Diets Low in Sulfur Amino Acids are Associated with Lower Cardiometabolic Risk

by | Apr 5, 2021 | 2020, Amino Acids, Cardiovascular Health

Written by Joyce Smith, BS. This study suggests that diets lower in sulfur amino acids (SAA) and very close to the estimated daily requirement (EAR) of 15 mg/kg/day, are associated with a reduced risk for cardiometabolic diseases.

heart healthWhile SAAs are necessary for metabolism and overall general health, accumulating evidence from animal studies points to anti-aging benefits of a restricted SAA diet such as reduced age-relate diseases 1,2 and increased longevity 3. Well-documented evidence for healthy levels of SAAs include reductions in weight, adiposity 2,4, and insulin resistance (IR), and blood biomarker improvements in insulin, glucose, leptin, and adiponectin 2,5. Total SAAs, considered essential to the body, have an EAR of 15 mg/kg/day to meet the nutritional needs of half of our healthy adult population and a Recommended Daily Allowance (RDA) of 19 mg/kg/day. Methionine has an RDA of 12.mg/kg/day and cysteine’s RDA is 6.6 mg/kg/day to meet the nutritional needs of 98% of healthy adults 6,7. Very few studies have shown that the majority of adult diets consume SAAs that are well in excess of  dietary SAA requirements 7,8, thus prompting the current study 9 by Zhen and colleagues.

The team did a cross-sectional analysis of data on 11,576 participants from the Third National Examination and Nutritional Health Survey to determine whether excessive dietary intake of sulfur amino acids may be associated with an increased risk for cardiovascular disease (CVD) based on relevant risk-related biomarkers.

Overall, participants who ate foods containing fewer SAAs tended to have a decreased risk for cardiometabolic disease. Sulfur amino acid rich diets include protein-rich foods, such as meats, dairy, nuts and soy. After accounting for body weight, the researchers found that average American SAA intake was almost two and a half times higher than the EAR of 15 mg/kg/day and among participants in the highest SAA quintile, intake was over 4-times higher than the EAR.

Diets with reduced sulfur amino acids were associated with a decreased risk for cardiovascular disease; however, higher sulfur amino acid intake was associated with a higher composite cardiometabolic risk score after accounting for potential confounders like age, sex and history of diabetes and hypertension (Ptrend < 0.01). Risk scores for the three highest total SAA quintiles were significantly higher compared to the lowest SAA quintile (P < 0.01). When examining specific components of the composite risk factor, they found that participants in the lowest SAA intake quintile had significantly lower levels of cholesterol, glucose, glycated hemoglobin, uric acid, BUN, insulin and eGFR. Researchers suggest that the SAA reductions may have improved insulin secretion and its signaling pathway which in turn may have led to improved glucose stability and insulin sensitivity 8.

While dietary intake of total SAA was positively associated with levels of glycated hemoglobin, eGFR, cholesterol, HDL cholesterol, glucose, uric acid, BUN, and insulin (Ptrend 0.05), researchers found no associations between total SAA intake and blood pressure and serum levels of triglycerides, or CRP. They also found that high sulfur amino acid intake was associated with every type of food except grains, vegetables and fruit. Meats and other high-protein foods are generally higher in sulfur amino acid content, where as a plant-based diet containing fruits and vegetables contains lower amounts of sulfur amino acids. Thus many Americans who consume a diet rich in meat and dairy products, exceed the average daily requirement for SAAs.

This study provides the first epidemiologic evidence that excessive dietary intake of SAAs may be related to chronic disease outcomes in humans.  While this cross-sectional study evaluated dietary intake and cardiometabolic disease risk factors at only one point in time, the association between increased SAA intake and risk for cardiometabolic disease was strong. Researchers recommend a prospective longitudinal study that allows for analysis to further substantiate the effects of dietary SAA reduction and health outcomes over time.

Source: Dong, Zhen, et al. “Association of sulfur amino acid consumption with cardiometabolic risk factors: Cross-sectional findings from NHANES III.” EClinicalMedicine 19 (2020): 100248.

© 2019 This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Click here to read the full text study.

Posted April 5, 2021.

Joyce Smith, BS, is a degreed laboratory technologist. She received her bachelor of arts with a major in Chemistry and a minor in Biology from  the University of Saskatchewan and her internship through the University of Saskatchewan College of Medicine and the Royal University Hospital in Saskatoon, Saskatchewan. She currently resides in Bloomingdale, IL.

References:

  1. Cavuoto P, Fenech MF. A review of methionine dependency and the role of methionine restriction in cancer growth control and life-span extension. Cancer treatment reviews. 2012;38(6):726-736.
  2. Miller RA, Buehner G, Chang Y, Harper JM, Sigler R, Smith-Wheelock M. Methionine-deficient diet extends mouse lifespan, slows immune and lens aging, alters glucose, T4, IGF-I and insulin levels, and increases hepatocyte MIF levels and stress resistance. Aging Cell. 2005;4(3):119-125.
  3. Orentreich N, Matias JR, DeFelice A, Zimmerman JA. Low methionine ingestion by rats extends life span. The Journal of nutrition. 1993;123(2):269-274.
  4. Perrone CE, Malloy VL, Orentreich DS, Orentreich N. Metabolic adaptations to methionine restriction that benefit health and lifespan in rodents. Exp Gerontol. 2013;48(7):654-660.
  5. Malloy VL, Krajcik RA, Bailey SJ, Hristopoulos G, Plummer JD, Orentreich N. Methionine restriction decreases visceral fat mass and preserves insulin action in aging male Fischer 344 rats independent of energy restriction. Aging Cell. 2006;5(4):305-314.
  6. Rose WC. Amino acid, requirements of man. Paper presented at: Federation Proceedings. Federation of American Societies for Experimental Biology1949.
  7. Trumbo P, Schlicker S, Yates AA, Poos M. Dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids. J Am Diet Assoc. 2002;102(11):1621-1630.
  8. Yin J, Ren W, Chen S, et al. Metabolic Regulation of Methionine Restriction in Diabetes. Molecular nutrition & food research. 2018;62(10):e1700951.