The Study: Forty-nine healthy, postmenopausal women with Fitzpatrick skin type I (always burns, never tans) or II (usually burns, tans minimally) who completed the study 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 providing 2 grams of sugar. The control group consumed a calorie-matched nut-free snack in place of almonds daily: fig bar, energy bar or pretzels, which provided on average 8 g of sugar. 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.
Skin assessments were conducted at baseline, 8 weeks, 16 weeks and 24 weeks. These assessments included measuring facial wrinkles, skin pigmentation, transepidermal water loss, skin hydration and sebum production.
- Photographic image analysis showed that the almond group had significant reductions in wrinkle severity, by 15% at week 16 and 16% at week 24, compared to the control group (P<0.05).
- Average facial pigment intensity was decreased by 20% at week 16 in the almond supplementation group and remained so at 20% at week 24. There was no improvement in facial pigment intensity in the control group.
- There were no changes in transepidermal water loss at any time point among the almond and control groups.
- At the end of the study, there were increases in skin hydration on the cheek and forehead among both groups, compared to baseline.
- Both groups showed a significant increase in sebum production on the cheeks, but only those in the control group showed a significant increase in the forehead sebum excretion rate, with an increase of 45% and 155% at weeks 16 and 24, respectively (p<0.05).
Study Limitations: Since this study was limited to 24 weeks, results do not provide insight into longer duration and effects of eating almonds. Additionally, the study participants were postmenopausal women with sun sensitive skin types Fitzpatrick I and II, so results cannot be generalized to younger, male or higher Fitzpatrick skin type populations. And, although the snacks in both groups were calorie-matched, they were not macronutrient-matched.
Conclusion: Results of this study suggest that daily consumption of almonds could be an effective dietary contributor to improving facial wrinkles and reducing skin pigmentation among postmenopausal women with Fitzpatrick skin types I and II. Further studies should expand the study population with participants who are younger and have higher Fitzpatrick skin types.