Lycopene-Rich Diet May Curb Stroke Risk

Megan Brooks

October 09, 2012

October 9, 2012 — A diet rich in lycopene, found in tomatoes and tomato-based products, may reduce the risk for stroke in men, according to a Finnish population-based study.

The study, published October 9 in Neurology, found that men with the highest serum concentrations of lycopene were far less likely to have a stroke over more than a decade than men with the lowest lycopene levels.

"This study supports previous results that eating tomatoes and tomato-based foods is associated with a lower risk of any stroke and ischaemic stroke," Jouni Karppi, PhD, from the Institute of Public Health and Clinical Nutrition, University of Eastern Finland in Kuopio, told Medscape Medical News.

"The results support the recommendation that people get more than 5 servings of fruits and vegetables a day, which would likely lead to a major reduction in the number of strokes worldwide, according to previous research. This may decrease costs of health care in public health," Dr. Karppi said.

Potent Antioxidant

Lycopene is a potent antioxidant that decreases oxidative modification of low-density lipoprotein (LDL) cholesterol, the first pathogenic step of cerebrovascular events, Dr. Karppi explained. "Lycopene is the most efficient quencher of singlet oxygen," he added. "Lycopene reduces inflammation, inhibits cholesterol synthesis, improves immune function, and prevents platelet aggregation and thrombosis and thereby may decrease the risk of stroke."

The study team investigated the association of carotenoids, retinol and alpha-tocopherol, with stroke in 1031 Finnish men aged 46 to 65 years in the longitudinal population-based Kuopio Ischaemic Heart Disease Risk Factor cohort. Serum concentrations of retinol and alpha-tocopherol were measured by high-performance liquid chromatography at baseline.

During a median follow-up of 12.1 years, 67 men had a stroke, including 50 ischemic strokes.

After multivariable adjustment for age, examination year, body mass index, systolic blood pressure, smoking, serum LDL cholesterol, diabetes, and history of stroke, men in the highest quartile of serum lycopene ( > 0.22 µmol/L) were significantly less likely to have any stroke or ischemic stroke than men in the lowest quartile of lycopene (≤0.030 µmol/L).

Table. Risk for Stroke in Highest vs Lowest Quartile of Lycopene

Type Hazard Ratio (95% Confidence Interval) P Value
Any stroke 0.45 (0.21 - 0.95) .036
Ischemic stroke 0.41 (0.17 - 0.97) .042

 

Concentrations of alpha-carotene, beta-carotene, alpha-tocopherol, and retinol were not related to the risk for stroke.

Limitations Preclude Firm Conclusions

In comments to Medscape Medical News, Larry B. Goldstein, MD, director of the Duke Stroke Center at Duke University Medical Center in Durham, North Carolina, noted that the conclusions are subject to "all of the limitations of this type of study design (for example recall bias and an inability to account for changes in diet or other risk factors that may have occurred over time)."

"In addition, diet may be a marker for other factors that might affect risk (and) the study is based on a one-time dietary questionnaire with subjects then followed over time," Dr. Goldstein added. He was not involved in the study.

He also noted that the study was limited to Finnish men, and whether the findings would be similar in other populations is uncertain.

Nonetheless, Dr. Goldstein said, "The basic result is consistent with current dietary recommendations from the AHA [American Heart Association] — that diet should include 3 to 5 servings of fruits and vegetables daily and limit sodium consumption (for example, the DASH [Dietary Approaches to Stop Hypertension] eating plan). That diet can certainly include tomatoes and tomato-based products."

The study was supported by a grant from the EVO funding of Lapland Central Hospital, Rovaniemi, Finland. The authors and Dr. Goldstein have disclosed no relevant financial relationships.

Neurology. 2012;79:1540-1547. Abstract

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