Association between apple consumption and physician visits: appealing the conventional wisdom that an apple a day keeps the doctor away

Abstract

Importance: Fruit consumption is believed to have beneficial health effects, and some claim, "An apple a day keeps the doctor away."

Objective: To examine the relationship between eating an apple a day and keeping the doctor away.

Design, setting, and participants: A cross-sectional study of a nationally representative sample of the noninstitutionalized US adult population. A total of 8728 adults 18 years and older from the 2007-2008 and 2009-2010 National Health and Nutrition Examination Survey completed a 24-hour dietary recall questionnaire and reported that the quantity of food they ate was reflective of their usual daily diet.

Exposures: Daily apple eaters (consuming the equivalent of at least 1 small apple daily, or 149 g of raw apple) vs non-apple eaters, based on the reported quantity of whole apple consumed during the 24-hour dietary recall period.

Main outcomes and measures: The primary outcome measure was success at "keeping the doctor away," measured as no more than 1 visit (self-reported) to a physician during the past year; secondary outcomes included successful avoidance of other health care services (ie, no overnight hospital stays, visits to a mental health professional, or prescription medications).

Results: Of 8399 eligible study participants who completed the dietary recall questionnaire, we identified 753 adult apple eaters (9.0%)--those who typically consume at least 1 small apple per day. Compared with the 7646 non-apple eaters (91.0%), apple eaters had higher educational attainment, were more likely to be from a racial or ethnic minority, and were less likely to smoke (P<.001 for each comparison). Apple eaters were more likely, in the crude analysis, to keep the doctor (and prescription medications) away: 39.0% of apple eaters avoided physician visits vs 33.9% of non-apple eaters (P=.03). After adjusting for sociodemographic and health-related characteristics, however, the association was no longer statistically significant (OR, 1.19; 95% CI, 0.93-1.53; P=.15). In the adjusted analysis, apple eaters also remained marginally more successful at avoiding prescription medications (odds ratio, 1.27; 95% CI, 1.00-1.63). There were no differences seen in overnight hospital stay or mental health visits.

Conclusions and relevance: Evidence does not support that an apple a day keeps the doctor away; however, the small fraction of US adults who eat an apple a day do appear to use fewer prescription medications.

Figure 1

Self-reported Number of Visits to a Physician Within the Previous Year Among US Adult Apple Eaters vs Non–Apple Eaters χ² Test was used in comparison of proportions. ^a P = .03.

Figure 2

Percentage of US Adult Apple Eaters vs Non–Apple Eaters Who Did Not Use Each Specific Health Care Service in the Past Year χ² Test was used in comparison of proportions. ^a Persons who avoided more than 1 physician visit in the past year (P = .03). ^b Persons who avoided any use in the past year (overnight hospital stay P = .64; mental health visit P = .11). ^c Persons who avoided using a prescription medication in past month (P = .01).

Figure 3

Crude and Adjusted Odds Ratios for the Association Between Daily Apple Consumption and Avoidance of Health Care Services Adjusted models include covariates for age, sex, race or ethnicity, educational attainment, body mass index, smoking status, and health insurance type. ^a Persons who avoided more than 1 physician visit in the past year. ^b Persons who avoided any use in the past year. ^c Persons who avoided using a prescription medication in past month.

Figure 4

Crude Odds Ratios for the Association Between Dose Response of Daily Apple Consumption and Avoidance of Health Care Services Apple eating according to consuming no apples (<149 g) or a small (149–181 g of raw apple), medium (182–222 g), or large (≥223 g) apple per day. P values are for the trend across apple categories. ^a Persons who avoided more than 1 physician visit in the past year. ^b Persons who avoided any use in the past year. ^c Persons who avoided using a prescription medication in past month.