Peanut butter is big news lately. Two recent studies have found previously unknown health benefits of this staple food. The first, jointly conducted by Purdue University and the Federal University of Vicosa in Brazil, published in the British Journal of Medicine (Reis CE, 2013 Jun; 109(11)), found that eating peanuts or peanut butter at breakfast helped control blood sugar throughout the day – even through a high-glycemic lunch – and controlled appetite for up to twelve hours.
Study participants, obese women at high risk for Type II Diabetes, underwent three phases during this study. Along with a breakfast of cream of wheat and orange juice, they were fed 1.5 ounces of dry-roasted peanuts. In phase two they had three tablespoons of peanut butter with breakfast. In phase three (the control,) they ate no peanuts or peanut butter at all. In all three phases they were later served a high-carbohydrate lunch of white bread with strawberry jam. Blood glucose levels were analyzed via blood samples after each meal. Participants were asked to rate their appetites three hours after each meal and keep a food diary for the rest of the afternoon and evening.
The conclusion: Participants who started their day with peanuts or peanut butter maintained lower and more consistent blood sugar levels throughout the day, even after their sugary lunch. They also reported less desire to eat for up to 8 – 12 hours after breakfast than the control group. This is attributed to the fact that peanuts promote an increase in the secretion of the hormone PYY which has an appetite suppressing effect. Peanut butter appeared to have a slightly greater effect on appetite suppression and blood glucose levels, which researchers suppose may be due to the fact that the processed product (containing ruptured peanut cells and greater surface area) may have helped further slow the rate of carbohydrate absorption from the gut into the blood stream. The researchers do not necessarily think this effect extends to other types of nuts or nut butters, but that peanuts have a unique synergy due to the fact that they contain more protein (8g per ounce) than any other nut and are also a good source of fiber providing 2.5g per ounce.
Another study, jointly funded by the Breast Cancer Research Foundation and the U. S. National Institutes of Health (Health Day News, 2013), fount that eating peanut butter early in life may reduce a woman’s risk of developing benign breast disease (a risk factor for breast cancer) later on in life. The study followed over 9,000 girls age 9-15, into young adulthood – a total of 14 years. Those who ate peanut butter at least three days a week had a 39% lesser incidence of benign breast disease. Researchers say the causal, link in this case is not completely clear, but that it may be the predominance of plant protein in the diet of these girls, and the fact that it had likely replaced some of the animal protein they would have consumed in its place.
What is clear is that peanuts and peanut butter can be a tasty and healthful source of plant protein in your diet. Be sure to read labels though.
Choose peanuts that are dry roasted rather than those roasted in added oils. Oils add unnecessary fat and calories, and can make the nuts go rancid more quickly than dry roasted. And choose lightly salted or no-salt options if possible. Choose peanut butter made with real peanuts and peanut oil. Organic peanut butter is best, but can be pricey. Just be sure to watch the label for added sugars, hydrogenated oils, and other added preservatives and fillers. You can even make your own tasty peanut butter at home: dump some dry roasted, unsalted peanuts in a blender or food processor and grind them down. Add peanut oil a little at a time until it reaches the desired consistency. It’ll keep in the refrigerator for a couple weeks. Use it as a dip for a crunchy apple, or spread it on whole grain toast, and you’ve got a delicious breakfast or snack in the making!
For healthy glucose levels and weight loss it is important to obtain the micronutrients your body needs. The best possible sources of micronutrients are found in the food you eat, especially in fruits and vegetables. Many circumstances may prevent you from eating healthily every day and taking nutritional supplements is an excellent way to improve your health and weight loss success.
- Health Day News. (2013, September 27). Can Eating Peanut Butter Cut Breast Cancer Risk Later in Life? Retrieved from Medline Plus: http://www.nlm.nih.gov/medlineplus/news/fullstory_141075.html
- Reis CE, R. D. (2013 Jun; 109(11)). Acute and second-meal effects of peanuts on glycaemic response and appetite in obese women with high type 2 diabetes risk: a randomised cross-over clinical trial. British Journal of Nutrition, 2015-23.