Table 1.
Summary of studies included for review.
| Intervention Diet &/Exercise | Intervention Focus | Study Design | Number of participants (analysis) | Sample type | Primary outcomes | Estrone (E1) | Estradiol (E2) | 2/16 α-hydroxy-estrone ratio | SHBG | Ref. |
|---|---|---|---|---|---|---|---|---|---|---|
| Diet | Alcohol | O | 1093 | Blood | Levels of DHEAS, E1, E2 were higher in women that consumed more alcohol. | ↑ | ↑ | (7) | ||
| Diet | Alcohol | O | 1291 | Blood | Androgens and E1 concentration positively associated with alcohol consumption. Individuals consuming more than 25g/day as opposed to non-consumers had a 20% higher concentration in DHEAS, free testosterone, and estrone, while SHBG were approximately 15% lower. | ↑ | ↑ | ↓ | (8) | |
| Diet | Alcohol | E | 53 | Blood | E1 levels increased with increased alcohol consumption | ↑ | (9) | |||
| Diet | Animal Products | O | 766 | Blood | Total red and fresh meat consumption were inversely related with SHBG, higher consumptions of dairy products were associated with increased levels of free and total E2. | ↑ | ↓ | (10) | ||
| Diet | Overall Diet | O | 653 (blood) 27488 (analytical) | Blood, | Women diagnosed with breast cancer were more often in the highest tertiles of the ERDP. The strongest correlates with unconjugated E2 were non-whole/refined grains, cheese, yogurt, and franks/luncheon meats. Only intakes for non-whole/refined grains and cheese were significantly correlated with the 2/16 ratio. | (11) | ||||
| Diet | DHA | E | 25 | Urine | DHA supplementation did not have a statistically significant effect on estrogen levels. | = | = | (12) | ||
| Diet | Fat intake | O | 324 | Blood | There was a positive association between estrone levels and total fat intake. DHEAS levels were significantly associated with the percentage of energy from total fat, saturated fat, monounsaturated fat, and polyunsaturated fat. | ↑ | (13) | |||
| Diet | Fat intake | E | 46 | Urine | The low-fat diet had an increase in E1, and E1+E2+E3, other metabolites were not significantly different between the three diets. | ↑ (low fat) | (14) | |||
| Diet | Fat intake | E | 17 | Urine | There was a statistically significant association between the high fat diet and E2 levels. | ↑ (high fat) | (15) | |||
| Diet | Fat Intake | O | 37 | Urine | A low-fat high fiber diet was associated with higher 2/16 urinary metabolite ratios. | ↑ (low fat high fiber) | (16) | |||
| Diet | Flaxseed | E | 99 | Blood | Women in the intervention group had an increase in 2-hydroxyestrone levels and the 2/16α hydroxyestrone ratio. | ↑ | (17) | |||
| Diet | Flaxseed | E | 30 | Urine | There was an increase in the 2-hydroxyestrone levels of women in the intervention group that was statistically significant, but changes in the 2/16 ratio were not statistically significant. | = | (18) | |||
| Diet | Flaxseed | E | 43 | Urine | The 2/16α-hydroxyestrone ratio decreased in the urine samples, 16a-hydroxyestrone ratio levels increased. | ↓ | (19) | |||
| Diet | Grape Seed Extract | E | 39 | Blood | The supplementation did not decrease plasma estrogens. | (20) | ||||
| Diet | Grapefruit | E | 59 | Blood | E1S levels increased hours after consuming the grapefruit, but returned back to normal. E1 decreased hours after consuming but returned to normal after 10 hours. | ↑(E1S) ↓(E1) | (21) | |||
| Diet | Grapefruit | O | 876 | Blood | There was a positive association between grapefruit intake and increased SHBG | ↑ | (22) | |||
| Diet | Green Tea | E | 937 | Blood, Urine | There were not reductions in sex hormone levels in the women in the intervention group. | (23) | ||||
| Diet | Mediterranean Diet | E | 106 | Urine | The reduction of total estrogen levels in the intervention group was statistically significant. This reduction was due to metabolites instead of E1, or E2 reductions. | (24) | ||||
| Diet | Overall Diet | E | 50 | Blood, Urine | Changes in body weight were significantly associated with changes in SHBG. | ↑ | (25) | |||
| Diet | Overall Diet | O | 205 | Blood | A western dietary pattern, often characterized with increased consumption of red meats, chicken, and eggs, was associated with higher levels of estradiol in the study. | ↑ | (26) | |||
