Functional Foods – Nuts

Nuts are one of the functional foods that are one of the high potassium foods. They are frequently avoided because of their high fat content, but the type of fats they contain is one of the main contributions to their favorable health effects beyond their high potassium content. The fats they contain are mostly the healthy fats, except for coconut which has a high saturated fat content.

The high potassium content of the various nuts contributes to their blood pressure lowering effect, as well as reducing the chances of osteoporosis. The potassium to sodium ratio reaches 1025 at the high end in unsalted nuts. These high ratios reduce aldosterone secretion by the adrenal glands, resulting in more excretion of potassium and less of sodium and calcium.

Favorable Effects Beyond Potassium

But many of the favorable effects on the heart and blood vessels may be from the fats that the nuts contain or the phytochemicals. Coconuts have mostly saturated fat, so they are not as healthy as other nuts or legumes. Walnuts have a large percentage of their calories in the form of polyunsaturated fat. Macadamia nuts have a large percentage of calories from monounsaturated fat. Others have variable percentages of polyunsaturated and monounsaturated fat.

Saturated fat has been shown repeatedly to contribute to atherosclerosis, producing plaque in blood vessels, which in the coronary vessels leads to myocardial ischemia and infarction (heart attack). Polyunsaturated and monounsaturated fats reduce plaque formation with less chance of peripheral vascular disease, heart attack and stroke.

The healthy components nuts contain include omega 3 fats, soluble fiber, polyphenols and flavonoids. Although these components are believed to have favorable effects on health, it has been difficult to show the benefit. The studies that isolated some of these components had variable results with some showing favorable effects, some showing no effect, and some showing unfavorable effects.

In many studies, the mono and polyunsaturated fats lower total cholesterol and LDL, as does the soluble fiber. The polyphenols lower free radicals and inflammation through their antioxidant activity, both direct and indirect as discussed here. Nuts help vascular dilatation and reduce hypertension. We have discussed several papers showing benefits from the type of fats in nuts here and the phytochemicals here.

Whole Nuts Are Better

The nuts themselves have been shown to have the favorable effects. Nuts have been one of the leading food groups to have favorable reports. The concern about weight gain from the high percentage of fat in nuts has been shown to be unfounded. Nuts can even be included successfully in a weight loss program. See our discussion here.

By acting through several pathways they can influence the body's physiology. When a single component, such as isolated vitamin E, is given, only one or a few pathways are affected. The body may not have the same response as when multiple pathways are affected in a synergistic fashion from all the components of the intact food.

Furthermore, when multiple food groups that have functional effects are combined, significant changes in the body's metabolism can occur. Using one component of a food is like using a garden hose to put out a house fire. Using one food group is like a fireman's hose. Using multiple food groups is like using multiple fire hoses.

For tables of the high potassium foods in different food groups, look under the list of posts for the table of interest here.

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