Introduction
Methods
Study Design and Subjects
Statistical Analysis
Results
Demographics
Variable | Value |
---|---|
Age, mean (SD) | 50.4 (14.3) |
Sex, n (%) | |
Male | 322 (26.7) |
Female | 884 (73.3) |
Average age at onset of psoriasis, mean (SD) | 27.2 (17.2) |
Severity of skin condition (without treatment), n (%) | |
Mild | 252 (20.9) |
Moderate | 509 (42.2) |
Severe | 444 (36.9) |
Body surface area (without treatment), n (%) | |
Barely any or very little | 94 (7.8) |
<5% body surface | 357 (29.6) |
5–10% body surface | 300 (24.9) |
11–20% body surface | 230 (19.1) |
>20% body surface | 224 (18.6) |
Presence of psoriatic arthritis | 529 (43.9) |
Family history of skin condition, n (%) | 581 (48.3) |
Average BMI, mean (SD) | 28.4 (7.4) |
Underweight (<18.5), n (%) | 35 (2.9) |
Normal (18.5–24.9), n (%) | 403 (33.6) |
Overweight (25–29.9), n (%) | 360 (30.3) |
Obese 30+, n (%) | 396 (32.8) |
Race, n (%) | |
White | 1066 (87.2) |
Asian/Pacific Islander | 60 (5) |
Hispanic | 47 (3.9) |
Native American | 16 (1.3) |
African American | 8 (0.7) |
Other | 25 (2.1) |
Highest level of education, n (%) | |
Less than high school | 14 (1.2) |
High school graduate | 207 (17.3) |
Undergraduate | 371 (30.9) |
Graduate/professional degree | 608 (50.7) |
Area in which you live, n (%) | |
Urban/suburban | 945 (79) |
Rural | 251 (21) |
Average annual household income, n (%) | |
<$20,000 | 88 (7.4) |
$20,000–$40,000 | 151 (12.7) |
$40,001–$60,000 | 168 (14.1) |
$60,001–$100,000 | 242 (20.4) |
>$100,000 | 298 (25.1) |
Prefer not to say | 242 (20.4) |
Daily Consumption in Psoriasis versus Control Group
Dietary intake | Psoriasis data (n = 1017) Mean ± SD | NHANES data Mean ± SD (n) |
p value |
---|---|---|---|
Daily added sugar (tsp.) | 10.6 ± 7.64 | 15.3 ± 10.7 (2815) | <0.0001 |
Daily whole grain (oz.) | 0.704 ± 1.17 | 0.846 ± 1.35 (2842) | <0.0001 |
Daily fiber (g) | 13.7 ± 5.69 | 14.5 ± 5.64 (2609) | 0.0002 |
Daily dairy (cup) | 1.25 ± 0.891 | 1.45 ± 0.91 (2847) | <0.0001 |
Daily calcium (mg) | 741 ± 397 | 827 ± 423 (2609) | <0.0001 |
Daily fruit/vegetable/legume (cup) | 2.58 ± 0.957 | 2.51 ± 1.08 (2724) | 0.0070 |
Perceived Dietary Triggers and Helpful Additives
Dietary Modifications and Reported Outcomes
Dietary removals | Dietary additions |
---|---|
% of respondents reporting trial of dietary item removal (n = 1037) | % of respondents reporting dietary item addition (n = 988) |
Junk foodsa: 66.7% White flour products: 55.7% High fat foods: 50.4% Red meat: 49.5% Alcohol: 45% Gluten: 44.6% Dairy: 41.3% Tobacco: 36.1% Sodium/salt: 34.5% Nightshadesb: 28.8% Caffeine: 27% Pork: 26.8% Shellfish: 18% Other: 9.2% | Vegetables: 58.8% Fish oil/omega-3: 56.8% Oral vitamin D: 55.6% Fruits: 54.7% Probiotics: 44.4% Organic foods: 39.6% Other: 9.2% |
Dietary removals | Dietary additions |
---|---|
Respondents reporting full clearance or improvement of psoriasis with removal of the following from their diet (%) | Respondents reporting full clearance or improvement of psoriasis after addition of the following to their diet (%) |
