Nutrition Research

Summary

Limited research indicates that L-carnitine supplementation (under medical supervision) may improve exercise tolerance in individuals with peripheral arterial disease (PAD). Moderate consumption of alcoholic beverages has been associated with a decreased risk of developing PAD.

Disease Overview

Peripheral arterial disease (PAD) results from atherosclerosis of the arteries that supply blood to the head, organs, and limbs. PAD most commonly affects the arteries in the legs.

Due to the narrowed arteries and reduced blood flow to the extremities, cramping, pain, and fatigue may occur, especially during physical activity. The activity-induced muscle pain associated with PAD is clinically termed intermittent claudication. Left untreated, PAD can lead to tissue damage or infection.

See below for specific information about nutrients and dietary factors relevant to intermittent claudication.

Table 1. Conditions and Causes of Narrowed or Blocked Arteries
Condition Caused by Atherosclerosis of
Coronary Artery Disease the arteries that supply blood to the heart
Carotid Artery Disease the arteries that supply blood to the brain
Peripheral Arterial Disease the arteries that supply blood to the head, organs, and limbs
DEFINITIONS
Atherosclerosis - the buildup of plaque inside arterial walls
Plaque – a deposit of fat, cholesterol, immune cells, fibrin (a blood clotting protein), and other substances that forms inside arterial walls
Claudication - pain caused by insufficient blood flow during exercise
Periphery - the outer regions of the body; away from the heart

Nutrition Research

DEFINITIONS
Test tube (in vitro) experiment - a research experiment performed in a test tube, culture dish, or other artificial environment outside of a living organism; in vitro is a Latin phrase meaning in glass
Animal experiment - a research experiment performed in a laboratory animal; many different animal species are studied in the laboratory, including terrestrial (land), aquatic (water), and microscopic animals
Observational study - a human research study in which no experimental intervention or treatment is applied, and participants are simply observed over time
Randomized controlled trial - a human research study in which participants are assigned by chance alone to receive either an experimental agent (the treatment group) or a placebo (the control group)
Placebo - a chemically inactive substance

 

L-Carnitine

What it does

General

  • L-carnitine is a compound that can be made inside the body and obtained from food and dietary supplements. It is considered a conditionally essential nutrient because in some situations, the body’s demand for L-carnitine exceeds its capacity to make it.
  • L-carnitine helps the body convert fat into useable energy.

Peripheral Arterial Disease (PAD)-specific

  • Supplemental forms of carnitine, L-carnitine and propionyl-L-carnitine, administered in conjunction with standard drug therapy appear to improve cardiac and skeletal muscle function during ischemia.
  • Propionyl-L-carnitine in particular may benefit ischemic tissue by replenishing intermediates of energy metabolism or by increasing blood vessel dilation (widening).
What we know
  • Several randomized controlled trials have found that oral supplementation with propionyl-L-carnitine improves exercise tolerance in some patients with intermittent claudication.
DEFINITION
Ischemia - inadequate blood supply to an organ or part of the body

For references and more information, see the section on intermittent claudication and PAD in L-carnitine article

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Alcoholic Beverages

What they do

General

  • Alcoholic beverages contain ethanol and other ingredients with bioactive properties that may benefit health.
  • When consumed in moderation (no more than two drinks/day for men and one drink/day for women), alcoholic beverages have been associated with beneficial effects in the cardiovascular system.

Peripheral Arterial Disease (PAD)-specific

  • Moderate alcohol consumption favorably influences several atherosclerotic risk factors: it increases HDL-C levels, inhibits factors involved in blood clot formation, and may have an anti-inflammatory effect.
What we know
  • There is some evidence that moderate alcohol consumption is associated with a decreased risk of PAD.

For references and more information, see the section on the Potential Health Benefits of Moderate Alcohol Consumption in the Alcoholic Beverages article

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