The study carried out by the Ohio State University (OSU) and Linus Pauling Institute at Oregon State University looked at how vitamin E form α-tocopherol availability is affected by dairy fat intakes in people with Metabolic Syndrome (MetS).
"What we found was that tissues of obese people are rejecting intake of some of these lipids because they already have enough fat," said Margaret Traber, a professor in the College of Public Health and Human Sciences at OSU, and a principal investigator at the Linus Pauling Institute.
"In the process they also reject the associated vitamin E. So even though the tissues are facing serious oxidative stress, the delivery of vitamin E to them is being impaired, and they are not getting enough of this important micronutrient."
Fat and vitamin E
Fat generates oxidants that increase metabolic stress, the authors said. Vitamin E, along with vitamin C and some other antioxidants, are natural dietary defences against this problem. However they said millions of Americans – more than 92% by some measures – eat a diet deficient in vitamin E, often about half the desired amount.
Oregon State University said MetS affects more than one out of every three adults in the US. It is characterised in people who have at least three of five common issues that raise health concerns - excess abdominal fat, high blood pressure, low ‘good’ cholesterol, and/or high levels of blood sugar and triglycerides.
The researchers were interested in how dairy fat affects α-tocopherol pharmacokinetics in MetS, theorising that as a fat soluble micronutrient vitamin E would be available at increased levels in overweight people who consume large amounts of fatty foods.
The randomised, crossover, double-blind study was conducted in healthy and MetS adults who were given encapsulated α-tocopherol at recommended daily levels with either non-fat, reduced fat or full-fat milk before blood sample collection (72 hour intervals).
The vitamin E family
There are eight forms of vitamin E: Four tocopherols (alpha, beta, gamma, delta) and four tocotrienols (alpha, beta, gamma, delta).
The majority of the science in the past has looked at vitamin E in the alpha-tocopherol form in the context of cardiovascular disease, cancer, and eye disease.
The results showed that regardless of health status, increasing amounts of dairy fat did not affect the bioavailability of α-tocopherol. The MetS group had lower absorption of α-tocopherol than the healthy group of participants. The authors concluded that their findings support higher dietary requirements of vitamin E for adults with metabolic syndrome.
“Weight loss can sometimes actually worsen a nutrient deficiency.”
“…when people try to lose weight, often the first thing they do is limit their fat intake,” Traber said. “This may make sense if you are trying to reduce calories, but fat is the most common source of vitamin E in our diets, so that approach to weight loss can sometimes actually worsen a nutrient deficiency.”
A reasonable approach, they said, would be to try to eat a balanced and healthy diet, even if attempting to lose weight, while also taking a daily multivitamin that includes 100% of the recommended daily allowance of vitamin E, which is 15 mg per day in the US.
The European Food Safety Authority (EFSA)’s Dietetic Products, Nutrition and Allergies (NDA) pnael has established adequate intakes (AIs) of 13 mg/day for men and 11 mg/day for women.
Source: American Journal of Clinical Nutrition
2015; 102 (5): 1070 DOI: 10.3945/ajcn.115.118570
“α-Tocopherol bioavailability is lower in adults with metabolic syndrome regardless of dairy fat co-ingestion: a randomized, double-blind, crossover trial”
Authors: E. Mah et al