Nut and Seed Consumption

Fungus / Mycotoxin Exposure

A 1993 study demonstrated 24 different types of fungi that colonized the inside of peanuts. This was after the exterior of the peanut had been sterilized! [Etiology and Prevention of Atherosclerosis. Fungalbionics Series.1998/99]

Elevated LDL/HDL Ratio

“Solid data has shown that eating one to three daily portions of almonds (28 to 84 grams) can help lower LDL cholesterol levels,” said study co-author Rick Mattes, Ph.D., R.D. from Purdue University in West Lafayette, USA. “But many health care providers have been hesitant to recommend almonds as a daily snack because they’re a relatively high-calorie food and could contribute to weight gain. This study challenges that assumption.” [British Journal of Nutrition Sept. 2007]

In the study, women were instructed to eat 344 calories worth of almonds (around 56 grams) every day for one 10-week period, and then eat their customary diet for another 10 weeks. The women did not gain weight during the period they consumed almonds.

Elevated Total Cholesterol

Good fats that come from raw nuts and seeds are an important part of any cardiovascular protective diet. Pecans, for example, will lower total cholesterol, triglycerides, apolipoprotein B and lipoprotein(a). [A Monounsaturated Fatty Acid Rich Pecan Enriched Diet Favorably Alters the Serum Lipid Profile of HealthyMen and Women, Jnu 2001;131: pp.2275-2279]

Whole almonds or almond oil (replacing half of the habitual fat intake) reduced plasma triglyceride, total and LDL-cholesterol concentrations, and increased HDL-cholesterol levels in a trial of 22 men and women with normal lipid levels. [J Nutr 2002;132(4): pp.703-707]

Macadamia nuts have also been found to reduce total and LDL cholesterol, thus reducing cardiovascular disease risk. Please see the link between Increased Risk of Heart Disease and Nut and Seed Consumption.

Problem Caused By Being Overweight

A study examining the effect of nuts on insulin resistance and in patients with type 2 diabetes found that nuts may also increase weight. Twenty people participated in the study by eating about 3 ounces of almonds a day for four weeks. Though the nuts did not substantially influence insulin sensitivity, body weight increased significantly, which may have affected changes in insulin sensitivity. Cholesterol, both good (HDL) and bad (LDL), decreased significantly after the four-week period.

In patients with diabetes, the increase in almonds did not alter blood sugar control. The study suggests that in order to avoid weight gain, nuts must be replaced by other sources of energy in the diet. [American J Clinical Nutrition November 2002;76(5): pp.1000-6]

Others have reported that the continued consumption of nuts commonly prevents people from losing weight.

However, this may not be the case with almonds. In this study, women were instructed to eat 344 calories worth of almonds (around 56 grammes) every day for one 10-week period, and then eat their customary diet for another 10 weeks. The women did not gain weight during the period they consumed almonds.

The researchers determined that the study participants felt satisfied, so they naturally compensated for most of the calories in almonds by reducing their intake of other foods in their normal daily diet. They also noted a decrease in total carbohydrate intake, suggesting almonds may have replaced carbohydrate-rich foods.

Additionally, the researchers found that the fibre in almonds appears to block some of the fat they contain from being digested and absorbed. This means that almonds may provide fewer calories than would be expected. [British Journal of Nutrition Sept. 2007]

Increased Risk of Diabetes ll

In a study of 84,000 female nurses in the U.S., women who ate about 5 ounces of nuts a week had a 27% lower risk of developing diabetes than those who rarely or never ate nuts. In women who ate 1 to 4 ounces of nuts a week, the risk was 16% lower, and for those who ate less than 1 ounce per week the risk was eight % lower. [JAMA November 26, 2002;288: pp.2554-2560]

This benefit was probably due to the content of essential fatty acids in nuts and the frequency of EFA deficiency in the general population. Since consuming too many nuts can lead to weight gain and thus an increasing diabetes risk, moderation in their use is recommended.

Increased Risk of Coronary Disease / Heart Attack

Incorporating macadamia nuts into a heart healthy diet can reduce cardiovascular disease risks according to Penn State researchers.

“We looked at macadamia nuts because they are not currently included in the health claim for tree nuts, while other tree nuts are recommended as part of a healthy diet,” says Dr. Amy E. Griel, recent Ph.D. recipient in nutritional sciences. “Macadamia nuts have higher levels of monounsaturated fats, like those found in olive oil compared with other tree nuts.”

The researchers used a controlled feeding study to compare a heart-healthy diet with 1.5 ounces – a small handful – of macadamia nuts to a standard American diet. The participants had slightly elevated cholesterol levels, normal blood pressure and were not taking lipid lowering drugs. Researchers randomly assigned participants to either the macadamia nut diet or the standard American diet and provided all meals for the participants for five weeks. The participants then switched diets and continued eating only food provided by the researchers for another five weeks.

The Healthy Heart diet with macadamia nuts did reduce total cholesterol, low-density lipoprotein cholesterol and triglyceride levels compared with the standard American diet.

“We observed a reduction in LDL similar to that seen with other tree nuts like walnuts and almonds,” says Griel. [Researchers from the nutritional sciences department on this study included Griel; Deborah M. Bagshaw, Clinical Coordinator Amy M. Cifelli, research dietitian; Yumei Cao, graduate student and Penny M. Kris-Etherton, distinguished professor. May 2007]