Alcohol: 251 of 462(53.8%) Gluten: 247 of 459 (53.4%) Nightshadesa: 156 of 297 (52.1%) Junk foodsb: 346 of 687 (50%) White flour products: 288 of 573 (49.9%) Dairy: 204 of 424 (47.7%) Shellfish: 73 of 186 (39%) High fat foods: 193 of 519 (36.9%) Caffeine: 102 of 275 (36.4%) Pork: 99 of 276 (35.6%) Tobacco: 131 of 370 (35%) Red meat: 156 of 509 (30.4%) Sodium/salt: 76 of 356 (21.2%) | Fish oil/omega-3: 250 of 556 (44.6%) Vegetables: 247 of 575 (42.5%) Oral vitamin D: 216 of 545 (41%) Probiotics: 178 of 434 (40.6%) Organic foods: 150 of 388 (38.4%) Fruits: 187 of 534 (34.6%) |
Special diets | |
---|---|
% of respondents reporting trial of special diet (n = 481) | Respondents reporting full clearance or improvement of psoriasis after special diet (%) |
Gluten-free: 35.6% Low carbohydrate–high protein: 16.6% Paleolithic: 11.6% Vegetarian: 9.7% Mediterranean: 5.8% Vegan: 5.4% Other: 9.7% | Pagano diet (13 of 18, 72.2%) Vegan diet (20 of 29, 70%) Paleolithic diet (42 of 62, 68.9%) Gluten-free diet (101 of 191, 52.9%) Low carbohydrate–high protein diet (45 of 89, 51.7%) Mediterranean diet (15 of 31, 48.4%) Vegetarian diet (21 of 52, 40.4%). |
Demographic Factors Associated with Favorable Dietary Outcomes
Intervention | Multivariate analysis | ||
---|---|---|---|
Variable |
p value | OR (95% CI) | |
Avoidance of red meat | Age (increasing) | 0.04 | 0.98 (0.97–0.99)a
|
Race (white) | 0.0084 | 0.46 (0.26–0.82)b
| |
Avoidance of pork | Race (white) | 0.03 | 0.45 (0.22–0.92) |
Avoidance of high fat foods | Age (increasing) | 0.03 | 0.99 (0.97–1.00) |
Race (white) | 0.03 | 0.53 (0.30–0.93) | |
Avoidance of sodium | Age (increasing) | 0.0008 | 0.97 (0.95–0.99) |
Race (white) | 0.03 | 0.45 (0.22–0.93) | |
Avoidance of white flour | Age (increasing) | 0.03 | 0.98 (0.96–0.998) |
Positive of celiac disease | 0.005 | 4.3 (1.5–11.9)c
| |
Avoidance of caffeine | Severe psoriasis | 0.004 | 2.30 (1.30–4.00)d
|
Avoidance of alcohol | Age | 0.0001 | 0.97 (0.95–0.98) |
Addition of fruits | Race (white) | <0.0001 | 0.22 (0.11–0.45) |
Positive family history of psoriasis | 0.04 | 1.76 (1.03–3.0)e
|
Attitudes and Perceptions About Diet
Questions and responses |
n (%) |
---|---|
Currently, what role is diet playing in managing your skin condition? | |
Skin condition completely controlled by diet | 27 (2.2) |
Diet is helping significantly with skin condition | 201 (16.7) |
Diet is helping slightly with skin condition | 210 (17.4) |
Diet has no effect on skin condition | 200 (16.6) |
Not sure how diet affects skin condition | 521 (43.2) |
Other | 47 (3.9) |
How difficult/burdensome is it to follow a special diet? | |
Very difficult | 226 (18.7) |
Somewhat difficult | 473 (39.2) |
Not difficult | 324 (26.9) |
Not applicable | 183 (15.2) |
What difficulties did you encounter in modifying your diet? | |
Will power/too limiting | 237 (36.5) |
Time/inconvenience | 113 (17.4) |
Family/social pressures | 88 (13.6) |
Dining out/travel | 88 (13.6) |
Affordability | 74 (11.4) |
Access | 48 (7.4) |
How important is it that physicians discuss with patients the role of diet in managing skin disease? | |
Very important | 781 (64.8) |
Somewhat important | 290 (24) |
Minimally important | 102 (8.5) |
Not important at all | 33 (2.7) |