None listed
Conditions
Brief summary
A previous study suggests that the skin responds to increases in plasma vitamin C availability. There appears to be very high vitamin C content in the dermal fibroblasts, the site of collagen formation, confirming the essential nature of vitamin C to support this activity. Therefore in order to test the effect of diet on skin status, a dietary intervention study is proposed in which individuals are supplemented with kiwifruit, as an excellent dietary source of vitamin C, for two months allowing full plasma saturation to occur. We will measure skin vitamin C content before and after the intervention. To our knowledge there is currently no information of this type available. We will recruit individuals with low vitamin C status as indicated by a plasma vitamin C level <45 µmol/L. Participants will be supplemented with two Sungold kiwifruit per day for eight weeks; this is equivalent to ~250 mg vitamin C per day. We have previously shown that two Sungold kiwifruit per day is sufficient to achieve plasma saturation within one week of beginning supplementation. The study will comprise a two week lead-in period to allow the participants’ time to control their dietary vitamin C intakes. This will be followed by an eight week intervention period with kiwifruit. Whole skin biopsies to obtain tissue for the measurement of whole skin vitamin C content will be taken by punch biopsy before and after the kiwifruit intervention.
Interventions
The overall aim of this project is to determine whether kiwifruit, as a dietary vitamin C source,
impacts on human skin vitamin C levels. We will undertake a kiwifruit intervention for eight weeks with a group of healthy volunteers with low vitamin C status at baseline, to determine whether increased intake can improve skin vitamin C levels. Plasma and skin vitamin C status will be determined before and after the eight week intervention.
Participants will be given two Sungold kiwifruit per day (
The overall aim of this project is to determine whether kiwifruit, as a dietary vitamin C source, impacts on human skin vitamin C levels. We will undertake a kiwifruit intervention for eight weeks with a group of healthy volunteers with low vitamin C status at baseline, to determine whether increased intake can improve skin vitamin C levels. Plasma and skin vitamin C status will be determined before and after the eight week intervention. Participants will be given two Sungold kiwifruit per day (average weight 80 g each fruit), to be consumed as raw fruit, at any time during the day. The period of the intervention is 8 weeks. The participants will be given fruit on a weekly basis, with sufficient fruit for 7 days per pack (14 fruit). Uneaten fruit will be returned at the end of the week. Compliance will also be determined by monitoring participant plasma vitamin C status (we have previously shown that this should be saturated if two kiwifruit per day are consumed).
Sponsors
The University of Otago, Christchurch
Study design
Allocation
Non-randomised trial
Intervention model
Single group
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
Inclusion criteria (all required): Aged 18 – 75 years; Low/below average plasma vitamin C levels (< or = 45 µmol/L); Residing in Christchurch for duration of 10 week study.
Exclusion criteria
Exclusion criteria (one required): Fear of needles; Allergy/intolerance to kiwifruit; Taking prescription medication (within past three months); Excessive alcohol consumption (fewer than 21 standard drinks/week); High fruit and vegetable consumption (at least 5 servings per day); Diabetes mellitus; Bleeding disorders; Skin conditions such as eczema; A personal history of abnormal scarring; A Fitzpatrick scale type of 4 or more; Obese (BMI greater than 35 kg/m2).
Outcome results
None listed