Whole blood count data and hematological parameters in US vegetarians: a cross-sectional study

Area of Science:

• Nutrition Science
• Hematology
• Public Health

Background:

• Previous studies suggest vegetarians may have lower white blood cell (WBC) counts, but results are conflicting.
• Existing research often relies on small sample sizes and convenience sampling, limiting generalizability.

Purpose of the Study:

• To investigate the association between vegetarian diets and whole blood count (WBC) parameters in a large, representative US population.
• To compare WBC and hematological parameters between lacto-ovo-vegetarians (LOVs), semi-vegetarians (SVGs), and omnivores.

Main Methods:

• Utilized data from the National Health and Nutrition Examination Surveys (NHANES), employing a complex, multistage, probability sampling design.
• Compared crude and multivariable regression-adjusted cell counts between dietary groups (LOVs, SVGs, omnivores).

Main Results:

• Analysis included 8,232 participants; vegetarians were younger, had healthier BMIs, and a higher proportion of females.
• While LOVs showed directionally lower WBC counts, differences were not statistically significant compared to omnivores.
• Vegetarians exhibited lower red blood cell counts and hemoglobin levels; no other significant WBC differences were observed.

Conclusions:

• Hemogram alterations in vegetarians were directionally consistent with prior research but lacked statistical significance for WBC and neutrophils.
• Factors such as statistical design, BMI, and dietary vitamin B12 intake may influence observed hematological differences.