Symptoms of vitamin E deficiency are rare, but according to at least four national surveys, most Americans consume less than the government’s Recommended Daily Allowance (RDA) of this essential nutrient.1 The authors of an August 2015 study published in PLOS-One call vitamin E a “shortfall nutrient” because over 90% of Americans consume insufficient quantities and because low vitamin E status has been linked to multiple health consequences, including increased total mortality.2
Vitamin E is clearly important, but can the Paleo diet provide adequate levels? After all, some of the most frequently cited “best dietary sources” aren’t Paleo compliant. Are supplements necessary? The RDA for males and females above 14 years of age is 15 mg daily. The following table shows vitamin E values for 100 grams of various foods and their corresponding RDAs.
The foods highest in vitamin E are predominantly seeds/nuts and their oils. Seed oils are excluded from the Paleo diet, however, primarily because they contain excessive amounts of polyunsaturated fatty acids (PUFAs). Almonds, hazelnuts, and sunflower seeds are good Paleo vitamin E sources. Fruits and vegetables are also good, but they contain very low amounts. Those small amounts accumulate, however, so collectively they are indeed significant.
Probably the best Paleo vitamin E source is olive oil. One tablespoon packs 1.9 mg, which is 10% of the RDA. You can add a few tablespoons of olive oil on salads or cooked vegetables, or use it for cooking. Olive oil becomes even more attractive when you consider its relatively low levels of PUFAs.
We should note that vitamin E functions primarily as an antioxidant, which means it protects against cellular damage by scavenging for free radicals. PUFAs have a high propensity to oxidize and oxidation creates free radicals. Therefore, high levels of PUFAs can negate vitamin E’s benefits. If we refer back to our chart, we see that many foods rich in vitamin E are also PUFA-rich.
Back in 1988, Brazilian scientists theorized that total vitamin E content is not the best indicator of vitamin E activity for vegetable oils. Using high-pressure liquid chromatography, they analyzed various oils for vitamin E activity and determined that high PUFA content offsets vitamin E activity and that oil refinement causes vitamin E losses upwards of 22%, especially during steam deodorization.3 They proposed that for vitamin E, unrefined oils beat their refined counterparts and that the ratio of vitamin E to PUFA better indicates vitamin E potential compared to absolute vitamin E levels.
A British Journal of Nutrition study published this month (October 2015) reiterates the same point: “The vitamin E requirement will increase with an increase in PUFA consumption and with the degree of unsaturation of the PUFA in the diet.”4 Another just-published study is also raising interest about vitamin E, particularly for its conclusion that those who have metabolic syndrome (about one-third of the US population) don’t absorb vitamin E as effectively as those who are healthy.5 Lead author of this latter study, Richard Bruno, commented, “Dietary requirements of nutrients are generally defined only in the context of what a healthy person needs, but considering that two-thirds of Americans are overweight or obese, a healthy person might not be representative of our society. This work tells us that at least one-third of Americans have higher vitamin E requirements than healthy people.”6
With all this in mind, one might conclude that supplementation is the best way to maintain adequate vitamin E levels. In the 1980s, scientists began to understand how free radicals contribute to atherosclerosis, cancer, vision loss, and various other chronic conditions. This sparked interest in the preventative potential of antioxidant supplements, particularly vitamin E. Several observational studies, including the Nurses’ Health Study, suggested 20 – 40% reductions in heart disease risk among people taking vitamin E supplements.7
Follow-up randomized controlled trials, however, dampened enthusiasm for vitamin E supplements, both for heart disease and cancer prevention. One meta-analysis even concluded that high-dose vitamin E supplementation may increase all-cause mortality and should be avoided.8 For those who are interested, the Harvard School of Public Health has an excellent summary on the history of research on vitamin E supplementation.
In conclusion, supplementation may provide benefits for certain conditions, but food sources of vitamin E are widely considered to be superior. Many of the richest food sources, however, are high-PUFA seed oils. High levels of PUFAs counteract vitamin E’s antioxidant capacity. It’s best to eliminate vegetable seed oils from your diet. The Paleo Diet provides plenty of vitamin E via olive oil, small quantities of seeds and nuts, and large amounts of vegetables.
5. Mah, E., et al. (October 7, 2015). α-Tocopherol bioavailability is lower in adults with metabolic syndrome regardless of dairy fat co-ingestion: a randomized, double-blind, crossover trial. American Journal of Clinical Nutrition [epub ahead of print].