0.38 compared to non-vegetarians, which is 62% less.