What this means
Higher total serum IgG levels have been associated with protection from cardiovascular events in ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial). Antibodies against oxidized low-density lipoprotein (LDL) have also been linked to favorable clinical and vascular imaging outcomes.
A plain-English summary is on its way. Until then, this is the start of the authors' own summary.
- Who it was tested in
- Not stated
- Kind of research
- A study
The science
- Original title
- Effects of Walnut Consumption on Anti-MDA-LDL Antibodies and Immunoglobulins in the WAHA Randomized Trial.
- Authors
- Sharma T, Chiva-Blanch G, Caga-Anan M et al.
- Journal
- JACC. Advances
- Published
- Oct 29, 2026
- Study type
- Study
- PMID
- 42954696 ↗
Abstract
Background
Higher total serum IgG levels have been associated with protection from cardiovascular events in ASCOT (Anglo-Scandinavian Cardiac Outcomes Trial). Antibodies against oxidized low-density lipoprotein (LDL) have also been linked to favorable clinical and vascular imaging outcomes. The aim of this study was to determine whether regular walnut consumption influences circulating immunoglobulins, malondialdehyde-modified LDL (MDA-LDL), a highly immunogenic form of oxidized LDL, and antibodies against MDA-LDL.
What they did
The Walnuts and Healthy Aging study was a two-center, randomized controlled trial conducted in Spain and the United States. Adults aged 63 to 79 years were assigned to a walnut-enriched diet or a control diet excluding walnuts for 2 years. Serum total immunoglobulin G (IgG), total immunoglobulin M (IgM), MDA-LDL, and IgG and IgM anti MDA-LDL antibodies were measured by enzyme-linked immunoassays in 474 participants.
What they found
Baseline immunoglobulin concentrations differed substantially by study center. Participants from the United States had 25% lower total IgM and IgG concentrations than participants from Spain. Walnut consumption increased total serum IgG by 11% in the U.S. cohort (95% CI: 0%-24%; P = 0.040), whereas pooled analysis showed a 6% increase across both cohorts (95% CI: 0%-12%; P = 0.041). Over the 2-year study period, total IgM and both IgG and IgM anti-MDA-LDL concentrations declined significantly in both the control and intervention groups. Long-term walnut consumption was associated with a modest increase in total serum IgG but had no significant effect on total IgM, MDA-LDL, or antibodies against MDA-LDL. Baseline IgG and IgM concentrations were substantially lower among U.S. participants, suggesting that geographic, environmental, social, or genetic factors may modulate immune biomarkers independently of dietary intervention.
The authors' abstract, grouped under plain headings from its own section labels.
Sharma T, Chiva-Blanch G, Caga-Anan M et al. Effects of Walnut Consumption on Anti-MDA-LDL Antibodies and Immunoglobulins in the WAHA Randomized Trial. JACC. Advances. 2026. doi:10.1016/j.jacadv.2026.103288. PMID: 42954696. https://pubmed.ncbi.nlm.nih.gov/42954696/