Omega-3 deficiency impairs honey bee learning

Abstract

Deficiency in essential omega-3 polyunsaturated fatty acids (PUFAs), particularly the long-chain form of docosahexaenoic acid (DHA), has been linked to health problems in mammals, including many mental disorders and reduced cognitive performance. Insects have very low long-chain PUFA concentrations, and the effect of omega-3 deficiency on cognition in insects has not been studied. We show a low omega-6:3 ratio of pollen collected by honey bee colonies in heterogenous landscapes and in many hand-collected pollens that we analyzed. We identified Eucalyptus as an important bee-forage plant particularly poor in omega-3 and high in the omega-6:3 ratio. We tested the effect of dietary omega-3 deficiency on olfactory and tactile associative learning of the economically highly valued honey bee. Bees fed either of two omega-3-poor diets, or Eucalyptus pollen, showed greatly reduced learning abilities in conditioned proboscis-extension assays compared with those fed omega-3-rich diets, or omega-3-rich pollen mixture. The effect on performance was not due to reduced sucrose sensitivity. Omega-3 deficiency also led to smaller hypopharyngeal glands. Bee brains contained high omega-3 concentrations, which were only slightly affected by diet, suggesting additional peripheral effects on learning. The shift from a low to high omega-6:3 ratio in the Western human diet is deemed a primary cause of many diseases and reduced mental health. A similar shift seems to be occurring in bee forage, possibly an important factor in colony declines. Our study shows the detrimental effect on cognitive performance of omega-3 deficiency in a nonmammal.fatty acids | alpha-linolenic acid | Apis mellifera | associative conditioning | proboscis extension response

Bumble bees regulate their intake of the essential protein and lipid pollen macronutrients

“…Excessive amount of ω-6 in diets (i.e. ω-3 deficiency) has been linked to chronic diseases in humans (Simopoulos, 2002(Simopoulos, , 2008, and impaired learning and physiology in honey bees (Arien et al, 2015). Moreover, high polyunsaturated fatty acids (including essential fatty acids) in the diet might lead to lipid peroxidation and cell damage, and cell membrane composition has been linked to the vast difference in maximum lifespan between honey bee queens (highly monounsaturated) and workers (highly polyunsaturated) (Haddad et al, 2007).…”

Best be(e) on low fat: linking nutrient perception, regulation and fitness

“…amino acids (AAs), when assessing pollen nutritional quality. Moreover, while FAs are essential for bees (Arien et al ; Annoscia et al ), increased FA concentrations in pollen had a more detrimental effect on survival and reproductive fitness than AAs. Our results consequently suggest that, when assessing pollen nutritional quality, B. terrestris , and potentially also other bees, ‘prioritise’ perception of one particular nutritional cue, which also appears to be the nutrient with the strongest fitness consequences.…”

The Importance of Phytoplankton Biomolecule Availability for Secondary Production

“…To our knowledge, our study is the first to report direct negative effects of ω-6 FAs on Daphnia or any zooplankton species, and these kinds of observations are scarce for invertebrates or aquatic organisms in general. However, in terrestrial environments it is shown that a high pollen ω-6:3 ratio can cause the collapse of honey bee colonies, since the relative dietary shortage of ω-3 compared to ω-6 decreases bee health and greatly reduces their learning abilities (Arien et al, 2015). Further, excess dietary gain of ω-6 FAs is known to promote cardiovascular disease, cancer, and inflammatory and autoimmune diseases in humans (Simopoulos, 2008).…”