| Diet | Pomegranate | E | 64 | Blood | When stratified by BMI, normal weight women in the intervention arm had a statistically significant decrease in serum estrone and testosterone levels, but not in women that were overweight or obese by the BMI scale. | ↓ (normal weight women) | (27) | |||
| Diet | Soy | E | 60 | Blood | No statistically significant changes in the experimental group. | (28) | ||||
| Diet | Soy | E | 18 | Urine | The 2/16α hydroxyestrone ratio was increased by the low iso (65+/- 11 mg soy isoflavones per day) diet. | ↑ | (29) | |||
| Diet | Soy | O | 144 | Blood | Women who consumed greater than the median (32.2 pg/mL) had E1 levels that were lower than those below the median. | ↓ | (30) | |||
| Diet | Soy | O | 167 | Blood | No statistically significant changes. | (31) | ||||
| Diet | Soy | E | 57 | Blood | There were no associations between sex hormones and the diet interventions between the arms. There were some statistically significant changes in testosterone, but not between the three groups. | (32) | ||||
| Diet | Soy | E | 20 | Blood | There was an increase in SHBG from baseline to the end of the ten weeks. | ↑ | (33) | |||
| Diet | Soy | E | 74 | Blood, Urine | No statistically significant changes. | (34) | ||||
| Diet + Exercise | Weight Loss | E | 421 | Blood | Estrone decreased in all interventional arms, estradiol decreased in the diet and diet + exercise arms. SHBG increased significantly in the diet and diet + exercise arm. | ↓ | ↓ (diet, diet + exercise) | ↑ (diet, diet + exercise) | (35) | |
| Diet + Exercise | Weight Loss | E | 7 | Blood, Breast Fluid | Reductions of estradiol in ductal fluid and the blood sample were found at 12 weeks. | ↓ | (36) | |||
| Diet + Exercise | Weight Loss | E | 22 | Blood | SHBG increased in both groups, 39% in the HRT group and 42% in the non HRT group. | ↑ | (37) | |||
| Diet + Exercise | Weight Loss | E | 243 | Blood | Overall, participants in the intervention arms had a decrease in all measured hormones and an increase in SHBG. | ↓ | ↓ | ↑ | (38) | |
| Exercise | Activity Level | O | 2082 | Blood | Increased physical activity was associated with lower levels of estradiol. | ↓ | (39) | |||
| Exercise | Activity Level | O | 542 | Urine | Higher average activity levels was associated with overall lower levels of parent estrogens. | ↓ | ↓ | (40) | ||
| Exercise | Activity Level | E | 173 | Blood | Exercisers had a decrease in estrone at the 3 and 12 month time frames, and an increase in SHBG. At 3 and 12 months, concentrations only changed in exercisers that lost at least.5%. body fat. | ↓ | (41) | |||
| Exercise | Activity Level | O | 1804 | Blood | Sitting for at least 10 hours a day is correlated with increased unconjugated estrone and estradiol. | ↑ | ↑ | (42) | ||
| Exercise | Activity Level | O | 806 | Blood | Inverse association between usual physical activity and free estradiol levels, and a positive association with SHBG. | ↓ | ↑ | (43) | ||
| Exercise | Exercise Type | E | 35 | Blood | No effect on estrone or estradiol. | (36) | ||||
| Exercise | Training | E | 163 | Urine | Overall, there were no changes between the groups in their estrogen metabolite ratio. | (44) | ||||
| Exercise | Training | E | 320 | Blood | Before weight change was adjusted for, total estradiol, free estradiol, and SHBG changed in the exercise intervention group. | ↓ | ↑ | (45) | ||
| Exercise | Training | E | 400 | Blood | The exercise prescription was associated with decreases in E2, estrone, and free E2 and increases in SHBG, but the differences between the high and moderate prescriptions were not statistically significant. | ↓ | ↓ | (35) | ||
| Exercise | Training | E | 307 | Blood | While participants in the intervention group had an overall decrease in estradiol levels, there were no statistically significant changes in estrogen metabolism pathways. | ↓ | (37) | |||
| Exercise | BMI EMM | O | 267 | Blood | Women with high BMI and low physical activity had the highest levels of levels of estrone and free estradiol. | ↑ | ↑ | (46) |
Abbreviation for SHBG is sex-hormone binding globulin, DHEAS is dehydroepiandrosterone sulfate. Study designs as O for an observational style study and E for an experimental style study, and Ref. is reference.
“↑”, “↓” and “=” stand for "increased" , "decreased" and "no change".