Table 1. Characteristics of the included studies.
| Study | Subjects | Study design and duration (y) | Cases/subjects | Lycopene source and ascertainment (dose) | Stroke type | Stroke ascertainment | Adjustments |
|---|---|---|---|---|---|---|---|
| Jacques, 2012(19) | Male and female,mean aged 54 y in Framingham | Follow-up study11 | 99/2667 | By a validated SFFQ, considering food sources and multivitamin supplements(7.9 mg/d) | total stroke including transient ischemic attack | Hospitalization records, physician office visit records reviewed by a panel of two neurologists, with obvious criteria | Age, sex, SBP, TC, ration of TC/HDL, BMI, smoking, number of packs/d, hypertension treatment, diabetes, intake of saturated fat, energy, β-carotene, flavonol, vitamin C and vitamin E |
| Karppi, 2012(15) | Male,aged 46–65 y,27.5% are current smoker in Kuopio | Cohort study12.1 | 67/1031 | Serum lycopene,Assessed by HPLC,(<0.03 ~ >0.22 umol/L) | any stroke and ischemic stroke | The FINMONICA stroke register data that annually rechecked and Finnish national hospital discharge registry and death certificate registers. | age, examination year, BMI, SBP, smoking, serum LDL cholesterol, diabetes, and history of stroke |
| Ito, 2006(9) | Male and female,aged 39–80 y, 52.4% male, 11.1% female are smokers in Hokkaido | Population-based follow-up study11.9 | 37/3059* | Serum lycopene,Assessed by HPLC,(0.3346 umol/L) | total stroke | Using mortality records from Agency of general affairs and the ministry of health and welfare | sex, age, smoking status, alcohol consumption, BMI, SBP, serum total cholesterol, serum value of TG, ALT activity |
| Hak, 2004(8) | Male, aged 45–70 y in Boston | prospective, nested case-control analysis13 | 297/594 | Plasma lycopene, considering dietary intakes using validated SFFQ,Assessed by HPLC | ischemic stroke | Medical records reviewed by neurologist | BMI, TC, HDL cholesterol, history of hypertension, DM, parental history of MI < 60 y, frequency of vigorous exercise, alcohol consumption, multivitamin use, assignment to aspirin or β-carotene treatment or placebo. |
| Sesso, 2003(18) | postmenopausal female,aged 53.9 ± 7 y in United states | prospective cohort study7.2 | 247/38445 | By a 131-item validated SFFQ,(16741 ~ 3326 ug/d) | total stroke | Defined as a typical neurological deficit, sudden or rapid in onset, lasting > 24 h. | age, randomized aspirin, randomized vitamin E, and randomized β-carotene, BMI, exercise, smoking, PHU, parental history of MI < 60 y, diabetes, hypertension, high cholesterol, intake of fruit and vegetables, alcohol, fiber, folate, non supplemental vitamin E and saturated fat. |
| Hirvonen, 2000(17) | male smokers,aged 50–69 y | Cohort study6.1 | 914/26 593 | By self-administered, validated, modified diet history method.(0·59 mg/d) | cerebral infarctions, subarachnoid hemorrhages, and intracerebralhemorrhages | Identified from national registers by using the unique personal identification number. The validity of the stroke diagnoses has beenevaluated. | age, supplementation group, SBP, DBP, serum TC, HDL cholesterol, BMI, height, smoking-years, number of cigarettes daily, history of diabetes or coronary heart disease, alcohol intake, and education. |
| Ascherio, 1999(16) | Male,aged 40–75 y,With multivitamin supplement | Prospective observational study8 | 328/43738 | By repeated and validated FFQ, lycopene intake was updated using cumulative averages during the follow-up(3442 ~ 18798 ug/d) | total stroke, ischemic,hemorrhagic, and unclassified stroke | By participant's medical records, with a typical neurologic defect of sudden or rapid onset that lasted at least 24 hours | Age, calendar time, total energy intake, smoking, alcohol consumption, history of hypertension, parental history of MI < 65 y, profession, and quintiles of BMI and PA. |
SFFQ: semiquantitative food-frequency questionnaire.
FFQ: food-frequency questionnaire.
HPLC: high-performance liquid chromatography.
FINMONICA: Finnish part of Monitoring of Trends and Determinants in Cardiovascular Diseases.
BMI: body mass index.
SBP: systolic blood pressures.
DBP: diastolic blood pressures.
TC: total cholesterol.
TG: triglyceride.
ALT: alanine transamininase.
DM: diabetes mellitus.
PHU: postmenopausal hormone use.
MI: myocardial infarction.
PA: physical activity.
*: End point is stroke mortality.