Higher Intake of Berries Associated with Lower Allostatic Load

by | Mar 6, 2024 | 2024, Aging, Fruits and Vegetables

Written by Taylor Woosley, Science Writer. Findings of a cross-sectional research analysis of 7684 NHANES participants shows that consumers of total berries (p=0.0026), strawberries (p=0.013), and blueberries (p=0.008), respectively, had significantly lower mean AL composite scores, compared to subjects who did not consume berries. 

fruits and vegetables - berriesAllostatic load (AL) increases as we age and is described as the physiological wear and tear on one’s body due to long-term exposure to environmental and social stressors1. Prolonged stress results in the secretion of certain hormones or chemicals from the body, indicating the body’s constant stressful condition and affects the vital organs such as the brain, heart, or liver2. This stress is associate with persistent activation of the hypothalamic-pituitary-adrenal axis, which can lead to acute to chronic inflammation3.

Berries contain therapeutic amounts of anthocyanins, proanthocyanins, phenolic acids, flavonoids, flavonols, alkaloids, and ellagic acid derivatives and their intake is associated with a reduced risk of oxidative stress and inflammation4. The bioactive compounds in berries scavenge reactive oxygen and nitrogen species by donating electrons to free radicals, thereby protecting DNA, proteins, and lipids from oxidative damage5. Increased intake of foods containing flavonoids/polyphenols has been associated with playing a pivotal role in the prevention of oxidative stress-induced human diseases6.

Zhang et al. conducted a cross-sectional research analysis using a nationally representative sample of US adults to assess the association between berry consumption and physiological dysregulation from stress responses measured by AL scores. Data used in the analysis was from four cycles (2003-2010) of the National Health and Nutrition Examination Survey (NHANES). Participants included had available data regarding demographic, dietary, and medical information collected through at-home interviews or phone interviews and an in-person visit. During the visit, subjects participated in dietary interviews, medical examinations, and laboratory analysis of urine, blood, and other tissue samples.

A total of 7684 participants were included in the cross-sectional analysis. Berry intake was assessed based on provided dietary information and two 24-hour food recalls. The AL score composition measured 14 biomarkers pertaining to the cardiovascular domain, the autonomic domain, the metabolic domain, and the immune domain. The cardiovascular domain included fasting LDL-cholesterol, high-density lipoprotein cholesterol (HDL), total cholesterol (TC), fasting glucose, fasting insulin, and glycated hemoglobin (HbA1c). The autonomic domain featured pulse rate, systolic blood pressure (SBP), and diastolic blood pressure (DBP). The metabolic domain included insulin resistance measured through HOMA-IR, fasting triglycerides, and waist circumference. The immune domain was C-reactive protein (CRP) and white blood cell counts (WBC). A lower AL score indicated a lower extent of dysregulation.

Covariates included in the final analysis were the self-reported sociodemographic factors of age, sex, race/ethnicity, education level, and poverty-to-income ratio (PIR). Furthermore, covariates were lifestyle factors of current smoking status, physical activity, marriage status, medication usage, and body mass index. Multivariable-adjusted linear regression models were utilized to investigate the association between berry intake and each biomarker relevant to AL. Out of the 7684 participants, around 19.3% (n=1485, 61.9% female) consumed berries. Significant findings of the study are as follows:

  • Consumers of total berries (p=0.0026), strawberries (p=0.013), and blueberries (p=0.008), respectively, had significantly lower mean AL composite scores, after fully adjusting for confounders, compared to subjects who did not consume berries.
  • A significant dose-response relationship was noted between greater consumption of total berries (p=0.0007), strawberries (p=0.02), and blueberries (p=0.001) and lower mean AL composite scores.
  • Using the larger initial sample of 15,620 subjects, berry consumers had a significantly lower mean AL immune score (p=0.029) and a lower mean AL autonomic score (p=0.026) compared to non-consumers. Furthermore, a significantly lower mean autonomic score was observed for blackberry consumers versus non-consumers (p=0.007).
  • Mean pulse rate was significantly lower in consumers of blueberries, cranberries, blackberries, and cranberry juice, respectively (p<0.05, for all).

Results of the cross-sectional research analysis show that total berry consumption was associated with lower AL, with higher blueberry and strawberry intake being significantly related to a lower AL composite score. Furthermore, berry consumers reported lower cardiovascular, metabolic, immune, and autonomic domain scores. Study limitations include the inability to account for time-varying changes in biomarkers due to only using biomarker measurements at one time point, potential recall bias of self-reported recalls, and the potential for residual confounding.

Source: Zhang, Li, Joshua E. Muscat, Vernon M. Chinchilli, Penny M. Kris-Etherton, Laila Al-Shaar, and John P. Richie. “Berry Consumption in Relation to Allostatic Load in US Adults: The National Health and Nutrition Examination Survey, 2003–2010.” Nutrients 16, no. 3 (2024): 403.

© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/
4.0/).

Click here to read the full text study.

Posted March 6, 2024.

Taylor Woosley studied biology at Purdue University before becoming a 2016 graduate of Columbia College Chicago with a major in Writing. She currently resides in Glen Ellyn, IL.

References:

  1. Adams-Campbell LL, Taylor T, Hicks J, Lu J, Dash C. The Effect of a 6-Month Exercise Intervention Trial on Allostatic Load in Black Women at Increased Risk for Breast Cancer: the FIERCE Study. J Racial Ethn Health Disparities. Oct 2022;9(5):2063-2069. doi:10.1007/s40615-021-01145-x
  2. Noushad S, Ahmed S, Ansari B, Mustafa UH, Saleem Y, Hazrat H. Physiological biomarkers of chronic stress: A systematic review. Int J Health Sci (Qassim). Sep-Oct 2021;15(5):46-59.
  3. Miller ES, Apple CG, Kannan KB, et al. Chronic stress induces persistent low-grade inflammation. Am J Surg. Oct 2019;218(4):677-683. doi:10.1016/j.amjsurg.2019.07.006
  4. Hameed A, Galli M, Adamska-Patruno E, Krętowski A, Ciborowski M. Select Polyphenol-Rich Berry Consumption to Defer or Deter Diabetes and Diabetes-Related Complications. Nutrients. Aug 21 2020;12(9)doi:10.3390/nu12092538
  5. Stote KS, Burns G, Mears K, Sweeney M, Blanton C. The Effect of Berry Consumption on Oxidative Stress Biomarkers: A Systematic Review of Randomized Controlled Trials in Humans. Antioxidants (Basel, Switzerland). Jul 18 2023;12(7)doi:10.3390/antiox12071443
  6. Rudrapal M, Khairnar SJ, Khan J, et al. Dietary Polyphenols and Their Role in Oxidative Stress-Induced Human Diseases: Insights Into Protective Effects, Antioxidant Potentials and Mechanism(s) of Action. Front Pharmacol. 2022;13:806470. doi:10.3389/fphar.2022.806470