Effects of Kiwifruit Consumption on Human Plasma Triglyceride Concentrations (Study)
Kiwifruit which contain high amounts of vitamin C, vitamin E and polyphenols may be beneficial in cardiovascular disease (CVD); however very little is known about its cardioprotective effects.
The study evaluated whether consuming Kiwifruit modulated platelet activity and plasma lipids in human volunteers in a randomized cross-over study.
It reports that consuming two or three Kiwifruit per day for 28 days reduced platelet aggregation response – an important risk factor of CVD - to collagen and ADP by 18% compared with the controls (P<0.05).
In addition, consumption of Kiwifruit lowered blood triglycerides levels by 15 percent - another important risk factor of CVD - compared with control (P<0.05), whereas no such effects were observed in the case of cholesterol levels.
All these data indicate that consuming Kiwifruit may be beneficial in cardiovascular disease (CVD).
Study Materials and Methods
Thirty (12 males and 18 females) healthy volunteers took part in this study. Volunteers were aged 20–51 years and their mean BMI was 22.430.52 kg/m2. They were requested to maintain normal diet during the trial.
Subjects were allocated randomly to two groups (n¼15), each of which was given different order of Kiwifruit doses.
Group A took two Kiwifruit per day in the first period and three Kiwifruit per day in the second period, whereas group B took two and three Kiwifruit per day.
Each volunteer consumed two and three Kiwifruit per day for successive 28-day periods separated by at least 2-week wash-out periods.
Healthy subjects were recruited after assessment of their medical and dietary history. Exclusion criteria were the presence of overt vascular, hematological or respiratory disease, hypertension, infection, frequent consumption of drugs which affect platelet function (e.g., aspirin, paracetamol, ibuprofen, steroid, habitual consumption of omega-3 fatty acid supplements).
Determination of plasma lipids
Mean total cholesterol, LDL, and HDL cholesterol values in all groups were unchanged from days 0 to 28 in both groups, whereas triglyceride concentrations were significantly lowered on day 28 (1.160.45 mmol/l at day 0 vs. 0.870.29 mmol/l, P<0.05, at day 28 and 1.190.35 vs.0.84 0.35 mmol/l, P<0.05, in the case where volunteers consumed two and three Kiwifruit per day, respectively), compared with those on day 0 in both groups (P<0.05).
After the wash-out period (minimum 2 weeks), plasma triglyceride concentrations returned to the base line level.
Discussion: Lipid-lowering effect of kiwifruit Given the role of blood lipids in the development of atherosclerosis and CVD and the positive roles of fruits and vegetables on plasma lipids, we have assessed the effects of Kiwifruit on plasma lipids.
Lowering of plasma triglycerides by Kiwifruit was observed despite these volunteers maintaining their regular diet during the supplementation periods. None of the volunteers reported any loss of appetite or changes in their food intake during the supplementation.
The mechanism of action is not known; it is possible that the presence of certain components in Kiwifruit may be responsible for the lipid-lowering effects. However, further work is required to understand the mechanism of action.
It must be noted that the lipid-lowering effects of fruits and vegetables were also reported before.
Modulation of plasma triglyceride levels by Kiwifruit could be of potentially prophylactic and therapeutic benefit in preventing and halting pathological processes that lead to CVD.