The study at a glance.
28 healthy, postmenopausal women with Fitzpatrick skin type 1 (always burns, never tans) or 2 (usually burns, tans minimally) were randomly assigned to either an intervention or a control group. Almonds were provided as 20% of total daily calorie intake for the intervention group (340 calories/day on average), about 2 one-ounce servings. The control group consumed a calorie-matched nut-free snack in place of almonds daily: cereal bar, energy bar or pretzels. All participants were advised not to consume any nuts or nut-containing products over the course of the study (except for the almond snack for the intervention group). They otherwise were advised to continue their usual daily energy intake. After a four-week dietary wash-out period, participants were randomized to one of the two study groups detailed above. Study visits occurred at baseline, 4 weeks, 8 weeks, 12 weeks and 16 weeks. Facial wrinkles were assessed using high-resolution facial photography and validated 3D facial modeling and measurement at baseline, 8 weeks and 16 weeks. Skin barrier function was assessed by measurement of sebum production and transepidermal water loss (TEWL).
Results:
- Photographic image analysis showed that the almond group had significant reductions in wrinkle severity and width, by 9 and 10%, respectively, compared to the control group at the 16-week time point (P<0.02).
- There were no significant differences in sebum production between groups after 8 or 16 weeks.
- There were no significant differences between groups in transepidermal water loss (TEWL) from baseline after 8 or 16 weeks.
- There were no significant changes from baseline in skin barrier function (P=0.65) between the almond and control groups relative to baseline after 16 weeks.
Study Limitations:
Aging is a long-term process so the findings from this 16-week study may be difficult to reproduce and generalize to extended periods of time. Skin-aging is also multi-factorial in nature and although certain groups were excluded (i.e., those with a smoking history), there is variance in aging confounders, such as frequency of UV light exposure and emotional stress, which were outside the scope of the study. This study was limited to cosmetic evaluation, as no measurements were made regarding collagen production. Study did not evaluate disease or younger subjects, so results are limited to otherwise healthy post-menopausal females. In addition, this was a pilot study with a limited number of participants. Future studies should expand to a larger recruitment pool.
Conclusion:
Results of this pilot study suggest that daily consumption of almonds may play a role in reducing wrinkle severity in post-menopausal women. The outcomes warrant future studies with expanded population groups and additional evaluations for signs of skin aging.