Health Benefits of Almonds, Pecans and Macadamia Nuts

Miscellaneous Nuts

Almonds reduce the risk of heart disease, research shows

Eating almonds can reduce the risk of heart disease by keeping blood vessels healthy, research has shown. Research found that they significantly increase the amount of antioxidants in the blood stream, reduce blood pressure and improve blood flow. These findings add weight to the theory that Mediterranean diets with lots of nuts have big health benefits.

Scientists have found that eating almonds in your diet can reduce the risk of heart disease by keeping blood vessels healthy.

Research found that they significantly increase the amount of antioxidants in the blood stream, reduce blood pressure and improve blood flow. These findings add weight to the theory that Mediterranean diets with lots of nuts have big health benefits.

The study was led by Professor Helen Griffiths, Professor in Biomedical Sciences and Executive Dean of the School of Life and Health Sciences at Aston University in Birmingham, UK. Researchers tested the effects of a short-term almond-enriched diet on healthy young and middle-aged men as well as on a group of young men with cardiovascular risk factors including having high blood pressure or being overweight.

A control group ate what they normally would, while another group consumed snacks of 50g of almonds a day for one month.

At the end of the study period, the group eating an almond-enriched diet had higher levels of antioxidants (alpha-tocopherol) in their blood stream, improved blood flow and lower blood pressure, potentially reducing their risk of heart disease.

Almonds are known to contain a range of beneficial substances such as vitamin E and healthy fats, fibre which increases the sense of fullness, and flavonoids which may have antioxidant properties. The team believes it is likely to be the combination of all these nutrients working together to create the overall health benefits rather than just one particular nutrient in isolation.

Professor Griffiths said: "Our study confirms that almonds are a superfood. Previous studies have shown that they keep your heart healthy, but our research proves that it isn't too late to introduce them into your diet -- adding even a handful (around 50g) every day for a short period can help. You could replace a daytime snack with a bag of almonds or add them to your regular meals like porridge or muesli to help reduce your risk of heart problems."

 

Antioxidants in pecans may contribute to heart health and disease prevention

A new research study from Loma Linda University (LLU) demonstrates that naturally occurring antioxidants in pecans may help contribute to heart health and disease prevention; the results were published in the January 2011 issue of The Journal of Nutrition.

Pecans contain different forms of the antioxidant vitamin E—known as tocopherols, plus numerous phenolic substances, many of them with antioxidant abilities. The nuts are especially rich in one form of vitamin E called gamma-tocopherols. The findings illustrate that after eating pecans, gamma-tocopherol levels in the body doubled and unhealthy oxidation of LDL (bad) cholesterol in the blood decreased by as much as 33 percent. Oxidized LDLs may further contribute to inflammation in the arteries and place people at greater risk of cardiovascular problems.

"Our tests show that eating pecans increases the amount of healthy antioxidants in the body," says LLU researcher Ella Haddad, DrPH, associate professor in the School of Public Health department of nutrition. "This protective effect is important in helping to prevent development of various diseases such as cancer and heart disease."

These findings are from a research project designed to further evaluate the health benefits of pecans, according to Dr. Haddad. She analyzed biomarkers in blood and urine samples from study participants (a total of 16 men and women between the ages 23 and 44) who ate a sequence of three diets composed of whole pecans, pecans blended with water, or a control meal of equivalent nutrient composition. The pecan meals contained about three ounces of the nut. Samples were taken prior to meals and at intervals up to 24 hours after eating.

Following the test meals composed of whole pecans and blended pecans, researchers found that amounts of gamma-tocopherols (vitamin E) in the body doubled eight hours after both meals, and oxygen radical absorbance capabilities (ORAC—a scientific method for measuring antioxidant power in the blood) increased 12 and 10 percent respectively two hours after the meals. In addition, following the whole-pecan meal, oxidized LDL cholesterol decreased by 30 percent (after 2 hours), 33 percent (after 3 hours), and 26 percent (after 8 hours).

"This study is another piece of evidence that pecans are a healthy food," says Dr. Haddad. "Previous research has shown that pecans contain antioxidant factors. Our study shows these antioxidants are indeed absorbed in the body and provide a protective effect against diseases."

Research from Loma Linda University published earlier in the Journal of Nutrition showed that a pecan-enriched diet lowered levels of LDL cholesterol by 16.5 percent—more than twice the American Heart Association's Step I diet, which was used as the control diet in that study. Similarly, the pecan-enriched diet lowered total cholesterol levels by 11.3 percent (also twice as much as the Step I diet).

Macadamia nuts good for the heart  

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.

Individual calorie levels were used for each participant so that they did not gain or lose weight during the study. Both diets were matched for total fat, containing 33 percent calories from total fat. The Heart Healthy diet with macadamia nuts had 7 percent saturated fat, 18 percent monounsaturated fat and 5 percent polyunsaturated fat. The standard American diet had 13 percent saturated fat, 11 percent monounsaturated fat and 5 percent polyunsaturated fat.

The macadamia nut diet included macadamia nuts as a snack, mixed into meals, as a salad topping and in cookies and muffins.

"The total fat was the same in both diets," says Griel. "We substituted the macadamia nuts for other sources of fat and protein in the diet. For example, we could switch skim milk for 2 percent milk and add some macadamia nuts."