The wide impact on health of a relative omega-3 deficit reflects the multiple actions of selective hormone receptors which respond differently to n-3 and n-6 hormones. As a result, unintended dietary imbalances that cause imbalance among tissue precursors of hormone actions have selective effects on nearly every cell and tissue in the human body and influence many aspects of human physiology and pathology. The list of health problems related to omega-3 deficits with elevated proportions of omega-6 in the hormone precursors has grown to include atherosclerosis, thrombosis, arrhythmia, heart attacks, stroke, immune-inflammatory disorders, asthma, arthritis, cancer proliferation, obesity, psychiatric disorders, depression, suicide, homicide[21, 22], oppositional behavior, unproductive workplace behaviors, length of stay in hospitals and annual healthcare claim costs.
Health risk assessment (HRA) with a simple low-cost finger-tip blood sample[10–12] informs individuals of their personal essential fatty acid status. Such test results relate quantitatively to the risk for cardiovascular mortality (death = 3 × (%n-6 in HUFA) - 75;). The biomarker value of the% n-6 in HUFA links the balance of n-3 and n-6 acids in daily foods to the risk of many aspects of immune-inflammatory and cardiovascular disease[17, 18].
The associated health claim costs for disorders linked to omega-3 deficits[18–24] are predictably less as people voluntarily choose foods that lower their HRA value from its current USA average level near 80% n-6 in HUFA to a lower value near 60%. Figure2 illustrates that such a lowering represents changing the average daily Omega 3–6 Balance Food Score from −7 to −3. Figure 3A illustrates that a majority of vegetables have Scores more positive than the typical daily American average balance near −6 or −7.
The Omega 3–6 Balance Scores rapidly and easily identify food items that can move a person’s daily average Food Score from −7 to −3 or to an even more positive value. For example, combining a tablespoon of flaxmeal (+32) with a half cup of oatmeal (−4) or adding flax oil (+46) to canola oil (−11) helps maintain a more positive overall food balance. Similarly, peanut butter (−24) with added flax meal and oil has a more positive score. Consumers can readily see that eating farmed (+28) or wild (+73) grilled salmon can do much to providing a more positive overall daily food balance.
The ease with which Omega 3–6 Scores help interpret the impact of foods is illustrated with the top 100 foods from a USDA Key Foods list based on NHANES 2007–08 intake data. The un-weighted average Score of the 100 items is about −6, equivalent to an HRA value of 78% n-6 in HUFA (commonly reported for Americans). None of the 100 items was a seafood. When the ten most negative food items are removed, the un-weighted average Score of the remaining 90 items is about −3, equivalent to an HRA value of 60% n-6 in HUFA (commonly associated with a Mediterranean diet). Traditional Mediterranean foods do not include the ten items removed: soybean oil, -50; mayonnaise, -46; tub margarine, -39; microwave popcorn, -37; “Italian” salad dressing, -35; potato chips, -29; stick margarine, -28; vegetable shortening, -28; peanut butter, -24; tortilla chip snacks, -24. However, they do include some seafood items that would move the daily overall average to values more positive than −3.
The rise in dietary omega-6 intake caused by added food oils in USA food supplies during the 20th century has been associated with a rise in the prevalence of many chronic disorders. As a result, much discussion now addresses dietary approaches that can lower the preventable risk for these serious health problems. Recent comments have emphasized the need to account fully for all n-3 and n-6 dietary intakes to avoid mis-interpreting the outcomes from large clinical trials.
Until now, concerns over unwanted balances among n-3 and n-6 essential fatty acids have often addressed the concept of n-3/n-6 ratios without providing an explicit estimate of how such ratios of fatty acids in foods quantitatively impact the balance of HUFA accumulated in tissues. We believe that the new explicit Omega 3–6 Balance Food Scores can help people easily identify and make informed food choices that lower their personal health risk assessment biomarker value.
Limitations of diet and risk assessment
Attempts to describe quantitative abundances of nutrients in foods eaten are confounded by varietal and seasonal differences in nutrient composition, imprecise recall of quantities eaten and highly diverse intakes in meals from day-to-day and week-to-week. Nevertheless, estimates are useful for predicting how the amounts of vitamin-like n-3 and n-6 nutrients in our food affect average proportions of n-3 and n-6 hormone precursors accumulated in our body. Quantitative descriptions of accumulated n-3 and n-6 hormone precursors are confounded by diverse modes of recording and reporting tissue composition. Finally, relating relative tissue abundances to receptor-mediated health outcomes is confounded by diverse biomarkers used to characterize health risk. Biomarkers that are only predictive of harm and are not factors mediating harm have distracted attention and resources away from decreasing preventable mediators during primary prevention[24, 29]. The earlier developed interactive planning tool, KIM-2, successfully links key variables for a single day’s intake. However, some people want only to consider the impact of a single food in overall health conditions. Omega 3–6 Balance Scores were developed as a tool for them to evaluate a single food independent of any other food that may be eaten. Calorie-weighted average scores for a day’s combined food are analogous to en% values in daily menu plans of the existing interactive KIM-2 software. Figure1 shows how a day’s calorie-weighted average score predicts the likely%n-6 in HUFA using 46–4.57 × calorie-weighted average. Thus, the 3–6 differences among essential fatty acids (rather than 3/6 ratios) give a useful tool to use in discussing a food’s contribution to health.