Journal of Nutrition & Food Sciences
Open Access

Unexpected Outcomes for a High-Foliage Diet

Bill Lands^{* *}Correspondence: Bill Lands, Department of Food Sciences, College Park, USA, Email:

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Description

A 2022 review of lipid nutrition had an unexpected prediction that plant-based diets of non-captive primates may give a tissue balance of n-3 and n-6 Highly Unsaturated Fatty Acids (HUFA) like that seen in blood lipids of people eating traditional Inuit and Japanese foods [1]. This is significant because lower proportions of n-6 in HUFA (i.e., higher proportions of n-3) in blood lipids of such people associate with a lower risk for cardiovascular disease and death [1]. As a result, supplemental n-3 HUFA is widely used to modify the high-risk “Western” diet and lower the Health Risk Assessment (HRA) biomarker, %n-6 in blood HUFA. The review explores the concept that “healthy normal diets” balance intake and expenditure of food energy and balance proportions of n-3 and n-6 HUFA in tissues.

An empirical equation was developed to fit observed hyperbolic, competitive patterns of HUFA accumulation by rats, mice and human volunteers in Chicago and Japan [2]. Overall, it successfully predicted the diet-induced HUFA balance for nearly 4,000 people in 92 subject groups in 34 published studies from 11 different countries [3]. The enzyme dynamics for forming HUFA by the elongation-desaturation pathway appear to be highly conserved since primates and rodents diverged from mammalian precursors 50 million years ago. This retention allows controlled diet-tissue studies with small rodents or primates to serve as surrogates for the likely HRA biomarker produced in an unlikely process of asking human volunteers to eat a single daily diet for prolonged periods.

Importantly, high-foliage diets of primates have nearly equal intakes of 18:2n-6 and 18:3n-3 with negligible amounts of n-3 or n-6 HUFA which animal tissues form from ingested 18:2n- 6 and 18:3n-3 Polyunsaturated Fatty Acids (PUFA; 2). The essential n-3 and n-6 PUFA nutrients compete more efficiently than endogenous n-9 acids for the desaturation and elongation enzymes that produce and accumulate tissue HUFA [1]. Growth of rat pups increased as dietary PUFA increased from 0% to 1% of food energy (1 en%) and it related to the proportion of n-3 and/ or n-6 in HUFA accumulated in tissues. Eating 0.1 en% PUFA gave about half of the maximum response and more than 1 en% PUFA did not further increase the growth or the proportion of its derived HUFA in tissues.

The 2022 review describes how embedding the equation in a relational database, https://omegameals.com, facilitates predicting tissue HRA values likely to result from eating selected combinations of food items [1]. The balance among eleven n-3 and n-6 nutrients in each food item summarize as a single Omega 3-6 Balance Food Score needed to predict the likely HRA score for the overall daily diet [4]. Scores for over 5,000 food items listed at https://omega3scores.com guide alternate food choices for “repair” of diets and recipes. The OmegaMeals.com software allows in silico studies to guide food choices which produce a HRA marker that can be confirmed by direct lipid analysis. Values are familiar examples of food intakes and HUFA balances seen with USA volunteers; 42 en% fat, 10 en% 18:2n-6, 2 en% 18:3n-3 and a HRA value of 79%. The low HRA value of 27% for a prototypic hominid primate was unexpected.

Fatty acids were 14 en% in the diet of non-captive mountain gorillas; mostly 18:2n-6 (30%), 18:3n-3 (21%) and 16:0 (24%) [5]. Herbaceous leaves had more n-3 than n-6 and fruits had much more n-6 than n-3. The prototypic diet suggests that evolving hominid primates may have eaten foods dramatically different from current Daily Nutritional Goals in 2020–2025 Dietary Guidelines for Americans [6]. The advice for Americans to eat 10- fold more 18:2n-6 than 18:3n-3 has no accompanying supportive rationale or interventional evidence of benefit. It contrasts with the fact that higher %n-6 in human tissue HUFA associates with higher risk for chronic cardiovascular and immune-inflammatory disorders.

There may be merit in developing experiments with small primates or closely related rodents (e.g., guinea pigs) eating highfoliage diets. The recommended guinea pig food, timothy hay, probably gives a low HRA value like that seen for humans eating “anti-inflammatory” diets. We need to learn more about new combinations of food items that humans may find more rational, desirable and healthier than current diets labelled as “vegetarian”, “Mediterranean”, or “paleolithic”.

Acknowledgement

Jim Hoyt designed computer software and websites for making in silico estimates of n-3 and n-6 nutrient impacts on health risk assessment and Dr. Norberta Schoene guided our focus on Recipe Repairs.

Competing Interest

The authors declare that they have no competing interests.

References

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