Cracking the Peanut: Keeping up with healthy eating habits – a two-part series

Over the years, many health studies have emerged that conclude that nuts are extremely beneficial to good health (this isn’t news to us!). The claims are plentiful and point to the power of peanuts. Let’s take a closer look at why USA-grown peanuts should have a commanding presence in homes across Canada.

Cardiovascular Health: Eating peanuts and peanut butter can reduce the risk of cardiovascular disease (CVD). Studies have found that diets high in monounsaturated fatty acids contribute to a decreased risk of CVD. In additional to their fatty acid composition, peanuts contain other constituents that may contribute to a reduced risk of CVD.

A study published in the American Journal of Clinical Nutrition found that diets high in monounsaturated fatty acids contributed to a decreased risk of CVD. Regular consumption of foods rich in monounsaturated fats such as peanuts, peanut butter and olive oil (along with a diet low in saturated fat) decreased total cholesterol by 10% and LDL cholesterol by 14%. Overall risk for heart disease decreased by 21% versus 12% for a standard Step II low fat diet1.

In addition to their fatty acid composition, peanuts contain other constituents that may contribute to a reduced risk of CVD. Researchers at Purdue University found that regular peanut consumption lowered serum triacylglycerol, increased serum magnesium concentration and augmented intakes of folate, copper, alpha-tocopherol, arginine and fibre2.

Weight loss: Peanuts and peanut butter are known to have high satiety values, so a standard serving size of peanuts or peanut butter (30 grams/2 tablespoons) will keep you feeling full longer than carbohydrate-based foods.

A recent study showed that participants’ hunger was reduced for 2½ hours following a snack of peanuts or peanut butter, versus only 30 minutes after eating various other snack foods (such as pickles and rice cakes). The participants eating peanuts and peanut butter also consumed fewer total calories throughout the day3. Researches affiliated with Harvard Medical School found that people who followed a moderate-fat, Mediterranean-style diet lost more weight and keep it off for a longer period of time than those who followed a low-fat diet. The moderate-fat diet encouraged the consumption of monounsaturated fats such as peanuts, peanut butter, olive oil and other nuts. At the end of the 18-month study, those who followed the moderate-fat diet on average had reduced their waist size by an impressive 6.9 cm and lost 4.1kg in weight. Those assigned to the low-fat diet actually increased their waist size and gained an average of 2.9kg4.

Peanuts and diabetes: A study published in the Journal of American Medical Association found that eating nuts and peanuts may lower the risk of Type 2 diabetes in women. Reduced risk was greatest in those who had the highest nut consumption. Those who:

  • • never/almost never ate nuts had no change in risk;
  • • consumed nuts less than once per week, had an 8% lower risk;
  • • consumed nuts one to four times per week had a 16% lower risk;
  • • consumed nuts five or more times a week had 27% lower risk; and
  • • consumed peanut butter five or more times per week had a 21% lower risk compared to women who never or almost never ate peanut butter5.

Peanuts and fat: While it is important that the general population moderate its fat intake, this does not mean fats should be altogether eliminated from the diet. In fact, the nutrition recommendations for Canadians suggest that about 30 per cent of calories from fat are an appropriate level for most adults and children. It is very important to evaluate the kind of fat making up this 30 per cent. The good news is that 85 per cent of the fat in peanuts in the ‘good’ unsaturated fat.

Peanuts – a low glycemic index choice: The glycemic index (GI) ranks carbohydrates based on their immediate effect on blood sugar levels. Foods with a low GI index fill you up longer and therefore may help you lose weight. The good news for peanut lovers is that the glycemic index for peanuts is very low at just 14, which is a similar GI to green vegetables (GI of 15).

The shakedown on sodium and peanuts: The vast majority of peanut butter available in Canada contains less than 140 milligrams of sodium per stated serving, and is actually considered ‘low in sodium’ by the Canadian Food Inspection Agency. All-natural and no-salt-added peanut butters contain no sodium at all. As for salted peanuts, according to the Canadian Nutrient File, salted, oil-roasted peanuts contain 117 milligrams of sodium per Food Guide Serving (¼ cup or 60 millilitres) – that’s less sodium than you’ll find in a slice of bread or a bagel.

Stay tuned for Part Two of this article in the fall issue of In a Nutshell where we will highlight the five essential nutrients of peanuts.

1 Kris-Etherton, P.M., Pearson, T.A., Wan, Y., Hargrove, R.L., Moriarty, K., Fishell, V., and Etherton T.D. “High monounsaturated fatty acid diets lower both plasma cholesterol and triacylglycerol concentrations,” American Journal of Clinical Nutrition, 1999. 70: 1009-15.
2 Alper, C.M., and Mattes, R.D. “Peanut consumption improves indices of cardiovascular disease risk in healthy adults.” Journal of the American College of Nutrition, 2003. Vol. 22, No. 2, 133-141.
3 Kirkmeyer, S.V. And Mattes, R.D. “Effects of food attributes on hunger and food intake.” International Journal of Obesity, September 2000. Vol. 24, No. 9, 1167-1175.
4 McManus, K., Antinoro, L., and Sacks, F. “A randomized controlled trial of a moderate fat, low-energy diet with a low-fat, low-energy diet for weight loss in overweight adults.” International Journal of Obesity, October 2001. Vol. 25, No. 10, 1503-1511.
5 Jiang, R., Manson, J.E., Stampfer, M.J., Liu, S., Willett, W.C, Hu, F.B. “Nut and peanut butter consumption and risk of type 2 diabetes in women.” Journal of American Medical Association, 2002. 288: 2554-2560.