Health

Another warning about supplements comes from a finding that older adults taking more than twice the recommended daily allowance (RDA) of folate were more likely to have peripheral neuropathy if they had a common genetic variant linked to reduced cellular vitamin B12 availability.

B12 deficiency is a common problem for older adults, and those with this gene variant (estimated to occur in one in six Americans) are vulnerable to conditions related to vitamin B12 deficiency even if they consume normal amounts of B12.

The study, involving 171 older adults (60+), found that those with the GG variant of the TCN2 gene were three times more likely to develop peripheral neuropathy. But among those who consumed more than twice the RDA of 800 micrograms of folate, individuals with the gene variant had seven times the risk of peripheral neuropathy compared to those without. There was no significant difference for those consuming less than 800 micrograms of folate a day.

Note that the average daily folate intake for U.S. adults over 50 is in fact more than twice the Recommended Daily Allowance. Moreover, it's estimated that some 35% of Americans take folate supplements.

https://www.eurekalert.org/pub_releases/2016-10/tuhs-hfi100716.php

Hathairat Sawaengsri, Peter R Bergethon, Wei Qiao Qiu, Tammy M Scott, Paul F Jacques, Jacob Selhub, and Ligi Paul Transcobalamin 776C→G polymorphism is associated with peripheral neuropathy in elderly individuals with high folate intake Am J Clin Nutr 2016 104: 6 1665-1670; First published online October 12, 2016. doi:10.3945/ajcn.116.139030 

A review and meta-analysis of studies from 1982 to 2015, evaluating relationships between egg intake and coronary heart disease (total of 276,000 subjects) and stroke (total of 308,000 subjects) has found that consumption of up to one egg per day had no association with coronary heart disease (CHD) and a 12% reduction of stroke risk.

The study follows on from a 2015 meta-analysis in which dietary cholesterol was shown to have no association with cardiovascular diseases, including coronary artery disease and stroke. Consistent with this, the 2015 Dietary Guidelines for Americans placed no daily limit on dietary cholesterol and noted eggs are an affordable, accessible, nutrient-rich source of high quality protein.

https://www.eurekalert.org/pub_releases/2016-11/enc-oep102816.php

Alexander, D. D., Miller, P. E., Vargas, A. J., Weed, D. L., & Cohen, S. S. (2016). Meta-analysis of Egg Consumption and Risk of Coronary Heart Disease and Stroke. Journal of the American College of Nutrition, 35(8), 704–716. https://doi.org/10.1080/07315724.2016.1152928

A mouse study has found that fish oil, which contains high levels of omega-3 polyunsaturated fatty acids, significantly helped clear amyloid-beta peptides (involved in the development of Alzheimer’s) from the brain.

https://www.eurekalert.org/pub_releases/2016-10/foas-abo102616.php

Huixia Ren, Chuanming Luo, Yanqing Feng, Xiaoli Yao, Zhe Shi, Fengyin Liang, Jing X. Kang, Jian-Bo Wan, Zhong Pei, and Huanxing Su. Omega-3 polyunsaturated fatty acids promote amyloid-β clearance from the brain through mediating the function of the glymphatic system. FASEB J. doi:10.1096/fj.201600896 ; http://www.fasebj.org/content/early/2016/10/07/fj.201600896.abstract

A study involving 1,818 Hispanic Americans has confirmed that diabetes, whether controlled or not, is linked to worse measures of cardiac structure and function, and also shows that this happens very early in the development of diabetes.

https://www.eurekalert.org/pub_releases/2016-10/cums-gia102116.php

Demmer, R. T., Allison, M. A., Cai, J., Kaplan, R. C., Desai, A. A., Hurwitz, B. E., … Rodriguez, C. J. (2016). Association of Impaired Glucose Regulation and Insulin Resistance With Cardiac Structure and Function. Circulation: Cardiovascular Imaging, 9(10), e005032. https://doi.org/10.1161/CIRCIMAGING.116.005032