Dietary Intake of Whole Walnuts in Adult Subjects Under Low Cardiovascular Risk
Dietary Intake of Whole Walnuts in Adult Subjects Under Low Cardiovascular Risk
This cross-over study investigates health effects of dietary intake of whole walnuts towards
 cardiovascular risk factors in adults under low cardiovascular risk.

 Investigators hypothesize that daily intake of whole nuts as a replacement meal, would
 improve cardiovascular risk factors, including traditional risk factors and molecular
 biomarkers.

 The participants are randomly assigned to receive either study treatment, or no treatment,
 and are crossed after five weeks.

 The study subjects are instructed to continue with their habitual diet and physical activity.
Recent literature data raise important questions on the beneficial effect of dietary fats.
 Dietary intake of nuts, although with high caloric burden, is however characterized with high
 intake of fatty acids with known beneficial health effects. Those fatty acids include mono-
 (MUFA) and polyunsaturated fatty acids (PUFA), to whom beneficial health effects are
 ascribed.

 Among nuts, walnuts are characterized with comparatively high levels of MUFA and PUFA,
 especially content of alpha-linolenic PUFA, considered essential fatty acid, since not
 synthesized endogenously in humans. Dietary intake of alpha-linolenic acid is shown to be
 inversely related with cardiovascular risk factors, both in interventional studies and
 epidemiological cohorts. Molecular background of alpha-linolenic actions is bidirectional,
 and includes the action itself, as well as beneficial endogenous conversion towards
 long-chain fatty acids, including eicosapentaenoic and docosahexaenoic fatty acid.

 Although high caloric intake is indicated with intake of walnuts, literature data suggest
 that consumption of walnuts does not increase body weight.

 Dietary intake of walnuts has been shown to decrease cholesterol fractions, triglycerides and
 apolipoproteins in adult population. Also, consumption of walnuts was associated with
 decrease in blood pressure.

 The study design is cross-over, controlled, randomized nutritional intervention. The
 participants are randomly assigned to receive either study treatment, or no treatment, and
 are crossed after five weeks.

 The study subjects are instructed to continue with their habitual diet and physical activity.
 Additionally, study subjects are instructed to avoid walnuts and nuts other then study
 treatment, during the complete study period of 10 weeks.

 Sample size calculation was conducted by use of online calculators, and was based on the low
 density lipoprotein (LDL) cholesterol. Namely, in order to achieve decrease in 0.5 mmol/L, in
 a sample with projected standard deviation of 0.7 mmol/L, and type I and II errors being 0.2
 and 0.05, respectively, 62 subjects are needed.
Inclusion Criteria:

 Presence of at least one of the following criteria, formerly assessed through routine
 medical examination:

 -  dyslipidemia, defined as the presence of either: elevated total cholesterol (>5.2
 mmoL/L), and/or elevated LDL-cholesterol (>3.4 mmoL/L), and/or elevated triglycerides
 (>1.7 mmoL/L), and/or decreased HDL-cholesterol (<1.6 mmoL/L)

 -  elevated blood pressure (systolic/diastolic ≥120/80 mmHg), or regular
 anti-hypertension therapy

 Exclusion Criteria:

 -  presence of allergy on any nuts

 -  presence of any chronic disease, excluding following conditions: hypertension and
 diabetes mellitus type 2

 -  smoking

 -  statin therapy

 -  pregnancy and/or lactation