Prevalence of PAD Reduced With Increased Consumption of Fruits and Vegetables

Study Questions:

Does greater consumption of fruits and vegetables help to prevent peripheral arterial disease (PAD)?

Methods:

Approximately 3.7 million American adults were self-referred to 20,000 US sites to undergo a screening exam for PAD with ankle-brachial index (ABI). These same individuals completed a written questionnaire that included assessment of frequency of fruit and vegetable dietary intake. The questionnaire described 5 categories of fruit and vegetable intake ≥3 servings/day: daily, 4-5 times/week, 2-3 times/week, once/week to once/month, and less than once/month.

Results:

PAD was defined as ABI ≤0.9 or history of lower extremity revascularization procedure. Severity of PAD was further categorized as ABI <0.5, ABI 0.7–0.5, and ABI 0.9–0.7. PAD was found to be present in 6.3% of those screened. A stepwise inverse association between fruit and vegetable intake and PAD prevalence was found (p < 0.001 for trend) after multivariable adjustment for age, sex, race/ethnicity, and clinical risk factors (diabetes, hypertension, hypercholesterolemia, sedentary lifestyle, tobacco use, family history of vascular disease, and body mass index). After stratification by cigarette smoking status (current, former, or never), however, the inverse association was found to be present only for current or former smokers. The inverse association was found to be stronger for those with ABI <0.5 or 0.7–0.5 than for those with ABI 0.9–0.7; the p-value of the trend was <0.0001 at each stratum. Of various hypotheses discussed in the article regarding the mechanism of this association, the prevailing explanation is that antioxidants found in fruits and vegetables demonstrate evident disease-preventing effects only in an environment of significant oxidative stress, which does occur with smoking. In PAD, oxidative stress is thought to play a role in both the initial onset and subsequent progression of the disease; greater antioxidant intake may inhibit or retard the initiation and progression of the disease. Mean age of participants was 64.1 ± 10.2 years. The study found that a minority (29.2%) of individuals consume ≥3 servings of fruits and vegetables daily. Just over half (52.1%) report consuming ≥3 servings of fruits and vegetables on most days of the week. There was notable variation in fruit and vegetable consumption by age, sex, race/ethnicity, region, state, and income level (according to reported zip code). Demographic factors predicting those least likely to consume ≥3 fruits and vegetables daily included males, non-whites, residents of Southern states, low-income individuals, and unmarried individuals. Current or former smoking and fast food consumption were all negatively associated with daily consumption of at least 3 fruits and vegetables per day. Individuals who consumed fish, nuts, red meat, and had a non-sedentary lifestyle also had a daily consumption of at least 3 fruits and vegetables.

Conclusions:

Greater consumption of fruits and vegetables is associated with a lower prevalence of PAD. After stratification by cigarette smoking status (current, former, or never), however, the inverse association was found to be present only for current or former smokers. One possible explanation is that antioxidants in fruits and vegetables may retard PAD by counteracting the oxidative stress incurred from smoking.

Perspective:

There has been limited prior investigation into the association between fruit and vegetable intake and PAD in patients that takes into account clinical risk factors. This study demonstrated an inverse association in current or former smokers, suggesting that antioxidants in fruits and vegetables may counteract the oxidative stress incurred with smoking. Nearly half of 3.7 million Americans who participated in this study do not consume at least 3 fruits and vegetables on most days of the week, providing evidence for continued efforts to improve the nutritional habits of all Americans.


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