Resveratrol, Pregnancy, and Acceptable Daily Intakes
According to Yahoo! News, women who might become pregnant should not use resveratrol supplements. Pregnancy is an especially sensitive experience and women should be cautious about the substances ingested (and inhaled). After all, cigarette smoking is known to increase the risk of premature birth. Although alcohol consumption increases the risk of spontaneous abortion, it is the dose that matters. Pregnant women are advised to avoid alcohol altogether but 1 or 2 drinks once or twice a week is permitted.
Recent resveratrol headlines should have a similar caveat. Roberts and colleagues fed pregnant female macaques a diet containing 0.37% resveratrol for 9 months. A 0.37% diet means 0.37g resveratrol per 100g of food (or 370 mg resveratrol per 100g diet). The investigators do not report the body weight of these female primates or their food intake.
According to the National Primate Research Center at the University of Wisconsin, the average weight of a female Japanese macaque is 8.4 kg. Adult Japanese macaques (13-15 kg) living in captivity eat ~723-1000 grams of food per day. Thus, 370mg/100g food times 750g food/day equals 2,775 mg of resveratrol consumed daily. In a 10 kg primate, this calculates to 277 mg/kg body weight.
DSM Nutritional Products manufactures and sells resveratrol. An ADI, measured in units of mg per kg body weight, is the amount of a substance that can be ingested over a lifetime without appreciable risk. Our acceptable daily intake (ADI) for resveratrol is 7.5 mg per kilogram body weight per day. For a person weighing 60-70 kg (132-154 lbs), that is 450- 525 mg resveratrol per day. Feeding a 10 kg primate 277 mg resveratrol per kg is ~37 times the ADI. At this excessive dose, Roberts and colleagues did not find any statistically significant effect of resveratrol supplementation on fetal body mass or mass of any fetal organs (including pancreatic islet mass o β-cell mass). The sole exception was fetal pancreatic mass. Finding a single statistically significant comparison among a dozen comparisons is a statistical probability.
Like other researchers who tested more moderate doses in humans, resveratrol supplementation in primates had positive effects on vascular function and lipid metabolism. This study confirms reports that resveratrol supplementation may improve biomarkers of metabolic function.
Pregnant women should still be careful about what they eat and drink. Scientists need to adhere to ADIs when testing the safety of biologically-active compounds. Journalists should provide context on dose when translating science for the public.
Roberts VHJ, Pound LD, Thorn SR, Gillingham MB, Thronburg KL, Friedman JE, Frias AE, Grove KL. Beneficial and cautionary outcomes of resveratrol supplementation in pregnant nonhuman primates. 2014 FASEB J doi: 10/10.1096/fj.13-245472
Andersen A-M N, Andersen PK, Olsen J, Gronbaek M, Strandberg-Larsen K. Moderate alcohol intake during pregnancy and risk of fetal death. 2011 Int J Epidem doi: 10.10193/ije/dyr189
Sawada A, Sakaguchi E, Hanya G. Digesta passage time, digestibility, and total gut fill in captive Japanese macaques (Macaca fuscata): Effects Food Type and Food Intake Level. 2011 Int J Primatol doi: 10.1007/s10764-010-9476-5
Konings E, Timmers S, Boekschoten MV, Goossens GH, Jocken JW, Afman LA, Muller M, Schrauwen P, Mariman EC, Blaak EE. The effects of 30 days resveratrol supplementation on adipose tissue morphology and gene expression patterns in obese men. 2014 Int J Obesity doi:10.1038/ijo.2013.155
Wong RH, Howe PR, Buckley JD, Coates AM, Kunz I, Berry NM. Acute resveratrol supplementation improves flow-mediated dilatation in overweight/obese individuals with mildly elevated blood pressure. 2011 Nutr Metab Cardiovasc Disdoi:10.1016/j.numecd.2010.03.003