Metabolic Syndrome Risk Reduced in Women Who Breastfeed

Women who breastfeed for longer durations over their entire lifetime have a lower risk of metabolic syndrome, according to a new study conducted by the Korean National Health and Nutritional Survey.

Purpose of the Study

The authors of the study wanted to assess the relationship between lifelong duration of breastfeeding and its relationship to occurrence of metabolic syndrome and its various components in Korean women aged between 19 to 50 years. Also, while earlier studies reported that breast feeding might influence components of metabolic syndrome (MetS), few studies have studied the link between breast feeding and metabolic syndrome in its entirety.

Earlier studies that were performed to assess the association and breastfeeding threw up inconsistent results.

What is Metabolic Syndrome?

 
Metabolic syndrome (MetS) refers to varying combinations of certain risk factors such as

hypertension, insulin resistance, elevated fasting glucose, abdominal obesity, and dyslipidemia [decreased high-density lipoprotein cholesterol (HDL-C or good cholesterol), elevated low density lipoprotein cholesterol (LDL-C or bad cholesterol) and high triglyceride (TG) levels.

The occurrence of metabolic syndrome in turn is related to increased incidence of heart disease, diabetes, kidney disease, stroke and death rates.

Details of the Study

 
The study conducted by the Korean National Health and Nutritional Survey included a total of nearly 5000 parous women between 19 and 50 years. The participants were divided into four groups according to the duration of breast feeding over their entire lifetime

• ≤5 months
• 6–11 months
• 12–23 months
• ≥24 months

The adjusted odds ratios (ORs) of MetS and its components and its relationship to the duration of breastfeeding were assessed among the participants.

Women in this study were diagnosed to be suffering from metabolic syndrome if 3 or more of the following five criteria were present namely

• Central obesity (WC >80 cm) using the International Obesity Task Force criteria for Asian-Pacific populations to determine waist circumference
• Systolic BP ≥130 mmHg, Diastolic BP ≥85 mmHg, or treated with anti-hypertensive medication
• HDL-C <50 mg/dL in women or on lipid lowering medications
• TG ≥150 mg/dL or on lipid lowering medications
• Fasting glucose ≥100 mg/dL or previously diagnosed with Type 2 diabetes mellitus

Findings of the Study

 
The findings of the study were as follows

• Women who breastfed for ≥12 months during their lifetime had a lower risk of MetS than those with lifelong breast feeding for ≤5 months.
• Breast feeding for 12–23 months was shown to be linked to lower risks of high blood pressure and elevated blood glucose.
• Women who breastfed ≥24 months demonstrated a lower risk of MetS than those who breastfed for only 12–23 months during their life.
• Breast feeding for ≥24 months was associated with decreased risk of high blood glucose and triglycerides
• However, the relationship between breast feeding ≥24 months and elevated BP was not statistically significant.

The above findings suggest that lifelong breast feeding for 12 months or more may be associated with lower risk for MetS in parous women.

Potential Limitations of the Study

• The results demonstrate an association between breastfeeding and metabolic syndrome but not a causal relationship.
• The duration of breastfeeding was based on the women’s recollection of the event which may have been mistaken.
• The degree of breastfeeding was not used for the analysis.
• The findings of the study could not be analyzed in the context of pregnancy related conditions such as gestational hypertension and diabetes which could lead to metabolic syndrome later in life.

Suggested Mechanisms of How Breastfeeding Could Decrease MetS Risk

• A suggested possible explanation is that breast feeding, a normal physiologic form of energy expenditure could stimulate long-term protective health outcomes in the mother.
• Women who breastfeed more have reduced activation of hypothalamus-pituitary-adrenal axis and greater vagal tones, leading to lower levels of stress which in turn reduces the risk of developing metabolic syndrome.

Benefit of the Study

 
The results of this study might promote the declining practice of breastfeeding globally among women in the present day due to various reasons.

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It will be fitting to conclude with the remarks of Susan G. Kornstein, MD, Editor-in-Chief of Journal of Women's Health, in which the research was published, who said "The advantageous effects of breastfeeding for newborns and babies are well established, and this study, which suggests that breastfeeding may protect the mother against metabolic syndrome, further adds to the evidence base supporting the benefits of breastfeeding for maternal health," 

Reference:

1. The Relationship of Metabolic Syndrome with Stress, Coronary Heart Disease and Pulmonary Function - An Occupational Cohort-Based Study - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4537246/)

Source-Medindia